f,
_J
.SURVEYOR III PARTSND A iVlATERIALS/EVALUATION EFFECTS OFLUNAB
RETURNEDROMTHE MOONEY APOLLO F XII
SUBMITTEO JANUARY 22 1971
CASE copF_
LE
r- ................
-I
', HUGHES
I L ................ MUGHIrg .a AIRCRAFT COMPANY
_
I
ACKNOWLEDGMENTS
Studies spacecraft with most Department. The Blair
and
evaluation
of
the
returned areas the
parts
of
the
Surveyor
III
involved several technical of the work conducted within
of Hughes Aircraft Hughes Materials
Company, Technology
!:
P.M.
following principal investigators for technical direction and w¢)rk
merit special acknowledgment: on surface contamination of nlaterials tests and prepGerpheide, J.R. Jones, and and metallurgical properin conjunction with the parallel camera, under the overall
studies; D.G. Buettner for general supervision aration of the draft of the final report; B.A. P.M. Winslow for tests of physical, rrmchanical, ties, respectively. This work was conducted effort on the returned Surveyor IlI television direction of E.I. Ilawthorne. Acknowledgment is due S. Jacobs and
L.J.
Leger
of
NASA-MSCand
W.F. Carroll of JPL for their contributions should also be made of the support of B. and J.G. Zarcaro of NASA-MSC, without progran_ would not have been possible. Special to the
to the program. Recognition Milwitzky of NASA Headquarters whose personal interest this
spacecraft who made
tribute is extended by the designers the Apollo Program Office and to the return of this valuable hardware from
and
Apollo
the
builders XII surface
of Surveyor astronauts of the moon.
ABSTRACT
Results of engineering tests of parts of the Surveyor Ill spacecraft brought back from the moon by the Apollo Xll astronauts are presented. These parts include the scoop from the soil mechanics/surface sampler: section of television camera cabling; and sections of support aluminum tubing -- polished, as we[[ as painted with white inorganic paint. These parts resided on the moon Z-I/Z years prior to their recovery. Tests were conducted to determine the effects of this exposure to the [unar environment. It exceedingly whi_:h was damage and ties occurred, of the scoop The the was deternl[ned The that major to be all of the was parts withstood the environment
a
we[[. determined coating and motor
effect attributable of dust. cold
the discoloration to the combined changes were noted.
of surfaces, effect of radiation in physical properThe perfornlance
with lunar no effects was nominal.
No major welding
tests of astronauts, Company
data presented in this report are supplemented Surveyor III television camera retrieved by which are contained in a companion report, SSD 00545R.
by results the Apollo ill }tughes Aircraft
of
vii
CONTENTS
I,
INTRODUCTION, I. 1 1.2 1. 3 I. 4
,
OBJECTIVES,
AND
SCOPE 1-1 1-3 1-4 1-5
Introduction Objectives Scope Report Organization ASSESSMENT General Conclusions OF RESULTS and Recommendations Exposure
GENERAL 2. 1 Z. Z Z. 3
Assessment of Effects of Lunar Candidate Future Studies AND PARTS INITIAL EXAMINATION
2-I 2-2 2-5
,
DESCRIPTION RETURNED 3.1 3.2 3.3 3.4 3.5
OF
Soil Mechanics/Surface T V Cable Polished Tube Painted Tube Analysis of Photographs of Surveyor Ill AND ANALYSIS OF
Sampler
(SM/SS)
Scoop
3-1 3-11 3-Zl 3-Z6 3-Z7
and Crew
Observations
4.
TEST
RETURNED
PARTS 4-2 4-20 4-25 4-32 4-44 4-48 4- 57 4-69
4. I 4.2 4.3 4.4 4.5 4.6 4.7 4.8 ll. SURFACE
Examination of Scoop Motor and Gear Assembly Friction and Wear Test of Scoop Joint Pin Chemical Analysis of Organic Materials Properties of Wire and Cable Metallurgical Analysis Analysis of Lunar-Cut Ends of Polished Tube Optical Property Measurements Analysis of Contamination of Polished Tube DISCOLORATION AND CONTAMINATION STUDIES
II. I Introduction l l.g Data Available From Prelaunch, Post-Recovery Examination !!. 3 Evolution of Test Plan
11-1 Landing, and 11-3 11-7
ix
11.4 11.5 APPENDICES A B J REFERENCES
Summar Damage
7 of Test Model
Results
11-10 11-25
Sectioning of Polished Tube List of Laborator 7 Log Books Containing Test Supporting Data for Surface Effects Study
Data
A-I B-I J-I R-l
X
ILLUSTRATIONS
Page
_
3333-5 3- 6 3-7 3-8 3-9 3-10 3-11 3-1Z 3-13 3-14 3-15 3- It) 3-17 3-18 3-19
SM/SS Retrieval Raised Retrieved Laboratory Location
Scoop Mechanism of Surveyor Position Surveyor of Various IIl
3-2 III Parts, Showing Scoop and in SM/SS Lunar on Scoop Lunar in 3-3 SM/SS Receivin_ 3-4 Materials Finishes SM/SS 3-4 3-8 Material 3-9 3-10 3-13 3-14 3-15 3- 16 3- 16 3-18 3-19 3-20 3-21 3-Z2 3-2% 3-26 Brushes Brush Brushes, Housing Train, Shaft, 4-9 I, Showing Showin_ Transfer 4-9 Wear 4-10 4-10 Indicating Showing Support S('()c_p Absence 4-13 Drive Metallic Bearings M()tor BearinR 4-14 4-16 4-17
Scoop Distribution of Lunar Material Enlarged View of Slvl/SS Scoop, and Wiring "Mud-Cracking" of SM/SS Scoop
on SM/SS Showin_ Paint
Sample Environmental Sealed Container (SESCI Retrieved Surveyor III Television Camera View of Surveyor III TV Canlera on Moon, Sh(_wing External Cabling Section of External Cable From Surveyor III TV Can_era Tefhm Wrap Removed Fronl External Cable of ZV Call;era Surface of Teflon FEP Wrap of External Cable Nylon Tie Cords of External Cable Wrap Epoxy on Nylon Tie Wraps (595X Magnificatic,nl Returned Section of Polished Aluminum Tubintz in Lunar Receiving Laboratory View of Surveyor Contaminated Side III on Moon of Sections Section
A
and G of
G
of
Polished Tube
Tube
4-3 4-4 4-5 4-6 4-7 4-8
Enlarged View of End of Showing Contaminants Surveyor III SM/SS Scoop Contact Surface of Sco()p Flirt(88X Magnification) Contact Surfaces of Sco()p (50X Magnification) Scoop Motor Con_mutator Gears of Scoop Motor of Significant Wear Spline Contact Portion of Sc()op
Polished
Gear
PhotomicroRraphs Phot()nlicrographs
_)f I)isassen_bled ()f I)isassell_bled
A
xi
4-9 4-10 4-11 4-12 4-13 4-14 4-15 4-16 4-17 4-18 4-19 4-20 4-21 4-22 4-23 4-24 4-25 4-26 4-27 4-28 4-29 4-30 4-31 4-32 4-33 4-34 11-1 11-2 II-3 11-4
Photomicrographs Photomicrographs Pin From Surveyor
of of
Disassembled Disassembled III SM/SS Scoop
Scoop Scoop Prior
Motor Bearing Motor Bearing to Testing Pin Pin and
C D
4-18 4-19 4-21 4-22 4-22 4-23
(5X Magnification) Test Setup for Wear Analysis of SM/SS Scoop Appearance of Control Pin Before Test Friction Test in Vacuum of Surveyor Ill Scoop Control Pin Photomicrographs and Wear Test Infrared Transmission Ultraviolet Spectrum Cable Wrap Thermograms Microstructure of SM/SS Scoop Pins After
Friction 4-24 4-26 llI 4-29 4-30
Spectra of Teflon
of Teflon FEP From
FEP Surveyor
of Teflon FEP of Polished Aluminum
Tube of Aluminum Tube
From 4-44 Tube 4-45 From 4-47
Surveyor Ill (lO00X Magnification) Microstructure of Control Sample ( 1000X Magnification) Microstructure of Painted Aluminum Surveyor III (1000X Severed Surveyor Magnification) Enlarged Indentations View on Magnification) III Polished
Aluminum
Tube Magnification) Aluminum 4-23 4-25
(7X 4-49 4-52 Tube 4-53 (525X 4-54 (Z100X 4-54 4-54 4-55 4-56 4-56 4-63 4-67 4-70 From 4-71 TRW 11-13 in II-14
of Figure Surveyor Tool of Bottom of Right
4-22a (2IX llI Polished Area Area of of
Made by Cutting Enlarged View Magnification) Enlarged View Magnification)
Figure
Figure
Enlarged View of Left Area of Figure 4-23, Showing Scoring Caused by Cutting Tool (1050X Magnification) Control Sample of Polished Aluminum Tubing Sketch of Cutting Tool Sketch of Fracture During Tube Cutting Operation Spectral Reflectance Measurements of Aluminized Teflon FEP From Surveyor III Cable Wrap Percent Reflectance of Surveyor III Polished Tube Around Its Circumference Infrared Sides Infrared SM/SS of Reflectance Section G of Spectra Polished Spectrum of Contaminated Aluminum of Lunar and Tube Dirt Showing From on Moon Clean
Reflectance Scoop
Lower Shroud Measurement White Painted SESG in Quartz Separated Reflectance Effect Inorganic of
of Surveyor III Camera, Positions Tube Section Returned Vacuum Chamber and Dust Effects
Radiation Radiation Painted
Spectral II-22 of White Camera
on Spectral Reflectance Surfaces of Surveyor
III
11-29
xii
A-I A-2 A-3 A-4 A-_
A-tl
Sectioning Polished Section Indicating Section Figure Secti_m Indicating Section Figure Surveyor Orientation Shadow Pc)sition From
Arrangen_ent Aluminum A of Polished
Polished Aluminum Tube, Showing Identifying Aluminum Tube Shown Removed Tube Segments Tube
for
Tube Marks in Figure
A-1 A-Z A-1, A-3 Hughe_ A-l, A-% A-3
Further" Subsections A-4 of Polished Aluminum A-3, G of Showing Polished Further Aluminum
at tlughes Shown in Removed Shown in at Figure
Further Subsections Removed G-Z of Polished Aluminum Tube A-5, III Showing on Crater of Surveyor of 10 Further Wall III Surveyor Degrees Position in Segments Crater
at Hughes Shown in Removed at Hughes
A-3 J-2 J-4
,I-1
Photograph of Sun at Lunar Module
III Model, Before Sunset, of
Simulating Viewed J-5 Module J-6 of Surveyor J-7 J-9 J-10 and J-11 J-IZ
,I -4 l-_ ,I - () I -7
Approach and Landing Configuration Relative to Surveyor III View of Relative Locations on Lunar [II and Lunar Module [Iiustration of Shadow Through Shadow Patterns on Elevation Spectral Reflectance of White After Laboratory Ultraviolet Lower Shroud of Surveyor III Measurement Positions Reflectance Low'or Shroud Figure Quartz gests Sketch Versus Wavelength at Various TRW With Painted Painted Light-Tight Tube Section
Lunar
Surface
,I - q 3 - 19
Hole in Camera Clamv Drive Motor Housing Inorganic Paint Before Exposure Camera, Showing TRW of Surveyor Locations Shield of Tube III Shown for Camera in
,l-ll ,I- 12 ,I-13
,1-9 Chamber of White of White
J-15 Vacuum J-17 N eturned of Prior of in J-18 Four Samples to Light J-19 Wavelength Vacuum Four to Samples Light J-Z0 Prior of Light of After Positions Wavelength Vacuum
,I-14
SESC, Showing Measurement Spectral Reflectance Versus _)f White Painted TubeHigh Exposure Spectral Reflectance Versus of White Exposure Spectral of White Spectral of White Painted Reflectance Painted Reflectance Painted Tube-
Medium
TubeTube
Versus Wavelength 1 AU Prior to Versus Wavelength (Sample 778-70)
Four Samples Exposure One Sample 6 Days at
J-Z1
,r-17
J-IN
l AU Prior to Light Exposure Spectral Reflectance Versus Wavelength of Different Sample of White Painted Tube (Sample 800-70 in Figure ,l-lZl After 48 Hours Exposure to Light at 1 AU Spectral Reflectance Versus Wavelength of Four Samples of White Painted Tube After 48 Hours Exposure to Light at 1 AU 19 Lower Bracket Shroud Upon of Surveyor Return From III Camera Moon With Attached Cable
J -22
J-22
J-23 J-24
,l-
xiii
J-20
J-Z1 J-22
J-23 J-24 J-25 J-26 J-27
Cable Bracket Superimposed on Lower Shroud of Surveyor III Television Camera: Shroud Exposed to Light for About 5 Months, Cable Bracket Unexposed Location of Samples Cut From Cable Bracket Spectral Reflectance Versus Wavelength of Sample of Camera Cable Bracket (Sample 518 of Figure J-Z1): Measurements Taken in May 1970 Prior to Light Exposure Support Collar of Surveyor III Television Camera Photograph of Surveyor III on the Moon, Showing TV Support Tubing Reflectance of Bipod Bracket Tube Experimental Configuration for Thermal-Vacuum Exposure of Surveyor III Sample 909 Ratio of Reflectance of Painted Surfaces Covered With Lunar Dust to Reflectance of "Clean" Surfaces (White Inorganic Paint)
J-25 J-25
J-26 J-28 J-29 J-31 J-39
2 -43
xiv
TABLES
1 7..I 3-2 2-3 3-I 4-I 4-2 4-3 4-4 4-5 4°6 4°7 4-8 4-9 4-10 4-11 4-12 4- 13 4-14 4-15 4-16 4-17 4- 18 4- 19
I-
Summary of Mission Performance Assessment of Effects of Lunar Effects Observed Assessment of Effects of Lunar Effects Not Observed Assessment of Effects of Lunar Effects Observed
of Surveyor Spacecraft Exposure - Expected ExposureExposure Expected
1-2 2-3 2-4
Unexpected 2-5 3-6 4-3 4-4 4-5 4-6 4-7 4-11 4-14 4-28 4-28 4-34 4-34 4-34 4-35 4-35 4-37 4-38 4-39 4-42 4-45
Scoop Materials and Finishes Composition of Scoop Motor Brush Materials Resistance Measurements of Windings of Scoop Motor Calibration of Brake Used for Testing of Scoop Motor Summary of Results of Tests of SM/SS Scoop Motor and Gear Train Comparison of Test Results of Scoop Motor With Requirements Results of Arc Emission Spectrographic Analysis of Brush and Black Debris in Motor Housing List of Figures 4-7 Through 4-I0 Showing Disassembled Views of Bearings and Races Elemental Analysis of Teflon and Nylon Spin Density of Teflon FEP and Nylon Capacitance of FEP-Polyimide Insulated Wire From Surveyor III Cable Insulation Resistance of FEP-Polyimide Insulated Wire From Surveyor III Cable Conductor Resistance of Surveyor III Cable Capacitance of Surveyor IllScoop Wires Insulation Resistance at 500 Volts DC of Surveyor Ill Scoop Wires Physical Properties of Bare Conductor Wires From Television Cable Physical Properties of Conductor Insulation From Camera Cable Tensile Strength and Elongation of Teflon FEP and Mylar From Surveyor Ill Camera Cable Tensile Strength and Elongation of Scoop Wires From Surveyor Ill Aluminum Alloy Samples Selected for Metallurgical Analysis
XV
4-20
Results
of Reflectance
and Transmittance
Measurements 4-58
4-21
4-22
of Aluminized Teflon FEP From Surveyor III TV Camera Cable Wrap Results of Infrared Reflectance Measurements of Aluminized Teflon FEP From Surveyor III TV Camera Cable Wrap, Teflon Side Summary of Samples and Conditions of Spectral Reflectance Measurements of Aluminized Teflon FEP From Surveyor III Cable Wrap Percent Reflectance as Function of Wavelength for Both Contaminated and Uncontaminated Sides of Polished Tube Sections Electron Microprobe Analysis of Contamination on Section G of Surveyor Ill Polished Tube (Comparison With Lunar Material) Reflectance l_easurements of Samples From Lower Shroud of Surveyor III Camera Variation of Reflectance With Time as Result of Photo Bleaching Effect of Thermal Bleaching (Vacuum Versus Air) on Spectral Reflectance of Irradiated Samples of Inorganic White Paint Used for Surveyors Comparison of Several Techiques for Assessment of Fractional Area Covered by Lunar Dust Possible Sources of Dust Contribution to Discoloration Normal Emittance Measured on Lower Shroud Surface Percent of Spectral Reflectance Versus Wavelength of Samples From Surveyor Ill Camera Connector Bracket After Exposure to White Light Photo Bleaching Samples of Surveyor Ill Camera Shroud Cut in July 1970 for Science Studies Percent Reflectance of Samples From Surveyor III Camera Shroud Cut for Science Studies in July 1970 Percent Reflectance of Samples From Surveyor III Camera Shroud Cut for Science Studies in October 1970 Effect of Thermal Annealing in Air on Spectral Reflectance of Samples Cut From Lower Shroud of Surveyor III Camera in October 1970 Effect of Thermal Annealing on Spectral Reflectance of Surveyor III Camera and Laboratory Samples of White Inorganic Painted Surfaces
4-61
4-63
4-23
4-66
4-24
4-68 II-12 II-18
II-I II-2 11-3
II-20 II-24 II-27 J-13
11-4 11-5 J-I J-2
J-27 J-33 J-34 J-36
J-3 J-4 J-5 J-6
J-37
J-7
,.T-38
xvi
I.
INTRODUCTION,
OBJECTIVES,
AND
SCOPE
i.
|
INTRODUCTION This report Hughes 1971 XII Soil Section 7-3/4 4 inch white on presents Aircraft the following astronauts: mechanics/surface of inch section paint conducted under a contract with NASA Manned Houston, Texas. A separate report, Test and Television Camera Returned from the Moon, SSD 00545R {Reference 1) contains the results of period under a companion contract with the (JPL) on the television camera also retrieved television section of of sampler camera polished tube cable aluminum coated tubing with inorganic (SM/SS) scoop the results Company Surveyor of the during III test the parts and period evaluation 7 January from program 1970 the moon
conducted 22 by January the Apollo • • •
by
to
returned
aluminum
This program was Spacecraft Center (MSC), Evaluation of Surveyor III Hughes Aircraft Company tests conducted during this Jet by Propulsion the Apollo XII J._boratory astronauts.
Surveyor III, one of seven Surveyors designed and built by Hughes, was the second of five spacecraft to land successfully on the surface of the moon. Its soft landing took place ZOApril 1967 in a small crater in the Ocean of Storms, subsequently named the Surveyor Crater. All subsystems operated successfully throughout the first lunar day except for sorr, e minor anomalies. The Surveyor of the lunar terrain. day were unsuccessful; nights was not a design formance of the III television camera Attempts to revive however, survival requirement. A is presented took more the spacecraft of Surveyors brief summary in Table 1-1. than 6000 photographs on the second lunar throughout lunar of mission per-
Surveyors
1-I
W w 0 >, '0 _ :_" _" 0 t)
E
4a °,.* "_m
2 <_._
L) L)
<
eL Ca g C 0 0 0 0 N 0 N
0
'.3_
°'o
g " N N
0
e_
0 m
0
_
0
Z <
0
c_ 0 A J
ig
Z
m e_ °_ 0 C 0 C o_ °_ ._
E
0
_
0
E
0
0
Z
Z
e, 0 L
0
g 0 u u _ g I&l @ ¢11 u _r) (y) .,. m.
_o :> _o oo a.a. :> _.a,
_l
> H
;> H
:> H
L ! ¢11
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Z
<
or)
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_3 0 ._ _a m C @ C 0
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1-Z
Two and a half years later, corresponding to cycles, the Apollo Xll Lunar Module landed nearby. the mission plan based on recommendations by Hughes and o_hers, the Apollo astronauts retrieved the parts examining and taking a number retrieve to be of photographs of the
32 lunar day-night In accordance with (Reference 2), JPL, noted above after spacecraft. a compreand
hensive
The decision to study of benefits
the Surveyor accrued and
of
III parts followed the relative merits
difficulties of retrieving various parts of the Surveyor spacecraft. In addition to listing the scientific benefits, the study (Reference 2) employed the unique opportunity to obtain information on the effects of thermal cycling, radiation, and meteoroid exposure; occurrence of cold welding; and consequences of prolonged exposure of various optics, materials, components, and subsystems which would be applicable to future space programs. The retrieved parts were delivered to the MSC Lunar Receiving Laboratory (LRL) in Houston, where they remained in quarantine until 7 January 1970. From 7 to 16 January, a microscopic visual exan_ination and extensive photography were conducted in the LRL by Hughes, NASA, and JPL personnel. On specially test and parts testing potential cognizance many of 16 January the prepared Hughes evaluation program and to of the steps. security maximize uniqueness ':-" parts were shipped on a H,_hes airplane facility in Culver City, California, and was initiated. The program entailed measures and the amount These of the carefully of information were and of planned and obtained to the the formal strict in of
control tailored future the
sequenced for use in full
applications.
operations equipment
conducted the irreversibitity
1. 2
OBJECTIVES
The primary object.ives of this study were to determine the various effects of the prolonged exposure to the lunar environment on the retrieved parts. The test plan was structured to obtain maximum information on those conditions and changes which could be attributed to the effects of this environment while exposing a minimum amount of material to destructive testing. The opportunity. study of the returned hardware offered a unique engineering It was believed that the assessment of the conditions of the
Management companion
of the program is report on the Surveyor
described in III television
detail
in Appendix A camera {Reference
of
the l).
1-3
various materials and components would yield valuable data for future applications and could point out fruitful research and development. The returned parallel scientific
engineering design areas for additional
A
hardware also presented a unique scientific investigation of the returned Surveyor parts
opportunity. instituted
under NASA-JPL coordination was vigorously supported by Hughes as a secondary objective of this program. Results of the science test and evaluation program will presumably be reported separately. It throughout obtaining Surveyor was specifically the study that diagnostic data spacecraft was understood at the inception testing and analysis solely on the design integrity and not a program objective. of this program for the purpose performance of and of the
I. 3
SCOPE
A separate task was defined for each of the returned parts studied. A combined evaluation task was conducted to compare and integrate the information obtained. Results of these efforts are presented in the following sections of this report. Tests included a detailed visual and microscopic examination of all parts and surfaces; extensive measurements of physical, chemical, metallurgical, and electrical properties of materials and components to determine any changes that might have been induced by the lunar exposure; and tests of the SM/SS scoop motor and its components to assess the functional performance and determine the degree of wear. In addition, a special surface discoloration and contamination study was undertaken in conjunction with the companion Results of this special study veyor III television camera are report Surveyor III television reported in this report {Reference 1). camera and in test the program. Sur-
The purpose of this joint surface study was to determine the nature of the the external surfaces. The study, which science investigations by the JPLtechnical television camera contract, included an
discoloration and contamination discoloration and contamination was coordinated with the pertinent coordinator of the companion attempt to identify the relative
of
contributions of the various possible causes of the discoloration: solar radiation, deposition of organic materials or products of outgassing from other portions of the Surveyor spacecraft, impingement of lunar dust during the original Surveyor landing and during the Apollo XIILunar Module descent, and even vacuum possible testing prelaunch ). contamination (e.g., during solar-thermal-
Section ...... These the
1 1 and Appendix J (with a separate list of references). The '"_.... "_ _'_ "'_'*'_ in _"* c,_-_,_-_ of _h,_ _,_l,*vi,ion rarn_ra r_port. sections were extracted verbatim for inclusion here to simplify of publication of both reports.
process
I-4
in
the
The course
various of the
parallel program
science investigations by special visual, measurements; preparation and other. report are and
were microscopic, removal transmittal of
actively and selected of control
supported photosections, samples
graphic examinations; Optical samples, etc., for evaluation; and background information; Also included in this
comments
relative
to
certain
other
parts of Surveyor III which were not mal compartment mirrors and solar preliminary engineering assessment XII astronauts, coupled with a study craft on the moon. This assessment studies may be useful. attention this program camera. of information conducted on effort was directed
recovered {Reference 3), i.e., the therpanel. These comments are based on a of the photographs returned by the Apollo of their comments when viewing the spaceis by no means complete, and future
Particular conducted on the television total amount cable section and wires
to
avoid
duplication
between
tests the
and those conducted on the companion study of The two programs were coordinated to maximize obtained. For example, studies of the external here complemented the studies of internal cables the companion was made contract. throughout the program to ensure that
conducted A concerted
adequate planning preceded the performance of all tests, thereby ensuring nlininlum disturbance of parts and materials that might be used for future studies. A basic ground rule was established early in the program that at least 50 percent of all retrieved materials be retained in the original condition. This ground rule was strictly observed with one necessary exception, that is, the dismantling and testing of the scoop motor. All test procedures and program milestones based upon them were fully coordinated with the customer, and all decisions to conduct irreversible tests were approved by the customer. All results of tests were recorded in program log books, and a in
careful monitoring and accounting Appendix B; all Of major eva|uation Hughes test
and inventory system of all parts. A list of the are available in program significance of results to was intimately available the the
was established program log files.
for books
surveillance is given
to
the
successful availability familiar included
performance of 1) past with design the
of the Surveyor of in
tests and records
and Z) spacecraft. previous
personnel Past records data.
design data and,
the Surveyor many cases,
1. 4
REPORT The
ORGANIZATION technical a general material is discussed of in results the following and major sequence. conclusions Secand
tion
Z presents
assessment
1-5
recommendations. Section 3 contains a description of the returned parts, including their location on the Surveyor III spacecraft, and the results of the visual examination conducted to assess their appearance after 2-I/2 years exposure to the lunar environment. Section 4, which constitutes the major segment of this report, gives the results of tests and analysis conducted on various parts. The material is generally grouped by technical areas of investigation. Thus, for example, results of metallurgical tests on all the various materials are presented in one subsection. The final portion of the report deals with the discoloration and conlamination of the surfaces of the returned parts. As noted earlier, this work was conducted as a joint effort with the companion contract on the retrieved Surveyor III television camera and is presented in a separate section (Section 11) and appendix {Appendix J), extracted verbatim from Reference 1. This material is supplemented by an additional analysis of the contamination of the polished tube in Section 4.7, including a discussion of the sectioning of the tube in Appendix A.
1-6
Z.
GENERAL
ASSESSMENT
OF
RESULTS
Z. 1
GENERAL
CONCLUSIONS
AND
RECOMMENDATIONS
Extensive studies were conducted on the Surveyor III parts returned from the moon by the Apollo XIIastronauts. These studies are believed to have produced a significant amount of useful information directly applicable to future programs. Significant effects of lunar exposure have been noted, including some that had not been previously anticipated (Reference Z). Of equal significance were some effects previously conjectured, for which no apparent evidence was observed. It is believed that the test program, albeit limited in scope, was reasonably comprehensive. A fairly complete sequence of tests was conducted on the various components and materials, including chemical, physical, mechanical, electrical, and metallurgical examinations. Nevertheless, these tests can by no means be termed exhaustive, and additional work may be warranted. Publication of results of the parallel science investigations still in progress will also help define any additional effort desired. It is believed that the results of this investigation to determine the effects of prolonged lunar exposure on a variety of materials and components, coupled with a similar investigation of the Surveyor III television camera presented in a companion report (Reference 1), may be directly applicable to future spacecraft design. It is therefore recommended that a careful review of the test data contained in this report be made in the • course of design of future spacecraft. Accordingly, a wide dissemination of this report to space systems designers is suggested. Any additional tests required would thus be determined as appropriate for each particular application. The principal list of major effects originally conjectured Section 2. Z. Section The most properties conclusions observed, (Reference 2.3 cites of this study are summarized below. A as well as comments on some of the effects 2) but not observed, is presented in some examples of possible follow-on studies. is that change although changes was found which occurred would have
in many
significant of the
conclusion materials
no
Z-1
prevented
Z-1/Z years
any
material exposure
or any part from performing its to the rigorous lunar environment.
task
even
after
The second most significant conslusion was the discovery of a heavy coating of lunar dust on the exposed surfaces. This coating was to a large extent caused by the landing of the Apollo lunar module, in addition to the effect produced by the original abnormal landing of the Surveyor III. It is noteworthy that the Apollo lunar module descent engine was able to produce this effect from the relatively large distance of 500 feet between its landing area and the Surveyor III spacecraft. Results of the surface discoloration and contamination studies
indicated that this effect was primarily caused by radiation damage and lunar dust coverage, with a relatively minor contribution from organic deposits. The relative contributions of radiation and dust varied from alldust in some areas to all-radiation in others, with the majority of exposed surface areas discolored by a combination of these two factors. Radiationinduced effects were proportional to the degree of solar exposure. The amount of dust deposited was generally higher than expected. Future recoveries of valuable hardware from space should carefully consider landing techniques and protection of critical surfaces in light of the information desired. For example, if the interaction with the landing terrain is significant (e. g., lunar dust), the landing should be planned a sufficiently large distance away. If a study of the optical characteristics of the surfaces of the recovered parts is important, the returned parts should be carefully protected from the environmental conditions, such as air, light exposure, etc. In retrospect, it is believed that the results of the analysis of the retrieved Surveyor III parts would have been significantly more informative had it been possible to observe the above recommendations to a greater degree. The results of the study-also suggest a possible change process for future applications. The use of inorganic structures should be avoided if exposure to severe is anticipated. in a paints thermal
material fiberglass cycling
on
Z. Z
ASSESSMENT
OF
EFFECTS
OF
LUNAR
EXPOSURE of in
The following sections of the report present a detailed analysis the tests conducted and results obtained. These results generally fail three categories: 1) observed changes due to the effects of the lunar environment which had been previously anticipated, 2) absence of these effects which were originally conjectured or anticipated, and 3) changes and effects which had not been originally expected. The principal results obtained in these below in summary form in Tables 2-1, three Z-Z, categories and 2-3. are pre-
sented
Z-Z
TABLE 2--I. ASSESSMENT EXPOSURE -- EXPECTED
OF EFFECTS EFFECTS
OF LUNAR OBSERVED
Effects
Comment
Discoloration paints
of white and blue
Attributable
to radiation
and coat-
ing with lunar dust (dust effect greater than anticipated)
Bleaching paint
of degraded
white
Attributable to exposure to laboratory fluorescent lighting Attributable and lunar contributions Attributable dust to solar radiation
Discoloration
of teflon FEP
coverage (relative not separated) to solar radiation
Decrease of tensile strength of teflon FEP cable wrap (Z mil film)
Discoloration
of nylon
ties
Attributable Attributable
to solar to solar
radiation radiatLon
Discoloration of epoxy adhesive on knots in nylon ties
Surface FEP
cracking
of teflon
Attributable
to solar
radiation
2-3
TABLE Z-Z. ASSESSMENT EXPOSURE --EXPECTED
OF EFFECTS EFFECTS NOT
OF LUNAR OBSERVED
Effect
Comment
Blistering surfaces
of polished
aluminum
Conjectured protons Reported studies
effect of solar wind
in some
laboratory
Effect not strongly Significant pitting of metals painted surfaces by micrometeoroids and
anticipated
Only three possible primary impacts observed; only one on Surveyor III television camera* Similar results obtained on companion test program of Surveyor III camera (Reference 1)
Cold welding of mechanisms, gears, fasteners, and other metal surfaces
Loss of adhesion and of inorganic paint Degradation properties of electrical of wires
cohesion
Since effect not strongly anticipated, results not surprising Diagnostic tests conducted ambient conditions only No tests conducted under
in vacuum
Changes in chemical of organic materials
structure
Since pated,
effect not strongly anticiresults not surprising.
'_Reference and
102
(see
separate
list
of
references
for
surface
discoloration
contamination
studies at end of this report).
Z-4
TABLE
2-3.
ASSESSMENT UNEXPECTED
OF
EFFECTS EFFECTS
OF LUNAR OBSERVED
EXPOSURE
-
Effect
Comment
Increase alloys • •
in hardness
of aluminum
Due or
to higher
thermal for
exposure over 4000
at hours
250°F
Polished Painted
tube tube
Strong adherence nlateriais to one alun_inum tube
of lunar side of polished
Effect apparently incurred landing of Surveyor III High velocity in aluminum particles
during
imbedded
Severe "mud-cracking" of inorganic paint on fiberglass substrate
Due paint
to thermal and
mismatch
between
fiberglass
substrate
large adhering SM/SS
amount to all scoop
of lunar surfaces
material of
Presumably
caused
by
lunar scoop
material remaining in the and failing out in transit
Difficulty naut on polished Surveyor support
experienced by astron_oon in atten_pt to cut tube section from III flight control unit structure
Cause
remains indicates of same
unknown that aluminum construction severed by radar antenna
Analysis tube was
as
that subsequently astronaut from support
2.
3
CANDIDATE Examples
FUTURE of possible
STUDIES additional engineering tests on the returned
Surveyor IlI parts are presented in this subsection. These possible areas of study that may be profitably conducted are submitted without any specific recomn_endations since, as noted previously, the conduct of such additional tests depends on the intended application. For any such specific future rtesign an,_l;_-at;nn a review in depth of the results presented in this report and of the candidate tests listed below w[[[ lead to the final selection. A further results input to this decision science is also expected to be when forthcon_ing they becon_e from the
of the paraiie[
investigations
available.
2-5
coloration specific
Additional measurement and contamination tests include:
and studies
analysis may be
relative warranted.
to the surface Examples
disof such
Analysis of contamination on teflon not conducted within the limitations Quantitative conducted tube and
FEP wrap from of this program
TV
cable
-
analysis of contamination of polished tube -- not because of restrictions on the use of the polished because of program limitations _ be warranted following completion and other science tests now in
Such additional tests as may of the organic determination progress Examples included (Reference of additional candidate in the companion report 1).
tests relative to surface discoloration on the Surveyor III television camera
are
Availability of the photographs of the Surveyor III spacecraft taken on the moon by the Apollo astronauts suggests that a critical analysis be conducted, based on further study of these photographs, to assess the condillon of the spacecraft after Z-I/Zyears of Lunar exposure. Only a very brief review of these photographs was conducted in this program. A more extensive review beyond the scope of this program, based on a full assessment of the materials and processes employed in the construction of Surveyor III, may prove valuable. Additional effort may be warranted to determine or to confirm the proposed cause of the observed degradation of physical properties of certain materials, including copper conductors of the external cable, teflon insulation, and others. Results of the study indicated that changes had occurred that may be important to long-life future space vehicles. However, both the exact nature of these changes and their causes remain somewhat inconclusive. While no significant changes in the electrical properties of wires were observed during measurements made in air, the existence of significant effects of lunar exposure noticeable in measurements under vacuum conditions cannot be totally discounted. Such measurements, while considered beyond the scope of this program, may prove worthwhile.
$Onty
a limited
qualitative aluminum
analysis tube was
of one
heavily
contaminated
location
on the polished
conducted.
Z-6
3.
DESCRIPTION
AND
INITIAL
EXAMINATION
OF
RETURNED
PARTS
This section describes the parts of the Surveyor III spacecraft returned by the astronauts which were tested and evaluated in the course of this program and presents the results of the initial visual and microscopic examination conducted prior to detailed testing. The parts described and visually examined include the scoop from the soil mechanics/surface sampler (SM/SS), the external cable from the Surveyor III television camera with its teflon wrap, a section of polished aluminum tube from the Surveyor III structure, and a section of aluminum tube from the television camera support painted with white inorganic paint. The painted tube and a section of the teflon FEP cable wrap were returned from the moon in a special sealed container. The other parts were returned in an ambient envi ronment. included in this section is a brief discussion photographs taken on the moon by the Apollo XII astronauts of the Surveyor III spacecraft. Also of some of the of other parts
3. I SOIL 3. 1. 1
MECHANICS/SURFACE and Retrieval
SAMPLER
(SM/SS)
SCOOP
Description
The SM/SS, designed and built by payloads of Surveyor III. Its purpose was mechanics experiments in order to obtain teristics of the lunar surface and provide Apollo landings.
Hughes, was one of the major to perform certain lunar soil scientific information on characengineering data for subsequent
The basic SM/SS mechanism consists of a bucket or scoop attached to the end of a "lazy-tongs" extension arm, shown in Figure 3-1. The arm is attached to a base which can be pivoted in etevation and azimuth with respect to the spaceframe. It is driven by three motors that control the azimuth, etevation, and extension motions. A fourth motor opens and closes the scoop door. The joints of the lazy tongs extension mechanism include torsion springs that provide the extension force. The retraction force is provided by a motor which winds up a steel tape attached to the scoop. The elevation drive motor includes a positive latching clutch which
3-1
Figure
3-1.
SM/SS-ScoopMechanism
(Photo
Rl13487)
can be disengaged from the gear train by actuation of a solenoid; the elevation torsion spring to drive the mechanism downward. details on the scoop motor are given in Section 4. I. After completion the scoop was it was removed scoop that in of the soil mechanics in the raised, fully from the spacecraft, the spacecraft cold welding
this allows Further
face, Before
[eft
experiment on the lunar surextended position {Figure 3-2). one of the astronauts manually without had not encountering occurred with MoS itsetf in difficulty; the joints.
pushed the this indicated
toward significant
The joints and When released indicating that
bearing surfaces by the astronauts, the springs were
had been lubricated the scoop reextended still working well.
2 compounds. easily, thereby
3-Z
+
.
Figure Raised
3-2. Retrieval Position (NASA
of Surveyor III Parts, Photo AS-IZ-48-7133)
Showing
SM/SS
in
3-3
Figure 3-3. Retrieved Surveyor III SM/SS Scoop in Lunar Receiving Laboratory (Photo 4R14713)
k
O
®
SEE TABLE
3-1
FOR
EXPLANATION
Figure Materials
3-4. and
Location Finishes
of Various on SM/SS
Scoop
3-4
One possible difficulty anticipated in removing the scoop was cutting of the stainless steel retraction tape, which can be seen in Figure 3-I. The tape extended from the retraction motor and looped around a bracket on the scoop. It was spot welded onto itself about half way between the scoop and the retraction motor. After an unsuccessful attempt at cutting the tape with the bolt cutters, the astronaut apparently twisted the tape with a quick motion and broke it. It is believed that the tape broke at the spot weld. The tape then s[ipped through the scoop and onto the lunar surface. The astronaut then bolt cutters. In all, three scoop motor were attached cut the scoop arms behind the front joint with the arms were cut. The four wires leading to the in the form of a wire bundle to one of the arms Figure at the 3-3 shows the scoop, Manned Space Center arms, in
and were also cut in the process. and the first joint after unwrapping January 1970. The scoop shown in Figure twisted together strands of 34 AWG 0. 009 inch thick Z2 AWG and 600 3. 1. Z Visual The 7 January revealed ure 3-3. I_mter ethylene. tests It
consists of the materials listed in Table 3-I located as 3-4. The wires operating the scoop motor are four wires with a 1 inch pitch pattern. Each wire consists of 19 silver-plated copper. The wire is insulated with teflon TFE, wrapped and fused. The wire is rated at volts.
Examination scoop storage bag was opened for initial visual examination in Fig-
1970 at the Lunar Receiving Laboratory. the heavy lunar soil coating over all of When the bag was split open, an unusual indicated is believed that the that odor was not associated the odor was associated were to lunar taken, Hughes soil. the at
This examination the scoop, as seen odor was detected. with with the scoop for furthur Prior to scoop was Hughes. the the was heated lunar
polymaterial.
After numerous in its polyethylene bag next step was removal lunar thorough material visual from and
photographs and transferred of the surface
rewrapped studies. The removal of the subjected The lunar to a material
the exterior microscopic
surfaces, examination
from inside the scoop was then removed by Professor R. Scott for lunar soil mechanics investigation.:'.'The scoop was again visually examined to determine any effects that might have been masked by the lunar material. The scoop was then transmitted to JPL for radiation counting as part of the associated science stud[es. Upon return to Hughes, the scoop was partially disassembled, and measurements were conducted on disassembled units such as the motor and the gear assembly. Some parts of the scoop were then examined in more detail witha scanning electron microscope (SEM). Results of this examination are discussed below.
California separately
Institute as part
of Technology. of the science
Results report.
of
analysis
will
be
reported
3-5
TABLE
Item (See Figure
3-1.
SCOOP
MATERIALS
AND
FINISHES
3-4)
Material
Specification
1
0.
040
inch with
6061-0 alloy blue sheet paint _"
QQ-A(Aluminum
ZS0/l
1 Alloy)
aluminum coated
Black
anodized
MIL-A-8625, Class 2,
Type Black
II,
6061-0
aluminum
AA-A-Z50/I
1
250 low alloy H condition
steel
MIL-H-6875
0. and
075
inch
titanium
sheet,
MIL-T-9046, Composition C
Type
Ill,
6A 1-4V aged
solution-treated
0.06Z laminate with
inch
plastic sheet coated paint _
L-P-509, (Plastic
Grade Laminate)
GII
blue
0.03Z sheet
inch
teflon
TFE
MIL-P-2)Z4Z,
Type
I
Machined aluminum coated
from alloy with blue
7075-T6 bar stock paint :_
QQ-A-225/9 (Aluminum Alloy)
7075-T6 anodized
aluminum
black,
QQ-A-
Z25/'_ Type Black If,
MIL-A-8625, Class 2,
_The a The sium blue top
blue coat white silicate pigment
paint of paint
coating blue inorganic had
consisted paint. clay blue a china
of
two The
coats total was
of paint
white
inorganic was and that silicate)
paint 8 a
and units. potas-
thickness except
pigment paint
(aluminum similar
binder. The was added.
a proprietary
Lunar
MateriaL
The scoop was heavily coated with Lunar material, as can be seen in Figure 3-3. The lunar materiaL adhered fairLy well to the painted surfaces, partLy because of the roughness of the paint. However, Lunar material was noted to adhere weLl to smooth as weLl as rough surfaces. A uniform layer of dust was noted on the nonpainted surfaces, but the dust layer was heavier on the painted surfaces. The majority of the lunar materiaL undoubtedly came from the scoop during handling in recovery and return. The dirt which fell out of the scoop was redistributed over aLl the surfaces. The ._t,__L=j._,.,,, TFE _,_=***"'--7 ,.,,:- Figure J--_,_ ............n .leon.. _,,a*" ....... ,,o, ._.._.t,,-=material on it, but this material adhered when the scoop was turned upside down. The distribution of lunar material on the scoop is seen in Figures 3-5 and 3-6. The teflon FEP-insulated wires retained a slight amount
3-6
of lunar material, when loose material lunar material did
as
seen in Figure was redistributed not adhere as well
3-6, but this during the to the steel
was return screw
probably collected trip to earth. The heads and to the and dis-
black anodized aluminum, as seen corners. It was noted later during adhering t0 the inside of the scoop tribution. The inside of the scoop Inorganic Paint Surfaces
in Figure 3-6, except in recesses disassembly that the lunar material was very uniform in thickness and was painted with inorganic paint.
The inorganic blue paint described in the footnote to Table 3-1 seemed mostly unaffected by the lunar exposure except for "mud-cracking" and for some chipping at corners. The mud-cracking was found only on the fiberglass surface (Figure 3-7). The mud-cracking has been attributed to the differences in the coefficients of thermal expansion between the inorganic paint and the substrate. Chipping of the paint was noted on the ends of the tubes that were cut on the moon during the retrieval operations. This chipping was due to the brittleness of the paint. A tape test using a 3M 250 adhesive tape showed no evidence of reduction in adhesive or cohesive strength of the paint when tested away from the chipped area. The paint appeared to have faded slightly from its original blue color to a lighter shade of blue. This was the result of exposure to solar radiation. Organic Paint Surfaces
The black areas on the tubing (Figure 3-5) are coated with a black organic paint-3M Black Velvet, carbon pigmented, in a silicone alkyd binder. The coating of the paint was uniform. An overcoating layer of lunar material was noted which gave the coating a grayish appearance. A similar appearance would be expected of a black organic coating covered with any kind of dust. The.3M 250 tape test was conducted on the black paint, and no adhesion or cohesion failures were noted. An SEM examination was then conducted,with no unusual effects noted. It appeared that the coating had not been affected by the lunar environment except for its surface contamination. Results of optical property measurements of the black paint are included in the surface discoloration and contamination study, Section 11. Some increase in reflectance was found. Black Anodized Aluminum Surfaces
Anodized alumindm, dyed black (Mil-A-8625, Type'II, Class 2, Black), was used on areas designated as items 2 and 9 in Figure 3-4. No fading or degradation was noticed. Reflectance measurements were not made because of the small sample size and because of the desire to minimize destruction; the change in reflectance was small as estimated by eye and was considered as probably insignificant to the total solar absorptance.
3-7
Teflon A scoop slight sheet
TFE of 0. 032 inch thick teflon TFE was bonded to the base of the a
jaw. color The
No evidence change from TFE teflon
of lunar exposure its original milky insulation on the
effects was noted other white to a light yellow. appeared to be
than
wires
only
slightly
affected by lunar have been present TFE teflon wraps nation or loosening.
exposure. Very slight cracking prior to the lunar exposure. was clearly visible and showed
was observed. The bond line no indication
This may between the of delami-
L
Figure (Photo
3-5. Distribution 4R14815)
of
Lunar
Material
on
SM/SS
Scoop
3-8
Figure 3-6. Eniarged View of SM/SS Scoop, Showing Lunar Material and Wiring (Photo 4R15123)
o O oN.) oo
Figure
3-7.
"Mud-Cracking"
of SM/SS
Scoop
Paint
(Photo
4R15118)
3 -10
3. 2
TV
CABLE
3. Z. I
Description The
and.Retrieval of this study its return of the lower was removed to earth. The shroud. This from cable section the was was outer of moon in 3-9.;:_
Surveyor Located used for in vacuum thermal the cable
cable used in a portion III television camera after on the Lunar southeast side
electrical and physical measurements. were also planned for the aluminized control wrap of the cable. To accomplish was cut from the Surveyor III camera
Reflectance measurements teflon FEP used as an this, a small section during recovery on the (SESC), shown seen in Figure Figure 3-10. from the SESC
and placed in the sample Figure 3-8.'.'-" The various The position of the cable It had been planned
environmental sealed container sections of the cable can be on the spacecraft is shown in to remove the cable section
under
the original vacuum conditions and to mount a piece of the teflon FEP in a vacuum chamber for measurement of its spectral reflectance. However, a leak in the SESC was uncovered prior to its opening. Descriptions of the SESC, its opening, the nature of the leak, and its effect are presented in Section ll and Appendix J. Despite this Leak, the planned transfer was performed and the spectral reflectance measurements were conducted according to the The was about about 50 diameter. original cable 7 inches plan. section long removed and I/Z from inch the side of the television The cable camera
in diameter.
contained
small conductors and Z Large coaxial Each of the small conductors was
conductors, 3/8 inch in made of 19 strands of silverFEP
plated copper or copper ahoy twisted together and insulated with teflon overcoated with a thin Layer of poLyimide. These small conductors are described in Table 4-15 (Section 4). The cable section also included a single solid resistance. The bundle was one side. was Lon held FEP, nonmagnetic conductor having a high thermal and electrical
wire then This
bundle
was
held
together 0.000Z5
with inch shield top on
nylon thick for the
cord. mylar, cable. the
This
wire on tef-
overwrappedwith served as an
electrical
aluminized The mylar cable was
inpLace 0.00g
with nylon cord. The inch thick and aluminized
covering of one side.
was turn.
The 0.00Z The
aluminized inch thick teflon FEP
teflon FEP tape used as the outer and 1 inch wide, overlapped about side faced outward and was used
50 for
wrap of percent thermal
the cable on each control
;:4 The color; This
original black comment
photographs and white applies
in the Surveyor Parts Test Program files are prints made of these originals are presented here. to other photographs in the report, as indicated.
in
3-11
of the
cable.
Nylon
cord
was
used
to secure
the
teflon.
The
knot
of the teflon,
nylon cord nylon, and The
was held with an unfilled epoxy polyamide adhesive. epoxy were directly exposed to solar radiation. individual Teflon materials FEP-This were material as follows: was 0. 00Z Type on inch thick film
The
1)
covered
by Federal Specification L-P-5Z3, Non-cementable). It was aluminized
I (General Purpose, one side to a thickness percent in an initial emittance
equivalent to a light transmittance of less than 1.0 the wavelength region of 0.3 to 0.8 micron. It had solar absorptance at 80°F of 0.70 of 0. 15 +0. 03 and +0.05. a total normal
z)
NylonMIL-T-713,
The
lacing Type
cord is covered in Military P, unwaxed (polyamlde).
Specification
5)
Epoxy Adhesive -- The unfilled epoxy polyamide prepared by Hughes; no general specifications available.
adhesive for it are
was
4)
Mylar-L-P-377,
The mylar Type If.
film
is covered
by
Federal
Specification
3. Z. Z
Visual Teflon The TV
Examination FEP cable segment examined is shown in Figure 3-11. at on ::: Before of
the surface was unwrapped, cations up to 40X. Some the cable exposed to the stress points, such as ible under a microscope peared to be reflective which appeared brown The nylon from the in Figure noted that
it was examined n_icroscopically cracking was observed in the solar radiation. The cracking in the material. were difficult on one side of deposited and section the some of brown coating held
teflon occurred
magnLfithe side at high
folds but except because
These cracks to photograph.:::::facing outward material. of the teflon teflon from was below
were clearly visThe wrap apfrom the camera
removed is shown was also
ties were cable. 3-1Z,-':= son]e
cut, This where aluminum
unwrapped the TV
and cable It be that
area is clearly on the teflon to light, it
discernible. appeared to was obvious
quite thin or the film had
n_issing a significant
altogether. When transnlissLon.
Original Photographs photographs tion was
in color. at 40X not were not adequate magnification included to show in the are available in progranl the files. of These reproduc-
the report observed 3-12
because effects.
quality
Figure (NASA
3-8. Photo
Sample Environmental S-70-21226)
Sealed
Container
(SESC)
3-13
Figure (NASA
3-9. Photo
Retrieved S-70-21152)
Surveyor
III
Television
Camera
3=14
!
Figure
3-I0.
View
of Surveyor
IIl TV
Camera
on
Moon,
3-15
Figure 3-11. Section of External TV Camera (Photo 70-5797)
Cable From Surveyor III
Figure 3-12. TV Camera
Teflon Wrap (Photo 70-5758)
Removed
From
External
Cable
of
3-16
One
Several possibility
possibilities exist is that inadequate
as to why metallization
the
aluminization occurred
in
was so processing.
thin.
The teflon was metaliized in long rolls, and thin spots were occasionally found. There was some metal on the surface, and it is therefore quite possible that it appeared to be good when cut from the roll. Since each individual piece of material was not tested for specification conformance, unless a careful examination was conducted the thin metallized piece would have been placed on the spacecraft. The second possibility is that the metal was abraded from the teflon during cable manufacturing or subsequent handling operations. Another possibility for the thinness or absence of metallization is a failure in the interlayer cohesion. If a thin batch was found during processing, it is likely that the metallizer would have reprocessed the batch by adding more aluminum. This could have resulted in poor adhesion which would later lead to separation. A final possibility is loss of aluminum due to thermal cycling on the lunar surface. Other areas of the camera were wrapped with the same type of material, and no loss of aluminum was noted. Thus, if the thermal cycling did cause this loss, it must be concluded that initial processing of the material was poor, leading to the later failure. In any event, this thinness or absence of aluminum coating is considered to be a Secondary result of lunar exposure. Only one small piece of the several sections examined evidenced this effect. Evaporation of the aluminum must also be ruled out since the temperatures reached on the moon were not sufficiently high for this to occur. Sections of both the brownish area and the unaffected area of the
teflon FEP were examined under an SEM to determine the origin of the discoloration. Figure 3-13a shows a typical area of the unaffected surface at a magnification of 105X. The marks seen on the surface appear to be scratches rather than cracks. Some debris, probably of lunar origin, can be seen--the black specks in the center of the photograph. Figure 3-13b, taken at a magnification of ll-0X_ shows a brownish area. The surface is uniformly covered with debris. Figure 3-13c, taken at a magnification of 1080X, shows an area where some of the debris had been removed, revealing the characteristic appearance of the teflon FEP below. Figure 3-13d, taken at a magnification of ZISOX, indicates the character of the debris.
brown
It was in the
noted that area which
the nylon received
ties had the most
turned solar
from milky radiation.
It
white to dark is believed
that a large part of this discoloration may have been caused securing adhesive which wicked around the tie cord. During analysis, the darkened nylon was dissolved in formic acid; a dark brown insoluble mass precipitated. When the nylon solution, it appeared milky white. When the nyion ties were the cable, they were stiff and had lost their pliability in the and, to a lesser extent, in the lighter areas.
by the knotchemical in this process, was taken out of removed from darkened area
3-17
a) 105X
Magnification
(Photo
00628-13)
b) With Lunar Magnification)
Material (Photo
(I10X 00628-14)
c) Lunar (1080X
Material Magnification) Figure
Partially (Photo 3-13. Surface
Removed 00628-15) of Teflon
d) Enlargement Magnification) FEP Wrap of
of Figure 3-13c (Photo 006Z8-16) External Cable
'_'=_v
3-18.
After removal of the outer the nylon tie cords used underneath
wrap of teflon the wrap had
FEP, also
it was noticed that discolored in an
irregular pattern but to a lesser extent. This solar radiation through the teflon FEP in areas was thin or missing, as shown in Figure 3-II. An SEM examination The general weaving pattern 104X. tligher magnification it', Figures The surface material, 3-14b facing presumably Epoxy and c at outward was conducted is shown in photographs magnifications to the lunar
is attributable to exposure t(, where the aluminunl coating
of a darkened Figure 3-14a of individual of 1050X environnlent and is
piece of nylon. at a magnification strands are show,_ ZI00X, covered respectively. with a
of
epoxy.
As previously noted, the epoxy was dark brown. This area hact been exposed to solar radiation. This was also evident in areas where the adhesive had splashed onto the teflon FED, as can l)e seen it`* Figure 3-11. No other visible damage appeared to have occurred, and S/£M exa_ination showed no evidence of cracking. A representative area is shovcn at a t_agnification of 595X in Figure 3-15.
-%
,"
......
I
_*r .....
:_,.
D^*+
....
/I/laY
Magnification)
{Photo
00628-17)
Figure
3-14.
Nylon
Tie
Cords
of
External
Cable
Wrap
3-lq
b) Individual Fibers (1050X fication) (Photo 006Z8-18) Figure 3-14 (continued).
Magni-
c) Individual Fibers (ZI00X fication) (Photo 006Z8-Z0) Tie Cords of External Cable Wrap
Magni-
Nylon
Figure (595X
3-15. Epoxy Magnification)
on Nylon Tie Wraps (Photo 006Z8-Z0)
3 -20
Wires Initial examination of the wires in the bundle under the teflon and
n_ylar wraps of the external cable revealed nothing unusual. Later inspection revealed some cracking of the polyimide; however, this had been noted on wires prior to launch. The coaxial cable sections showed no visible evidence of change.
3. 3
POLISHED Description A
TUBE and Retrieval of the polished moon. aluminum This tubing tubing was cut from the was 0.5 inch in diameter thickness 3-16._:: Its location of 0.035 inch This section on the
3. 3. I
Surveyor and per was
7-3/4 inch III spacecraft of one
section on
was made WW-T-700/3. cut from
2024-T3 The of the
aluminum tube section radar antenna
alloy, with a wall is shown in Figure support struts.
spacecraft can be seen in Figure 3-17a. It is the from the cylindrical antenna in the lower left area frame, The exact position along this support strut was removed is not known.
longer of the from
tube extending spacecraft to the which this section
Figure Lunar
3-16. Returned Section of Polished Receiving Laboratory (NASA Photo
Aluminum S-70-Z1223)
Tubing
in
--bOriginal
in
color.
3-2l
a) Showing
Location
of
Removed
Polished
Tube
(NASA
Photo
AS12-48-7114)
3-22
b) Showing Area Where (NASA Photo AS12-48-7125) Figure 3-17
Removal
of
Polished
Tube
Originally
AtteFnpt_'d
(continued).
View
of
Surveyor
IH
on
Moon
3 -23
Figure spacecraft which
3-17b was
shows the originally
polished slated
aluminum for removal
tube by
on the Surveyor the astronauts.
This
tube was the nearer one of the two tubes supporting the Surveyor III flight control unit which houses the Canopus sensor mounted on its top.::-" This aluminum tube was of the same alloy, temper, diameter, and wall thickness as the radar antenna support tube actually severed by the astronauts, as confirmed by subsequent analysis of Surveyor III design records. The astronauts reported from the moon that they were unable to cut this tube although tion on a the few minutes radar antenna flight later they support successfully strut using performed the same this cutters. cutting The operaastroattempt at its
nauts confirmed to sever this extreme polished
during their debriefing control support tube reason for tube remains tube section
that they through failure
did not erroneously the thicker brackets to cut this particular
ends. aluminum The
The
this original unexplained. was returned
severed
to
LRLwtth was were
the conducted released
other 7 January for study.
retrieved 1970 by Extensive
Surveyor Hughes and photographs
III parts. A visual examination NASA personnel when the parts were also taken at this time.
Examination of the tube for micrometeoroid impacts was then conducted by NASA personnel. Detailed examination of specific sections of the tube indicated the presence of possibly two hypervelocity in,pacts of 50 microns or longer. These areas were preserved for additional investigation; results of this work are expected to be published separately. Following this examination, the tube was sectioned NASA direction. Details of this sectioning, as well at Hughes, are presented in Appendix A. Sections the two ends of the tube were delivered to tlughes for g Visual Prior to Examination to the sectioning thorough visual was at the of the polished examination. on one (section AI. tube at The n_ost side G) of and MSC, the obvious the tube. l)ecame tube was surface The deposit gradually into six parts as of later secA and G taken exanlination.
under tioning from 3. 3.
subjected
a
characteristic was very heavy lighter toward
a brownish deposit one end of the tube other end (section
Results of subsequent of the contamination studies 4. 6, and 4.7, respectively.
metallurgical on this tube, Figure 3- 18
and optical investigations, are presented in Sections shows the contaminated
4. side
and 5, of
--,,e had
.,. mm 1_
f'"ttgllL .... corlurot a shattered
unit mirror
was erie surface
,1
illei-l[ equip on top.
_
uux,....
:pl evtuu_
"
I
y
II
.
I_,_IlLIOIIeU
_
__:
.....
a
I
___k: Wlll.
k
.1_ 11
3 -24
Figure (Photo
3-18. Contaminated 4R16634}
Side
of Sections
A and
G of Polished
Tube
sections Section adhered
A and G of the A is the shorter to the surface.
polished of the
tube, mounted on rods after two sections. The contaminant
sectioning. strongly
section of the
Figure 3-19':: shows G. The jagged area lur_ar cut. Just below
an enlarged view of the "lunar-cut" end of near the top of the photograph is at the start it is an indentation in the tube. This indentawas cut. Its signifiin Figure 3-19 that this indentation and
tion was r_ade by the bolt cutters at the time the tube cance is described in Section 4.5. It should be noted the contaminant remained as an unbroken film within along the edge; this gives an indication of its adhesion.
Original
in color.
3 -25
Figure 3-19. Tube Showing
Enlarged View of End of Section Contaminants {Photo 70-5549}
G of Polished
3.4
PAINTED Description
TUBE and Retrieval
3.4. 1
A 4 inch section of aluminum tube coated with inorganic white paint was cut from one of the camera support struts with the bolt cutters by the astronaut, who then placed it in the SESC along with the cable section described in Section 3. Z. An experiment was planned in which the optical properties of the white paint were to be measured while still in vacuum. Then, under carefully controlled conditions, the coating would be exposed to various amounts of air, followed by a regulated amount of Light. A discussion of the tests actually conducted is given in Section 1 1 and Appendix J.
3-26
The inorganic white paint is a Hughes formulation,'.'_ consisting of a calcined clay pigment which is primarily aluminum silicate. The binder is potassium silicate. The coating is applied to a thickness of 5 to 8 mils. It had an initial edlar absorptance of about 0. 17 and a total normal emittance of about 0.9Z. 3.4. Z Visuat Examination
The first visual examination was made when the SESC was opened. This was done under lowlevel red light illumination. The basic observation made at this time was that the paint was still adhering to the tube. The tube was sectioned into two parts: one about 3 inches long and the other about l inch long. The 3 inch piece slated to be used in the optical studies was placed into its special container. The other piece was placed in a JPL container for science studies.
The next visual examination occurred at the end of the programmed testing. This examination was made with the tube section still in the quartz vacuum chamber used for the optical measurements. _-'* The paint was discolored to a yellowish-tan appearance. Variations in color were found around the tube. Similar color variations were observed on the struts attached to the TV camera support collar, as described in the companion report (Reference l). The paint had adhered well except at the ends where the bolt cutters were used. There was also a small chip in the middle that had probably occurred within the SESC during transit from the
moon.
3. 5
ANALYSIS SURVEYOR
OF PHOTOGRAPHS III
AND
CREW
OBSERVATIONS
OF
Numerous photographs of the Surveyor spacecraft were taken by the astronauts during recovery operations. Althougha detailed analysis of these photographs is beyond the scope of this program,*** limited examination was conducted to assess, at least in a preliminary way, the condition of some of the parts and systems of Surveyor Ill not returned by the astronauts. Figure 3-17b shows the top of the electronic equipment compartment B, the large rectangular compartment. The compartment was covered with aluminized Vycor 9710 second-surface mirrors bonded to a thin aLuminum substrate with a silicone adhesive, RTV-ll. Although some warping of the composite occurred as a result of the mismatch of the thermal expansion coefficients, the mirrors were still in place.
._re
"Re fe re nce The
_c X=-,"See
4. section is still in this chamber. follow-on studies.
tube Section
Z. 3 for
suggested
3 -Z7
The top of the flight control boxj previously noted and shown in Figure 3-17b0 presents a striking contrast to the above observation. This box is located at the lower left side of the photograph. This surface is similar to that on top of compartment B except that the mirrors on this bo_ were bonded witha hard epoxy adhesive. The mirrors were shattered, presumably as a result of thermal cycling during lunar days and nights. Just to the right of the flight control box in Figure 3-17b is the Surveyor Canopus sensor. Markings which appear to be blisters can be seen on the side of the sunshield. This surface was aluminized teflon FEP film bonded in place. If these markings are probably caused by bubbling of the adhesive. indeed blisters, they were
All other areas of the spacecraft appear to be in good shape. Nylon wraps used to secure cables appear intact. Adhesively joined teflon, which covered propellant tanks, appears to be in nominal condition. The composite structuressolar panel, planar array antenna, and omni boom antennaall appear normal. The paints used on the spacecraft also appear intact after the 3-I/2 year exposure to the lunar environment. The above comments are indicative of a high degree of survival of the spacecraft. A more extensive analysis of the photographs may, however, alter some of these conclusions. Such an analysis would utilize in greater depth the knowledge of the materials and processes actually used in the construction of Surveyor III. A more comprehensive interpretation of these photographs could prove to be of direct value to future spacecraft designs.
3-28
4.
TEST
AND
ANALYSIS
OF
RETURNED
PARTS
A Surveyor
summary III parts 4.
of is
the tests presented the
and analysis in this section. results Section pin of the of tests 4.2 scoop
conducted
on
the
returned
Section scoop motor and wear test Results wrap Section
1 contains
and describes joint. on
evaluation a special
of
the
SM/SS
and gear conducted
assembly. on the
friction
the
cable
of chemical and on the 4.4 gives of the included
analysis nylon ties the results
conducted of the cable of tests
the teflon are presented on of the the and
FEP in wires
material Section and scoop
4.
of 3.
conducted of cable and electrical
electrical insulation wires. These tests characteristics. Results including on of Results reflectance, its in the of
television camera measurements
SM/SS physical
tubes,
metallurgical microscopic Section ends of
analysis examination
of the polished and microhardness 4.6 gives aluminum spacecraft characteristics, reflectance, the tube
and
painted aluminum measurements, of led to an analysis to the deterits removal.
are presented performed ruination
4. 5. Section the polished on the
results which prior
orientation
Surveyor of optical infrared
of measurements transmittance,
and
on
the
i.e., spectral aluminized
teflon from the television camera cable wrap and on the polished aluminum tube are presented in Section 4.7. Aluminized teflon optical measurements included measurements on the wrap of the cable section returned under ambient the sealed conditions container. and vacuum measurements on the teflon wrap returned in
Section jointly camera aluminum
Results 11 (and with the
of the surface contamination studies are reported Appendix J). As a supplement to these studies, companion contract on the returned Surveyor III 1), results Surveyor of analysis of III are presented the in contamination Section 4.8.
in conducted television on the polished
(Reference tube from
4-1
As discussed in were also conducted in comparison to assist in to the effects of prolonged lunar environment. In results obtained, each
the respective subsections, tests of control samples many instances. These tests served as a basis for the identification of changes that could be attributed exposure of the retrieved Surveyor parts to the addition to a description of the test conducted and subsection also includes an evaluation of the results, of samples, and the effects past test materials of this exposure. data available specifications In from were
with primary emphasis on determination addition to data obtained on control Surveyor program files, the literature, used to assist in this evaluation.
4.
1
EXAMINATION Tests
OF
SCOOP
MOTOR gear in
AND
GEAR of the
ASSEMBLY SM/SS scoop, described
in 4.
Section 1. 1
3.
of the motor and 1. 1, are discussed
assembly this section.
Description dc scoop motor was built by AiResearch by Hughes. One modification conbrushes with Boeing Hot Compact 046-45 the scoop door through a 1400:l ratio
The high speed (13,000 rpm) Manufacturing Company and modified sisted of replacing the spring-loaded brush material. The motor actuated gear train. The composition 4-1. Traces of graphite-forming at 1600OF The candidates, diselenide, vacuum the idle
in Table the use atmosphere
of the brush material in the metallic carbides are also dies. The brush material in an isostatic press. of selected
scoop motor present as a is formed
is shown result of in an argon
Boeing compact was such as silver-molybdenum silver-graphite, etc., because it
for the motor brushes disulfide, compacted because of low friction and the motor to rotate at
over other niobium wear in 20,000 rpm in
tests and condition. The drive lubrication. and and
permitted
unit
grease covers, disassembled coating, air.
was Hughes
originally degreased
designed the ball
to
function bearings,
with an removed
organic the
end
spray-coated the unit with Lubeco 905.* The for lubrication but were run in after spraying the debris was blown out of the bearings with
bearings were not and curing the clean dry filtered
*A
proprietary
bonded molybdenum
solid
lubricant
made graphite,
by and
Lubeco lead
Corporation, sulfide.
containing
disulfide,
4-2
TABLE 4-I.
COMPOSITION OF SCOOP MOTOR BRUSH MATERIALS
Composition (by weight), percent
Material
Molybdenum Molybdenum Tantalum
disulfide
80 15 5
The pinions rinsed, and coated with rotating wire filtered nitrogen. 4. 1. 2 Initial X-Ray
and planet gears with Lubeco 905 brushes, and the
were before debris
all degreased, assembly. was removed
lightly sandblasted, They were burnished by blowing with
dry
Examination
of
Returned
Part
that lunar
The motor and gear assembly was X-rayed might have occurred to the mechanism as a environment. No damage was detected. Resistance Prior and Continuity of and of Motor
to result
detect any of operation
damage in
the
resistance motor
case
to disassembly of the windings were measured,
the SM/SS the resistance The winding
scoop motor between resistance
and gear the windings was measured
train, the and the with a
Wheatstone bridge {Shallcross voltage of 4.5 volts dc. The measured using a multimeter measurements are shown in the wire and nominal resistance well 4. 1.3 insulated Functional This of the SM/SS at two different conditions. and later at test from the Checkout was conducted case.
Model 638-R 4) having an internal battery resistance of the windings to the case was (Simpson Model 260}. The results of these Table 4-2. The results indicated no breaks in values. The motor was also found to be
of
Motor to determine the assembly (5 and 10 made first functional characteristics conditions under stall 10 -8 Torr
scoop motor and gear train values of applied torque These determinations were atmospheric pressure.
under starting in-lb} and also in vacuum at
4-3
TABLE
4-Z.
RESISTANCE MEASUREMENTS OF SCOOP MOTOR
OF
WINDINGS
Resistance Motor Terminals* B-C A-C A-B A, B, to case C 1 0 megohms 1 0 megohms First Terminal - Negative First Terminal 44. 44.25 37. 15 - Positive ohms ohms O0 ohms
41. 14 ohms 41.27 36.77 ohms ohms
:_Terminals C is the
A and common
B are ground.
for
the
clockwise
and
counterclockwise
windings;
Calibration In order to be able to apply measured amounts of torque as a load on the output shaft of the gear train at a pressure of 10 -8 Torr, an electromagnetic brake (Stearns Style SMB, Model 3, rated at 9 watts, 90 volts dc, and 60 in-lb)was calibrate_at four pressures--atmospheric, 5 x 10 -3 Torr, 10 -4 Tort, and 5 x 10Torr. Calibration was accomplished through the wall of the vacuum chamber using a mechanical feedthrough shaft strong enough to accommodate the torque. Atorque arm 1 inch long was secured to the shaft outside the vacuum chamber. The torque was measured with a Chatillon torque watch, having 0. Z5 pound divisions and a full scale capability of 30 pounds. Voltage applied to the brake winding was measured by a digital voltmeter. Results of this calibration are shown in Table 4-3. It was not possible to perform a direct calibration at 10 -8 Torr of the limitations of the seal associated with the mechanical feed-
because
through. However, calibration values were obtained by extrapolating a plot of the measured values, Calibration was further extended to ZZ in-lb in anticipation of stall torque measurements, Minimum required stall torque of the scoop motor was given as 12 in-lb at 18.2 volts and 70°F. Since no maximum torque was given for these values, exact calibration could not be pe rformed.
4-4
TABLE
4-3. CALIBRATION OF TESTING OF SCOOP
BRAKE MOTOR
USED
FOR
DC Pressure Torque:
Voltage
Applied
to
Brake Torque:
Winding, 10+0.5 19.5 15.0 14.0 13.0 I0.0
volts in-lb
5 + 0.5 in-lb 12.0 7.0 6.5
Atmo
s phe ric Torr
5 x 1 0 -3 10 -4 Torr -6
5 x 10 10 -8
Torr r;:,
6.5 6.0
Tor
_:"Not directly
calibrated
(see
text).
Mea
SU rement
s train assembly
A fixture was designed and built to allow coupiing of the gear output shaft to the electromagnetic brake and mounting of the entire on a vacuum chanaber flange equipped with a viewing port. Electrical connections for the motor, brake, and a small illumination of the chamber were brought out through a multipin ically sealed feedthrough. The vacuum chamber was evacuated sure of 10 -8 Tort and maintained at or below that pressure [or room temperature before the test commenced.
lamp for hermetto a pres24 hours at
The scoop motor was supplied with power from a 18.2 volt source capable of supplying a current of t ampere. A 15 ohm resistance, rated at 25 watts, was connected in series in the return line. Results of measurements were obtained and are shown sequentially in Table 4-4 for both counterclockwise (CCWI and clockwise (CWI motion. Although the preflight test value requirements were for atmospheric pressure, tests were first conducted on the returned part in vacuum to gain an insight as to how the motor would have performed if reactivated in vacuum. Te_t values for the scoop motor shown in Table 4-4 are compared with required values in Table 4- 5. The operation of the motor, gear train assembly, and electromagnetic brake was observed through the viewing port during all of the measure.......... ,o,_as_o, currents, _,=_o, a,,_ torques. Ba_ed -upon LIIICbtctLt2 "' ..... d requirements, the motor functioned properly in every respect.
4-5
< Z
0 -_
u3
o
oO
o
Z < a_ 0 0
< Z
t4_
o
l.n L_
0
< 2: < Z
,,.o
o_
c_
143
< Z .< Z
o0
< Z < Z
n
0 0
o
un
u3
o aO
0 u_
o
U'_-
0
oo •d_
o cO
un co
o un
o o ¢x]
¢_ 0
_.,0._
o0
c_
4_
c_
¢x]
c_
rq
o_
('%1
c_
,gl
0
,_
r:
c_
c_
o_
c_
.co_
! I
a0
I
O0 I
4_
X
_0
0
o
o
0
o
© _._
i
°1..i J .ra
<
"0 "0 0 0 0 ¢_ o ÷ I_ • u 0
!
0
t,l
o" 8) 0
4_
0
d:>
+ le_ ÷1 • 0o un .__
I (J
_J
o_
!
¢J
<
_J
0
0 0
[-,
0
"On_
_
°-..
n_
>o
e_e_ e_n
_o._
_
o_
nn nn
<.<
<<
<<
4-6
TABLE
4-5.
'COMPARISON WITH
OF TEST RESULTS REQUIREMENTS
OF
SCOOP
MOTOR
Returned Measured in Vacuum (10-8 Torr) Not measured
Surveyor
III
Part
Preflight Requirements (Minimum Measured at Atmospheric Pressure
}
Cha ra cte risti
c
Measured at Atmos phe ric Pressure 10
Insulation megohms Speed, rpm
resistance,
Applied voltage 1 8.2 _v,_s "_" dc Applied 10 +0. torque 5 in-lb of
of of
7.5 7.9
(CW) (CCW)
6.7 6.8
(CW) (CCW)
Temperature 70OF Load to stall at 18.2 volts 70°F, in-lb
motor dc at
55 48
(CW) (CCW)
21 18
(CW) (CCW)
12
4. 1.4
Examination
of
Gears
and
Bearings
After completion of the motor test, the motor and gear assembly was disassembled for detailed examination of the gears and bearings. ing disassembly, no anomalies were noted; the motor was free of dust, no evidence of cold welding could be detected. The various components were then examined, as described in the following paragraphs. Brushes The observed appearance at one of the brushes corner of brush is shown 1 {Figure in Figure 4-1. A large 4-la). It was not possible part. 4-lb. A similar small The brushes
Durand
was
chip to
operation, chip was
or during disassembly missing from brush 2,
as
of the seen
returned in Figure
4-7
appeared sign of and very
quite excessive
smooth wear.
in
the commutator Some wear debris The brushes
contact was were
areas, visible generally
on
with the
no apparent coil spring found to be in
plate good
in the brush condition. r
housing.
C ommutato
The appearance of the worn brush contact surface and of the unworn portion of the surface is shown in Figure 4-Z.* Sliding was in the direction of the striations and original machining marks. Analysis of Figure 4-2 confirms the anticipated lunar performance of the 046-45 brush material: low friction and wear and a smooth homogeneous transfer film of lubricant, as seen in the area on the left side of the figure. Two photomicrographs taken at a wear magnification surfaces is masses Housing The Figure 4-4. in the areas desirable to material was spectrograph. The condition of the housing at the commutator end is shown in particularly It was any lunar emission of of 50X brushes (Figure 1 and 2. 4-3) show closeups The typical pitted resulted sliding. from of the corresponding appearance of worn the plucking out of
composites discrete
evident. This of composite
probably during
Considerable black debris was found in the housing, directly surrounding the commutator and the brushes. analyze the nature of this debris to determine whether present. This analysis was conducted using an arc Results are summarized in Table 4-6. method of analysis used was semiquantitative. The
debris
material was placed on a filter paper prior to analysis. The second column in Table 4-6 presents results which include the elements of the filter paper. For comparison, the brush material was similarly analyzed by breaking oft a small amount of the brush and placing it on the filter paper. Results of this analysis Table 4-6. paper itself. The molybdenum, fact that in Table resulting the 4-6, from brush material (type 046-045} is composed of 63 percent The seen of The a "control" last column sample gives are shown results of in the the third analysis column of the of filter
32 percent sulphur, and debris appears to contain is due to the addition of wear of the copper
5 percent tantalum only Z5 percent a relatively large
(no silicon). molybdenum, as copper content,
commutator.
Original
in
color.
4-8
a) Brush
1 (Photo Figure
00628-Z9) 4- I. Surveyor III SM/SS
b) Brush Scoop
2 (Photo Brushes
00628-30)
Figure 4-2. Contact Surface of Scoop Brush 1, Showing Transfer Film (88X Magnification) (Photo 0062831)
4-9
a) Brush
1 (Photo
00628-3Z) Surfaces of Scoop
b) Brush Brushes,
Z (Photo Showing
00628-3ZX) Wear
Figure 4-3. Contact (50X Magnification)
Figure Housing
4-4. (Photo
Scoop
Motor
Commutator
006Z8-33) 4-10
TABLE 4-6. ANALYSIS
RESULTS OF BRUSH
OF ARC EMISSION SPECTROGRAPHIC AND BLACK DEBRIS IN MOTOR HO USI NG
Composition, Debris Element Filter Plus Paper Brush Plus
per
cent_:
"Filter Paper (Control)
Material Filter Paper
Molybdenum Copper Silicon Iron Calcium Aluminum Magnesium Silver Titanium Chromium Cadmium Boron
25 24 10 1.3 0. 2.8 0.38 0.13 0.31 0.12 0.11 <0. 05 87
55 0.77 3.2 1.1 0.77 0.22 0.15 0.55 <0. 0.10 Nil Nil 05
Nil 1.6 25 5.9 6.5 Nil 9.6 Nil Nil 1.4 Nil Nil
Not less
all elements than 100
present percent).
are
included,
notably
oxygen
(therefore,
total
is
dust is aluminum
The most derivable in the
conclusive evidence from the observed debris. Table 4-6 of in
of the presence ratio of silicon shows that the
or absence of lunar to iron and calcium to ratio of silicon to iron is Table 4-6 0. 31; the concluded that at all.
7.7; the corresponding shows that the ratio corresponding ratio it is extremely unlikely
ratio for lunar dust is 1.57. Similarly, calcium to aluminum in the debris was the lunar dust is 1. 79. It is therefore that the debris contained any lunar dust
4-11
Therefore, it is highly probable that the debris was composed of products of wear of the brush and the commutator, plus an indeterminate amount of earth dust, which probably accumulated in the housing during manufacture, overhaul, and test. Absence of lunar dust contamination is not surprising in view of the very small clearance between the motor shaft and housing. Minor Several Hardware nonfunctional items were visually examined:
Insulator -- Brush to End Cap. This phenolic laminate structure was partly covered with black debris, probably from the brushes. .Screw--Gear were apparently disulfide and Plate to End Cap and Gear Box Cover. Threads lubricated with some form of molybdenum remained in good condition.
End Cap. The blind hole contained a porous (oilite-type) steel bushing that was covered with light rust. Analysis of this part did not produce any significant findings. Gears The gears examined included pinions, planetary gears, and gears with internal splines. All of the gears were fabricated from 440-C corrosion-resistant steel. The gear train reduced the motor speed to the level required for the operation of the scoop. All gears from the gear train were examined microscopically and to be in excellent condition with respect to the amount of wear on the The lubricant coating in the contact zone (pitch line) appeared uniand only a very small amount of fine lubricant debris was found in the of the teeth. Neither galling nor metallic debris was observed.*
found teeth. form, roots
Photomicrographs indicating the condition of several typical gears are presented in Figure 4-5. By contrast, Figure 4-6 of the spline portion of the drive shaft shows areas where metallic contact occurred. This part had not been coated with Lubeco 905, nor did it appear to have any other form of lubrication.
':"This was Surveyor lubricant
in strong contrast to III television camera, (Reference 1, Section
some of the which were 10.6).
gears of the coated with
retrieved a different
film
4-17
|
•
\
Figure 4-5. of Significant
Gears Wear
of
Scoop
Motor
Gear
Train,
Indicating
Absence
4-13
Figure Showing
4-6. Spline Portion of Scoop Drive Metallic Contact (Photo 006Z8-38)
Shaft,
TABLE 4-I0
4-7. LIST OF FIGURES 4-7 THROUGH SHOWING DISASSEMBLED VIEW OF BEARINGS AND RACES
Figure
Description
4-7a 4-7b 4-7c
Suppc_rt Support Support 100X Support Scoop Scoop Scoop Scoop Scoop area Scoop area Scoop 0a Scoop Scoop Scoop
bearing, bearing, bearing,
splined splined splined
shaft shaft shaft
drive, drive, drive,
ball ball inner
I, 2,
Z00 200X race
X
(typical) (typical)
ball
path,
4-?d 4- 8a 4-8b 4-8c 4-9a 4-9b
bearing, motor motor motor motor motor l motor Z motor motor motor motor
splined bearing bearing bearing bearing bearing A, A, A. C. C.
shaft ball inner outer bail, inner I,
drive, Z00X race race Z00X race
outer (typical) ball ball (typical) ball path, path, path,
race
ball
path,
18X
i00X 33X
100X,
4-9c
bearing
C,
inner
race
ball
path,
100X,
4-9d 4-I 4-10b 4-I0c
bearing bearing bearing bearing
C, D, D, D,
outer ball, inner outer
race Z00X race race
ball
path,
33X
(typical) bail ball path, path, 100X 33X
4-14
Bearings Individual bearings, as well as those assembled in gears, were examined. The bearings were all radial ball bearings, open, with crown-type steel separators. All had been lubricated with Lubeco 905 prior to installation. The bearings supported the main drive shaft of the motor, the splines and pinions, and the planetary gears of the reduction gear train. No manufacturer's identification was found on most of the bearings. The bearing surfaces were found to be too rough to perform torque measurements. This was presumably due to the unusual method of original application of the dry film lubricant, as described in Section 4. I.I. However, tests on a Barden Smootherator showed a dwell {roughness) level of 9 to I0 on a scale of I to I0; a good smooth bearing would have had a reading of 2 to 3 on this scale. A slight buildup of lubricants was noted at each ball position. This also could have resulted from the method of application. A number of photomicrographs bearings from the scoop motor and brief description of each are given corresponding figures (4-7 through to obtain each photograph. were taken of the disassembled gear box. A list of these bearings in Table 4-7, which also references 4-10::-') and gives the magnification
and a the used
Examination of these photomicrographs shows that the transfer lubrication film on the balls and races was not uniform. This may account for the roughness of the bearings. Some of these bearings, primarily those still pressed into gears, contained very small quantities of a semitranslucent greenish substance on the race lands and on ball retainers. This material was not present in a quantity sufficient to have affected the performance of the bearings. The most likely source of this material is the original grease which was packed in the unit when it was received from the vendor {AiResearch). It is assumed that the grease was not entirely removed during the degreasing operation. 4. 1.5 Discussion The motor 1) of Results conclusions train: were drawn from the examination of the
scoop
following and gear
After 2-I/2 years on the lunar would probably have functioned on the lunar surface.
surface, properly
the motor and gear train had it been reactivated
':'Originals
in color.
4-15
a)
Sp!ined
Shaft
Drive,
Ball (Photo
I 006Z839)
b)
Splined
Shaft
Drive,
Ball (Photo
2 00628-40)
(Z00X
Magnification)
(Z00X
Magnification)
¢-%
_n1_,,,1
_k_¢_
Drive,
• .......
Ball Path (Z00X (Photo 00628-41) Figure 4-7.
Magnification)
u I opL_u_u Drive, Guter Ball Path (18X Magnification) (Photo 00628-4Z) of Disassembled Support Bearings
Race
Photomicrographs
4-16
a) Ball (Z00X Magnification) (Photo 00628-43)
b) Inner Magnification) Figure
Race
Ball Path (100X (Photo 00628-44) Photomicrographs of
c) Outer Magnification) Disassembled
Race
Ball (Photo Motor
Path (33X 00628-45) Bearing A
4-8.
Scoop
4-17
a) Ball (Z00X Magnification) (Photo 006Z8-46)
b) Inner Race _..,,n-ll Path Area 1 (100X Magnification) (Photo 00628-47)
c) Inner Race Ball (100X Magnification) _'igure 4-9.
Path Area Z (Photo 00628-48)
d) Outer Race Ball (33X Magnification) of Disassembled Scoop
Path (Photo
006Z8-49) Bearing C
Photomicrographs
Motor
4-18
a) Ball (Z00X Magnification) (Photo 006Z8-50)
b) Inner Race Ball (100X Magnification) Figure 4-10.
Path (Photo
00628-51)
c) Outer Race Ball (33X Magnification) of Disassembled Scoop
Path (Photo Motor
006Z8-5Z) Bearing D
Photomicrographs
4-19
2)
The method of application of the lubricant to the would not have been satisfactory for this mission had been operated under a low torque condition. method would have been to completely disassemble and to lubricate and burnish only the races with 0.0001 inch of coating. An acceptable alternate been to use a bearing with a lubricative composite Boeing material motors. Hot Compact 046-45 for use with copper is a highly commutators
ball bearings if the unit The preferred the bearing less than would have retainer.
3)
satisfactory brush in high-speed
dc
4.2
FRICTION
AND
WEAR
TEST
OF
SCOOP
JOINT
PIN
The MoS 2 the SM/SS scoop. yield information Therefore, a test time of the lubricant vacuum conditions. remaining life of surface. 4.2. 1 Description
lubricated pin was removed from the joint returned with Visual examination indicated wear tracks but did not on the lubricative ability of the molybdenum disulfide. was devised whereby the coefficient of friction and lifeof the Surveyor III pin could be determined under The results of this test could be used to predict the this lubricated pin had it been reactivated on the lunar
The joint of the SM/SS scoop, which can be seen in Figure 3-3 (Section 3), consisted of a pin rotating in a bushing. The pin is a 0.25 diameter rod 1.75 inches long. It is made from 403 CRES per Federal Specification QQ-S-763, CL 304, Condition A, passivated. The middle section of the pin is coated with Lubeco 905_: = over a length of about 0.7 This section of the pin operated against the hard anodized bushing. 4.2.2 Visual Only evidence Examination nominal that cold force was required to remove welding had occurred. the pin, and there
inch
inch.
was
no
The pin was examined microscopically at various magnifications. Figure 4-11 shows a typical surface at a magnification of 5X. The wear pattern indicated that the coating had been subjected to uneven wear during service. The characteristic parallel wear marks indicate edge loading on the solid lubricant film. This is attributed to incomplete machining of the edges of the bushing. The remaining thick. coating thickness was measured film, uniform in thickness, was with a micrometer. determined to be The 0. 0002 inch
Described
in Section
4. 1. 1. 4-20
Figure 4-II. Pin From Surveyor III SM/SS Scoop Prior to Testing (5X Magnification) (Photo006Z8-53)
4.2.
3
Test
Setup
and
Sample
Preparation
The friction and wear test was conducted in a Hughes lubrication testing facility, using a "monorail" slider test configuration. This configuration was selected because of the small size of the Surveyor iII part to be tested. The existing facility limited the test load achievable; modification of a larger test facility which would provide for higher test loads was beyond the scope of the program. The monorail slider with attached weights totaling 224.4 grams was traversed axially back and forth over the coated portion of the pin. The oscillatory motion of the specimen mover was transmitted through a thinwalled forced transducer ring which sensed the frictional force. The individual components and_ the test setup are shown in Figure 4-!2. The longitudinal slot in the slider was machined to a radius smaller
than that of the Surveyor pin. Consequently, the sliding contact during the axial motion occurred between the surface of the pin and the edges of the slider. Contact area was determined by measuring the actual wear area. The unit loads achieved in this test were only Z4 psi, compared to 240 psi for actual operation of the pin in its intended function. Test control pins were machined lubricated portion of the Surveyor 905 and burnished with a Q-tip to 4-13 shows the appearance of the from 304 CRES to the same length III pin. They were lubricated with a coating thickness of 0. 000Z inch. finished control pin.
as the Lubeco Figure
In actual operation, the Surveyor III pin was inserted into a hard anodized aluminum bushing. It would have been expensive and extremely difficult to machine aluminum for the slider. Accordingly, it was decided to fabricate the slider from stainless steel, rounding the leading edges to prevent scraping of the lubricant. In view of the fact that this investigation was concerned only with the lubricant, any convenient metal could have been chosen for the upper specimen without significantly affecting the results. 4-21
Figure Scoop
4-12. Test Setup Pin (Photo 00628-54)
for
Wear
Analysis
of SM/SS
4r-
Figure (Photo 4.2.4 Discussion
4-13. Appearance 00628-55) of Results
of Control
Pin
Before
Test
The coefficients of kinetic friction obtained during these tests are plotted in Figure 4-14. Figure 4-15a shows the photomicrographs of the sliding surfaces of the Surveyor Ill pin. This should be compared with the original appearance shown in Figure 4-I I. The appearance of the control pin after the friction test is shown in Figure 4-I 5b. The significant observations resulting from these tests are summarized below, with reference to Figures 4-14 and 4-15. 4-22
100,000 cycles; that the cycles.
The lubricant coating cycles• The test on no sign of failure had control coating would
on the Surveyor III the control pin was occurred up to that have withstood about
pin failedafter terminated point. It twice
approximately after 458. 000 is estimated number of
this
The steady-state friction of the lubricated pin from the Surveyor scoop was lower than that of the control pin. The explanation of this nomenon lies in the previous histories of these coatings. The Surveyor pin had been operated prior to launch for an unknown number of cycles under loads of 240 psi. operation on the moon. On experienced Lubeco 905 the other hand, prior to the bonded solid The pin then experienced several hundred
III pheIII of
cycles
the only wear which the coating test was burnishing with a Q-tip. lubricant does not reach a minimum
of the control The friction steady-state
pin of
value until the molybdenum disulfide lamellas are sufficiently oriented parallel to the sliding surfaces. This state can be brought about either by wear-in or by burnishing prior to use. It is unlikely that Q-tip burnishing imposed high enough unit loads to produce this preferred orientation. The test load of 24 psi was apparently insufficient to wear the freshly applied coating to the same degree as the operational loads.
0.30 • LUBECO
L 905
I LUBRICANT 10 -8 Tort PIN
I /_ C) SURVEYOR CONTROL III PIN SCOOP PIN
• PRESSURE • NO --
LESS THAN
FAILURE
Of: CONTROL CYCLES (TEST
0.25
AFTER 458,000 DISCONTINUED)
I
I
Z O. 20 __ 0.15 '-2 o.l(
I
I
I [,
¢
/ / I I
! t I
I
I I
0.05
0 i0 20 ,._ 40 THOUSANDS OF ,=n _v CYCLES IN ,.n VACUUM -zn _ w on
Figure Scoop Coefficient
4-14. Pin and of
Friction Control Kinetic
Test Pin Friction
in
Vacuum
of
Surveyor
III
Versus
Number
of
Cycles
4-23
a)
Surveyor
III
Pin
(Photo
00628-57)
b) Figure 4-15. After Friction
Control
Pin
(Photo
00628-58) of SM/SS Scoop Pins
Photomicrographs and Wear Test
Failure of the Surveyor III During the next 15,000 cycles, the welding occurred at about I00,000 after it was removed from the test that under higher loads this failure shorter interval.
pin coating was first noted at 85,000 cycles. coefficient of friction increased until cold cycles as verified under a microscope chamber. Past experience indicates would have occurred within a much
A stick-slip motion of the monorail slider was prevalent throughout both tests. During the incipient failure mode, this motion was magnified to a severe, steadily worsening, jerky motion. The appearance of the actual scoop pin and the monorail surfaces after the test showed clearly that metal-to-metal contact between the slider and the pin did occur. No evidence of metal-to-metal contact could be seen in the dummy specimen. Reducing the cycling speed during the test from the normal 60 cpm to 3. 5 cpm had only a negligible effect on the friction of either type of coating. This is not surprising since the investigations were performed in vacuum only. Past da_a indicate that variation of cycling frequency has a negligible effect on performance under vacuum test conditions. On the
4-24
other hand, a slight reduction in friction is noticed laboratory tests at atmospheric pressures. The coefficient of friction was This is characteristic of molybdenum lubricants.
at higher
speeds
in
much lower in vacuum than in air. disulfide containing bonded solid
The major difference between the life of the Surveyor III scoop pin and the control pin was due to the previous wear to which the scoop pin had been subjected during preflight testing and during the lunar operations. Although measurements of both pins indicated an equal thickness of lubricant (about 0. 0002 inch), the volume of lubricant on the scoop pin was possibly much lower, as discussed below. The thickness of the lubricant applied to the control pin was intentionally chosen to correspond to the 0. 0002 inch thickness of the lubricant on the scoop pin, as measured by the micrometer. However, micrometer measurements record only the peak heights of the coating. As discussed in Reference 5, the lubricant is removed in chunks during the wear process rather than in uniform layers. Thus, the surface of the scoop pin lubricant coating actually had a formation of peaks and valleys-the latter corresponding to the area where chunks of lubricant had been removed in the course of its wear history. From the above data, some estimate can also be made of the probable life expectancy of the scoop pin had it continued to be operated on the lunar surface. Such an attempt would most likely have resulted in the worn portion of the coating breaking down first. The pin joint would then probably have continued to operate for a number of additional cycles. Reference 6 indicates that the wear life of a bonded solid lubricant in oscillating motion is inversely proportional to load. Since the scoop pin failed in laboratory testing at approximately 100,000 cycles at 24 psi, it is estimated that it would probably have functioned for 10,000 cycles in the lunar environment beyond the number of cycles for which it had functioned at the end of the first lunar day.
4. 3
CHEMICAL
ANALYSIS
OF
ORGANIC
MATERIALS
Tests were conducted to determine whether any detectable chemical changes occurred in the various organic materials as a result of lunar exposure. The materials tested included teflon FEP from the television cable wrap and nylon from the external ties of the cable.
4-25
o
o
r._ G
o i _
_z _
"_
m
=
e_
"..,,-i
.A
!
_u
4-26
The elemental spin density measurements.
test analysis,
series
included electron
infrared paramagnetic differential
and
ultraviolet resonance analysis,
transmission measurements and viscosity
spectra for
determination,
thermal
returned insulation Appendix 4. 3. 1
Chemical Surveyor of the I. Z of Teflon Infrared
analysis of the other organic materials present III hardware, teflon TFE, and polyimide of internal television camera harness is presented the companion report (Reference 1 }.
in the in
the wire
FEP transmission as a function of wavelength was measured on
a sample of teflon FEP after the aluminum had been removed with diluted hydrochloric acid. Results were then compared a similar piece of unflown material. Spectra from both the sample and the unflown control sample were virtually identical Transmission spectra were of then measured on both
by wipin_ it with tests of Surveyor III (Figure 4-16}. samples in the
ultraviolet and visible regions 750 millirnicrons, using a Perkin Figure 4-17 shows the results trace of an absorption peak can ing peak may be identified with cative of defluorination. This to the solar wind: bombardment tion of fluorine and subsequent Elemental control analysis sample. was
the spectrum in the range from Z00 to Elmer Z0Z ultraviolet spectrometer. obtained for the Surveyor III specimen. A be seen at Z15 millimicrons. This developthe formation of isolated double bonds, indicould conceivably be the result of exposure by hydrogen atoms could result in abstracelimination of the fluorine radical (fluoride_}. on are the Surveyor III shown in Table sample 4-8. and on
a non-flight
performed The results
The electron paramagnetic measured in an attempt to detect resulted in the formation of free an unflown sample were measured ature and also at approximately
resonance (EPR} of the teflon FEP was possible radiation damage that might have radicals. Three Surveyor III samples and on an EPR spectrometer at room temper-140°C. The maximum possible spin derived from the and sensitivity of the the measured spectra. 60 gauss. The
density (shown in Table 4-9), the significant parameter EPR measurements, is dependent on the sample size instrument, multiplied by the observed line width of For the sensitivity materials of the tested, the line EPR spectrometer of the possible The limited induced microwave
width was on the o{2er of used was 6 x 10 spins.
Because conclusions on not be obtained. would mask _._a .... _'_ _. ....
aA*_._l.4_ I.a i.ay
sensitivity effects power
of the spectrometer, quantitative of the radiation environment could saturation level of the spectrometer the nf number _,,rh of ._pin spin centers centers would
a
any evidence aa.,a,.,
_A_.a. al.eAa.
of a small w,,.,h_.,_,,_
_ _a _.a_ l..v.
vj
increase in the nurn.h_r
......................
4-Z7
TABLE
4-8.
ELEMENTAL
ANALYSIS
OF
TEFLON by
AND Weight
NYLON
Percentage Material Carbon 24.04 III) 23.81 24.00 HI) value 62.00 63.69 Hydrogen O. 08 0.13 0 9.43 9.80
Nitrogen
Fluorine
Teflon Teflon Theoretical Nylon
FEP FEP
(not
flown)
71.72 72.33 0 11.43 12.33 76. O0
(Surveyor value
(Surveyor
Theoretical
TABLE
4-9.
SPIN
DENSITY
OF
TEFLON
FEP
AND
NYLON Maximum Possible
Material
Sample Temperature, oC
Sample mg 25 25 335 601 452 25 25 106 94 40
Mass,
Spin Density, spins/cm 3 4. 0 x 1015 2. 2 x 1015 2.9 x 1015 6.2 x 1015 7. I x 1015 I. 7 x lO 16
FEP FEP FEP Nylon Nylon Nylon
(Surveyor (Surveyor (not flown)
III) III)
-140 -140 25
and and
(Surveyor (Surveyor (not flown)
III) III)
-140 and -140 and -140
4-28
0.0 0.1 0.2 0.3 0.4 0.5 0.6 _0.7 0.8 0.9 1.0 I.I
i
--_- -_--l-r---t--_----_-
;
',
!
-i--i +-_ .......... 1--_-
_!_
' ........ i
_--!_ [
.... .
! t _t_i :
i : ; ....
± _-_:-_]_t_1 .......
..... i..... i '. ........... i.........
!L_
i
......
+
,
_ ....
_-
-_
i
_-
-_-
........
-_:
..............
-"
::I: I_ i ......
..... ,,Il!:i!l ,.... :
w_k|t_GlrM IW4,L_IIONS)
',
,l .......!i i; _
.....
Teflon
:_:
i
Figure From Absorption
4-17. Surveyor
Ultraviolet III Cable versus wavelength
Spectrum Wrap
of
FEP
be
reduced
by
the
decay
of
free
radicals
over
long
periods be reached: no major
of
time
in
the
air. within
Consequently, the sensitivity
onlya gross limitations
conclusion could of the instrument, the
i.e., degradation could was be felt of the
was observed. The capability of modified to operate ina low power that the additional effort required electron paramagnetic resonance
EP1R spectrometer bridge configuration. However, it to provide for this improvement measurement was not warranted.
sample changes point, by this weight
Differential thermal analysis was conducted on the Surveyor III of teflon FEP and on the unflown sample to determine whether any occurred in thermal properties. Parameters such as the melting glass transition temperature, and decomposition point were measured technique; these, in turn, provided data on any changes in molecular or composition of these organic materials. The samples differential and on thermal standard analysis glass bead test was samples conducted used as and were rams on the reference. teflon The
FEP
thermograms obtained are shown in Figure teflon FEP from the samples are seen to
for the Surveyor IiI sample 4-18. No significant changes lunar exposure. The the rmog be virtually identical.
for the noticed of the
unflown sample in the two teflon
4-Z9
J
a)
I
SURVEYOR I
I
III I
I
l
EXTERNAL
I
CABLE I
I
E
jf
/
\
0 50 100 T. °C 150 (CORRECTED 200 FOR 250 CHROMEL ALUMEL 300 350 400 450 SOD
THERMOCOUPLES)
b) 0
CONTROL i
SAMPLE
I-
<_
50
1OO T. *C
150 (CORRECTED
200 FOR
250 CHROMEL ALUMEL
]DO
350
400
4SO
SOD
THERMOCOUPLES)
Figure
4-18.
Thermograrns
of Teflon
FEP
4-30
4.
3.3
Nylon A chemical cable analysis Both was light conducted of and darkened the nylon pieces from were the exterior examined.
television
ties.
Infrared spectra made of the nylon by the attenuated total reflectance method were not satisfactory. Samples were then made for infrared transmission measurements by suspending the material in potassium bromide pellets. Both light and dark areas appeared normal and virtually identical. This was true both for 6 nylon and for 6,6 nylon. Additional spectra were made of samples which had been dissolved and precipitated. Both the Surveyor III sample and the unflown sample appeared to be the same. No changes were seen in the transmission of solutions of exposed
nylon in formic acid, from which insoluble peak (Z670 to 2750 A) found in the unexposed nounced in the Surveyor III sample. This of hydrogen-bonded water or to a trace of with the elemental was lower in the hydrogen to 9.43 Molecular of its of the
material was filtered. A broad sample became more prowas probably due to the existence solvent. This was consistent the hydrogen in percent content weight of
analysis shown in Table 4-4 since Surveyor III sample. The reduction is a significant change. weight of a polymer can solutions. The difference same structure can establish a viscosity measurement
viscosity samples weight. sample.
be correlated with the relative in relative viscosity between two the relative values of molecular was conducted on the nylon
Accordingly,
The nylon samples were dissolved in formic acid. Some insolubles were noted-possibly epoxy adhesive. These were filtered off, washed, and dried. The weight ofinsolubles was subtracted from the total weight to obtain the net weight of polymer in the solution. The viscosities of solution and solvent were determined by measuring the flow rate in a Model I 00 Ostwald viscometer, loaded with 7 ml of solution. The measured elution period of each solution was reproduced with a maximum spread of 0. l second at flow times of 85 to I00 seconds. The results indicated an estimated molecular weight of 26,000 unflown control sample. for the Surveyor Ill sample and 20,000 for the
Since samples of the flown and unflown nylon were from different lots, the molecular weight difference noted may not be highly significant; it was well within the expected lot-to-lot variation. However, the higher value of 26,000 for the Surveyor III sample could indicate a minor degree of polymer crosslinking caused by the lunar radiation environment. Elemental analysis and electron are paramagnetic shown in Tables resonance 4-8 and 4-9. tests p! No sigfor
pi _-_*'" _^*_ " " Results of these measurements
nificant changes resulting from the lunar exposure were uncovered. As seen in these tables, elemental analysis indicated no changes in the nylon tie materials, and spin density measurements showed no evidence of an increase in free radical density. 4-31
A sample of nylon was examined by differential thermal analysis detect any changes in thermal properties as a result of lunar exposure. Comparison of the results with an unflown control sample indicated that change in properties had occurred. 4. 3. 3 Epoxy The epoxy used of the difficulty as a knot adhesive was of separating it from not chemically the nylon. analyzed
to no
because
4.4
PROPERTIES
OF
WIRE
AND
CABLE
Results of electrical and physical measurements of the returned Surveyor III television cable and its wrap, and the wires of the SM/SS scoop, are presented in this section. To evaluate the results obtained, tests on similar materials were conducted in some instances on control samples. with test gram In other cases, results on similar results wires were compared with and cables available specifications from Surveyor or pro-
stores. available. Results as approximations. since tests requiring To partially compencontrol samples of the same as the avail-
In some cases, only limited sample sizes were of tests on those samples must therefore be interpreted This is particularly true for physical measurements standard sizes of specimen could not be performed. sate for this difficulty, the sizes of test specimen of similar materials were selected in those cases to be able 4.4.1 retrieved Electrical The electrical Surveyor III samples.
Measurements measurements of the television camera included In addition, cable and the
scoop wires are described insulation resistance, and strength of the scoop wires
below. Measurements conductor resistance. was determined.
capacitance, the dielectric
tions. camera Surveyor obtained
In most cases, these measurements were compared with Some measurements were also made of the spare Surveyor and parts available from stores for a direct comparison III results. No data were available for comparison of for the capacitance of the SM/SS scoop wires. Cable From TV Camera
specificatelevision with the results
The 7 inch section of TV cable {described in Section 3.2) was not disassembled for the preliminary electrical measurements. Before the measurements w=rc made, the ,_lu,,,,,,L_.,_d teflon FEP outer wrap on one-half of the 7 inch section was removed. On the opposite end, with the teflon still intact, approximately I/4 inch was slit and folded back so the wires in the bundle could be identified.
4-32
The
conductors
were
identified
and
marked
with
tags
on
one
end. for
Twelve typical conductors electrical measurements.
and two coaxial cable Capacitance readings
sections were selected were taken between
adjacent conductors in the bundle and of the coaxial cables. Nondestructive were made individual between conductors
between the shield and the conductors insulation resistance measurements at lO0 volts dc. Resistivity of
the same conductors was then measured.
made Inc. tance.
Capacitance using a direct The test leads Contacts to
Measurements. reading Type were kept as the wire ends
The capacitance measurements were 130 L-C meter manufactured by Tektronix, short as possible to reduce lead capaciof the cable sample were made with two between in a fixture to assure Results the having contact. of the similar of a proIll Ill
heavy wire probes with sharp points that could be inserted strands of the conductor. Each wire probe was mounted a small lever which allowed movement of the wire probe The fixtures were held in position by a permanent magnet. measurements measurements are were presented made on in Table a section 4-10. of a For cable
a comparison, from the interior from as the to the
Surveyor type acceptance test (TAT) camera available gram stores having the same configuration and wires television camera. Values obtained were comparable sample, as evident from Table 4-10. Insulation between manufactured adjacent by be Resistance. wires Industrial at The 100 volts Instruments, insulation dc with a Inc. resistance Model The
Surveyor Surveyor Surveyor
was
measured was used by These
L-7 megohmmeter, test at 100 volts
considered to for capacitance the megohmmeter. values are all 104 megohms.
nondestructive. measurements, The results well in excess of
The test setup was similar to that with the Type 130 L-C meter replaced of this test are given in Table 4-11. the minimum specification value of
Resistance typical A sharp wires probe were was
Measurements. conducted inserted on into
Resistance a Leeds and each lead of an ohmmeter An additional and resistance
measurements Northrup 4286 each conductor.
of Kelvin The
selected bridge. levels at perof
resistance were first checked with between the probes and the wire. each end for contact voltage drop, formed on the Kelvin bridge. Results 4-12. copper SM/SS
to verify the contact probe was then inserted measurements were
in Table for the
of the measurement for a All of the values obtained alloy wire size used: 27.1 Scoop Wires
few typical were below ohms/1000
conductors the maximum ft.
are
shown specified
The scoop wires (described solar radiation during the 32 lunar effects on the electrical properties surements conducted are described
in Section day-night were of below.
3. I) cycles. particular
were
directly Consequently, interest.
exposed the The mea-
to
4-33
TABLE
4-10.
CAPACITANCE FROM
OF FEP-POLYIMIDE SURVEYOR III CABLE
INSULATED
WIRE
Capacitance, picofarads / foot Number Wire Configuration Samples II of Tested TAT Cable 9.3 Surveyor III TV Cable 6.2to 9.8
Two parallel not twisted Two Coaxial (center wires, cable
wires,
twisted 2
19 to 10.8,
34 10.9
to shield)
TABLE
4-II. INSULATION INSULATED WIRE Number
RESISTANCE FROM SURVEYOR of Samples Tested l0
OF
FEP-POLYIMIDE III CABLE Insulation (7 inch >l Resistance sample}
Test
Configuration wires,
Two parallel not twisted Two wires, twisted Coaxial (center
x 10 7 megohms
0. 8 x 1 0 7 megohms
cable to shield)
>I x 1 0 8 megohms (not measurable)
TABLE
4-12. Sample I 2 3 4 5 6
CONDUCTOR
RESISTANCE Conductor
OF
SURVEYOR ohms/1000
III ft
CABLE
Resistance,
23.6 23.8 23.9 24.2 23.6 22.8
4-34
with test
Capacitance a Type 130 method was
Measurements. L-C capacitance the same as that
Capacitance measurements were made meter manufacturedby Tektronix, Inc. The used for the external television camera from the scoop arm for these tests. The Results are presented
cable, discussed during the test. scoop wires were in Table 4- 13. Insulation was measured at I minute. Results specified minimum TABLE 4-13.
above. The wires were not removed The scoop arm was used as a ground arbitrarily numbered 1 through 4.
Resistance. The insulation resistance 500 volts dc with a megohmmeter for are shown in Table 4-14. All values of 1 x 107 megohms. CAPACITANCE Between Wires OF SURVEYOR
between a minimum exceeded
conductors of the
III SCOOP
WIRES
Measurement
Capacitance, 4.9 5.0 5. 0 4.9 8.0 8. 5 8. 0 8. 0
picofarads
1 and 2 and 3 and 4 and 1 and 2 and 3 and 4 and
2 3 4 1 ground ground ground ground ground
1 + 2 + 3 + 4 and 1 + 4and 1 + 4 and 2 + 3 and 2 + 3 ground ground
12.0 15.0 10.5 10. 5
TABLE
4-14.
INSULATION SURVEYOR Between Wires
RESISTANCE III SCOOP
AT WIRES
500
VOLTS
DC
OF
Measurement 1 and 2 and 3 and 4 and 2 3 4 1
Insulation
Resistance, 4 x 107 5 x 107 5 x 10 7 5 x 10 7
megohms
1 + 2 + 3 + 4 and
ground 4-35
5 x 10 7
Dielectric Strength. Dielectric strength was measured between the various conductors. The applied 60 Hz ac voltage was increased at a rate of 100 volts/sec and then held for 1 minute at the maximum test voltage. The following wire combinations were tested: 1 and 2, 2 and 3, 3 and 4, 4 and 1, 1 and ground, 2 and ground, 3 and ground, and 4 and ground. Results indicated that the dielectric strength exceeded 3000 volts at 60 Hz in all cases. This was greater than the required specification value of 2200 volts dc for 1 minute. Conductor Resistance. The resistance of three conductors was measured using a Leeds and Northrup Kelvin bridge. The test leads were soldered to the conductors being measured. The test length for two of the conductors was 7.75 inches. The resistance values obtained for these conductors were 13.9 and 12. 1 ohms/1000 ft. The resistance of the third conductor was measured to be 14.7 ohms/1000 ft for a test length of 3.03 inches. All of the above values were within the specified resistance of 14.8 ohms/ 1 000 ft, maximum. 4.4.2 Physical Tests
This subsection describes tests conducted to determine the physical properties of the wire, insulation, and other materials of the retrieved television camera cable and SM/SS scoop wires. These tests included measurements of tensile strength and elongation on an Instron tester. In addition, cut-through resistance was measured on the wire insulation. Comparison tests of control samples of similar materials were conducted, as applicable. As mentioned earlier, these samples were of the same size as the Surveyor III samples, which in many instances were of limited size. It was felt that assessment of changes brought about by the lunar environment could in many cases be made more appropriately by comparison with control samples rather than with specifications, since nonstandard specimens may not produce specification values. Television Camera Cable Elongation Measurements. The obtained on materials from the are summarized in Tables 4-15, tensile strength television 4-16, and
Tensile Strength and and elongation measurements cable and on control samples 4-17. Table and elongation measurements shows tensile mylar cable
4-15 presents results of the measurements of tensile strength of the bare wire conductors. Table 4-16 summarizes similar on the various electrical insulation materials. Table 4-17 strength and elongation measurements for the teflon FEP and wraps. strength All _ .... re!y and elongation data on samples samples available were less than _ _*,o _ _.........._*_"_'"* dama ge gri .....
Attempts to obtain tensile of the lacing tape were unsuccessful. 1 _,_ !ong _-_ ......................................... _,,,1A "_t *-o _'_ to individual strands of the tape.
4-36
TABLE
4-15.
PHYSICAL PROPERTIES FROM TELEVISION Ultimate Breaking St rength pounds,
OF BARE CABLE
CONDUCTOR
WIRES
Ultimate Tensile Strength, psi Elongation, percent
Item
Copper clad from coaxial Surveyor sample III
steel cable flight
wire
15.7
71,300
9.0
Control sample (non- flight ) 22 AWG conductor made of 19 strands of silver-coated OFHC strand diameter Sample Surveyor Specification copper 0. 0063 ) from III value (each inch
16.7
75,800
9.0
19.0
32,100 32,100 35,000 to
28 45 to 55
24 AWG conductor made of 19 strands of silvercoated alloyed {chromium, cadmium) copper {each strand 0. 005 inch diameter ) Sample Surveyor from Ill 20. I 53,900 6
Specification (chromiumhard)
62,000 copper -
12
4-37
TABLE
4-16.
PHYSICAL
PROPERTIES FROM CAMERA
OF CONDUCTOR CABLE
INSULATION
Ultimate Breaking Item Strength, pounds
Ultimate Tensile Strength, psi Elongation, percent
FEP insulation coaxial cable Surveyor Control
on
III sample sample from
10.5 13.0
985 1,225
156 256
Polyimide coating FEPpolyimide insulation Surveyor Control
III sample sample from
2.4 3.1
10,000 14,000
14 % (7
Polyimide coating FE P- polyimide insulation Surveyor Control
III sample sample
3,720 4,330
400 351
I
No the a significant change was OFHC annealed copper in tensile strength apparently on the hours. properties correlation size. The values conductor with the thickness of for both of observed conductor, of the due moon. between in
I I
the copper-clad as seen in Table copper the long thermal is estimated that 200 ° and 250°F steel 4-15. wire Itowwas was
and ever, noted. which
in
reduction
alloyed to It
conductor annealing the wire for an
This reduction was this wire experienced to
subjected accumulated
an average temperature time of about 4000 of tests of physical indicate a reasonable samples of the same However, the
in Table the control was samples values of the supports limited consistency about
Results 4-16
insulation shown values obtained for the FEP insulation the Surveyor III
9 mils.
obtained
and the control for this material previously discussed the size validity samples of results
samples are not totally (not shown on the table). effect of the limited technique sizes III 4-38 and
consistent with specification This is a clear illustration size available for test and of comparing of control control tests samples. samples of these The
of the selected with corresponding between Surveyor
indicates
TABLE
4-17. AND
TENSILE MYLAR
STRENGTH AND FROM SURVEYOR Ultimate B r eaking Strength, pounds
ELONGATION ILl CAMERA
OF TEFLON CABLE
FEP
Ultimate Tensile Strength, psi
Sample
Description 1 from
Elongation, in 1.0 inch
FEP sample Surveyor III FEP sample Surveyor III FEP FEP control control
0.76 2 from 1.21 sample sample 1 2 2• 02 2.04
1,267
95
2,017 3,367 3,400 2,500 minimum
107 370 380 250 minimum
Specification (L-P-523)
requirement
Mylar sample Surveyor ILl Mylar Surveyor sample III
1 from 0.74 2 from 0.97 requirement 12,900 25,000 minimum 21 70 to 130 12,000 36
Specification
that no significant effects can be attributed to the lunar exposure. The polyimide data indicate a reduction in strength for the Surveyor sample. The sample was difficult to obtain, and variations in tests were large. Thus, values shown are only approximations. The differences between the physical properties of the Surveyor LLI FEP insulation sample and control sample on Table 4-16 are considered well within the expected data scatter for such sample sizes*. Tensile inch thick strength teflon and elongation FEP aluminized were measured on two samples on one side from the TV cable• of the This
0. 002
material was the outer wrap of the cable; the teflon exposed to the sun. Two adjacent samples were cut Surveye_v TTT t_fl_n ................. FEP wrap, ,,_,.h 0. Rnn ;,,_, .,.;.1.
side had been directly from one section of the by I inch '_-_L^
For comparison, the expected insulation is greater than 2500
ultimate psi. 4-39
tensile strength
of the FEP
samples were tested
ASTM to the
in an lnstron testing machine. The method used was D-838. Two control samples of fresh aluminized teflon FEP were cut same size as the Surveyor III samples and tested in the same manner. of the teflon FEP effects of radiation during visual
The reduction in elongation and tensile strength shown in Table 4-17 is consistent with the anticipated the teflon FEP and the cracking observed in the teflon examination.
in
A sharp decrease in both tensile strength and elongation of the 0.00025 inch mylar was measured. This was not causedb7 solar radiation since the mylar was protected by 0.004 inch of teflon, which effectively shielded out all the low energy protons of the solar wind as well as the ultraviolet. The reduced values were attributed to the "crumpling" that occurred in the material. There were a great many folds in this material, which could have resulted in significant weakening. It should also be noted that the reduced strength of the mylar wrap did not impair its ability to function as an effective electrical shield for the cable. Cut-Through Insulation Measurements. Cut-through tests were conducted on the FEP polyimide-insulated wires from the camera cable. Two techniques were used to evaluate the cut-through strength. First, the static load necessary to immediately cut through the insulation to the conductor was determined. Second, the static load for cut-through of the insulation Z4 hours after loading was determined. Both measurements were made by placing a 90 degree wedge with a 0.01 inch radius at the V on the surface of the wire at right angles to the conductor. Loads were applied to the top of the wedge while the sample was at room temperature. A control sample was measured for comparison with the Surveyor III sample. The polyimide-FEP insulated Surveyor III wire was found capable of supporting 180 grams for 24 hours before cut-through, while the control sample supported Z80 grams for the same length of time. This result was in apparent conflict with the tensile strength measurements, which showed no significant difference in the tensile strength of the insulation between the Surveyor III and control samples.
The apparent difference can be readily explained when it is noted that the polyimide coating over the teflon on the wires from the Surveyor III cable was found to have been cracked and crazed in many places. The polyimide coating was intended to provide the basic toughness to the insulation. With this cracked and crazed coating, the estimated value of the cut-through was expected to be that of the FEPalone, i.e., on the order of 150 grams. This estimate was very close to the measured value of 180 grams. Thus, the cutthrough measurement, in effect, verified the poor performance of the poly-
4-40
SM/SS
Scoop
Wires elongation measurements were bare conductor from the scoop of these tests are summarized in Table 4-18 lunar exposure indicates of either made of the wires using an in Table 4-18.
electrical Instron
Tensile strength and insulation and the tester. The results
Comparison changes can
with specifications be attributed to the
that no significant material. on the scoop The cutis consistent is therefore of the electrical by the
Insulation cut-through measurements were conducted wires using the method described in the previous subsection. through value of 140 grams obtained after a 24 hour exposure with expectations for this teflon TFE insulation. This result consistent with the above conclusion that the tensile strength insulation of the lunar exposure. 4.4.3 Discussion Electrical SM/SS scoop wires was not significantly
affected
of Results Measurements
Review of the data presented in Section 4.4. 1 leads to the general conclusion that no significant changes were noted in the electrical properties of the television cable wires and of the SM/SS scoop wires that could be attributed to exposure to the lunar environment. Any deviations noted were either minor or most likely attributable to the test limitations associated with the limited lengths of samples available. Insulation resistances were well within specification limitations, as were conductor resistances. Similarly, the dielectric strength measurements of the scoop wires yielded nominal results. The only apparent discrepancy was the somewhat lower value obtained for the capacitance of the cable wires compared to those measured on a similar spare cable from Surveyor stores. It is most likely that this discrepancy reflects the above-mentioned limitation of available lengths of samples. The capacitance of the scoop wires appeared normal; no direct comparison could be made with other similar wire configurations because of nonavailability of similar insulated wires in an identical configuration. Physical Property Measurements
Results of the tests described in Section 4.4.2 indicate that a number of changes traceable to the effects of lunar exposure occurred in some of the physical properties of both the conductor wires and the cable wraps. However, these changeswere in no instance large enough to impair the ability of any of the materials tested to function in full comp]iance with design requirements.
4-41
TABLE
4-18.
TENSILE
STRENGTH AND FROM SURVEYOR
ELONGATION III Ultimate Tensile Strength,
OF
SCOOP
WIRES
Ultimate Test Sample 6 Breaking Strength, pounds
psi
Elongation, Percent
22 AWG conductor made of 19 strands of silver-coated OFHC copper (each strand 0. 0063 inch diameter) Sample from Specification Surveyor value Ill 10.4 30, 000 3Z, 000 to 35, 000
25 45 to 55
Insulation,
teflon TFE Surveyor value III 5.63 5000 2500 6500 250 to
Sample from Specification
to
250
350
The reduction in tensile strength of the alloyed copper is considered to be the result of thermal annealing. On the other hand, the soft copper (OFHC) was fully annealed prior to its flight application; thus, no changes resulting from the lunar exposure would be expected. This was confirmed by test results. The apparently lower tensile strength of mylar can be attributed to handling during the manufacture of the cable and during tests of the cable. It is unlikely that any reduction occurred as a result of lunar exposure. The effect of such prelaunch handling could undoubtedly lead to physical cracks or tears in the mylar. Caution in the handling of this thin material is prudent. A review of the results of measurements of the physical properties of the teflon insulation indicates that the teflon FEP material from the television cable wrap experienced a 50 percent decrease in tensile strength, while the teflon TFE insulation from the scoop wire and teflon FEP-polyimide insulation from the internal wires of the camera cable experienced at most only a small reduction in tensile strength.
The loss in tensile strength of the teflon FEP is attributed to the radiation environment, namely, the low energy protons of the solar wind. The teflon FEP cable wrap and the teflon TFE insulation from the scoop wires were directly exposed to this radiation environment, while the insula-
4-4Z
tion on
the cable wires was shielded by the overwraps. The difference in measured tensile strength between the two samples directly exposed to the radiation environment cannot be explained by a difference in intrinsic susceptibility of the two types of teflon to radiation since both have about the same sensitivity to radiation (Reference 7). It is difficult to explain this observed difference between the degradation of the 2 rail teflon FEP cable wrap and the 9 rail teflon TFE insulation of the scoop wires. After a considerable amount of analysis, including outside consultation, the only possible explanation suggested for this observed difference is discussed below. This explanation is, in part, based on recent work at Hughes involving charged carrier migration in dielectric solids,.. _ The explanation attributes the observed degradation to solar wind protons and to the migration of the resultant charged carriers produced by the protons. Although the low-energy solar wind protons have only a range of a few microns in teflon, the charged carriers produced are estimated to migrate a distance on the order of 1 rail through the material in the course of prolonged lunar exposure. This phenomenon is compatible with the observed migration of the charged carriers produced along the proton track in dielectric solids. The effect of these charged carriers is increased crosslinking in the teflon, resulting in increased brittleness. When the teflon FEP was unwrapped from the cable, it was observed to be somewhat stiff. This unwrapping of the partially embrittled teflon FEP material may have caused some fractures in the layer, thus reducing its original thickness by as much as one-half and consequently reducing its strength by 50 percent. The teflon insulation from the wire would be expected to show a reduction in tensile strength of about 10 percent. It was difficult to observe this degree of change in tests of these samples of limited size. The above hypothesis is qualitative in nature and is based on the
extrapolation of data available for dielectric solids to teflon. However, in the absence of other plausible explanations, the hypothesis seems reasonable and is fully consistent with the observed experimental results. If the above hypothesis is valid, a significant consequence arises relative to possible future applications. Had the cable wrapped with teflon FEP been required to move or to flex during or after the 2-I]2 years of its lunar exposure, it is possible that significant cracking in the teflon wrap would have occurred. Results of the cut-through tests of both the wires from the television cable and the wires from the SM/SS scoop appeared consistent. The lower than anticipated value obtained for the FEP-polyimide wire was in agreement with the observation that the polyimide coating was fractured in many areas.
Conducted by Hughes Aircraft
H.
Levin in the Company.
Materials
Technology
Department
of
4-43
4.5
METALLURGICAL
ANALYSIS
Metallurgical analyses of samples of aluminum alloy from the various returned parts of the Surveyor III Spacecraft and control samples are discussed in this subsection. The samples of aluminum alloys tested and their origin on the retrieved Surveyor III parts are summarized in Table 4-19. The principal tests conducted were microscopic examinations and measurements of microhardness. 4.5.1 Polished Aluminum Tube polished same size,
Photomicrographs of a cross section of the Surveyor III aluminum tube and of a control sample taken from a tube of the alloy, and temper are presented in Figures 4-19 and 4-20.
°
O
.j
0 o
@
.e t_
k
t
o._°
, • ' "_, • •
°J,
:
_
•
•
:. b
a)
No Etching
(Photo
00628-64)
b)
Keller's
Etch
(Photo
00628-65)
Figure 4-19. Microstructure of Polished Aluminum Tube From Surveyor IIl (1000X Magnification)
4-44
O
S
•
A
a)
No
Etching
(Photo
00628-66)
b)
Keller's
Etch
(Photo
006Z8-67)
Figure (1000X
4-20. Microstructure Magnification)
of Control
Sample
of Aluminum
Tube
TABLE
4-19.
ALUMINUM ME TAL
ALLOY LU RGICAL
SAMPLES SELECTED ANAL YS IS
FOR.
Aluminum 2024-T3 WW-T-700/3
Alloy
Source
of Sample
Section G, Surveyor III polished tube (spacecraft structure) Support strut for Surveyor Ill television camera Scoop arm (machined from bar stock)
2024-T3 WW-T-700/3
7075 -T6 QQ-A-ZZ5/9
4-45
The seen in attacked was not normal No grain dition in sample attacked in Figure
grain
boundaries
in
the
microstructure
prior
to
etching
can
be
Figure 4-19a. Figure 4-19b shows that this microstructure was abnormally upon a very light application of the etchant. The san_ple repolished after etching and is available for further tests. The microstructure of the 2024-T3 control sample is shown in Figure 4-20. boundaries are visible in this control sample in the unetched conFigure 4-20a. The grain boundaries become evident in the control after etching in Figure 4-20b. However, the general structure is not as severely as that of the Surveyor III polished tube section shown 4-19b.
It is evident from the above comparison that additional grain boundary precipitation of the precipitation hardening compounds, or overaging, occurred during the lunar exposure. Prolonged exposure at 250°F of aluminum 2024-T3 will cause increased hardness resulting from increased precipitation at the grain boundaries (Reference 8); this increased precipitation will be evident in the unetched c ondition. Microhardness surveys using a 50 gram Knoop indenter revealed that
the average hardness of the Surveyor III polished tube was 137. 5, expressed in terms of Brinell hardness numbers. The corresponding value for the control tube sample was 124.0. The nominal hardness for this alloy in the T3 temper is considered to be in the rangeof 110 to 130 on the Brinell scale. No significant variation in hardness was seen from the edge to the center c,f the cross section of the polished tube. The above measurements led to Lhe conclusion that the increase in hardness of the Surveyor III polished aluminun_ tube was caused by the lunar thern_al environment. Separate that the maximum during its stay properties periods up tensile and The increased is greater, 4.5.2 thermal analysis conducted by Hughes and temperature which the polished aluminum on the lunar surface was 250°F +25 ° . The JPL indicated tube reached mechanical
of Alclad 2024-T3 aluminum alloy after thermal exposure for to 6000 hours is given in Reference 8 _':-_. At 250°F, increased yield strengths are noted for exposures as short as 600 hours. tensile strength is modest; but the increase in yield strengt'_ reaching 25 percent after 6000 hours exposure. Tube microstructure that taken of a longitudinal control sample section shown of the in Figure painted 4-20a.
Painted
tube
was
The unedged similar to
of
the
The microstructure The appearance shown in Figure to the sample
of the painted tube after is normal and similar to that 4-20b. The grains are more orientation.
etching is shown in of the etched control elongated in Figure
Figure 4-21. sample 4-21 due
Figure similar alloy
21, page strengthening and not the
229;
although would cladding is
these occur subject
data are based on with unclad aluminum to the precipitation
Alclad aluminum, since the ZOZ4base hardening.
4-46
*
POo o @
of Painted III
Figure 4-21. Microstructure Aluminum Tube From Surveyor (1000X Magnification} Keller's etch (Photo 00628-68)
Thirteen microhardness measurements were conducted on a sample of the painted tube. The measured values were converted to Brinell hardness numbers, using standard tables, in the same manner as was done for the polished aluminum tube• The resultant average Brinell hardness number was found to be 133; the spread was reasonably small. This value falls between the Brinell hardness numbers obtained for the Surveyor III polished tube and for the control sample.
It should be noted that the painted tube is expected to have had a lower equilibrium temperature on the moon than the polished tube because of the presence of its thermal coating. Since the above hardness measurements represent averages of a number of measurements with relatively grouping, reasonable credence can be attributed to their significance. it could be inferred from these measurements that the painted tube had gone some additional aging during its lunar exposure relative to that of _..I_._AA =,l.,,,,v,;._.,,,-_ t-_,'_ _leh_,,gh _h_ cnnclusion is not evident from the phot omic r og rap hs.
close Thus, underthe
4-47
4.5.3
Scoop
Arm examinations and hardness measurements were con-
Microstructural
ducted on both ends of the SM/SS scoop arm, made of 7075-T6 aluminum, as indicated in Table 4-19. One end of this tube, which was severed by the astronauts on the moon, was unpainted and anodized. The other end, severed in the laboratory for this measurement, was painted with the original blue paint. Microstructure examination and hardness measurements were also conducted on a control sample of this material. Results of microstructure ends examinations indicated a striking similarity the
in appearance of both Hardness measurements, polished Brinell end, and unpainted aluminum. aluminum hardness
of the scoop arm and conducted in the same yielded 150 for
of the control sample. manner as those for
sample, numbers:
the following results the control sample,
in terms of 157 for the unpainted and
156 for the painted end. ends are well within the
The hardness values of the painted typical hardness range for 7075-T6
Results variation 2024 alloy. Reference8 about 500 of
of
hardness
measurements
could
be
attributed
to
the
normal
the 7075 alloy, which is not as temperature-resistant as the On the other hand, they could be the result of lunar exposure. _`shows that a slight strengthening of the 7075 alloy occurs after hours exposure at the lowest reported temperature of Z25°F and in 1000 this mechanical properties occurs hours. At higher temperatures alloy was strengthened by aging upon continued exposure below Z25°F, it is conat lower temperatures.
that a decrease in excess of ceivable that
4.6
ANALYSIS
OF
LUNAR-CUT
ENDS
OF
POLISHED
TUBE III polished ends are a metalends, and to the in this
An analysis was conducted on the two ends of the Surveyor aluminum tube severed by the astronauts on the moon. These two referred to as "lunar-cut" ends. Results of this analysis, including lurgical evaluation, a study of the characteristics of the lunar cut an evaluation of the original orientation of the polished tube relative Surveyor section. spacecraft inferred from the above study are presented
This analysis was motivated by the desire to compare the metallurgical properties evident from the cut performed on the moon with those characteristic of similar cuts under ambient conditions, by the desire to obtain a better understanding of the resulting characteristics of the deformed, cut ends, and by the desire to affirm the orientation of the tube for subsequent surface contamination studies. The two ends available for this study were sections Aand G of the tube; as discussed in AppendixA, these were made available to Hughes.
Figure
23,
page
Z31.
4-48
4.6.1
Analysis
of Cut
An examination was performed of the lunar-cut ends of the polished tube section. The appearance of the lunar-cut surface of section G of the polished tube is shown in Figure 4-22a. Figure 4-22b is a side view of this section looking at the side shown at the bottom of Figure 4-22a. As or can be seen in Figure 4-22a, cutting of the tube distorted it into pear-shaped cross section. The appearance of this surface that, as the tube flattened, the cutting tool indented the metal and sheared the wall on the flattened sides. As the wall was thinned increased, An and extend-
an oval indicates partially
by the cutting action and the forces imposed by the cutting tool the tube deformed; final rupture of the wall occurred by fracture. indentation caused by the cutting tool just below the cut surface ing across one side of the tube can be seen in Figure 4-22b.
i
4,
a) Figure
End 4-22.
View
(Photo
00628-69) Surveyor III Polished
b)
Side
View Tube
(Photo (7X
00628-70) Magnification)
Severed
Aluminum
4-49
The cut surface was examined extensively by the SEM, and selected photos are shown in Figures 4-23 through 4-27. Figure 4-23 is an enlarged view of Figure 4-ZZa and reveals some areas of the lunar cut in greater detail.
Figure 4-Z4 shows the indentation made by the cutting tool previously shown in Figure 4-22b. A very small sphere having a diameter of 0.0003 inch is shown on the indented surface of Figure 4-_4c. Lack of charge buildup on the specimen in the SEM indicates that this sphere is metallic.* Similar spheres have been observed on the fracture faces of various metals.
Figures 4-25 through 4-Z7 show typical areas of the fracture observed on the lunar-cut end from section G. Figure 4-25 corresponds to the bottom (6 o'clock) area of Figure 4-23. On the left is the smooth surface made by the cutting action of the tool. The surface on the right is where the fracture propagated by tearing after stress buildup under deformation by the cutting tool. This torn area shows the dimple fracture characteristic of a ductile break. The dimple fracture is shown in greater detail in Figure 4-26. Figure 4-27 shows in greater (9 o'clock position) which was folded the surface in the direction in which visible. detail the area on the left in Figure 4-23 over by the cutting tool. Scoring of the cutting blade was moving is clearly
A tube of the same alloy (aluminum 2024-T3), size, and temper as the Surveyor III tube and cut with the same type of tool is shown in Figure 4-28a. While this cut surface is not identical to that of Figure 4-22a and 4-Z3, it contains the same features of sheared metal part way through the wall and ductile tearing through the remainder of the wall. Also, the indentation on the wall seen in the lunar-cut sample below the cut was noted in some areas of this control sample. SEM photographs of portions of Figure 4-28a are shown in Figures 4-28b and c. Figure 4-28b is an enlargement of the radial crack in the wall on the left (9 o'clock position} of Figure 4-28a. Figure 4-28c is an enlargement of the bottom (5 o'clock position) of Figure 4-28a and shows the results of a combined shearing and tearing action caused by the cutting. This is similar in appearance to the corresponding areas on the lunar cut previously shown on Figure 4-25. Analysis of the above figures indicates no distinctive differences between the cuts made on the moon and the cuts made in the laboratory using a tool similar to that used by the astronauts. The only exception is the crack in the 9 o'clock position of Figure 4-28a on the sample cut in the laboratory. The contour or deformation of the retrieved tube and the control tube at the cuts are slightly dissimilar, but this is strictly a function of the position of the tube cutter at the time the cut was made.
_"_Otherwise, sphere is
the lunar
sphere would appear material although
very bright. this cannot be 4-50
It is unlikely that proven conclusively.
this
4.6.
Z
Orientation
of
Polished
Tube
on
Spacecraft
This similarity aluminum tube and of with the unique shape mining the approximate the lunar characteristic identified. studies tamination and surface. pattern Determination
in appearance of the surfaces of the retrieved the control sample cut with similar cutters, along of the cut tubes, give rise to the possibility of deterorientation of the polished aluminum tube while on orientation could resulting from these of this orientation of the be established conclusively if a cutting operations could be would be useful for solar wind of tube. and the the brownish con-
This
for the analysis on one side of an
the nature and source Surveyor III polished of the action of,
Accordingly,
analysis
resulting
patterns t_ol Both
obtained from, the use of the cutting tool was conducted. The cutting is sketched in Figure 4-29. Its action can be described as follows: blades of the tool squeeze the tube fairly uniformly as the tube assumes an oval shape. As the tube deforms, the blades uniformly indent the
flattening sides of the tube for about 75 percent of the circumference of the tube before rupture commences. If the tube is positioned between the blades close to the fulcrum, the tube will be oval-shaped after cutting. If the tube is positioned away from the junction of the blades nearest the fulcrum, the tube will be pear-shaped, with the apex at the end farthest from the fulcrum. In the latter case, rupture commences at the small pinched end. Both blades appear always follow the to cut or indent path of the blade. equally. The Observation fracture of a of as the tube fracture-
does
not
cut
initiated revealed times the fracture intact. Thus, the was not abnormal.
the characteristic pattern sketched in Figure 4-30. Somefollowed one of the cracks, leaving an indented surface indentation observed on one side of the lunar-cut tube
It was considered tube, the other astronaut the tube and bent it to
likely grasped facilitate
that, while one astronaut the previously cut and its removal. Accordingly,
was cutting the hence free end of tests were con-
ducted to determine if a combination of cutting and bending produced any identifying features on the cut surface. It was observed that in cutting samples without bending one out of seven samples had the indentation previously described. With samples that were partially cut and then broken off by bending, six out of nine tubes exhibited the indentation on the side toward which the bend was made. The l} above If the apex cutting tube-cutting contour of the tool. the fracture is present, the probato assist the separation is higher tube was completely sheared through. occurred on the side toward which of tube experiments the cut end is the point led of the farthest to tube the is from following pear-shaped, the fulcrum conclusions: the the
of
Z}
if an indentation offset from bility that the tube was bent than the probability that the On bent tubes, the indentation the bend was made.
4-51
Figure 4-23.
Enlarged View of
Figure
4-22a 4-52
(21X
Magnification)
(Photo
00628-71)
a)
ZIX Magnification (Photo 00638-73)
b)
78X (Photo
Magnification 00628-73)
c)
16, O00X Magnification (Photo 00628-74)
Figure Tube
4-34. Made by
Indentations Cutting Tool
on
Surveyor
Ill Polished
Aluminum
4-53
_,,.._S4 .jl'll"/_, r .
_. _ '
4" , .ai_- f._"'*',%<,_/:-,_.
,
Figure 4-Z5. _rea of Figure " cation) (Photo
Enlarged View of Bottom 4-Z3 (5Z5X Magnifi0062-8-75)
Figure 4-2-6. Area of Figure cation) (Photo
Enlarged View of Rilht 4-2-5 (ZI00X Magnifi006Z8-76)
¢
Figure 4-Z7. Enlarged View of Left Area of Figure 4-Z3, Showing Scoring Caused by Cutting Tool (1050X Magnification} {Photo 0962_8-77) 4-54
--
°
°
•
a)
End
View
7X
Magnification
Photo
00628-7F,)
,l
D
4P
• .at o,%
m
r:/f
gE sl.
b) Left Showing (Photo Area of Figure 4-28a, Crack (28X Magnification) 00628-79)
,i
.,.4 ¸
J* . .. ,_sl
c) Bottom of Figure Combined Shearing Caused by Cutting (Photo 0062-8o80)
4-28a, Showing and Tearing (720X Magnificati,,n)
Figure
4-2_.
Control
Sample
of
Polished
Aluminum
Tubing
4-55
lEVELED
Figure
4°29.
Sketch
of Cutting
Tool
Cable cutter and aluminum; by astronauts
HKP 8690FS for copper same model as used on moon
START OF
Figure During
4-30. Tube
Sketch Cutting
of Fracture Operation
4-56
that
the
With top
reference of the tube moon.
to Figure section Thus,
G
4-23, was this
the nearest flat
first the region
conclusion fulcrum was closest
of
strongly the tool to and
indicates when facing
the
tube was cut on the toward the astronaut. Examination tube, section 70 degrees could shape cut. section A, with
of revealed respect
the to
severed that the this tube
end
of
the
cut
section
of
the
Surveyor
III
cut was axis.
made at an No continuous
angle of about blade indentation
be seen on either side of this tube, nor was there any distinct pear to identify the position of the tube in the cutting tool at the time of the Based on the above discussion, this end of the polished aluminum tube, A, was the first to be cut on the lunar surface. on the moon was described their debriefing: The end of the tube moved to at that time moved to the and removed it as the
The cutting sequence of the polished tube in the following manner by the astronauts during astronaut who performed the first cut of the right his left while facing the tube; the second astronaut right. The second astronaut held the tube section first astronaut made the second cut. A operations aluminum was cut final on tube first. description of the probable the moon can now be inferred. which was the support strut This strut was about 3 feet nature
and sequence of the cutting The uphill side of the polished of the Surveyor radar antenna above the lunar surface. The
cutters were probably held downward at an angle of about 45 degrees from the horizontal. The astronaut must have reached over to his right in order to cut this end (section A) at the 70 degree angle. It appears that the astronaut then moved to the left to cut the other end of the tube while the second astronaut moved in to hold the severed section A in his hand. The second cut, section G, shows naut. This indentation holding the previously cutting of the second an indentation on the side of the probably occurred becaus.e the cut section A and bent it slightly section, G, was completed. tube facing the astrosecond astronaut was toward him before
The brownish contamination on the polished aluminum tube was located on the side of the tube which corresponds to the apex of the pear shape of section G in Figure 4-23. This deposit was, therefore, on the side away from the fulcrum of the cutting tool, that is, from the astronaut, as discussed above. This places the brownish contamination on the inboard side the of the spacecraft. tube in its original position on the moon, that is, the side facing
4.7
OPTICAL Results of the
PROPERTY
MEASUREMENTS of optical tube are properties presented to of aluminized in this subsection. teflon
FEP
and
of measurements polished aluminum
These measurements face discoloration and Appendix J. However, of optical measurements Surveyor television III parts camera,
were not originally considered contamination studies reported they could be considered to conducted on various other external in those surfaces sections. 4-57 of the
be a part of the surin Section 11 and supplement the results surfaces of the retrieved retrieved Surveyor III
and of the presented
N
,-11_
il l:
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•
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0
.<
i .°
4-58
The optical properties of and Appendix ft. The data on the portion of the surface contamination
the painted tube tube reflectance study.
are reported were considered
in
Section to be
l 1 a
The measured.
optical properties The paint was
of heavily
the paint coated
used with
on the SM/SS scoop lunar soil. To make
were the
not
measurement, it would have been necessary to cut a sample from the scoop. This destructive test was not warranted since the blue paint used on the scoop was very specialized and not in general use. Also, as described in Section ll, interpretation and separation of the lunar dust effect from the paint requires No significant tive testing 4.7. 1 supporting data were the scoop Teflon spectral teflon studies that were beyond the scope lost by not making this measurement, was thereby minimized. FEP reflectance FEP used cable than on this In on measurements an outer with layer as were made on the TV on samples camera cable. was previously Reflectance of this and program. destruc-
of
Aluminized Several aluminized
of
the
as
wrap
The wrap described
removed as having
from the a thinner
returned normal sample, addition, a sample
the camera of aluminum. as
measurements having a normal transmittance
were made aluminization. were measured
well spectral having
on a comparison sample and total hemispherical a thin aluminization. were made using a measurements were and normal emittance
Reflectance and Gier-Dunkle integrating made using a Gier-Dunkle values were calculated. In addition, returned in integrating Reflectance Results aluminized are shown two from areas the of
transmittance sphere. heated
measurements Infrared reflectance hohlraum cavity,
FEP in an
a vacuum test was conducted on the SESC.* The spectral measurements sphere of the Edwards design. ** and Transmittance of Measurements reflectance and
samples were
of
the teflon performed
measurements
transmittance camera cable were conducted the
of wrap on
teflon FEP from the Surveyor in Table 4-20. Reflectance on side the of
III television measurements teflon from
teflon side of the aluminized the wrap that faced outward
FEP: Area 1 was taken camera cable; it was portion was control columns
covered of the relatively sample of the ments
with a brownish cable wrap which clean. For of teflon FEPare table include on conducted the
contamination. Area 7 was taken from the faced towards the camera cable; this sample comparison, reflectance measurements on a also included in Table 4-20. The last two of two the hemispherical from the transmittance Surveyor III cable measurewrap. samples
results
SESC
_',.7',.-
operations by
are TRW
discussed under a
in Hughes
Appendix subcontract.
J. 4.2.
Performed
4-59
As noted in Section 3.2.2, the aluminization of this teflon FEP was quite thin and missing in some areas. With the proper thickness of aluminum coating, values of transmittance on the order of I percent or less
would be expected. indicate much higher increase in transmittance of reduced aluminization. Results values, is of transmittance as high as attributable measurements 9 to 19 percent to and a measure for in Table 4-20 area I. This of the magnitude
Reflectance measurements with the Gier-Dunkle integrating sphere were conducted with a sample backed with a black surface of low reflectance (less than 3 percent). The measured reflectance, shown in Table 4-20, is therefore that of the aluminized teflon; with the teflon side out, the transmitted light The was eliminated of by both absorption of the in Surveyor the black III backing. is lower than that from the
reflectance
samples
of the control sample. This lower FEP is attributable to the following the transmittance data, the presence effect of radiation damage. These It had originally been hoped that the study, discussed in Section 11 and that could lead to the separation of limited scope and time of the study In addition to the spectral
reflectance of the Surveyor III teflon factors: some loss of aluminization of the brownish contamination, and contributory factors cannot be separated. surface discoloration and contamination Appendix J, would provide information these contributory causes; but the did not permit this. and transmittance, infrared
reflectance
reflectance was measured on a sample of teflon FEP from the Surveyor cable as well as on a control sample. Results of these measurements presented in Table 4-21. The sample tested had been adjacent to area Table 4-20. This sample had a brownish contamination on its surface similar to that on area 1, but not as heavy. The qualitative the teflon brownish niques, brownish contamination is believed to be lunar material.
III are I of
One from this tech-
electron microprobe measurement was made wrap, but results were inconclusive. Further contamination, using electron microprobe or may be warranted. change in infrared of the brownish discussed. of these work of reflectance, contamination shown and in to
on a sample analysis of other suitable
the as
The presence previously
Table 4-21, the reduced
was due aluminization,
to
program. entail of the nization, firmly to the
Separation Additional the measurement teflon and establish effects FEP both, of
two effects is warranted ultraviolet, off areas.
{._[Abl_d.l
was
beyond the scope on the teflon FEP. visible, and infrared brownish These tests contamination, could then in "_-^
I,,,|1_
of the current This work would transmittance the serve ......
40-I. 1.1
after in the solar
cleaning selected
.
the '
alumito :k,.,_,.,_
LkIW,_LLC3-L.JII_
degree of radiation.
.......
UL
J'scoloration
,_c,
L_IIU|I
4-60
TABLE
4-Zl. RESULTS OF ALUMINIZED TV CAMERA
OF
INFRARED TEFLON CABLE
FEP WRAP,
REFLECTANCE FROM SURVEYOR TEFLON SIDE
MEASUREMENTS Ill
Reflectance Wavelength, 2.5 3.1 3.55 4.0 4.4 4.82 6.26 7.12 7.83 8.46 9. 06 9.65 10.24 10.84 11.46 12.10 12.78 13.51 14.29 15.12 16.05 17.11 18.30 19.70 21.42 23. 50 26. 17 Integrated emittance normal 0.71 microns Surveyor III 81.0 78.0 78.0 63.0 64.0 76.0 65.0 51.5 3.0 7.5 I0.0 38.5 11.5 40.5 34. 21.0 13.0 7.5 7.0 6.0 8.0 8.0 8.0 11.0 21.0 50.5 54. 0 5 Sample
,
percent Control Sample 92.0 92.0 93. O 59.0 84. 0 90.0 73.0
2.0 11.0 [3.0 3_.0 11.0 38. O 34. 0 22.0 13.0 2.0 5.0 3.0 5.0 5.0 5.0 I0.0 20.0 56. O 6O.O
0.70
4-61
Vacuum
Measurements
of SESC
Sample teflon wrap from the SESC_ were light illumination and in an inert for measurement. One sample the other with the aluminized side
Two pieces cut and transferred atmosphere to the was mounted with out. The quartz assembly was
of the TV cable outer under low level red quartz vacuum chamber the teflon side out and
The
tube then
was attached pumped down kept in the
through a tee to 10 -7 Torr dark during these
to a Varian by sorption operations
vac-ion and ion and
pump. pump-
ing. The samples were the following measurements.
during
The teflon side had an area which had been exposed to the space environment and an area which had been protected from direct irradiation by an overwrapped piece of aluminized teflon. The sample was positioned visually using dim red light. Physical measurements were made so that the positions could be reproduced during subsequent spectral reflectance measurements. The first series of spectral reflectance measurements _':_'-':_ was made
at a pressure of approximately 10 -6 Torr. Using a sensitive leak valve, air was bled in until the pressure was approximately 10-" Torr. The measurements were then repeated. Air was then admitted to the chamber, and the measurements were repeated at 1 arm pressure. The samples were then exposed for 48 hours to the irradiation of a xenon lamp through a filter which transmitted only at wavelengths greater than 0.4 micron. The irradiance was measured at the sample position using a calibrated radiometer. The irradiance was 214 mw/cm 2. The tested corresponding to of these tests are 4.7.2 Polished Reflectance spectral tube. tion of The the regions purpose brownish were samples the above presented Tube measurements conducted of these tests contaminant on was noted over the visible of the and near-infrared III and polished orientaof the cable figures are in Figure wrap and summarized 4-31. the test conditions in Table 4-22.
Results
sections
Surveyor the extent of the tube.
to determine on one side
See
Appendix by
J.
4.2
for under
discussion a Hughes
of
the
opening
of
the
SESC.
Performed
TRW
subcontract.
4-62
100 b) '
TABLE
4-22,
_U_.'MAR¥
UF SAIVPLES
ANI_. COhDITIONS
(_F SPECTRA_-_,_-._[rCT_NCE 9O
d)
FrO'IRE ] N2 _ 4-a'
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OF _
LAP'SURE TO SC)LAi_ * R,_-DIATIC, h_ *
pRES_bRF
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OF
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h
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NONE NONE t_ p • 3 I0 -1 NGNL NON[
__ U _'
60
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z
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hqcl_ON$
Figure Nrom
4,-31. Surveyor
Spectral III Cable
RefLectane__:_lea_arement_ Wrap _ ..... ..=ll - 6 3 -
of
Aluminized
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'i:Z!;!
The Reflectance been one
tube was measurements
cut to and
into
several sections, were obtained on
as described sections A and on on the section
in G, tube A.
Appendix which had was As
A.
made available side of the tube in Section 4.6, the spacecraft G came from
Hughes. heavier
The contamination on section G than this
on only con-
cluded toward Section antenna.
the contaminated side of and down about 45 degrees the end of the tube closest
tube pointed inboard from the horizontal. to the spacecraft radar
The determined
extent of contamination along by measuring the reflectance were made sphere. by placing Separate at a
the length along the
of each tube contaminated
section side.
was These
measurements Dunkle integrating every 1/4 reflectance inch at
each tube reflectance single position
section vertically measurements of 0.47 micron. contamination
in a Gierwere made The of the was
along the tube the circumferential be of
wavelength of heaviest
section G was found to reflectance was measured found on either section The circumference. reflectance The ends) were
about to be tube.
11 to about
13 percent. 38 percent.
Along section A, No axial gradient
of each measurement at
tube
section was was made at wavelength 8 degrees.
then the of
measured center of
around each tube Reflect-
the
(between the two ance measurements
a constant made every
0.47 The
micron. measurements
obtained are shown in Figure Locations of all measurements line, noted on these figures. to sectioning to serve as a in Appendix A. The function surements ends). one 180 of spectral wavelength were made reflectance
4-32a and b for sections A and G, respectively. were designated with reference to the bcribc This scribe line was made at the LRL prior reference. This is described in further detail
measurements from 0. 3 to of each tube conducted: line at the are one spot shown
were
then
made
as
a meatwo and
over a range at the center the were scribe measurements
2.6 microns. section (between along the of heaviest in Table
These the
Two measurements degrees from Results of these
scribe line contamination. 4-23. for any tube I'he
reflectance of the uncontaminated aluminum. Further tests are tamination is present on this would account for this reduction
side was less than expected planned",-" to determine whether side of the polished aluminum in reflectance.
polished lunar conwhich
Tests
now
in
progress
at
JPL.
4-65
o_
_o
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ord
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0 0
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0
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4-66
180 •
ANC. LJLAR P()SI AROUND TUBE
TIC)N
90 _
50
60
/U 270°
REFLECTANCE,
PFRCENT,_
/ I
/
/
/
/
/ /
0 o Q) _-.C'rIC)N CUT END A, UP LUNAR
180"
/
/
\\ ,\
'\
\
90 • \ \
\
\
\\ \
b)
SECTION CUT
ENO
G. LUNAR DOWN
Figure Polished
4-32. Tube
Percent Arc_und
Reflectance ()f Surveyor Its Circumference 4-67
III
0 Z 0 h
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N
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4-68
4.8
ANALYSIS
OF
CONTAMINATION
OF
POLISHED
TUBE
An analysis of the nature and source of the contamination of the retrieved Surveyor III polished aluminum tube was conducted and is sunlmarized in this subsection. This analysis supplements the surface contan_inationand discoloration studies of the other retrieved Surveyor 111 parts conducted jointly on this and the companion Surveyor III TV camera test program (Reference I). As mentioned previously, results of these joint studies are contained in Section ii and Appendix J. Study separately in this of the Surveyor study. analysis III Two tamination of the because Results of the spacecraft contamination it is somewhat presented orientation (discussed used tube was was of the more polished unique tube the is reported material here presented light
to
in this subsection should of the polished aluminum in Section 4.6). in an attempt to sections. First, measured. conducted. analyze the the infrared an
be viewed in tube on the
methods were on the polished on the tube contaminant to obtain
brownish reflectance
conof the
the contaminant analysis of the In order removing crystal
Second,
electron
microprobe
the infrared
spectrum
of the
contan]inant
without
it fron_ the tube, section G of the polished tube was placed at the position of an attenuated total reflectance (ATR) holder. The n_irrors
of the holder were adjusted so that as much of the reflected light fron_ the tube as possible was directed toward the entrance slits of the spectrophoton_eter. A spectral trace was then n_ade. A nornlalizing trace was obtained by placing a clean polished alunlinun_ tube at the san_e position. Data from the two spectra were compared; a plot of the resultant
data for the contaminant is given in Figure 4-33. No evidence of organic bands is seen in the figure,. It should be noted that the experimental techniques used may have reduced the sensitivity to the presence of organics. While no definite conclusions can be drawn regarding presence of sonic organics, results strongly suggest that the heavy contamination was not dominantly of organic A organic materials small in nature, on the such spacecraft. that as resulting from significant outgassing
anaount
of dust
had
previously
fallen
from
the SM/SS
scoop was placed on alunainuna foil, and its infrared using the ATR. This spectrum is shown in Figure the two spectra of Figures 4-33 and 4-34 indicates is probably lunar material. An electron microprobe brownish contaminant on examination the lunar-cut
spectruna was obtained 4-34. Comparison of that the contaminant
of the
was conducted end of section
on a snlall amount (3. This end had study and of Section had G been
previously exanlined was
been renaoved from section G for nletallurgical in an SEM. In addition, an uncontaminated area The results are presented in Table 4-24.
exannined.
4-69
@
c/3 ._3
u,._ = =
•
0
_
0
_m
0 m | _m _
_u
4-70
S..,
U')
|
....4
_o
4_
4-71
The high count for aluminum indicated in Table 4-24 is due to the base material. The other high readingstitanium, magnesium, iron, calcium, and silicon-- are characteristic of the lunar material. The above results were compared with the analysis of lunar material returned by Apollo XII (Reference 9) and Apollo XI (Reference 10). Results of this analysis indicate that the brownish contamination on the polished aluminum tube was lunar in origin.
4-72
"_."_' " ,'
'
. _ ,
, _
, ....
"I,
JC
S %
,_!"
•
• ,-::
1 1.
SURFACE
DISCOLORATION
AI_D
CONTAMINATION
STUDIES
." _i"it:'
1 1. 1
INTRODUCTION
,,"
::' ..: !.,,:.. [_ " "'"j! M ,,i. :_' "_ _ ¢' _ .,_!_ _ i, i_' ,':_::i_ ' "5' _ '!'i("_ _!:i_ I I
Results of surface designated as DOR studies, data in Appendix J. These two Hughes contracts (JPL contract) and
discoloration and contamination studies, '_ are presented in this section and supporting studies were conducted as a joint effort*": on the III parts: the TV camera
on the returned Surveyor other parts (NASA-MSC
contract} The studies were undertaken as a result of the initial observation that significant discoloration occurred on the exter'nal painted and polished zurfaces of the television camera and on the .polished aluminum tube from ",he spacecraft structure. The sealed container in which the painted tube sectionwas Initial of _he returnedwas observations and the notopeneduntillater. indicated difficulty both the extensive and its complex nature and nature separat-
discoloration
in understanding
camera at the LRL in January 1970, it became apparent tion of the painted surfaces was greater than had been patterns shadow ing the spectral
that the anticipated.
discoloraExpected
of radiation damage were not present. In addition, surface patterns were noticed. *** It was obvious that measurement of contributory causes. inorganic During the visual examination Ofuniquethe television reflectance of the white paint woutd'not sufficiently
::. "{_i!_:' W "•:_ .f_.
":_The letters D O R denote the suspected major contributions to surface effects--lunar dust, contamination by organic materials, radiation effectsafter effects of_nicrometeroid impacts-were found to be of-relatively small significance. ";"'This section and its corresponding appendix are labeled 1 1 and J, respectively, in the sequential context of the TV camera contract Final Report. These two parts of the report and a separate references page are incorporated verbatim for ease of publication into the Final Reports on both contracts. *::'*These incident darkening patterns sunlight. of the were not those that would be expected from radiation
_ i i
i:
:
"/'
_
i
|
' i:.ii',I I
paint,
as determined
by the
geometry
associated
with
the
i
,f
"*
""'*%
'
,_
"
."
,_
r'
.-.
,,,,
:'"
caused
Preliminary analysis by some combination 1) Dust module 2) from the
indicated that discoloration of the of th, _ following three factors: lunar surface -- from Surveyor
surfaces
was
III or lunar
landing,
or both outgassed from environments; Surveyor Ill or also contal_inatlon
Organic contaminationdeposited from prelaunch from rocket exhaust Solar radiation affecting pre sent
3) •,._. :. ,:: /:: '_. ": _ •_
the paints
and/or
the
organic
or other
f_
-(
contaminants
A special task was established to study this problem by analysis, supporting tests, and coordination with pertinent efforts conducted as part of the parallel science studies. The study was motivated by the desire to understand the nature and cause of this discoloration in order to assess the effects of lunar exposure for possible applications to future designs.
,_,
M
[_] '
Contamination port of lunar fines are significant for and contamination thermal history of engineering
of surfaces is important to optical systems. Tra_sand their associated effects on thermal control surfaces future lunar operations. Analysis of the discoloration effects could also help obtain reasonable estimates of the the camera, which would be of importance to biology and and otl_er science studic_.
investigations
u
mtW
!._ _"_.:. ::_. •.ti._, ._ _,_
p
An initial plan of attack was developed but bad to be abandoned later on. This plan was based on physical rer_oval of successive layers of dust and other contaminants from the surfaces by a variety of postulated techniques. It was thought that this sequence would permit the identification and separate examination of the contributions of the various sources of discoloration. Preliminary tests conducted revealed that the surface structure of the paint and its porosity would preclude such removal techniques. The plan finallypursued (discussed in Section II.3_ was based on an alternate approach which proved reasonably successful. i his plan entailed careful selection of a variety of samples and selective measurements supported by analyticalstudies of the totalproperties of these surfaces, The separation of the contributory factors would thus be accomplished by analysis and by interpretationof the test data obtained by the various techniques employed, using to the maximum possible advantage the knowledge of the relative locations of the selected samples at which the con,_.ributory effectswere present in significantlydifferentamounts. The test and analysis program included spectral reflectance studies at Hughes, supported by measurements at TRW, Inc. under a Hughes subcontract; analyticalstudies at JPL; and use of supporting data obtained from parallel science investigationscoordinated by JPL. Results of these
U
' '; _..' "._" (_(...,
J
m
|
m
i
• ; •; ;:_.
|
11-2
! !
"'
_ _
contributory
inputs
were
then
assessed
by
Hughes
and
JPL,
leading
to the
[J
prelin'_inary results reported here. It should be emphasized that the study is by no means con_lete. While significant progress has been made and an initial general understanding of the nature ,nd causes of discoloration achieved with a reasonable assurance of validity, mucn additional work may be warranted. In particular, further inputs from the yet incomplete preliminary scienc'e investigations may be of specific import. Results measuremelAs of the of the study reported here include numerous reflectance surfaces conducted by Hughes. Associated with
these
:. ...
,_ #_ _
reflectance measurements studies A ofmethod'ical and analysis optical thermal associated with the radiation were damage. tance data, conducted by JPL, is also summarized. Results were used in conjunction with the reflectance measurements relative effect3 of lunar dust and radiation. Inputs from the parallel science investigations,
ofbleachings the reflecof this study to separate the
.,_ :{:: _ , : " [_ • '_ _._
approved
by NASA
and coordinated the by JPL,Corporation;:: are also included. helpful The in indicating ion microprobe the amounts studies conducted at GCA were of lunar material on the painted and other surfaces, the depth of lunar material penetration, and the presence of other materials. Measurements of the quantity of trapped solar wind gas, conducted at the State University of New York (SUNY)," ..... were also used to advantage in indicating relative amounts of lunar l_aaterials on the various surfaces ':'''''::. Results of these parallel science studies at GCA and SUNY are only briefly discussed here; details of their investigations are e_ceected to be _ublished separately at a later date.
f_;
1
1.
_
DATA
AVAILABL]_
Jff-_ROM
PR_-_LAUNCH,
LAND_,
AND
-_
%_ ";"' _ _: -of the
A summary DOR study
and
assessment test plan
of the data is precented
available in this
prior section.
to the finalization Subsequent
discussion of the plan itself and of the test results obtained is to a large extent based on this information. Available data included prelaunch operations and their effects, effects and observations during the lunar recovery '. : examination operations of during and the returned the parts. of the return parts to earth, and results of visual
_.: ._._.
I
'By Dr. lv. .... ""By _":""_This
F.G.
Satkiewicz.
Professor approach
O. was
Schaeffex.. originally suggested by F. Fanali of ffPL.
'
_
N
II.2. I Prelaunch
Effects
The exterior surfaces of the Surveyor III camera were, for tile most part, coated with white inorganic paint used as the primary temperature control coating. The inorganic white paint was used on the exterior surfaces of the lower shroud, upper shroud, and mirror housing. The pain_ consisted of a calcined china clay pigment, primarily an aluminum silicate, in a potassium silicate binder. The coating was appDed to a thickness of 6 to 8 mils on a 6061-T4 aluminum alloy substrate. The paint was characterized by a low initial solar absorptance and a high initial emittance. : _- :' i ..
_ "_ _tv_
:,
Prior to launch, the Surveyor III camera was exposed to many possible sources of contamination, including those incurred in manufacturing and during thermal-vacuum testing. A rework of the thermal control surfaces was conducted on all Surveyors, including Surveyor III, just prior to launch in order to remove all visible contamination. Areas where the paint was missing were touched up with an organic coating. Other areas of discoloration were sanded down. Further details of prelaunch operations on the painted surfaces are presented in Appendix J-I. Two subsequent observations which have a definite relationship to the above prelaunch operations should be noted. The areas touched up with organic paint were observed on the returned camera to have discolored less than the adjacent areas covered with inorganic white paint. The scope of the study did not permit an exhaustive analysis of this effect, and further work may be warranted. However, it is postulated that tlle likely explanation of this apparent anomaly is that lunar dust does not adhere to organic paints as well as it does to inorganic paints The second also related to the white paint which than the unsanded a more extensive warranted. :": observation during the visual examination of the camera prelaunch touching up operations. Areas of inorganic had been sanded down appeared to have discolored less areas. Similarly, the scope of the program did not allow pursuit of this phenomenon, and further work may be
n
:;
:, : : ; 7 _ _ _i
_l
W
_ W D
=
--
m
i_. _ _ _':
_One of the suggested follow-on tests in the Final Report of the Surveyor III camera _ests, Section 1.6.3. One postulated mechanism is that the inorganic white paint was originally contaminated with some organic materials which were removed by the sanding operation; hence, the contribution total discoloration attributable to radiation would be less for the sanded areas. This, however, conflicts with the fact that no •significant traces of organics were found on the discolored inorganic white surfaces in the course of the study, as discussed later.
I
I
B
I
i
:,
11-4
"_
I
It is believed during the a protective launch. 11.2.2 prelaunch shroud
that
no
contamination
of the
external
surfaces was covered 203 seconds
occurred with after
at and transit launch.
phases.shroud Thewasspacecraft This ejected
Lunar
and
Recovery
Operations
_
the Surveyor bounced three times along the slope of the crater, Details of Surveyor III landed in a cloud of dust. The landing was abnormal: the orientation of the spacecraft and of the camera are presented in Appendix J. 1. The dust generated during the landing affected the condition of the C surfaces of the Surveyor III day noted camera. One evidence pictures of this effect was by
-i_
the
spacecraft considerable
during lunar veiling its glare
operations. television in the
obtained
• I
No major events are known during the Z-1/2 years of residence the arrival of the Apollo XII lunar The passed lunar module to the north approached of it, and
to have occurred in the adjacent areas of Surveyor III on the lunar surface until module. "" the Surveyor landed 535 feet III spacecraft away. Details from the of the amount as a
i
:_
east,
landing and Appendix operations Again, J. 1. of dust appears to have result
of the landing the important been deposited
configuration observation is are presented that a significant in on the Surveyor III spacecraft
i
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U
of this landing. During the second extravehicular activity period, the astronauts of Apollo XII arrived at the Surveyor III site and removed the various recovered items. A piece of a painted tube and several cable sections cut from the spacecraft were placed in a special container called the sample environmental sealed container (SGSG), which was tightly sealed and returned in vacuum and darkness. All of the remaining parts, which were cut: free of the spacecraft, including the television camera, a section of polished aluminum tubing, and were placed in separate In photographing _%: _ the astronauts reported the soil mechanics/surface pockets of the backpack. the spacecraft an extensive in the course sampler (SM/SS) scoop,
U
of the appearance.
above
operations, This report .
it had
brown
was repeated the Surveyor ro_d, rained
during the postflight debriefing when the III spacecraft as "looking like it had been upon, and finally left in the sun to bake". to the lunar module, the parts were later transferred astronauts to the
astronauts driven
described down a dusty
1
r
under
Upon return a shelf. All
stored command
the backpack module and
i: I
1
'I
*See purely
Appendix speculative,
J. 1.2.
Also cannot
effects be totally
of landing discounted.
of nearby
meteroids,
while
11-5
1
i
strapped into position. Thus complete immobilization was not achieved. For example, it is believed that the two dents in the sun visor of the camera seen in the frontispiece::' were probably incurred at the time of the hard landing of the command module in the Pacific Ocean. The parts were exposed to the oxygen environment module during the return to earth at a pressure of about 3 backpack containing the parts was transferred to the NASA Receiving Laboratory (LRL) with the astronauts. Early in period, the parts were taken out of the backpack, Theyv-ere graphed and then double-bagged in heat-sealed polyethylene release from quarantine on 7 January 1970. of the command to 4 psi. The Houston Lunar the quarantine first photountil their
"[_
• (!
• , ' ?. .; ._ Visual observation of the returned parts was conducted at the LRL in early January by Hughes, JPL, and NASA personnel. More detailed results of the visual observation conducted, insofar as it applies to the surface discoloration studies, are presented in Appendix J.Z. "A more cornprehensive discussion of the visual examination of the television camera is presented in Section 3.4. *::" The highlights of this examination are summarized _.: : below. of the camera earlier. These to develop the were surface surface
_8
_ m ,
Both extensive and non-uniform discoloration noted, including unique shadow patterns mentioned shadow patterns provided the basic background used discoloration and contamination study test plan. Discoloration with colors ranging expected. Shadow side of the camera was from patterns facing
_
_'" _i :_. _,
observed on all surfaces of the television gray to light tan. It was generally darker were discovered on the painted surface the lunar northwest. These areas overlying mirror
camera, than on the _
u
• --
i _ ;_ !-_
with surface protrusions, as wires, cables, and
such struts.
as screw heads, and The television camera
were associated parts, such was hazy.
:i:
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The shadow patterns appeared to be related uniquely to the location of the lunar module relative to the Surveyor III camera. It was assumed a result of the visual examination that the landing of the lunar module caused a severe shower of lunar dust which "sandblasted" the unshielded Surveyor III surfaces, eroding away previously darkened surfaces.
|
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|
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':'/," _ 5:, ::_: *Frontispiece Final Report; **Not included of the JPL contract not included in the in the NASA-MSC (Television NASA-MSC Final Camera contract Report. Test Final Program) Report. contract
|
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1 1 -6
I
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It should
be noted
that
discoloration
by
solar
radiation
had
been-
environment for the white expected was not to cause bleaching. expected painted surfaces. Return exposure to light would eventually cause bleaching. recommended by Hughes and JP]_, that all parts, camera, be returned in light-tight not possible for reasons of weight, vacuum space,
that of It was conjectured the air the camera in It was originally including the television This, however, was
containers. and schedule.
_t _ _._ _" { ._'. __: -_ _i :_ _ _ _ •
1 1.3
EVOLUTION
OF
TEST
PLAN
:
As noted earlier, the surface discoloration study plan underwent several cycles of changes. The process of arriving at the test plan was guided largely by the understanding of the mechanisms of damage, as it evolved, and by the applicability of the various test techniques considered. As these n_echanisms became more evident, appropriate changes in the plan were instituted. The final test plan thus reflects the eventually po3tulated n_echanisms of damage. This section briefly summarizes the evolution of the final test plan, lcadingto a summary outline of the test program conducted, described in the succeeding section. It is considered etppropriate and useful _o the understafiding of the final plan to review the factors that were involved in its development.
_:_i _ recovery discussed damage
A preliminary model of surface damage was postulated before the of the Surveyor III.parts as part of the original planning operations, in Reference 101." This earlier model considered meteroid as possibly significant and relegated lunar dust to a second-order
I
I
meteoroids were not significant; only one primary meteroid impact on the entire camera surface was reported by NASA {Reference 102). The lunar dust was found to be a significant factor, as noted in the previous discussion of visual tlowever, observations. visual effect, examination of the returned camera indicated that Based
_ :_:/ [_j_:, "
then
proposed:
on Some above, the organic
the contamination following
preliminarybeen had
damage deposited
model the was on
'
_
spacecraft prior to launch. This contamination was not removed during the cleanup operations on the thermal finish. During the landing on the moon, some solid matter from rocket exhaust was deposited on the various surfaces. The gaseous products from the vernier descent engines, which had a high vapor pressure, are not believed to have been deposited. During the landiug of Surveyor III, some small amount of dust was deposited on the spacecraft. In the course of the succeeding 2-1/2 years prior to the landing of Apollo :"References listed apart XII, ultraviolet radiation and low energy protons (1 key) degraded and
t *_,_ m
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ii
for Section from other
11 and Appendix references at the
J are common to both end of the volume.
reports
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11-7
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th_e optical properties of the surface_. The extent of this degradation = depended on the amount of exposure of each surface to sunlight, as noted in [he discussion in Appendix 3. 1.2. In addition, organic materials were deposited on the various painted surfaces of the spacecraft as a result of outgassing from_nearby parts of the spacecraft. These, too, were degraded by radiation. The landing of the Apollo XII lunar module was a major event, resulting in the showering of the Surveyor III with dust particles. Resultant shadow patterns are uniquely related to the relative location and orientation of the lunar mo ule_on the lunar surface. It was believed that the majority of the dust present on the surfaces of Surveyor III was deposited at the time of the landing of the Apollo XII lunar module.
_
W
_ _:_ 1_a _
:.
:
_ :_
_._ ;
•
C1
described.
The initial test plan was based on the preliminary damage model just This plan entailed the sequential removal of the various deposited
materials (organics and dust) by means of several proposed techniques. It_ had been hoped that this would separate out each constituent of the damage. With proper selection of surface samples, a reasonably quantitative model
== _ _
l :_ _;: -- :_: ,:
';-"
"": : •
could
thus
be constructed. techniques proposed
_ for the removal of the dust were _
. _ _ _.
The various
proposed collodioncasts,removal andnonaqueous for the of organics and ddst. removal soakwas organics of the tapes, liquidwash. Upon Solvent and dust, it was hoped that only the effects of radiation damage to the paint would remain. This procedure was to be supplemented with several analytical techniques deposited prior to, inthe used course the removal of various contaminants. These of, and after included techniques scanning the electron microscope(SEM) studies, various elemental probes, mass spectral analysis. The plan was not successful because it was impossible to separate the various contaminant levels. For example, collodion casts removed not only the large particles of lunar debris but the paint as well. Very fine lunar dust particles caught in the cracks and pores of the rough surfaces of the inorganic paint could be removed. As another example, SEM studies of the samples cut from the painted surfaces proved futile. Lunar material could not be spherelike particles.
_ --
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The final test plan developed and pursued entailed a direct analysis separated against dielectric paint background, except in the case of unique conditions, selective separation of contributory factors was accomplished by use of different techniques selected to emphasize the presence of particular sources of contamination, by selection of differentsamples exposed to predominantly differentsources of contamination, and by supporting analyticaltechnic_n_eshich were of assistance in correlating and w separating the contrib_utoryeffects.
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included
the
following
parts:
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televls;on camera: In summary, the test and analysis plan, finally embarked upon, 1) Careful selection of samples from various surfaces of the a) Separate lunar module dust effects from Surveyor dust
_: ","
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b)
Separate effects
areas
of high
incident
solar
radiation
from
areas
c)
Separate of ofno solar areas radiation possible no organic contamination of spectral technique
high
organic
contamination
from
::_ 'as (
I
Z)
Measurements a primary test
reflectance
of the various
surfaces
3)
Use of supplementary
measurements"
to attempt
to isolate
and
i
I
definethe microprobe extentofspecificcontributoryfactors: a) Ion studies for analysis b) Measurement of trapped helium
of contaminants the amount cf
!i!
to determine
,
I I IO I
c) . Measurements present Analysis: a) b) Direct
4)
,--r
analysis Mathematical effects of lunar which could
to determine
the amount
of organic
materials
i
_. .
of the analysis, dust
above
experimental by JPL, reflectance
data of the contributory
furnished to spectral
northern side of the camera apparently received a great deal of dust from the lunar module, proper while selection the southern samples had received side samples The of was of major little or no dust, Since the importance. from both sides were selected. Since one of the major suspected contributors to deposition of organic materials was the backside of the solar panel coated with an epoxy paint readily outgas, a sample of the top of the
'!,
• *These measurementS, the parallel science I assessment, these studies were
conducted by various science i_vestigators program, were coordinated by JpL. Selected furnished to _-" Hughes for possibI_ inclusion in this
as part of inputs from
"
,
11-9
ii i::
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television samples radiation. camera directly under the solar panel was included. were selected from areas of both high and low incident Similarly, solar
/i _, _'
The ion microprobe analysis of selected samples was conducted by the GCA Corporation. ;:" This technique consisted of sputtering surface materials and analyzing theoformed ions. Sputtering continued to ren_ove •material atthe rate of 400 A/min. Thus, depth profiles of contaminants such as dust, organics, etc., on the surface of the paint could be obtained.
d
_
_}
}
:; *'_': :._
_:' (_)
Direct analysis of the amount of the lunar material present on the various surfaces was conducted at SUNY. ** Lunar fines, very rich in helium, have been deposited by the solar wind over the centuries. By measuring the helium content of samples, the volume of lunar material : present could be determined for the various surfaces (Reference 11-3). Organic analysis was conducted at the University of California, Berkeley, *'_"" on samples prepared by Hughes. Experimental results have not yet been reported and were not available for inclusion in this analysis. Spectral reflectance measurements were conducted prior spectral samples, were to subreflectance as conducted
_ [_
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mittal were all also conducted outside Hughes on many of Extensive of samples to investigators tests by the other discussed in the following subsection• Some measurements at a TRW facility under a Hughes subcontract. _
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:_ ,_ i_ !!: _: _!
In addition, controlled photo bleaching and thermal exposures were conducted by Hughes on samples in an attempt to selectively bleach out the radiation damage. These experiments became necessary when it was observed that the discoloration of the painted surfaces exposed to room light was disappearing with time. This effect is also described in detail in the next section,
i
v
II.4 SUMMARY This O
OF
TEST
RESULTS a summary of the results of the tests con-
l
subsection
contains
basic dataaccordancein these studies are presented in Appendix 1I.3. The ducted in gathered with the general plan outlined in Section J.4. The bulk of the material presented here pertains to the measurements of spectral reflectance of samples of returned Surveyor III parts, as well as
|
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*Dr. **Dr. ***Dr.
F.G. Satkiewicz. Oliver Schaeffer. A.L. Burlingame.
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inorganic paint. The measurements include results obtained during various attempts tolaboratory intentionally samples alter the surfaces reflectance painted selected the control type of white of samples of control of with same by chemical, thermal, and optical techniques in order to obtain supporting by of included to the degradation theof analysis spectral reflectance. data.5PL Also the relation in of lunar dust is a summary this section of conducted A mathematical expression was derived, which, coupled with experimental data, could be used to separate dust effects from radiation effects. Further details of this analysis are presented in Appendix J. 5. A summary of the results of chemical analysis conducted
as part
of
also included. The reflectance measurements of the Surveyor III samples "submitted these investigatorsand GCA discussed are Corporation, in Appendix 6. the science to effort bySUNY coordinated J. 4,by JPL, is
11. 4. 1 Spectral Reflectance _easureme_ts
The
reflectance
of the lower
shroud
of the telewision
camera
was 5,
•
:
these numbered positions 6, and 7 were on the side
are referred of the shroud
to as "TRW positions". facing the landing site
Positions of the lunar
,,-,._._ '!:::_1-,_' ": " : • " ,. _:!_"i _ :¢.:,,,:".,,, ;{i [
the
The reflectance of the lower range from 0.3 to Z. 6 microns.
shroud was measured The technique used
in April 1970 over was substitutional,
cutting reported
was prohibited at where in this document that time.this These are the only measurements technique was used. All other
measure-
integrating taken in of of ments were sphere. by The data the:sample this seriescenter tests a are self-consistent made placing at the Gier-Dunkle first measurements were approximately 5 percent high.
_ ._:: ,_ _._ _ _Ti'_']
,
A decrease in reflectance over original values at 1.5 microns was found on most surfaces. This was not seen on TRW position 1 of Figure 11-1. This location was protected from _.he lunar environment by a bracket, whose photographs are shown in Appendix J (Figures J-19 and J-_-0). Laboratory studies have shown that neither ultraviolet nor solar wind protons will cause Thus, the attributed for this clay-silicateOrganic to lunar dust. contaminants a reflectance reflectance decrease drop I, is5 microns at inorganic paint. were ruled out as d,scussed later. The variance in the magnitude of the reflectance at I. 5 microns is a measure of the amount of lunar material present on the surface. Table I I-I summarizes the significant results obtained. An expression relating dust coverage to the reflectance is presented in Section 11.4. Z.
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Figure 11-2. WhitePainted Vor.u!_mReturned "_'ube FromMoor)inSESC Quartz Section in Chamber {Photo 00646-292)
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11-14
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Measurement An important tubc sample
of Tube spectral returned
Section
From
S._SC
painted
reflectance in vacuum
test was planned for the white by the Apollo XII astronauts. This
tube was collar from one of the tested support cu.t and was to be struts in vacuum of the tripod andbracket inofair. then the camera However, leak was found in the SESC. The proposed test was conducted even thougl_ • : ", '_ t-_ ''_,I'_" _!. ii!! Ii _' __, _ _. _-] _ The whiteno painted found the SESC a section in was transi_ could longer tube assumed inthat the partwas cut, andreturned be had been vacuum. ferred to a quartz vacuum chamber made light-tight with an external shroud. This is showniu Figure 11-2. The transfer was accomplished in an argon - of the white painted the tube was chamber measured was then evacuated. 10-7 The reflectance in vacuum (1 x Tort), in atmosphere, and quartz partial vacuum, and then at 1 arm. Several days later, for the first time from since ultraviolet.to earth, reflectance waswas then return Its the tube exposed remeasured. for 48 hours to bring ligh_ free
:.
No effect was noted on the reflectance as a result of the increase in pressure, first to 12 microns and then to 1 arm. This is consistent with earlier work by Hughes and others which indicated that this paint did not exhibit atmospheric bleaching. Had the white painted tube been at 1 arm previously have been as noted a result in this of the test. leak in the SESC, vacuum bleaching would not o¢
-? _ :-_ _
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:,-
_ '_ ;;_
No white light was allowed to strike the sample during these tests the white painted tube section. When light was necessary, low level red illumination was used. Any photo-induced bleaching could thus be studied under controlled conditions. The photo No bleaching bleaching test was conducted while the tube was at 1 arm.
:_ _ :_
•q,
occurred
at 1.5
microns,
but an increase
of approximately yellow when a dirty gray a uniform is
_ercent from foundmoon, 0.4 lost it_ yellow appearance was the at micron. The tube, which and turned was dark returned over the half exposed tu the white light; the other half reamined due the bleaching the radiation dark toyellow. photoThis increase of in reflectance '_ _ '):_ .." damage (i. e.,
.__ _ _: :_
_5
Within the paint. loss of yellow color)
No additional work was done with the tube. It was exposed briefly for photography (photofloods} at_d then returned to its light-tight container. Test_ of Section of Camera Tube Stored in Dark support 1970
•_'_ ;::
collar. ! _
A parallel experiment was conducted on another tube from the Thi_, collar was removed from the camera at LRL in January
':
dark storage, and a section of the tube was cut off. and was immediately that stored inyellow dark. two regions the this tube revealed it was with The collar one dark yellow and the other gray.
Visual examination of was removed thefrom the parallel to ax_s --
_ _
|
11-15
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.¢:_, _. ,;_. "": .,".' "The tests conducted on this tube are discussed in detail in
Appendix J. 4, 4. The tests consisted of measurements of spectral reflectance before and after the following two consecutive operations: a carbon tetrachloride soak and a thermal bleach. Results of these measurements, summarized below, are discussed in Appendix J and plotted in Figure J-25 for the three regions of the tube (gray, light yellow, and dark yellow). It is recognized that "some changes in the values of reflectance obtained in successive measurements may be attributed to the loss of lunar material or to the failure to perform the measurements at identical sample positions. The carbon tetrachloride soak was performed in an attempt to remove
r_
'-: ._ • Li] ::i_ ,'._: .:_
organics increase from small
the reflectance. in surface.
Measurements results after.thethis Thus, of
soakingindicated revealed either very a test an of such Subsequent material on
_
absence of organic materials or, at the very least, the absence organic materials that were removed by carbon tetrachloride. ion microprobe tests conducted at GCA indicated little organic the surface of the camera. Additional mass progress as part of the science investigation spectrometer may shed
U
tests now in further light when
D
g
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A thermal bleach test using this tube section was then conducted. The tube are reported. section was raised to about 430°F for 18 hours in air. Remeasureresults ment of the spectral reflectance indicated a significant increase in reflectance in the visible portion of the spectrum. The yellow color disappeared and the tube appeared dirty gray-white, similar to the tube that was photo bleached.
It was also noted that following the thermal bleach, unlike the photo bleach, the reflectance increased at wavelengths longer than about 1 micron. This is not surprising. The same increase was found at wavelengths longer than 1.3 microns in similar laboratory tests of unexposed Surveyor inorganic white paint. The increase can be attributed to the loss of water, loosely bound within the silicate structure. in an attempt to remove of the white paint, leaving not appear that 18 hours the only at u !
effect
These bleaching tests were undertaken of radiation on the optical properties of the same white paint, it does
of a sample :'!ii! :",
|
the dust discoloration. On the basis of the laboratory ultraviolet exposure 450 °F is sufficient to completely bleach out all the radiation damage Tests at higher temperatures were not conducted. Effects of Thermal and Photo Bleaching
I
lIB
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•.
It is apparent from the observed gradual bleaching of the lower shroud of the camera that a complete isolation of the returned materials from light and excessive heat was required. When this apparent lightening of color first b'ecame apparent, it was tentatively attributed to a gradual loss of deposited lunar material, or to bleaching of the paint. Optical measurements made as late as November 1970 showed that the reflectance
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at 1.5 microns remained nearly constant, indicating that very little lunar dust had been lost. The lightening of the surface must therefore be attributed to photo bleaching of the paint. cable bracket magnitude the of this was clearly from lower shroud was examined. ThisMay 1970 when been bracket had The establisbed in the kept dark since its removal from the camera in January 1970. Photographs same brownish and lowercolor. yellow in May the that appeared of the bracket shroud However, showed at that time shroud both had the grayish white, while the bracket retained the brownish color previously noted.
:" _ ;: _ _ ,¢ _ :_: --_. -_ J
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Samples cut from the lower shroud were exposed in November 1970 to the thermal annealing test conducted on the two tube sections. No increase in reflectance was observed. Time-dependent photo bleaching by arrbient (room) lighting had already raised the reflectance. This can be seen in Table ll-Z, which summarizes the results of these tests. Very little change with time occurred at 1.5 microns. It is surmised that the reflectance at O. 4 micron at the time of return from the moon must have been still lower than Z7 percent, the value shown in Table 11-Z for the April 1970 measurement. Based on the measurements of the tube r_turned in the SESC and the bracket which had been previously exposed to light, the reflectance is estimated be noted that this about Z0 percenttakenat the time regionreturn to have been should sample was from a of facingto earth. east, surface which was exposed to maximum solar radiation. a It
, _ _ _"_ r_:_ :_
Four samples were cut from the cable bracket (also facing east) in May 1970, and their spectral reflectance was measured. The samples were then returned to dark storage until August 1970 when the spectral reflectance was remeasured. No increase in reflectance was found. The spectral reflectance was remeasured in November 1970 after additional dark storage. There was still no change in reflectance. It therefore appears that dark
I_,
i_ _' _ O I2
Two samples from the cable bracket were then exposed in November storage preserved the optical conditions for many months. lighting of a laminar flow bench. The intensity of the light at the unprotected sample surface was Z00 watts/cruZ. One sample was protected by 1970 to the same light as the television camera, i. e., the fluorescent of polyethylene. clear The polyethylene film simulated other condition teflon which 0.01Z inch the by the in 0.00Z inch of teflon FEe and the and the television camera was maintaihed from the time of return until 6 January 1970. Actual room lighting conditions during the storage were not known. The light intensity reaching the samples was about 170 watts/era 2.
i'_
The spectral reflectance increased about 1 percent after 7Z hours of an increase to the light. inreflectance After of 17 days, 13 percent significant micron at 0.4 for both samples. with exposure bleaching occurred, This experiment may be interpreted to mean that the television camera probably saw very little light during its LRL quarantine period since the camera was quite brown when first viewed in January 1970.
11-17
; f'..t_
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A set of experiments was conducted to further assess the effect of thermal soak on reflectance and to determine the role attributable to the presence of oxygen in this process. Results are summarized in Table 11-3, with additional details in Appendix J. 4. Laboratory samples previously exposed to ultraviolet radiation and a sample of the returned Surveyor III camera exposed wcretested. in vacuum .18 hours at 450°F. TableAll 11-3, of were and As seen in inair. some thermalsomesoaks the samples were performed for
:
-_
Thermal soak in air of the laboratory samples gave results similar to those obtained for the returned lunar sample. While some restoration of reflectance was produced, exposure in air for 18 hours at 450°F did not completely restore the optical properties.
__:i.
when the laboratory and the lunar samples were thermally exposed in seen in Table 11-3, both samples an entirely different was vacuum. As The reflectance of was found resultdecrease obtained to significantly. Measurements of reflectance following the thermal exposure in vacuum were had been air. to in vacuum, ofsample, its reflecmade in subjected Subsequentheat thermal soak resulted of in restoration in air the laboratory which tance to the same values obtained for the sample exposed only to air and heat. This can also be seen in Table 11-3. Reduction is not understood. of reflectance as a result It was originally thought of thermal exposure that the reflectance in vacuum of these
I
I I
samples depleted. would rise For that significant; results
as the electrons of oxygen was not considered (color centers) were thermally reason, trappedpresence the of thermal exposure in air and in vacuum had been
I
I
unexpected to result had bearingthis onwas not the case. the surface discoloration expected be identical. no direct Evidently, However, and this contamination studies of the returned samples. This result may be unique to the clay-silicate paint. Further tests may be warranted if it is desired vacuum. to explain the results of thermal bleaching in 1I.4. Z Analysis
I
The discoloration model postulated due to a combinatio,, of two effects: solar
that the radiation
loss of reflectance was and surface coating by
IO
when the of incident dust. light passedlatter through the dust spectral andreflectance after reflection a layer lunar The reduction of layer occurredof the light from the painted surface in transmission through the dust.
a
I !
at lunar attempt to derive mathematical expressionAn analysis contribution for the was conductedof the JPL to dust to the overall decrease of reflectance. Results of this analysis are described in Appendix J. 5. As
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shOWneffectivelythere,expressed'the measuredas
reflectance
at
any
one
wavelength
can
be
Prn
=
90
D (1
- KAd
)2
:"
_
where
, _C!_ _+. i.? _}i "i:_ t_
Pm Po D
= original = measured = ratio and of
spectral spectral reflectance
reflectance reflectance of (other determined surface than
of of surface painted degraded dust) constant to
surface by Original of solar radiation reflectance wavelength)
_'_ :_
,,'-*. __ ',_" _ ,
contamination
K
= experimentally
(function
.,.!_._
A d
= fraction
of area
covered
by dust
_,: _ ,_ -,: "_ _, ,_}_ ,_
the To the
Using the effects of dust do so, the measurement spectral An example
above from
expression, those due
to
it is possible radiation and
_o separate contamination
analytically (term
D). to the
"_ ,_ !
factor
KA d must be determined of the final spectral reflectanoe
experimentally and the
in addition knowledge of
original
reflectance. of the results obtained by this technique is shown in
! '_ :_ ., ' ,_ '"_ 0 _' !_ _,
Figure B 11-3. A shows reflectance the original o.f one of the of the paint, the returned reflectance and curve shows Curvemeasured the samples of ::_ Surveyor III camera. Curve C shows what the reflectance of the surface of the sample would be if the dust were removed. Thus, curve C indicates the degradation caused by radiation damage only. Similarly, curve D shows what the reflectance of this sample would be in the absence is apparent of radiation from the
,_. : i:. , }
._
damage It should be noted that by dust only. and with degradation the same evidence
for the two samples, shown in Figures J=10c and ff-10f,should be compared measurements discussed Figure 1I=3. Figure J-10c applies to the obtained with the results shown in in Appendix ft. 4. I. In particular, results samples
"i ,
!il
wh°s e reflectance degradati°n is pred°_minantly attributablet° radiati°n'
_
_I
k_Designated
as 521 in Program
Test
Log Book.
11=21
... • . . ... . .. ..4 ;.. _..
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90
_
80
70
-"ua'_r"
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* A) REFLECTANCE MEASURED SURVEYOR C) OF ORIGINAL OF SAMPLE WHITE-PAINTED RETURNED SURFACES
"
30 20
m
U I1_
REFLECTANCE III CAMERA
AFTER REFLECTANCE SEPARATION OF RETURNED OF OUST (RADIATION DAMAGE ONLY)
EFFECTS SAMPLE
REFLECTANCE OF RETURNED SAMPLE AFTER SEPARATION OF RADIATION EFFECTS (DUST EFFECTS ONLY)
i
1.0 1.1 1,2 i n
'°
B
0.5 0.6 0.7 WAVE 0.8 LENGTH, 0.g M IC RONS
C_
o
0.4
il
I
Figure11-3, Separated Radiation and Dust Effectson SpectralRsflectance, Whiteinorganic paintedsurfaces ofSurveyorIII camera
ll-ZZ
I a I I
,
,
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,
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:
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,
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while
Figure
if-10f
applies
to a sample
primarily I1-3c
degraded illustrates
by lunar the photo
dust. bleach-
Comparison "of Figure in J-10c ing effect described Section and Figure 11,4. 1.
r _ _ _
Results of Related Investigations As described earlier, the surface discoloration and contamination studies utilized to the maximum extent possible the results of the effort conducted as part of the parallel science investigations under JPL coordinaLion. Results of these investigations will be reported separately.
11.4.3
[]
Some of the results obtained by using inputs available _he science investigators are summarized here. Table 11-4
to date from compares
:"
returned Surveyor II1 camera. The samples include surfaces covered by inorganic _btained pain*, as well as a polished a aluminum of surface white results by several techniques for number samples from the from the bottom of the lunar shroud. This particular comparison, shown here as an lunar dust relates at several the calculation This the fraction locations. example, to of calculation reflectance measurements as the basic raw data. in Table 11-4, location A is taken as a reference. compared helium the analytical are trapped experiments work conducted at GCA. technique conducted described at SUNY, was the area using total by of made covered For each technique listed The three techniques in Section and the'ion 11.3. Z, the microprobe
i
With the exception of the value obtained from reflectance analysis for location D (polished aluminum), the results in Table 1 1-4 show decreasing amounts of lunar dust on the various surfaces in the order shown. An microprobe additional highest exception dust from ion indicates coverage on location data,, for not depth less Table 0.4 nai:cron. B a shown in than 11-4, location computed values from Appendix The values ft. 5, using forexperimentally D weredetermined surfaces. The polished aluminum is a smooth surface Equation f?r _; Of K k painted" and - _pecular o:
_
the assumption K k is an undetermined amount. T_us, reflector, while of equivalent the painted surface inis error byand a diffuse •_-eflector. rough Determination of K k for the aluminum surface and resolution of the apparent inconsistency would not alter or improve the understanding of the discoloration. If warranted, additional measurements could be made in the future. Since KZ and K 3 of Equation 1 in Appendix J. 5 are proportional to
of transmission B shown Table not inconsistent with the fines for location through(notthe lunar inparticles, 1I-4) is apparent the heavier coating reflectance determinations: the smaller particles would absorb less light.
*It was possible polished surface
to determine from scanning
Ad as equal electron
to approximately microsopy.
0. 14 for the
11-23
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1 1.5 11.5.
DAMAGE 1 General
MODEL Assessment
and contamination studies, and to date of An overall assessment initiated results conducted of with s_rface of the an awareness discoloration the complexity of the problem and with due reservations, can now be attempted. It is believed that a reasonably good damage model has been obtained within _ i ::',; _:_ _ _:
J/
the limits
of the scope
of this
program that
and the time
available. of the surfaces of the of two both from the
The model returned dominant There Surveyor effects: still
proposes
the discoloration
IlI hardware is attributable radiation damage and lunar inconclusive evidence
to a combination dust, the latter
_#,_ "$; i£_ i __ _
is some
of organic
contamifiation,
but its
m
original Surveyor the landing discoloration the is landing and from the contribution to total believed of to beApollo lunar module. minor. The camera painted surfaces showed an overall dirty color in varying degrees, shades, and tones. This variation is the resnlt of the twc contributory effects: radiation damage to the paint and lunar dust coverage. While some areas are primarly affected by one or the other source, the of areas indicate varying contributions from both sources. The contribution attributable to radiation damage is proportional to the extent of solar exposure experienced. The dust coverage was signifigreater cantly than originally anticipated. Interaction of the lunar model descent engine with the lunar terrain disturbed the surface material and caused a major interaction with the Surveyor spacecraft even though the landing site w_s over 500 feet away. The proposed model has been majority
D
g
g
quantitatively
demonstrated
to be a
g
surfaces. The modelonehas not been selectedtested fully all the surfaces in reasonably corr._ct at several areasfor of theof affected Surveyor III order to synthesize the total complex discoloration pattern. Further investigation may be warranted if the additional degree of detailed knowledge is desired. information Science of value studies to this currently model. under
way may
B
yield
additional
The dust effects on operations. be or"value for future lunar reflectance for the specific thermal coatings used B have
and the radiation interaction lunar effects The damage informationmay on the Surveyor was not expected to
I I ! I
a significant impact on future space or lunar operations. A summary discussion of t_.e above contr-:buting factors in the remainder of this section.
is presented
11-_5
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1 l,. 5.2
Effects
of Lunar
Dust
:_ %.:;i " :!
With the exception of one small area designated in Figure 1 1-1 as TRW position 3, described below, all exposed surfaces of the camera had a coating of fine lunar material. The amount of this coa!ing varied from area to area: the "dirtiest" area was estimated to be about four to five times more heavily coated than the "cleanest" area. The varicus sources of lunar dust are listed in Table 11-5. These variations in the degree of cleanliness may thus be attributed to the quantity of dust imparted from the various sources to the differences in the adhesion of the dust to camera surfaces camera rougher addition, and to the various mechanisms of removal of the dust: prior to retrieval, during return, and during subsequent handling, n areas there tended some hold more was to variation in handling. material in surface during deposition the and during roughness of paint; the
E
['! _
disturbances
As discussed in Appendix J. '_. 3, the surfaces on the northwest side of the camera exposed _.o the lunar module landing site were substantially lighter than the immediately adjacent areas protected by projecting hardware such as struts. This difference in color was largely due to the removal of adhering lunar material from these expos.ed surfaces probably by the "sandblasting" effect of material disturbed by tb_. lunar module (LM) landing. These lighter areas on the LM side were darker than the overall color of the opposite side of the camera (away from the LM, facing southeast). Analysis indicated that less than half as much lunar material was present on the side away from LM as on the sandblasted areas facing the LM. These differences may be the result of one or more of the following: a much higher initial coverage on the LM side (Table 11-5, sources 1, 2, or 3a), incomplete removal by the LM effect of sandblasting, and deposition of particles disturbed by the LM, arriving later (Table 11-5, source 3a). The front of the lower shroud showed slightly less dust than the sandblasted parts facing the LM but still approximately twice as much as the side away from the LM. The differences between front and sides, toward and away from the LM, may be due to differences in g:ometry or adhesion during sources 1 and/or 2 (Table 11-5). The side of the camera's lower shroud away from the LM landing site was in the view of the approaching O LlVl, until the of _00 to several LM was 300 feet. hundred front was exposed final alanding angle snd feet east of its site at an altitude The at small with respect to the location at which the "first visible dust" was noted. This is discussed in Appendix J. 1.3 and cau be seen in Figure .I-4. Although it migh,', be argued that all of the contrast was due to dust stirred by the approach of the lunar modules, the absence of localized ssymmetry around protrusions on the side away from LLI indicate_ that the coatribation from LM approach was minimal on that side. It is not possible to conclude that the LM contribution was minimal on the front.
U
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11-26
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Number 1
TABLE II-5. POSSIBLE SOURCES OF CONTRIBUTION TO DISCOLORATION Possible Surveyor landing Source
DUST
i_
Z
Lunar transport from meteoroid
(i.e., impacts) secondary
debris
i_. .":'_! _'_] :j " ".'_ " " _-
3
Lunar Approach a) module b) Final descent effect) ("sandblasting"
-. ._-_ -. _... • :-j":._ 4
1- :%"-: : .
c)
I_te arriving descen _during
fines
from
final
Redistribution
return
and handling
.....,._
highest
The camera concentration
hood the top and the dust than the the LM. shroud, paint in on showed more side facing lower The with the
i ..:!
J
dust more effectively. However, particles from any of several sources with a high ballistic trajectory, sources 1, Z, 3b, and 3c in Table 11-5, would deposit top this area preferentially had a rougher ontexture,of the hood. would tend to trap and hold deposited which The Comparison mirror was known to have been dusty and/or pitted after as a result
of the amount
of dust
present
immediatei/
the Surveyor
_!_
of the as part of the parallel Surveyo_ landing of J. study abnormal science III, as discussed and in Appendix investigation vail be reported 1. Z. separately. Any increase noted would be the result of sources Z or 3a in Table 11- 5. II_._. _ to that the time of from LM, of the is A small present onatthe side away the retrieval designated camera TRW under area as position 3 in Figure 11-1, appeared to be free of dust. This area was beneath the cabledust may be due the "shadowing" running from Tbe absence of to front, along incident dust or caused by a removal mechanism the the surface.fromthe camera. of of left,side the not fully understood, $ landing
I
!
I ':Seen NASA-MSC the in the frontisiAece Contract of tLe JPL contract Final Report. Final Report; not included in
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Preliminary examination of screws _rom varicus parts of the camera showed quantitie_ of lunar material that were in general agreement with the amounts on the painted surfaces, discussed above. These examinations were informative since the dielectric lunar material could be identified on metallic surfaces but not oi,the dielectric paint. The screw head surfaces, partially exposed to the LM sandblast, showed asymmetry in dust coverage, with less material on the exposed than on the shadowed portions. Screws from the opposite side of the camera showed less material than the sandblasted surfaces. These studies are being pursued as part of the science tests. They have not yet been completed and will be reported separately. Shadow : patterns due to dust coverage are not apparent on the side of
_._
_ [._
the lower asymmetry away they are significant shroud Sources 3a, b, and c to dust coverage. would in Table 11-5 produce if from LM. contributors Asymmetry is not obvious from the examination to date of the screws from this side of the camera. "Redistribution of dust (source 4 in Table 11-5) did not appear to be a major factor. The lunar material on the side away from the LM landing site was therefore most probably the result of the initial Surveyor landing although lunar transport cannot be totally disregarded.
W
_ _ := :_
• _ : : ;
Organic One of the Contamination the study was that the contribution findings of of organic contamination to the discoloration appeared insignificant compared to the radiation and dust effects. Some evidence of minor organic contamination on some surfaces was reported in the parallel science studies, as noted in Reference 104, but this was not believed to have a significant bearing on the overall assessment presented here. Sal_ples are still being analyzed for organic materials by science investigators, and results will be reported separately when available. It should be recognized that the organic contaminants, even if sma.q enough to be of no significance to the discoloration of the Surveyor III camera, could be important to the design of optical instruments for future maySpacecraft'thereforeAnalysiSbe required.°f their presence and identification of their sources
l l.5.B
_ _ _
.!_ ?_
:_ ,_ -_ F_ =_ _ _ _ U _ _ I_ _
,_ '_' :
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:_
I 1.5.4
Radiation
Damage
• Radiation damage to the white paint was originally anticipated t _ be a major factor in the discoloration of the surfaces of the Surveyor III television It was expected bear a direct that the solar relationship absorptance, to the degree and hence the amount camera. of discoloration, would of solar ex_posure determined.by the geometry of the Surveyor spacecraft on the moon. However, the patterns expected were not evident during the initial examination.
ii
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11-28
I !
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.
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m
B
:,.:." :;;_;.._.. __- _ ": _ As reported _=bove, it was reasonably possible to isolate by from to to
measurementreflectance analysis and the contributions the total from the painted surfaces. .of the lunar dust it coverage This made possible separately analyze the._ patterns of discoloration and damage attributable
the discoloration in paint attributable Figure radiation to is verified solar radiation only. the As illustrated in 11-4, iteffects then indeed prowas that portional to the degree of solar exposure. The two locations on the lower shroud of the camera, positions Z and 5 in Figure 11-4, correspond to areas of near-maximum and near-minimum solar exposure, respectively.
• _
B
z n, bl _ O
o.,
0.8
.
6
_ W 0,7
U W ¢C 0,6 _ (AI SAMPLE FROM TRW POSITION NO. 2 (SEE FIGURE 11-1) (S) SAMPLE FROM TRW POSITION NO, 5 (SEE FIGURE ll-1)
o 0.4
0.6
0.8
1.0
_}
Figure11-4. Effectof Radiation Spectral eflectance on R Camera(Contributionsof Lunar Dust Removed ofWhiteInorganic Painted urfaces Surveyor S of III Analytically)
WAVELENGTH,
MICRONS
_1
.|
11-29
f-r
_" . +- •
. •
. "
.'.
:
_j_
APPENDIX
A.
SECTIONING
OF
POLISHED
TUBE
11
3
_s'2- 1 •
.
_a-:_':
-._.
/;"
identifying,
scribe
lines
and
letters
were
made
on the
tube
to provide
an
,:_" _ • ': _.. ."-_ _ :
IC.
orientation Duringreference, initial and examination was ofsectioned. the tube + the the polished tube at MSC, The polished tube is sketched in Figure A-I, which indicates the identifying scribe lines and the lettered segments subsequently sectioned. The tube ends were pinched during the hmar cutting operations into oval or pear shapes, as described in Section 4.5. Z. Two scribe lines were made on the tube close to each other, one light and one heavy, from apex to ._pex. Only one of these lines is indicated in the figure. The two scribe lines cross each other several times; in some places, there were separated
""_: I ::.:.-_=: :/,,-v: i
-"V.-;._ I identifying • !:!i! I
The
six sections letters for
into which each section
the tube marked
was then sectioned and the on the polished tube prior to the identifying section are also
indicated.muchas Figure A-Z* is a the byas 1/16inch. in Figure photograph The of lengthstube of after sectioning are shown A-1. each marks were made and prior to its sectioning.
/StmRE _aK
i,_i:: I It.., '
I
-@ _@_-' _ r-"' ,.o ,.,, "° "° -"'--i 44--4++
DIMENSIONS IN INCHES
Figure
A-I.
Sectioning
Arrangement
for Polished
Aluminum
Tube
-k:i,: |
| *
:, A-I
_i I
I
r_
o.c
U
0
d
.,(3
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or...
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.LUNAR
o _
/
A-4-_A-'_-o
/
/
IOW'ARD LUNAR
|
I
,I
'_ '_
A, 4.3
i
Figure A-3.
_:_ _
Section A of Polished
A-I,
Figure A-4.
Section A-4 of Polished
Shown in Figure A-3, Segments Removed
J
Aluminum Indicating Removed
Tube Shown in Figure Further Subsections at Hughes
Alun-,inum Tube Showing Further at Hughes
•
}.
\5 ' _
,ow,,.0,u,.,,,.
cui ZND
l_
•
Aluminum Tube Shown in Figure A-I, Indicating Further Subsections Figure A-5. Section G of Polished Removed at Hughes
Aluminum Tube Shown in Figure A-5, Showing A-6. Further Segments of Polished Removed Figure Section G-Z at Hughes
Sections I_ i ,,.,t _ t:,L
:,':_','.,;
A and G were
transferred
to Hughes
for
the studies
reported A
scientific investigation. During subsequent analysis Hughes, sections in this document. The other sections were distributed at elsewhere for and Qwere eventually subdivided further, as indicated Ln Figures A-3 through A- 6.
'_i_ _
,¢ .,'%'1 t
A- 3
:7a
_: _r, i t
!
t:
APPENDIX
B. LIST OF CONTAINING
LABORATORY TEST DATA
LOG
BOOKS
}Iughes Journal
Technical Nunlber
Title
F F F F F F F N F
1762 2287 2640 2639 2285 2288 1764 2453 2290
Physical Chemical Chenlical "rv Cable
Properties Properties Properties
Painted Polished SM/SS SM/SS Dust
Tube Tube Scoop Scoop Coloration and Contanlination Study
B-I
._'-'_
, _
_.....
.. _
7." ".'" .' '
2 , ,-
i,' :
.'
"
"
:°
"
:°
APPENDIX
J.
SUPPORTING
DATA
FOR
SURFACE
EFFECTS
STUDY
_
J.
1
BACKGROUND
DATA
ON SURVEYOR
SURFACE
CONDITIONS
! _
__: B
J. I. l
Prelaunch Surface ANDLANDINGOPERATIONS History Surveyor III underwent
of Surveyor testing tests
III prior to launch during vacuum
extensive
,_ ,_
which
it was
exposed
to thermal-vacuum
in an oil-pumped
_ i_
_A [_:
the TV chamber camera (liquid on Surveyor In vacuum testing contaminants before
was not ontrapped).spacecraft. the The nitrogen For almost in February 1967. The camera in a similar vacuum chamber• types to deposit on the
flight camera was placed all of the prelaunch testing, also underwent thermalThere were opportunities for prior to launch. held just at this .._ _ .,
of many
camera
_._ I
Athermal control surface launch. Repair of damaged
inspection and paint surfaces
rework were was conducted
discoloration of these time. These repaired and always appeared spots was an organic paint used on the The t_ _i r'- _7. -, _ '_ "_ _'_' :" _ •_ clamp rest
spots was different than that of the surrounding paint spots were found upon return of the camera. The lighter in color. The paint used to coat the repaired white (TiO z in an acr,/lic binder), not the inorganic of the which camera. the camera in place provided a unique spot to
held
procedure observe the forapparent inorganic the effect of the white to remove the visible contamination.
paint prelaunch was to lightly contamination, sand The back side of the
theThe cleaning so as surface clamp had been
". '_
partially clea'ned in this manner and was not repair, ted, It was uniform in whiteness after cleaning, Upon return of the camera to earth, the cleaned spot was seen to be lighter in color, and where the sanding had stopped the discoloration became deeper, This difference in coloration is attributed to prelaunch contaminants (probably organic) on the surface of the unsanded paint that discolored to a greater degree upon exposure to the lunar environment. *
• This study
observation and should
is
in conflict
with further
other
conclusions future
of the
contamination
be examined
in possible
studies.
J-1
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--
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_" REPRODUCIBILITY .... _., .... OF THE ORIGINAL
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The Surveyor IIIspacecraft was l_-nehed 17 April 1967 and landed on the lunar surface in the Ocean of Storms 20 April 1967. The landing longitude. determined mission site as The from details Surveyor and data was 2.94°S scientific results, latitude landing and site, 23.34°W etc., are described in detail in Reference 105. . _ :_ :L _i:.: (_ ;_:" ._,_, _J] :_:-_: The vernier engines remained on through the first two lunar t6uchdowns of Surveyor III at a thrust level equal to approximately 90 percent of the spacecraft lunar weight. This caused the spacecraft to rebound each time from the lunar surface. The vernier engines commandapp:.oximately 1 second before not rotate the third craft came to rest. The spacecraft did The uphill leg (Z) impacted first on e_.ch landing. were shut touchdown, during this down bY ground andthc cnancuver. space_
'-_
There were of anomalies analog telemetry the thermal data after landing of which required use a correction inthefactoi" to establish status spacecraft precluded comparison the and accurate with pos't-return conditions. Within the limits of the accuracy of the data, Surveyor III appeared to react thermally like Surveyor I except for some differences that could be attributed to landing orientation (Surveyor III was tilted and in a crater). Within the limits possible, there appeared to be a "lack of any thermally significant dust on the compartment faces" (Reference 105). Thus, the presence afterglare landing be ruled except of dust immediately veiling as indicated by and can neitherattenuation contrast the Surveyor III mirror. out nor observed verified for
Surveyor III came to rest on the sloping wall of a crater about ZOO meters in diameter and 15 meters deep, The spacecraft landed on the southeastern wall of the crater almost halfway between the center and the .. rim mean elevation mean the rim crest, the The spacecraft The of foot pads was the crest. of elevation toward the center of the crater at an angle somewhat about tilted very below 7 meters was nearly steeper than the mean
graph. Figurethe crater wall, orientationoi Stxrveyorand the cover photolocal slope of ff-Zshows the as seen in Figure l-I IIIin the lunar crater. _"_'.:,:_i _,_,_' LJ " The spacecraft's camera mirror assembly was rotated through a series of azimuth positions (and the camera mirror rotated through multiple elevation angles) during the TV photography sequence. Thus, the exposure of the mirror assembly to the various elements of the lunar environment sures this operation was really" complex summatior of No effortwas during during the various azimuth aand elevation positions.its individualexpomade 'o analyze this portion of the exposure because itconstituted such a _mah part of the totalexposure of the camera to the lunar environment years during the g-l/Z it remained o_,the moon.
$-3
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",._.
_
NORTH
o
O
• : LEG NO. 3
TV CAMERA (LOWER SHROUD)
g
_!_, MIRROR VIEW t EAST
• •
TO LM LANDING SITE
" "'_ (._" •
DOWNHILL SPACECRAFT SLOPE
LEG NO. 2
LEG NO. 1
U Figure Orientationf Surveyor inCrater J.2. o III
The on the Surveyor horizon last iII pictureilluminated was taken by_tthe setting sun. -39 degrees azimuth of a feature eastern Following this picture, the camera was stepped 4 or 5 times in elevation to the command either -Z8 or log). An additionalexpos-,re was commanded -33 degrees elevation position (there is some con£usion in in this position but, as expected, showed no image of the darkened lunar surface. The the lunar IIlspacecraft 1967, 14 days after touchdown. Surveyor night on 4 May was a ,parentlyin good condition when secured for No major everts occurred in the adjacent area during the Z-1/Z
R
i
I
years that significant IIIfactor. on the moon (Reference during the recovery was 106). Micrometeoroids the were not a Surveyor Photographs taken of camera indicate sharp outlines of the imprin_ of Surveyor III landing pads i: " i f _,., _ and the SM/SS trenches, with no eros'on noted. The camera was installed on the spacecraft skewed with re_pect to the spacecraft vertical axis the spacecraft tilt (~IZ degrees), axis of 23.5 degrees with respect west of north. The plane of the camera was nearly vertical and north. The -39 degree azimuth "lookiug" a few degrees (5 to 15 I with its vertical axis and this. combined with
produced s tilt of the camera vertical to local vertical in a direction 43 degrees flat front face of the lower shroud of the faced approximately 43 degrees east of position of the mirror assembly left it degrees) north of ]_cal east.
|
.,
,_ _:, _
A scale model of Surveyor was set up at JPL for a photographic sequence simulating a lunar day. The model was set at a tilt and position duplicating the Surveyor III attitude and orientation on the crater slope. 3,.4
! !
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Figure J-3. Shadow Photograph Surveyor Model, imulating of Ill S [j Moduleo Position fSunat 10Degrees Position (Photo 211-4068B) unset_ Before S Viewed fromLunar
-_
?
_
_] "
A collimated sun was a_ such that it Surveyor the same relative path model the model orierthetedreal sun over traversed over Ill. Photographs were then taken of _he burveyor model at three different viewing at 2 degrees Photographs locations. after sunrise were made at sunset. 10The series of of photoEraphs and before every degrees sun elevation is available from JPL (photographs Zll-404ZB and Zll-4046A through _ ZlI-4073B). arid
_
_
L_
_
_C i.._ _J
Figure J-3_ is one photograph from this sequence. Viewing position is from the luz_ar module landing spot with the _un at 170 degrees (I0 degrees before sunset). J. I. 3 Lunar Module Landing
erence 107 and summarized in Figure J-4. The. Apollo la_:aing al_proximately 53_ feet northwest of the SurveFor spac_,.-r_ft,.
"
site
was
iili I
H,
The _T.ollo
Xll terminal
descent
is described
in detail
in I'-_--. " _ U .....
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Fig,:re J-5. View of Relative Locations on Lunar Surface of Surveyor Ill and Lunar Module (NASA Photo AS12-48-71001
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J. Z
VISUAL The first
OBSERVATION indication that
OF
DISCOLORATION discoloration had occurred on the
severe
surfaces of Surveyor III came during the visit by the Apollo 12 astronauts to the landing site. To them, the once bright white paint and shiny polished aluminum appeared a uniform brown. The spacecraft condition described by the astronauts from the moon did not appear to be any different than anticipated since radiation, discoloration, and some dust coverage were expected in the white paint, as discussed in Section J.3. This aluminum silicate (china clay)/potassium silicate paint did not have superior radiation stability. However, when the parts were returned to earth and viewed for the first time, it was realized that the surfaces r'ere extremely discolored, more so than could be attributed to radiation camage in the paint. (]ii) -' conditions Prior to the Surveyor on return of parts III could parts recovery, be achieved: itwas hoped that two 1) to return parts in total
-: _
/_
U
_ _ _ ,: ./ 5 ._
darkness and Z) to return parts in vacuum, Except for a piece of painted tube and a cable section, these conditions were not possible because of weight, space, and schedule commitments. Therefore, the parts were returned in November 1969 exposed to air and some light. At the LRLin Houston, the parts were removed from the astronaut's backpack and, after a brief viewing, were dGuble bagged in heat-sealed polyethylene. They were stored until 6 Jaunary 1970. when they were released from quarantine.
=-4
At this point in time, there was no great concern over the lack of vacuum environment around the parts since tests conducted by Hughes and others showed that the clay-silicate paint did not demonstrate any oxygen {or air) sensitive bleaching in its optical reflectance. What effect lack of light protection would have was unknown. It could only be hypothesized that there would be some effect. Since the pax;ts were immediately exposed to light upon their return ard were photographed at that time and again during survey operation at LRL following release from quarantine, interest in eliminating light exposure to the surface was reduced. As a backup, the white painted tube section was still in the vacuum-tlght, light-tight container. The TV camera was coated over most of its surface with the inorganic white paint. When the camera was removed from its double bag, the ext_nt of discoloration became apparent. In addition, it was observed that significant variations in discoloration occurred over the entire surface. The side of the camera on which the mirror was located was a uniform tan or deep yellow-brown. The top and sides of the mirror hood were gray. The other portions of the camere, varied in colorat'_on between these two extremes. As me.,.ioned earlier, the expected patterns of radiation damage were absent. The mirror surface was quite hazy, or diffuse, leading to the conclusion at this early stage of the investigatiot, that the entire camera was covered with a contaminant (probably dust). The flow bench. to dismantling camera was photographed after being placed Visual examination of the camera was made for microbiological examination. During in a laminar at this time prior this examination,
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the that
first areas
shadow protected
patterns
were
observed. degree, from
These direct
patterns exposure
are
unique
in
to some
to the
outside
environment, were darker tion continued, of the shadows
such as below a wire in coloration than the numerous examples were found on the
which was very close to the surface, surrounding area. As the visual examinaof the shadow patterns were found. All north (lunar) nex't with side the of the removal .camera. of the lower
Partial
dismantling
occurred
;.: .:g • _. _
_'.
of this dismantling, microbiological the support collar on tile the mounting of camera. and bracket on the lower shroud to allow work interior As part shroud (through which the three connectors passed) were removed, wrapped in teflon film, and placed in a carrying case. These parts were not exposed . to any significant light until May, 4 months after removal from the On the north side of the bracket at the interface between the bracket lower shroud, a large amount of dark gray debris was noted. On the front half camera, was a hole camera beneath the of the support approximately support collar camera. and the
:aCi
'" " '-_"_' l!l .'_ _ -: _
•
of the of the
collar, located on the north side 1 inch in diameter. The surface was unpainted aluminum. When
the collar was surface. The passing through Figure J-6.
removed, an imag," of the hole was noted on the aluminum image was offset and appeared to be formed by something the hole in the collar off normal. • This is shown in
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The image itself was fairly bright, with the area surrounding image brownish and diffuse. When the support collar was removed, milligrams of dark gray to black debris were found on the aluminum face. Some of this debris was brushed into abottle for arc emission spe-.trographic pressure-sensitive When analysis, tape. the support and the Analysis collar majority was picked indicated that the was removed, a new up on clear _ebris was set lunar
the several sur-
dust. patterns
of shadow
was found, on side werethe associated of camera, aswith the in shown Figure 11-2 again {Section the north 11). These(lunar) patterns struts which attach the camera to the spacecraft. Again, very sharp images of the struts appear on the painted surface of the camera and are much darker than the surrounding area. Portions of the TV cabling shroud. When these were removed, north side of the camera below this were still attached to the camera lower shadow patterns were found on the cable which was located quite close to
SUPPORT COLLAR o O
_
f'_
TV CAMERA
, . _
FigureJ-6. lllust,at;onof _,hadow TiwoughHole in CameraClamp
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FigureJ-7. ShadowPatterns ElevationDriveMotor Housing(NASA PhotoS-70-21149) on the surface. Portions of this cable had been cut free the image of the cable remained on the surface where during the camera's lunar stay. during recovery, but the cable had been
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Another set of clear shadow patterns was found to be associated with the elevation motor housing located on the mirror assembly on the north (lunar) side of the camera as shown in Figure 3-7. ::* A clear pattern. much darker, is seen just below the wire running "Aongside the motor. Investigation examination of these shadow of the camera. p%tterns dominated Heads of the various the early screws stages were I
of visual : ,:_:: ,,,:'*: ,,_ ',_
found imaged on the north side of the camera in the darkened painted surface. These patterns provided the first evidence that all of the shadows had a unique directional characteristic. By visual sighting, it was possible to take a position such that all the darkened patterns disappeared behind the object which they imaged. It was independently discovered by Hughes and by MSC personnel that the shadow patterns were u,_iquely associated
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with
the
lunar
module
landing
position.
It was
assumed
at that
time
that
the landing Surveyor of the lunar andmodule caused the severe _ surface, dust removing storm which uponthe III sandblasted either impinged earlier deposited debris (dust) or radiation damaged paint and/or contaminants. Subsequent measui-ements by L.D. Jaffe (JPL) at Hughes identified the coordinates azimuth and of the origin Z9 degrees of the elevation OF shadows (camera SURVEYOR conducted as approximately lower shroud INORGANIC before Surveyor 90 degrees coordinates). WHITE launch PAINT to deterwhite paint. as
• _
.
J. 3
OPTICAL Laboratory
DAMAGE
", !i_ "': ._ . "' !:1
tests were
¢J
WT 'L_"
mine
the ultraviolet radiation stability of the Surveyor intests Reference were 109 using conducted a Hughes BH6up mercury at type to.lO00 with spectral This test was
inorganic
discussed Ultraviolet
arc hours lamp. duration, The
violet test was conducted at Hughes spectralreflectancemeasurementsweremadeinair. made in vacuum (Reference 110). mercury arc lamp.
reflectance measurements In1966, anultra- a also conducted using
" :_" -<._._. • :).'._ f_
paint paint
These test data indicate an increase of~0, 05 in 1000 hours. More important, did not exhibit any air bleaching as
in solar absoi'ptance the test showed of ultraviolet
that
of the this
a result
irradiation.
Research Institute for 2800 hours, discussed in Reference Ill, was measurements made in vacuum.
using a mercury arc lamp. This test, performed with all spectral reflectance Confirmation was obtained that upon
i;i. i! '!._ ._.){_
1967, ult_ aviolet In damage. a The spectral
test was conducted
character o'f the
at
the
Illinois in the
Institute S,.rveyor
of Technology inorganic
damage
[]
-;"_<:"":!!]_"t "" t.J
whitepaintisillustratedinFigure J-8. admitting air to the chamber the coating The influenCelunar environment°f low energy protons, a significant factor, on the Surveyor inorganic white paint had not been determined prior to flight. With the return of the Surveyor
did
not 100
show f_ #
any "'__
bleaching
or _i
_ eo w u • _ ,o i , 40 2_
_
-
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:: [! _ _ '<': "" " v, "' .,"
_O;
parts, effectthe of solar questionarose concerning A test the wind protons. was conducted at Hughes (1970) on a sample painted in 1965 and stored in the dark, free of airborne contaminants. The sample was irradiated at a flux of 1.3 x 10II protons/cm2/sec to a total fluence of Z. Z x 1016 protons/cm optical properties were measured to simula:e return of the Surveyor _-. The in air parts.
I;" "
[ I o.s. [ [ [ I
=_,*,BEFOREULTRAVIOLETF.XPOSURE
"
2._ 2.6
0.$
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na
damage It was found that there was region of over the spectral no optical inte re st, 0.3 to Z. 6 microns.
WAVELENGTH, MICRONS FigureJ-8. SpectralReflectance Whir( InorganicPaint of Beforeand After LaboratoryUltraviolet t!xposure
3"-11
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J. 4 ":':
DISCUSSION
OF
TEST
RESULTS in support of the contamination appendix, and detailed data obtained are presented in order of actual
A number study. These tests from each test are accomplishment. J.4.1 Reflectance
of tests were conducted are described in this presented. The tests
Measurements
of Lower
Shroud;::
camera !: _"
The first series of spectral reflectance measurements on the was made on the lower shroud on 28 April 1970. irrom January to the shielded fluorescent from the lighting blowing of a air by a
1970
until that time, the shroud was exposed laminar flow bench. It was, however, shield of teflon film.
,._
*Conducted
by
TRW,
Inc.
on a Hughes
subcontract.
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FigureJ-9. LowerShroudot SunteyorIll Camera,Showing TRW Measurement ositions P (SeeToxt)
,
IB
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a
i
iil
This positions positions presents inspection emittance
set
of measurements
was
made
by TRW
at a nurnber
of
Q
on the lower shroud, of each measurement spectral plots of these of each device, position model
using a wall-mount are sketched on measurements. using
integrating Figure J-9. Table J-I
sphere. The Figure J-10 shows the emittance
•
DB-100. as measured
a Gier-Dunkle
J.4.
Z
White
Painted section
Tube from in this
Section a TV container
Returned camer_ was
in Vacuum support a section strut was removed wrapped • by
A 4 inch (SESC). _(_ _ -: Also
included
of the
teflon
cable from the camera. It was the intent of this experiment to remove both the white the astronauts paintedplaced and (inorganic) sample in a tube environme.ntal and the teflon FEP sealed cable container wrap from the sealed container for a series of optical measurements. The parts were to be maintained under vacuum with no exposure to light. The original _est plan called for removal of both test parts from the SESC in a vacuum environment (glove box) and subsequent transfer to vacuum containers for optical measurements (spectral reflectance from 0. 25 to Z.5.microns). The transfer was to be accomplished under low level red light illumination, thereby minimizing TABLE any J-1. photo-induced NORMAL LOWER bleaching. FMITTANCE SHROUD SURFACE Normal J-9) Emittance O. 920. 7 MEASURED ON
:_ _i
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TRW , (see
Position Figure 1
z
3 .... 4 5
0.9z 8
0.9Z 0 0.929 0.9Z 6 : , ,
6
7 .
o. 9zo
0.9Z 5
g,r_,
9** Reference paint sample
O. 093 O. 92 0
_ ,_ _ _' ,,!)
*Although the accuracy of the measuring instruments does not justify three significantfigures, the third figure is retained depressed to indicate trends. **Note that this was polished aluminum surface.
•
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J-13
,•:,L°,
D
• ._" _i. "_ •_4 :: Lack of equipment availability precL.uded the SESC inert teflon transfer of parts in The facilities, vacuum; thus, leak checking, was and opening the transfer to be done of the under and done at JPL. The sectioning of the tube and were atmosphere provided (argon). by and the placement of All facilitiesin theand techniqueschambers employed leak Hughes samples new test were including performed by checking and are TRW. described in Reference 112 and are only summarized in this report. i " _: g_ • _ • _ : _:-._ '_. _ | Prior to opening, the SESC was leak checked in May 1970. The returned container from the neon was placed into a vacuum-tight container which was evacuated. This container was then backfilled with SF 6 at 100 mm of mercury over atmospheric pressure and held for 30 lxours.
_J2 V_
%_,:
)
The SESC was removed and leak checked; a major leak was found in _he -SESC in the area of the indium seal. The conclusion was that the leak had existed for some time and had probably been returned from the moon in this condition. Thus, the white paint and teflon both were exposed to air for several months. The vacuum test was lost. However, it was decided to conduct the test sequence per plan; accordingly, the SESC was opened and
U
[_
-. .•_ :_._
samplesThe placed interior intoof vacuum the inert chambers. atmosphere chamber was sterilized prior to establishment of the inert atmosphere. The 02 , H 2, N 2, H20, hydrocarbon content of the inert gas was monitored during the opening. Total impurities were less than 20 ppm.
the
and
_-]
'7
i
50 ppm
and
the
02
to 11 ppm.
It was
suspected
that
h':_her
readings
oi
A section of white painted tube about 4 inches long was found container. The tube was cut into two sections with a jeweler's saw. longer section {about 3 inches} was placed in a quartz vacuum chamber .:"_:_. :ili::.:_ ..._ " f_, {_,_ "-!,
in the The
m
§
(Figure section inside.
J-1l was
_to a firmly which mounted high in vacuum place
valve was and sealed
connected. tube shut, enclosing The the argon
Alight-tight
envelopewasplacedaroundt;hequartztube.
A section of the t,flon wrap was cut from the cable _or mounting in a similar vacuum tube. Two sections of te_,on about I inch by 1 inch were firmly mounted in the second vacuum-tigh*_ quartz tube, The chamber was sealed and made light-tight, The above illumination. operations were conducted under very low red light
_ i"
_ • _
re, moved
The two sealed chambers from the iner'_atmosphere
containing chamber
the test _pecimens and taken to TaW
were where
the
!
_!': _:):i
TaW, samples. the chambers samples evacuated without allowing any oxygen to reach were the The were retained i, darkncss, screens initial optical measurements were to be made. * Shortlyand grounded after reaching SThese measurements were made at Taw, Inc. under a Hughes : tbcontract.
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1.O WAVELENGTH, MICRONS
I.S
2.0
2.5
0.1i
0.5
|.0 WAVELENGT_I_ MICRON. _,
l.a
:L0
2.5
0.3
VariousTRW Locations Shownin FigureJ.9
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1.S
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2.5
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t=
-REPRODUCIBILITY
,OF THE ORIGINAl
PAGE iS_ POOR.,. "Wl: ""
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F i9ure 3-11.
Quartz Chamber With
Light-Tight.
Shield for Vacuum
Tests of White Painted
Tube (Photo 4R 186351
.. _
il
B
were placed in the ion pump exposed to the glow discharge The spectral
throats during
to ensure startup tube
that the samples of the ion pump. was measured
were
not
reflectance
of the
around
the
circumference at 90 degree increments, while the sample was at 5 x 10 -7 Tort. The measurements were made by positioning chamber in an Edwards integrating sphere, Room lights were these not possible operations; was would be made _ Figure so that J-1Z about
maintained the quartz off during
I "
only dim the quartz red light was used to position each themeasurement sample. It to rotate chamber so that in the same plane. The chamber was raised and lowered of the separa+_d tube theshowing uppermostmeasurement lowest orientation. and measurement. of these vacuur_ measurements, a leztk valve
is0.63 sketch a inch completion
"_
At the
•i:_ ' ,f. _
I
attached to the system was opened and tn¢ pressure in the quartz tube was raised to about 10 microns of Hg (10 -2 Tort). Each sample position was remeasured for optical reflectance. Again, no light was allowed to reach the sample tube except that of the mon_cb'romatic spectrophotometer beam. Following this set of measurements, air was admitted to the chamber, bringing the pressure up to 1 atm. The spectral reflectance at four sample in the dark.was position_ measured again. The samp _ :s then sat at 1 arm for 6 days _..
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LIGHT BLEACHING
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FigureJ-12. Sketchof WhitePainted.;ectionof Tube Returnedin SESC ShowingMeasurement PositiorJs
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778-70 800-70 The spectral reflectance shown in Figure 5o12. from a xenon arc lamp was again measured of the sample position The tube was then exposed to light at position through a Corning CS3-74 yellow filter. This H
!!
I I BI [] i
filter removed all illuminating wavelengths les's than 0.4 micron. The irradiance for the 48 hour period was 214 x:nw/cm 2. The surface of the sample tube closest to the irradiating source (Figure J-1Z) was halfway between two of the positions which had previously been m_asured. Following the 48 hour exposure spectral reflectance measurements were again made at the four positions previously measured, A measurement was also made at the surface closest to the irradiating source (sample position 800-70 on Figure C ,'; white J-18. J-1Z). painted tube, Results_f Figure J-13 discussed above, are the spec._ral in reflectance ,I-13 the Figures the measurements of presented of through shows the reflectance versus wave length of the four
i i
samples measured in vacuum prior to exposure. Figure J-14 shows the reflectance after partial pressurization at relatively low pressures, Figure J-15 shows reflectance of the four samples _fter they were exposed to I atm, still prior to any light exposure. Figure J-I6 shows the reflectance of one of the samples after 6 days exposure at I atm. Figure J-17 shows reflectance of another sample from a different portion of Figure J-12 taken after an exposure to light for 48 hours at 1 atm. Figure J-18 shows reflectance of the original four samples at 1 aim after they had been exposed to 48 hours of light. :-
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1.0
I
WAVELENGTH, Figure J-13. Spectral
MICRONS Reflectance Versus Wavelength
WAVELENGTH,
MICRONS Painted
of Four Samples of White
I
Tube - High Vacuum,
Prior to Light Exposure
I
il
,T-19 'L . ",
loo ._ so
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WAVELENGTH,
1.0
MICRONS
Ls
2.0
2.5
o.3
0.5
WAVELENGTHt
1.0
MICRONS
1.5
2.0
2._
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Figure J-14. Spectral Reflectance Versus Wavelength of Four Samples of White Painted Tube - Medium Vacuum, Prior to Light Expcsure
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PRESSURE: ATM
,_
0.3
0.5
1.0
1.5
2.0
2.5
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WAVELENGTH,
MICRONS
Figure J-15. Spectral Tube - 1 Atmosphere,
of Four Samples of White Painted
_
J-Zl .,
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c
_
¢,
B_ Q D
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20
0
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0.5 WAVELENGTH, 1.0 MICRONS 1.5 2.0 2.5
0.3
Figure J-16. Spectral Reflectance ,'_rsusWavelengthof One Sampleof White PaintedTube: Sample778-70 After 6 Days at 1 Atmosphere. Priorto Light Exposure a
loo
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20
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0.3
0.S
1.O
1.5
2.0
2.S
WAVELENGTH.
M IC RONS
FigureJ-17. Spectral Reflectance Versus Wavelength a of Figure J-12 After of WhitePaintedTube:Sample800-70 in Different Sample48 Hours Exposure to Light at 1 Atmosphere I
3-22
I
1)
\
Q D
zoo I o) _AMPLE I 778-70 .... ! I ¢)SAMPLE i 780-70 o
80
.....
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m _
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m
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zoo
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I b) SAMPLE I " ' 779-70 o _ d) I SAMPLE I 7el-70 o
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ee
ao
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0.3 0.5 WAVELENGTH, 1.0 MICRONS 1,5 2.0 2.5 0.3 0.5 WAVELENGTH, 1.0 MICRONS 1.5 2.0 2.5
r,_
0
_
Figure J-18. Hours Exposure to Li_t at 1 Atmosphere Tube After 48 Spectral Reflectance Versus Wavelength of Four Samples of White Painted
t ;
3-23
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7]
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O-
•
•': REISRODUCIBiLITYOF THE C_IGINA*L,.. PALE ,IS .POOR. ,.
QI
J.4.3 Reflectance of Cable Bracket From Lower Shroud i cables The bracket shown in Figure J-19:: used to attach the TV camera _ to the lower shroud was removed from the camera at the LRL on In May 1970, the bracket was removed from the dark for examinaticn. A 6 January 1970: Itwas wrapped in teflon FEPfilm dark. large disparity was found in the color of the bracket and storedinthe lower and that of the shroud of the camera. When the bracket was removed initially, the surface of the camera and bracket were a similar brown tone. In May, the shroud was found to be much lighter, with the bracket appearing to be the same color as it was upon _he first viewing of the Surveyor IIIhardware in January 1970. This difference in color :_sshown in Figure J-20. ;:-" _ _ i 1 |
|
coupons The four test were cut from the bracket, as shown in Figure J-21. Each sample was 1 by 2 cm. The spectral reflectance of these four coupons was measured. One sample, 518 in Figure J-21, was examined with a scanning electron microscope for the presence of lunar soil. Lunar material could not be distinguished from the paint. This was due to the charge buildup in the paint and lunar soil. All samples were then stored in the dark for 3-1/2 months, after which the spectral reflectance was remeasured. The original measurements of spectral reflectance versus wavelength conducted in May 1970 on one of the above samples, 518 mentioned above, are plotted in Figure J-22. Results obtained 3-1/Z months later in August 1970 showed no appreciable change. Results of spectral
B
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B
::-'Originaln color. i
I
.i_ 4 I
[:""
|
t
FigureJ-19. LowerShroudof SurveyorIII Camera With AttachedCableBracketUpon Return FromMoon (NASA PhotoS-70-21142)
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!; REPRODUCIBILITY OF THE C)RIGINAL PAGE IS POOR. _
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reflectance similar on the other three samples both in May and in August 1970 were to those of Figure J-22, In November 1970, samples 519 and 521 were selected for controlled still in dark storage) for spectral reflectance exposure to fluorescent lights. The samples light of a lamin.ar flow bench for 72 hours. bagged in polyethylene, with a total thickness ethylene bag separating the sample from the and then exposed to fluorescent were remeasured (they were One sample (521) was doubleof 0.012 inch of clear polyfluorescent lighting. Both
_(i E
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ki :-_
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Kodak Test
Neutral Card
r _ f_
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FigureJ-20. Cable Bracket Superimposed n LowerShroudof SurveyorIII Television o Camera: ShroudExposed Lightfor About 5 Months,CableBracketUnexposed to (Photo70-5364}
7!
:_ .
,=1
/
IIl
FigureJ-21. Locationof Samples From CableBracket Cut 3-25 ',
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D
100 -
o 0
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-
75
so
J U. W
J
te bJ
"
_: 25
O
/
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0.5 1.O J .5 2.0 2.5 3.0
0 B |
i
WAVELENGTH,
MIC
RONS
Figure J-22. Spectral Reflectance Versus Wavelength of Sample of Camera Cable Bracket: Sample 518 of Figure J-21: Measurements Taken in May 1970 Prior to Light ExposJre
to prevent were protected during astorage dust fallout and thickness The clear teflon of white samples with 0.00Z inch transit. of irradiance FEP film light reaching each sample was ~170 mw/cm 2. Following this exposure, the spectral reflectance of each sample was remeasured. The samples were returned to the laminar flow bench for exposure (17 ciays total) and then remcasured. ments are shown in Table J-2. J. 4.4 Measurements of Samples of Camera an additional Results 14 days of of these measure-
B
I
_ipod
Bracket
Support
Tube
i
,_
support collar (Figure 1970 when which TV camera J-Z3);'.' the was used to attach In January was first the camera disassembled, to the the spaceframe was removed, wrapped in teflon FEP film, and stored in the dark. In July 1970, the long tube from the bipod bracket side of the clamp on the left side of Figure J-23 was cut off the assembly for a series of tests. of I I
The bipod s'de of this assembly was located on the southern side the spacecraftduring the moon, III" hardware seen in Figure J-Z4 taken by the on Surveyor and can be recovery. astronauts
"i
tube vertically spectral Gier-Dunkle in a The The reflectance integratingtube sphere. measured tube had three the of the was by mounting different colors. The general overall color of the tube was light yellow. A dark gray region was noted on the westerly side of the tube, and a very dark yellow in region of these regions. the easterly was found on measured each side. The reflectance was
p
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in color.
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TABLE J-Z. WAVELENGTH PERCENT OF OF SPECTRAL SAMPLES FROM REFLECTA/X_CE VERSUS SURVEYOR lit CAMERA
,
)
CONNECTOR
LIGHT PHOTO BRACKET
BLEACHING AFTER EXPOSURE
TO
WHITE
r
Before I microns Wavelength, 0.295 0.355 0. 401) Sample 9.0 20.0 25.0
Exposure
to Light Sample 521::':_
Spectral Reflectance, perce_.t After 72 Hours Exposure to Light Sample 12.0 18.0 26.0 519 -" Sample 10.0 16.5 Z3.0 521
, After 17 Days Exposure to Light Sample
.....17.0
51%:'
519
Sample 14.0 28.0 36.0
521
10.0 18.0 22.0
Z8.0 39.0
e¢
i
0.430 0.458 0. 484
28.5 33.0 35.5 40.5 44.0
27.0 33.5 37.0 40.0 45.0
28.0 35.0 39.0 42.0 4b.0
Z9.5 35.5 38, 5 42.0 46.0
I [
46.0 47.0 49.0 56.0 56.0
45.0 47.5 47.0 50.0 ". 0
D
0.511 0.540
0.569 0.598 0. 630 L.J 9 ' "i:
4.
47,0 49.0 52.0 55.0 60.0 60.0 67.0
49.0 52.0 53.5 58.0 58, 0 59.0 62.0
49.0 51.5 54.5 58.0 59.0 60.0 62.0
49. F 51.0 55.0 58.0 58.0 60.0 6Z. 0
56.0 62.0 63.0 64.0 67.0 67.0 70.f
'
55.5 58.0 60.0 60.9 61.0 6Z. 0 63.0
o. 664 0. 700 O. 738 0. 781
_.._' il.
O.8Z8
0,8_0
66.0
_7,0
66.0
65,5
65.0
_7o0
64.0
_,0
70.0
72, r_
63.0
6_,0
I. Oil : "_", "_ !. 096 1. 200 I. 341 t 1. 536
71.0 71,0 74.0 75.0 74.0
68. 0 7Z, 0 75.0 75.0 7Z. 5
70.0 72.0 75.0 74.0 73. $
70.0 7_-.0 73.0 73.0 74. O"
74.0 75.0 75.0 75.0 75, 0
67.0 71.0 74.0 74,0 70.0
,
1. 854
68. $
65. 5
67. 0
68. 0
71.0
6tl. ¢
Z. 600
SS; 0
_$. 0
S7.0
$6_5
i,
Sl. 0
$6. 0
; _"
*Sample e_S_mple
519 (Ftlure J-ZI) 521 (Ftllurt* J-21)
wrapped in p_lyethylene unwrapped.
film.
3-Z7
4
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FigureJ-23. SupportCollar of Surveyor Television III Camera(NASA PhotoS-70-21157) tube was then suspended in a beaker containing CCI_ 4 and soaked for 1 hour. To minimize the washing surface, the tube was not agitated. beaker air dried, and soaked again During these experiments, the tube away of any lunar The tube was gently in fresh CC_ 4 this was maintained in the material removed time for dark. NaC1 window for no organic conwas found in the technique caused on the from the _-1/2 hours.
U
I
I,
I
U
m
The CC_ 4 was boiled down and evaporated on an infrared analysis, After the second soak in fresh CC14, taminant was found in the residue. Evidence of silicone residue from the first wash, but it is believed that faulty this c ontaminat_on. \ , three soak The spectra! positions on the experiment, the
: :-,' :] .., .!
reflectance of the tube was,remeasured tube following the CC_ 4 soak. Following sample was returned to dark storage.
at
the same the solvent I
The was
In September 1970, the tube section wa_ used in another experiment. sample was suspended in air and heated overnight. The tube section mounted in a glass test tube ,2_at was packed at the open end v'ith glass
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Figure J-24. Photograph of_urveyor III on the Moon, Showing TV Support Tubing (NASA Photo AS12.41_,7115)
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wool to minimize air currents. A thermocouple to the tube. The tube temperature was raised to later the temperature had fallen to d20°F due to temperature for the 15 hours was about 4Z5vF, in the dark during this experiment. The sample tube and the reflectance remeasured at the same The ments J. 4.5 _" ._ data from all three J-25. of Unexposed Surveyor White Paint reflectance was mechanically attached 450°_, Fifteen hours room cooling. The average The tube was maintained was removed from the three positions. wavelength measureM
D
!_1
tJ
iiim
i
versus
are shown Thermal
in Figure Annealing
(
_
A thermal annealing test was conducted on a Surveyor inorganic white paint sample that had been stored free of airborne contaminant since painting in 1965. The sample was held in air overnight at 4350F, a time of about 18 hours. The spectral reflectance of this sample was measured before and after thermal exposure in a Gier-Dunkle integrating sphere. No significant spectral difference was noted irom 0.3 to 1.3 micron. However, beyond 1.3, a significant increase occurred in _he reflectance spectrum, with the reflectance at 2.6 microns increasing 14 percent. This increase was due to the release of chemically corobined water iv, the clay-silicate system, J. 4.6
B
m
B
[]
i Reflectance of Surveyor Iii Samples Used in Science Studies B
In accordance with the test plan, a number of samples were cut from the shrouds of the TV camera in July 1970 for use in science studies. The sample cutting is documented in proper files. The samples were photographed, and then examined under a light microscope to 40X. The spectral reflectance of these samples was then measured in a Gier-Dunkle integrating sphere. The measuremevts were made during July 1970. Sample size for each experiment was 1 by Z cm. Some samples were taken from positions on the lower shroud where earlier spectral reflectance measurements had been made {by TRW). Thus, a time comparison could be made of any change in reflectance from April to July 1970. Table J-3 lists the samples cut in July 1970, location on TV camera, and the corresponding TRW measurement position, if any. The spectral reflectance '] C painted on the exterior with the Surveyor inorganic white paint. Sample 894 was polished aluminvm, areSamples in906, 907, 908, and 909 were but894 coated were the on data fo_' these samples given Table J-4. Allsamples interior side with an organic optical black paint. The reflectance of both side'sof these samples Additional shroud selection Sample for spectral was measured. were selected measurements to the;TRW Refl'_ctance and removed in October from the , lower Position
II
el
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samples reflectance
1970.
, _;,:_:
$-_/;:i' in:':_':_i'/_i_i _"!( _
was was close as again size
as by2 1 possible cm.
posttton$ measuremen_ shown
in:Figure _ere made
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FigureJ-25. Reflectance BipodBracketTube of
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! I PAGE BLANK NOT
TABLE D . Sample Log Number {Program • _ Test
893 ., _
J-3.
SAMPLES
OF SURVEYOR 1970 FOR SCIENCE
IIICAMERA STUDIES
SHROUD
CUT IN JULY Designation Taw ment (see
MeasurePosition Figure
2
Sample
Location Camera
t on the Surveyor Shroud
front (lunar), (flat side) near
III
Files}
J-9)
Lower facing
shroud, northeast
W
'_
center
'M
_
894
9
Lower
lunar,
shroud, back
surface,
bottom,
polished
facing
aluminum,
near 898 5
or curved
side
• ,
Lower shroud, northwest side facing lunar module site
(lunar) landing
"_
900
4
Lower shroud, southeast (lunar) side facing away from lunar module landing site Sun visor, top, facing up, centered (opposite side painted with organic optical black) hood, south
i : • :_
906
None
,+
907 +_
None
Mirror
assembly
lunar module facing away from landing site (lunar) side, {opposite side painted with organic Mirror (lunar) landing painted black) 909 None optical black} assembly hood, north side, facing lunar module site with (opposite optical side organic
t+
908 _(:!_
None
....
Mirror assembly hood, east (lunar) side, highest solar irradiance (opposite _ide painted with organic optical black)
,+
+'+ _ " _l:i_ +
t+ D D
_ o_oo_ooooooooooo_oooooooo
2
0
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sphere. The shroud had been continuously lighting since the earlier TRW measurements January (April 1970) and, in fact, since 6 1970, when the television was released from quarantine at the LRL. Table J-5 lists samples, responding TRW positions, and reflectance data, J.4.7 Thermal Annealing of Surveyor IllSamples
a Gier-Dunkle integrating exposed to fluorescent
camera cor-
both in air and in vacuum. conducted on Thermal annealing This section describes the tests was conducted of several Surveyor Ill samples these samples and presents the reflectance data obtained before and after these tests.
_( I
October
In November 1970, three samples that were cut and measured in 1970 were thermally annealed in air. The samples were thermally tube, 450°F discussed to and after the thermal
exposed the manner as the the samples in Section in J.4.4. same Temperature of bipod bracket wassupport raised maintained for 18 hours. The reflectance was measured
i
measurement 1031 were (TRW Surveyor position 3), and (TRW position exposure. The position samples 2"),tested III samples. 1035 1030 (TRW 7). As described earlier, these samples cut from the lower shroud were continuously exposed to light until their removal fror, a the shroud in October reflectance 1970. this valuesUntil before test, and they after were exposure storedare in the given dark.Table SF.ectra| in J-6.
I
I
part, designated as Vacuum-thermal sample painted sample previously The This
909 in white annealing Table tests J-3, were and on an inorganic Surveyor conducted on a tested in the Surveyor laboratories at Hughes.
nI
I
laboratory-tested sample had been exposed to ultraviolet radiation. Surveyor part 909 was cut from the front of the mirror housing. part faced east (lunar) while in the Surveyor crater. The exterior was was coated coated with with inorganic an organic white optical paint, black and the paint back (inward facing) (3M black velvet).
surface surface
laboratory
painted previously in January exposed 1965. Thewassample
The ultraviolet to ultraviolet
source was in the Hughes
a
_(
,
times the solar ultraviolet flux for 65 hours at a temperature in vacuum. Following this ultraviolet exposure in 1965, the BH6highpressuremercuryarc. The samplehadbeenexposedatfive stored in the dark until November 1970.
of Z50°F while sample was
J
The spectral reflectance both the Surveyor samples was measured just before oftest and immediately two samples were placed in individual glass tubes that
III after and were
the laboratory test. The evacuated to
approximately hours. The were to then removed held for the vacuum from 10-6 Torr. The 18 samples were samples heated then 450°F and chambers and their spectral reflectance was remeasured. Results of these measurements are presented in Table J-7. *See Figure J-9. :. ,, ,,. _:::,_:_ i
'i W ,
,, _ _,
,,
, ....
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TABLE
J-6. EFFECT REFLECTANCE
OF THERMAL OF SAMPLES III CAMERA
ANNEALING CUT FROM
IN AIR ON SPECTRAL LOWER SHROUD OF 1970
SURVEYOR
IN OCTOBER
Program
Log I030,
Spectral Reflectance,I031, percent Program Log
Program ... Log
I032
Wavelength, m icrons
Before Anneahng TRW
After Annealing Position 2_*
Before Annealing TRW
After Annealing Position 3
Before After Annealing Position 7 Annealing TRW
-,
m
0.295 0.355 O. 400
17.0 29.5 37.0
16.0 29.0 38.0 _-
23.0 44.0 60.0
25,0 45.0 57.0
10.0 16.0 24.5
13.0 20.0 25.0
O. 458 O. 430 0.484
45.0 41.5 45.0
44.5 42.0 46.5
70.0 66. 5. 70.5
68.0 65.0 71.0
30.5 27.5 32.5
31.0 28.0 32.0
_ i ; ! ' [ _-_
O. 540 0.51l O. 569 0.598 O. 630 O. 664 O. 700 O. 738
49.0 48.0 49.0 51.0 53.0 54.0 56.0 57, 0
49.0 46.5 49.5 52.0 53.0 53.0 55.0 58.0
75.0 74.0 76. 5 78,0 78.0 78.0 79.0 79. 0
73.0 73.0 75.0 77,0 77.0 79.0 80.0 80.0
35.0 34.0 37.0 37.5 38.5 39.0 40.0 43.0
35.5 33.5 37.5 40.0 41.0 42.0 44.0 47. S
_
i,.! [ _ --_
o. 781
O. 828 O. 880
59. 0
60.0 62.0
60.0
62.0 63.0
80.0
80. 0 8Z. 0
80.0
80. 0 80.0
45.0
46. 0 47.0
So.0
53.0 55.0
o. 940
1.096 l. Oll
6z. 0
65.0 64.5 68.0 70.0 63.0
65.0
66.0 66.0 70.0 72.0 71.0 70.0
8!. 5
8Z.O 81.. _ 81.5 8Z. 5 81.0 73.0
80.0
81.0 81.0 85.0 81.0 78.0
so. 0
53.0 53.0 56. 0 59.0 60. S 57.0
55.0
57.0 56.0
_