STEREO IMPACT by fionan

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									                                PLASTIC Team Meeting
STEREO IMPACT                      2000-October-20/21




    STEREO IMPACT OVERVIEW

         PLASTIC Team Meeting




                  1                        David Curtis
                                                      PLASTIC Team Meeting
STEREO IMPACT                                            2000-October-20/21

                          IMPACT Overview
•   IMPACT is a suite of 7 instruments built at 9 institutions by 31 Co-
    Investigators.
•   IMPACT is served by a single interface to the spacecraft C&DH
    system via the IMPACT IDPU
•   The IMPACT IDPU also services the PLASTIC instrument, so that
    PLASTIC requires no separate interface to the spacecraft C&DH
    system.
•   IMPACT and SWAVES communicate periodically via the
    spacecraft 1553 bus.




                                    2                            David Curtis
                                    PLASTIC Team Meeting
STEREO IMPACT                          2000-October-20/21

       IMPACT / PLASTIC Energy Coverage




                      3                        David Curtis
                                                                                                             PLASTIC Team Meeting
STEREO IMPACT                                                                                                   2000-October-20/21

                                   IMPACT Science Summary
  Table A.1 IMPACT Summary
  Experiment   Instrument      Measurement           Energy or Mag.       Mass   Power   Data    Time Res.    Instrument provider
                                                       field range        (kg)    (w)    Rate
                                                                                         (bps)
  SW             STE         Electron flux and        2-100 keV           0.35   0.20     64       16 s       UCB (Lin)
                                 anistropy
                SWEA        3D electron distrib.,      ~0-3 keV           1.71   1.10    394     3D=1 min     CESR (Sauvaud)
                            core & halo density,                                                  2D=8s       + UCB (Lin)
                            temp. & anisotropy                                                   Mom.=2s
  MAG            MAG            Vector field            500nT,           0.25    0.0    154       1/8 s      GSFC (Acuna)
                                                       65536 nT
  SEP             SIT          He to Fe ions        0.03-2 MeV/nuc        0.93   0.66    240       30 s       U. of Md. (Mason)
                                   3
                                    He                  0.15-0.25                                  30 s       + MPAE (Korth)
                                                        MeV/nuc                                               +UCB (Curtis)
                 SEPT        Diff. electron flux      20-400 keV          0.90   1.04    120       1 min      U. of Kiel (Mueller-
                             Diff. proton flux        20-7000 keV                                  1 min      Mellin)
                             Anistropies of e,p         As above                                  15 min      + ESTEC (Sanderson)
                 LET         Ion mass 2-28 &        1.5-40 MeV/nuc        0.51   0.18    320     1-15 min.    GSFC (von Rosenvinge)
                                 anisotropy                                                                   + Caltech (Mewaldt)
                              3
                               He ions flux &       1.5-1.6 MeV/nuc                              15 min.      + JPL (Wiedenbeck)
                                  anistropy
                                H ions flux &        1.5-3.5 MeV                                 1-15 min.
                                  anistropy
                 HET         Electrons flux &          1-8 MeV            0.70   0.07    120     1-15 min.    Caltech (Mewaldt)
                                  anistropy                                                                   + GSFC (von Rosenvinge)
                                       H             13-100 MeV                                  1-15 min.    + JPL (Wiedenbeck)
                                     He              13-100 MeV                                  1-15 min.
                                     3
                                      He            15-60 MeV/nuc                                 15 min
                  SEP                ----                 ----            1.69   1.55    ----       ----      Caltech (Mewaldt)
               Common                                                                                         + GSFC (von Rosenvinge)
   IMPACT        IDPU               ----                  ----            1.73   3.60     164      ----       UCB (Curtis)
   Common       (+Mag                                                                    +524
               Analog)                                                                   Burst




                                                                      4                                                             David Curtis
                                                                                                                                PLASTIC Team Meeting
STEREO IMPACT                                                                                                                      2000-October-20/21

                                     IMPACT Team Organization Chart
                                                                                      STEREO Project
                                                                                   L. Guhathakurta NASA
                                                                                            HQ


                                                                                      Mission Manager                        Project Scientist
                       Project Manager                                                   A. Harper                              J. Davila
                         J.T.Mueller                                                       GSFC                                   GSFC
                          JHU/APL

                                                        Science CoIs                    IMPACT PI
                                                                                         J. Luhmann
                                                                                             UCB                          Executive Comm.
                                                                                                                             R. Lin, UCB
                     Mission Systems Eng.                                                                             T. von Rosinvinge, GSFC             MOC              SSC
                          A Driesman                                                                                      J. Gosling, LANL              JHU/APL            GSFC
                           JHU/APL


                                                                                       Project Manager
                                                                                           D. Curtis
   Impact ICD
                                                                                             UCB
    Devel. Eng.
 T.Cole, E. Mengel
     JHU/APL




 PLASTIC                    SWAVES                  IDPU               SW Electrons & Mag           SEP Package                                         OPs/Data Manager
                                                                                                                            Ground System
 A. Galvin                    J.L                  D. Curtis             (Boom) Package           T. von Rosenvinge                                           UCB
                                                                                                                                UCB
   UNH                      Bougeret                UCB                      R. Lin                     GSFC
                             Meudon                                           UCB




                                                                                          SIT              SEPT             LET               HET            Data Access Center
                                       SWEA             STE             MAG            G. Mason         R. Mueller-         T. von         R. Mewaldt            C. Russell
                                    J.A. Sauvaud        R. Lin         M. Acuna                           Mellin          Rosinvinge         Caltech               UCLA
                                                                                       U. of MD
                                       CESR             UCB             GSFC                            U. of Kiel          GSFC




                                                                                  5                                                                     David Curtis
                                                            PLASTIC Team Meeting
STEREO IMPACT                                                  2000-October-20/21

STEREO Trailing Spacecraft, IMPACT Instrument Locations




                                                    SEPT-NS (Hidden)




                                     (SIT,SEPT-E,LET,HET)

                 (MAG)



                         (STE)

                    (SWEA)




                                 6                                     David Curtis
                                                   PLASTIC Team Meeting
STEREO IMPACT                                         2000-October-20/21




                            Stereo IMPACT
                        IMPACT/PLASTIC IDPU
                            00-07-19 Dave Curtis



                   160 mm
          200 mm




  60 mm




                       7                                      David Curtis
                                                          PLASTIC Team Meeting
STEREO IMPACT                                                2000-October-20/21


                                   Stereo IMPACT
                 140 mm            SWEA
                120 mm
                                   00-07-19 Dave Curtis




130°x360° FOV




                          150 mm




                                    8                                David Curtis
                                              PLASTIC Team Meeting
       STEREO IMPACT                             2000-October-20/21

                        SWEA/STE/MAG Boom




f200
                        Carbon Fiber Boom


         Magnetometer                         STE              SWEA




                                                         285
                                       1500


                                   9                     David Curtis
                                     PLASTIC Team Meeting
STEREO IMPACT                           2000-October-20/21

          SEP, Trailing Spacecraft




                    10                          David Curtis
                                    PLASTIC Team Meeting
STEREO IMPACT                          2000-October-20/21

          SEP, Leading Spacecraft




                    11                         David Curtis
                                                                                         PLASTIC Team Meeting
STEREO IMPACT                                                                               2000-October-20/21

   SEPT-NS
                    PDFE                        IMPACT Block Diagram
     TEL1
    (OF 2)


   SEP Main
   SEPT-EW          TEST      I/F                 LVPS (UCB)    IDPU
                             FPGA
                    PDFE

      TEL1                   SRAM               INTERFACE TO                                     TRIAXIAL
     (OF 2)                                      IMPACT IDPU        SEP         MAG
                                                                 INTERFACE   FRONT-END             MAG
   SIT               HVPS                                                                        SENSOR
            START              I/F                SEP CPU &
                     TOF        &                  BUFFER
            STOP             LOGIC                 MEMORY
                     PHA                                                        MAG
                                                                             INTERFACE
   LET               TEST                           RATE
                               I/F              ACCUMULATORS
                     VLSI       &
                     PHAs    LOGIC
                      (28)                                                     PLASTIC
                                                                             INTERFACE    PLASTIC
                                                HOUSEKEEPING
   HET               TEST                           ADC
                               I/F
                     VLSI       &
                     PHAs    LOGIC                SSD BIAS
                      (28)                                                     BURST
                                                                              MEMORY

   SWEA
                                                         LVPS
                                    16x                                        MICRO-
                                          COUNTERS                           PROCESSOR

                              HVPS
            ANALYZER
                                                                                1553      SPACECRAFT
                              HVPS            IDPU              SWEA /STE    INTERFACE
                                           INTERFACE            INTERFACE


                              HVPS               PHA/8                         LVPS       +28V
                             HVPS


   STE         CSA/8
    SSD/8




                                                                       12                                   David Curtis
                                                         PLASTIC Team Meeting
STEREO IMPACT                                               2000-October-20/21

                             C&DH Interface
•   All Command, Telemetry, Status, and Timing exchanged between
    IMPACT/PLASTIC IDPU and Spacecraft C&DH via 1553 bus
     – Implementation of 1553 Interface as called out in draft ICD is adequate
       for IMPACT needs
     – IMPACT will provide CCSDS-formatted packets for science and
       housekeeping telemetry (2100bps) as well as Beacon mode (32bps) data
       via the 1553 interface
     – Packets will be time-tagged (packet collect time) using UTC time code
       provided over the 1553 interface
     – Spacecraft status provided over the 1553 bus will be used to control the
       IMPACT instrument (e.g. some detectors off for thruster firing events)
•   A small quantity (<1kbyte/day) of time-tagged commands will be
    required to coordinate activities
     – The IDPU can perform this function if the spacecraft cannot
•   Instrument “Burst” mode data will be managed by the IDPU within
    the instrument telemetry allocation with no impact on the spacecraft

                                     13                              David Curtis
                                                        PLASTIC Team Meeting
STEREO IMPACT                                              2000-October-20/21

                             Power Interface
•   IMPACT converts unregulated 28V provided by the spacecraft per
    the ICD
•   IMPACT has three power inputs with separate converters for
    modularity and reliability:
     – IDPU/MAG
     – SEP
     – SWEA/STE
•   Separate power inputs from the spacecraft for each converter are
    desirable but not required
•   We currently expect to require no Operational Heaters (TBR)
•   We will require Survival Heaters when the instrument is powered
    off
     – Survival heat is also needed in some off-nominal attitudes, which may
       require powering off the instrument to enable the Survival Heaters if
       they are exclusive.


                                     14                            David Curtis
                                                        PLASTIC Team Meeting
STEREO IMPACT                                              2000-October-20/21

                          PLASTIC Interface
•   The IMPACT IDPU also services the PLASTIC instrument
    – The IDPU provides a single-point interface for both IMPACT and
      PLASTIC to the spacecraft C&DH system.
    – The IDPU will process, format, and pass on to the C&DH system
      PLASTIC telemetry
    – The IDPU will control the PLASTIC instrument operation
    – A high-speed bidirectional serial digital interface between IDPU and
      PLASTIC carries status, data, and control information.
•   Advantages of a shared IMPACT/PLASTIC IDPU
    – Real-time data from PLASTIC is used to control SWEA spacecraft
      charging bias
    – Coordinated collection of high speed “Burst” event data
    – Resource savings (Mass, power, $)
•   PLASTIC IDPU software developed at UCB to PLASTIC
    requirements
    – UCB wrote flight software for similar UNH instruments on CLUSTER
      and FAST
                                    15                             David Curtis
                                                         PLASTIC Team Meeting
STEREO IMPACT                                               2000-October-20/21

                       PLASTIC Interface Details
•   Common interface design for all instruments to IDPU
•   Bidirectional 3-wire serial interface proposed
     –   1Mbps, tested to 8m harness with low power 54AC drivers
     –   Details provided in design document to UNH
     –   Block oriented
     –   Timing: 1MHz IMPACT sample clock and spacecraft clock
•   Constraints:
     – No high-speed time-critical commanding; mode only
     – Instrument must block, sequence, and identify (block ID) data
       products into a single channel
•   Other issues:
     –   Memory buffer/accumulator space requirements
     –   Processing load requirements
     –   Burst memory usage (continuous stream)
     –   Software requirements
     –   PLASTIC simulator to UCB for S/W development
     –   IDPU simulator to UNH for PLASTIC development & test
                                     16                             David Curtis
                                                       PLASTIC Team Meeting
STEREO IMPACT                                             2000-October-20/21

                            PLASTIC LVPS
•   UCB to provide PLASTIC LVPS based on common design to 3
    IMPACT power converters
    –   Some customization for secondary supply voltages
    –   Common form factor desired
    –   Will meet EMC conducted & synchronization requirements
    –   Voltage and current requirements to be identified early




                                    17                            David Curtis
                                                    PLASTIC Team Meeting
STEREO IMPACT                                          2000-October-20/21

                        SWAVES Interface
•   Coordination of high speed “Burst” event data between SWAVES
    and IMPACT/PLASTIC scientifically highly desirable
•   Bandwidth required: A few words at a 5 exchanges/second
•   This has been accommodated via the spacecraft 1553 bus
     – avoids a physical interface between SWAVES and IMPACT




                                  18                           David Curtis
                                                     PLASTIC Team Meeting
STEREO IMPACT                                           2000-October-20/21

                              Magnetics
•   Magnetic Goals, as measured at the MAG sensor:
     – ±0.05nT Dynamic
     – ±1nT Static
•   Use of magnetic materials needs to be avoided/controlled
•   Current loops need to be minimized
•   Items close to MAG sensor are of particular concern (since field
    falls off at least as R3).
     – SWEA, STE, and IMPACT-provided rigid boom
     – deployable IMPACT Astromast (now provided by IMPACT team).
•   MAG team will work closely with APL to help meet these
    requirements at minimum cost
     – MAG team will screen selected spacecraft components
     – MAG Team will magnetically map spacecraft during I&T
•   Mission Constraints: Spacecraft rolls and having MAG on during
    boom deployment will aid in determining spacecraft DC magnetic
    fields so they can be subtracted
                                  19                            David Curtis
                                                         PLASTIC Team Meeting
STEREO IMPACT                                               2000-October-20/21

                   Electro-Static Cleanliness (ESC)
•   SWEA measures low energy electrons (down to about 1eV) whose
    trajectories are easily distorted by spacecraft charging
     – Desire is to avoid deflecting 1eV electrons more than 5°
•   All exterior surfaces shall be conductive to at least 108
    Ohms/Square (derived from a 1V charging requirement)
     – Exceptions, such as apertures, to be negotiated on a case-by-case
       basis, based on area, sunlight, and proximity to the SWEA FOV
        • 0.2% total non-conductive surface area goal
•   Possible Issues:
     – Solar Arrays: Study in progress to determine what level of ESC close-
       out of solar array cover glass is required
     – Deployable boom: will probably require conductive paint, such as
       what was used for Lunar Prospector Able mast
     – HGA: have had problems on previous missions getting the HGA
       exterior surface (paint) conducting
     – Thermal control paints
     – Apertures
                                     20                             David Curtis
                                                       PLASTIC Team Meeting
STEREO IMPACT                                             2000-October-20/21

                      Instrument-Level I&T Plan
•   Engineering Models of selected subsystems will be integrated and
    tested early to verify interfaces
•   Flight Instruments will first be functionally tested and calibrated at
    their home institution prior to delivery for integration to UCB
•   The instrument suite will be integrated and tested at UCB prior to
    delivery to the spacecraft integration
•   I&T testing at UCB includes interface and system level functional
    tests, compatibility tests, and environmental qualifications
     – Some instruments will have completed some environmental tests prior
       to delivery to UCB
•   Pre-delivery bake-out and exterior cleaning as required to meet
    spacecraft-level contamination control plan




                                    21                            David Curtis
                                                           PLASTIC Team Meeting
STEREO IMPACT                                                 2000-October-20/21

                       Instrument Verification Plan
•   System Functional Test proves end-to-end functionality
     – Constrained by inability to test SWEA and SIT detectors in
       atmosphere
     – This test is also performed in thermal vacuum
     – A limited version of this test is performed between environments
•   Environmental Tests:
     –   EMC
     –   Mass Properties
     –   Acoustics if indicated by analysis of design (not expected)
     –   Random Vibration
     –   Thermal Vacuum
•   Minimum 100 hours trouble-free operation prior to spacecraft
    integration
     – expect to have considerably more



                                       22                              David Curtis
                                                     PLASTIC Team Meeting
STEREO IMPACT                                           2000-October-20/21

                                  GSE
•   Electrical GSE includes:
     – Spacecraft-provided spacecraft interface emulators
     – UCB provided Telemetry/Command GSE (also used at spacecraft-level
       I&T and mission ops)
     – UCB-provided IDPU interface simulators for SEP, SWEA/STE, MAG,
       and PLASTIC
     – UNH-provided PLASTIC ETU/simulator for PLASTIC software
       development/test (TBR)
     – Bench equipment for low-level detector tests and calibrations
•   Electrical GSE are typically PC-based systems with commercial or
    custom interface cards to provide interface signal simulation
•   Radiation Sources will be used to stimulate detectors for
    comprehensive functional tests
•   Internal pulsers provide electrical stimulation for bench tests
    when radiation sources are not available
•   MAG team will provide magnetic screening GSE

                                   23                           David Curtis
                                                       PLASTIC Team Meeting
STEREO IMPACT                                             2000-October-20/21

                         IDPU Simulator GSE
•   Simulates IDPU serial interface to instruments (incl. PLASTIC)
•   Developed at UCB
•   PC-based system with custom I/O to simulate serial I/F
•   LabWindows CVI-based software
•   Delivered with baseline services:
     – Command interpreter& scripting user interface
     – Raw and statistical engineering displays
•   PLASTIC science displays to be provided by the PLASTIC team
     – Separate program running on same or another computer
     – Data provided over socket connection to UCB control software




                                    24                            David Curtis
                                                       PLASTIC Team Meeting
STEREO IMPACT                                             2000-October-20/21

            Command & Telemetry GSE Requirements
•   Works with Spacecraft Emulator at suite I&T level
•   Works with MOC at Spacecraft I&T level
•   Works with SSC at Mission Ops level
     – A common network interface for these three environments is highly
       advantageous and has been assumed in development plans
•   Runs commands and command scripts
     – STOL-like language
•   Remote commanding & display via secure internet connection
•   Displays housekeeping and instrument status information with
    limit-checking/alarms
•   Decommutates and passes on packets to Science Display GSE
    and/or remote C&T GSE via network
•   PLASTIC command scripts may be run on the IMPACT C&T GSE,
    or on a separate C&T GSE running the same software
    communicating either to the IMPACT C&T GSE or directly to the
    MOC/SSC
                                    25                            David Curtis
                                                    PLASTIC Team Meeting
STEREO IMPACT                                          2000-October-20/21

               Science Display GSE Requirements
•   Decodes and Displays science data from instruments
•   Provides adequate information to determine the health and
    functionality of the instrument in the I&T, Commissioning, and
    mission environment
•   Receives telemetry packets forwarded by Command & Telemetry
    GSE at the suite, spacecraft, and mission level via the network
•   Developed by the instrument builder and UCB.
     – PLASTIC team to develop PLASTIC science display GSE
•   Runs on a second workstation (PC) in order to provide more
    display space, separate science and engineering functions, and
    improve the reliability of the C&T system.




                                  26                           David Curtis
                                                                             PLASTIC Team Meeting
STEREO IMPACT                                                                   2000-October-20/21

  IMPACT Suite Integration GSE Configuration (at UCB)



    SIT                       Serial I/F
                 PLASTIC
   Stim.
   GSE
                              Serial I/F
                   SEP
   Radiation
   Sources                    Serial I/F                     1553 Bus
                SWEA/STE                       IDPU                        S/C Emulator
                              Serial I/F                                                  Ethernet
                                             MAG Elec.
   Shield Can   MAG Sensor    Analog                                       Command &
                                                                            Telemetry
                                                                Internet      GSE
                                                Remote GSE
                                 MAG
                                                                                          Ethernet
                             Field-Nulling
                                 GSE                                         Science
                                                                           Display GSE




                                              27                                           David Curtis
                                                                                             PLASTIC Team Meeting
   STEREO IMPACT                                                                                2000-October-20/21

              IMPACT Spacecraft Integration GSE Configuration



 SIT                      Serial I/F
              PLASTIC
Stim.
GSE
                          Serial I/F
                SEP
Radiation
Sources                   Serial I/F                  1553 Bus
             SWEA/STE                       IDPU                     Spacecraft                 MOC
                          Serial I/F
                                          MAG Elec.
Shield Can   MAG Sensor   Analog                                                                            Ethernet
                                                                                   Secure    Command &
                                                                                  Internet    Telemetry
                              MAG                                Remote GSE
                                                                                                GSE
                          Field-Nulling
                              GSE                                                                           Ethernet

                                                                                               Science
                                                                                             Display GSE




                                                        28                                                 David Curtis
                                                                      PLASTIC Team Meeting
STEREO IMPACT                                                            2000-October-20/21

           IMPACT Mission Operations GSE Configuration



             Serial I/F                             DSN                         MOC
 PLASTIC

             Serial I/F
   SEP                                                   RF

             Serial I/F               1553 Bus
 SWEA/STE                   IDPU                  Spacecraft                    SSC
             Serial I/F
                          MAG Elec.
             Analog                                                                         Ethernet
MAG Sensor                                                         Secure
                                                                  Internet   Command &
                                                     Remote GSE               Telemetry
                                                                                GSE
                                                                                            Ethernet

                                                                               Science
                                                                             Display GSE




                                             29                                       David Curtis
                                                    PLASTIC Team Meeting
STEREO IMPACT                                          2000-October-20/21

                       IMPACT GSE Software
•   The IMPACT Command & Telemetry and Science GSE are PC-
    based systems running LabWindows-CVI based software
•   The software is based on a long series of GSE developed at
    Berkeley, most recently for Lunar Prospector and HESSI.
•   The software is modularized so that much of the existing code will
    be usable
•   The software already has most of the features required (user
    interface, command scripting, database-driven command
    encoding and telemetry decoding, TCP/IP data interface, data
    decommutation and limit-checking, some science displays)
•   The programmer who developed the most recent version of the
    GSE (HESSI) is base-lined to develop the IMPACT version.




                                  30                           David Curtis
                              PLASTIC Team Meeting
STEREO IMPACT                    2000-October-20/21

            IMPACT Overview




                  31                     David Curtis
                                 PLASTIC Team Meeting
STEREO IMPACT                       2000-October-20/21

        UCB SWEA/IDPU/GSE Schedule




                    32                      David Curtis
                                   PLASTIC Team Meeting
STEREO IMPACT                         2000-October-20/21

          UCB Suite I&T Schedule




                    33                        David Curtis

								
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