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					  Health, Safety and Human Performance
Implications of the Small Pressurized Rovers




                 Mike Gernhardt
                  Nov. 25, 2008
        Challenges for EVA on the Moon

♦ Dealing with risk and consequences of a significant Solar Particle Event (SPE)
♦ Dealing with risk and consequences of a significant Solar Particle Event (SPE)
♦ Long duration missions with three 8hr EVAs per person per week
♦ Long duration missions with three 8hr EVAs per person per week
    • Apollo suits were used no more than 3 times
    • Apollo suits were used no more than 3 times
    • Individual crewmembers might perform up to 76 EVAs in a 6-month mission
    • Individual crewmembers might perform up to 76 EVAs in a 6-month mission
    • Suit-induced trauma currently occurs with even minimal EVA time
    • Suit-induced trauma currently occurs with even minimal EVA time
♦ With Apollo style un-pressurized rover (UPR), exploration range is limited by EVA sortie time
♦ With Apollo style un-pressurized rover (UPR), exploration range is limited by EVA sortie time
  and 10 km walkback constraint
  and 10 km walkback constraint
    • Science community input that optimal scientific return within this range could be accomplished
    • Science community input that optimal scientific return within this range could be accomplished
      within ~ 30 days of EVA
      within ~ 30 days of EVA
    • Two UPRs could extend exploration range up to 15-20 km (crew-day limited)
    • Two UPRs could extend exploration range up to 15-20 km (crew-day limited)
♦ Apollo highlighted the importance of dust control for future long duration missions
♦ Apollo highlighted the importance of dust control for future long duration missions
♦ Increased Decompression Sickness (DCS) risk and prebreathe requirements associated with 8
♦ Increased Decompression Sickness (DCS) risk and prebreathe requirements associated with 8
  psi 32% O2 cabin pressure versus Apollo with 5 psi 100% O2
   psi 32% O2 cabin pressure versus Apollo with 5 psi 100% O2
♦ The high frequency EVA associated with the projected lunar architectures will require
♦ The high frequency EVA associated with the projected lunar architectures will require
  significant increases in EVA work efficiency (EVA prep time/EVA time)
  significant increases in EVA work efficiency (EVA prep time/EVA time)
            “The Wall of EVA”
                                                                                                                                    “The Wall”
                                                                                                                                          ISS Construction
                                                                                                                                          (projected)
            250




            200




            150
EVA Hours




            100
                                                                          Pre-Challenger
                         Gemini                                           Shuttle                                    Shuttle
                                       Apollo/Skylab
             50




              0
                  1966

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                                                                                                                                    Year
                          “The Mountain of EVA”


                                                                                                                                                                                                                   “The Mountain”
            5000


            4500
                                                                                                                                                         Available Lunar EVA Hours
                                                                                                                                                         (LAT-2 Option 2) – based on
            4000
                                                                                                                                                         Three 8 hour EVAs per week
            3500
                                                                                                                                                         using Unpressurized Rovers
                                                                                                                                                            Need to extend range well
                                                                                                                                                         beyond 10 km
            3000
EVA Hours




            2500


            2000


            1500
                          Gemini                                                                                              “The Wall”
            1000
                                 Apollo/Skylab                             Pre-Challenger Shuttle                                            ISS Construction
             500
                                                                           Shuttle                                                           (projected)


               0
                   1966

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                                                                                                                                                                                                                                                    2030
                                                                                                                                   Year
The New Lunar Architecture Drives Out The Need For
A New Class Of EVA Surface Support Vehicles
              Small Pressurized Rover Design Features
              (Slide 1 of 2)
        Radiator on Roof: allows
        refreezing of fusible heat sink water                  Suitports: allows suit donning and
        on extended sorties                                    vehicle egress in < 10min with
                                                               minimal gas loss


  Suit PLSS-based ECLSS:
  reduces mass, cost, volume
  and complexity of Pressurized
  Rovers ECLSS




                                                                                Aft Driving Station:
                                                                                enables crew to drive rover
                                                                                while EVA




Ice-shielded Lock / Fusible
Heat Sink: lock surrounded by
5.4 cm frozen water provides
SPE protection. Same ice is
used as a fusible heat sink,
rejected heat energy by melting                 Work Package Interface:
ice vs. evaporating water to                    allows attachment of modular
vacuum.                                         work packages e.g. winch,
                                                cable reel, backhoe, crane
            Small Pressurized Rover Design Features
            (Slide 2 of 2)
                                                      Two Pressurized Rovers: low mass, low
                                                      volume design enables two pressurized
                                                      vehicles, greatly extending contingency
                                                      return (and thus exploration) range




   Exercise ergometer
   (inside): allows crew to
   exercise during translations
                                                                               Docking Hatch: allows pressurized
                                                                               crew transfer from Rover-to-Habitat,
                                                                               Rover-to-Ascent Module and/or
                                                                               Rover-to-Rover

                                                                                           Modular Design: pressurized
                                                                                           module is transported using
                                                                                           Mobility Chassis. Pressurized
                                                                                           module and chassis may be
Dome windows: provide                                                                      delivered on separate landers
visibility as good, or                                                                     or pre-integrated on same
better than, EVA suit                                                                      lander.
visibility




                      Cantilevered cockpit:
                      Mobility Chassis does not
                      obstruct visibility         Pivoting Wheels: enables crab-
                                                  style driving for docking
Comparison of Small Pressurized Rovers vs.
Unpressurized Rovers: Much more capability for the size
Small Pressurized Rovers: Functional Requirements
♦
♦   Power-up and Check-out including suit/PLSS power up and check-out: ≤1hr
    Power-up and Check-out including suit/PLSS power up and check-out: ≤1hr
♦
♦   Mate/de-mate from Hab/Lander: ≤ 10mins and ≤ 0.03kg gas losses
    Mate/de-mate from Hab/Lander: ≤ 10mins and ≤ 0.03kg gas losses
♦
♦   Nominal velocity: 10kph
    Nominal velocity: 10kph
♦
♦   Driving naked-eye visibility should be comparable to walking in suit i.e. eyes at same level,
    Driving naked-eye visibility should be comparable to walking in suit i.e. eyes at same level,
    similar Field-of-View
    similar Field-of-View
     • Augmented by multi-spectral cameras/instruments
     • Augmented by multi-spectral cameras/instruments
♦ Visual accessibility to geological targets comparable to EVA observations i.e. naked eyes ≤
♦ Visual accessibility to geological targets comparable to EVA observations i.e. naked eyes ≤
  1m of targets
  1m of targets
     • Possibility of magnification optics providing superior capability than EVA observations
     • Possibility of magnification optics providing superior capability than EVA observations
♦ Suit don and Egress/Egress
♦ Suit don and Egress/Egress
     • ≤ 10mins
     • ≤ 10mins
     • ≤ 0.03kg gas losses per person
     • ≤ 0.03kg gas losses per person
     • ≥ 2 independent methods of ingress/egress
     • ≥ 2 independent methods of ingress/egress
♦
♦ Vehicle Mass (not incl. mobility chassis) ≤ 2400kg
  Vehicle Mass (not incl. mobility chassis) ≤ 2400kg
♦
♦ Habitable volume: ~10 m3
  Habitable volume: ~10 m3
♦
♦ 12 2-person EVA hours at 200km range on batteries and nominal consumable load
  12 2-person EVA hours at 200km range on batteries and nominal consumable load
♦
♦ Ability to augment power and consumables range and duration to achieve ≥ 1000km
  Ability to augment power and consumables range and duration to achieve ≥ 1000km
♦
♦ PLSS recharge time ≤ 30mins
  PLSS recharge time ≤ 30mins
♦
♦ Crewmembers ≤ 20mins from ice-shielded lock SPE protection (incl. translation to Small
  Crewmembers ≤ 20mins from ice-shielded lock SPE protection (incl. translation to Small
  Pressurized Rovers and ingress)
  Pressurized Rovers and ingress)
♦ Heat and humidity rejection provided by airflow through ice-shielded lock and condensing
♦ Heat and humidity rejection provided by airflow through ice-shielded lock and condensing
  heat exchanger
  heat exchanger
   Black Point Lava Flow, Arizona
        October 18-31, 2008




     Preliminary Results of
Small Pressurized Rover Testing
     Hypotheses
1. Performance achieved during 1-day exploration/mapping/geological
1. Performance achieved during 1-day exploration/mapping/geological
   traverses using the Small Pressurized Rover (SPR) will be equal to or
   traverses using the Small Pressurized Rover (SPR) will be equal to or
   greater the performance achieved during Unpressurized Rover (UPR)
   greater the performance achieved during Unpressurized Rover (UPR)
   traverses, with less suit time.
   traverses, with less suit time.

2. Range achieved during 1-day exploration/mapping/geological traverses in
2. Range achieved during 1-day exploration/mapping/geological traverses in
   the SPR will be greater than during 1-day UPR traverses.
   the SPR will be greater than during 1-day UPR traverses.

3. Subjective assessment of contextual observations from inside an SPR will be
3. Subjective assessment of contextual observations from inside an SPR will be
   equal to suited contextual observations.
   equal to suited contextual observations.

4. Human interfaces to the SPR suit ports and alignment guides will be
4. Human interfaces to the SPR suit ports and alignment guides will be
   acceptable as assessed by human factors metrics.
   acceptable as assessed by human factors metrics.

5. The human factors and crew accommodations within the SPR will be
5. The human factors and crew accommodations within the SPR will be
   acceptable to support a 3-day exploration/mapping/geological traverse.
   acceptable to support a 3-day exploration/mapping/geological traverse.

6. Single-person EVA from the SPR exploiting the advantages of IVA and EVA
6. Single-person EVA from the SPR exploiting the advantages of IVA and EVA
   crewmembers will result in performance equal to or greater than a two-
   crewmembers will result in performance equal to or greater than a two-
   person EVA from the SPR or UPR, with less EVA suit time.
   person EVA from the SPR or UPR, with less EVA suit time.
       Study Design
♦ Two 2-person EVA crews
♦ Two 2-person EVA crews
   • One astronaut per crew
   • One astronaut per crew
   • One field geologist per crew
   • One field geologist per crew
   • Only one crew performed the 3-day SPR traverse
   • Only one crew performed the 3-day SPR traverse


                                        1-day                       3-day
                                UPR               SPR               SPR
           Crew A
                            Traverse UPR1A    Traverse SPR1A   Traverse SPR3A

                                SPR               UPR
           Crew B
                            Traverse UPR1B    Traverse SPR1B


♦ For the purpose of UPR-SPR comparisons, practically significant
♦ For the purpose of UPR-SPR comparisons, practically significant
  differences in metrics were prospectively defined for the testing of
  differences in metrics were prospectively defined for the testing of
  study hypotheses
  study hypotheses
   •
   •   10% difference in time, range and productivity metrics
       10% difference in time, range and productivity metrics
   •
   •   Categorical difference in subjective human factors metrics
       Categorical difference in subjective human factors metrics




                                                                                12
UPR 1-day Traverse Timeline
SPR 1-day Traverse Timeline
  SPR 1-day
Traverse Plan
  SPR 3-day
Traverse Plan
Performance Metric
Unique Performance Data
Sheets created for each
traverse based on pre-
defined traverse
objectives

Value of Traverse
Objectives pre-assigned
by Science Team

Data Quality scores
assigned post-traverse by
science team consensus
Hypothesis 1: Performance achieved during 1-day exploration/ mapping/
Hypothesis 1: Performance achieved during 1-day exploration/ mapping/
geological traverses using the Small Pressurized Rover (SPR) will be
geological traverses using the Small Pressurized Rover (SPR) will be
equal to or greater the performance achieved during Unpressurized Rover
equal to or greater the performance achieved during Unpressurized Rover
(UPR) traverses, with less suit time.
(UPR) traverses, with less suit time.

Data Collection: Performance and EVA Suit Time data collected during 2x
Data Collection: Performance and EVA Suit Time data collected during 2x
1-day UPR traverses and 2x 1-day SPR traverses [100% COMPLETE]
1-day UPR traverses and 2x 1-day SPR traverses [100% COMPLETE]

Results:
Results:

            EVA                                  Performance
            Time




        61% less EVA Time
        61% less EVA Time                     57% greater Performance
                                              57% greater Performance


  HYPOTHESIS ACCEPTED
  HYPOTHESIS ACCEPTED
  Hypothesis 1: Performance achieved during 1-day exploration/ mapping/
  Hypothesis 1: Performance achieved during 1-day exploration/ mapping/
  geological traverses using the Small Pressurized Rover (SPR) will be
  geological traverses using the Small Pressurized Rover (SPR) will be
  equal to or greater the Performance achieved during Unpressurized Rover
  equal to or greater the Performance achieved during Unpressurized Rover
  (UPR) traverses, with less suit time.
  (UPR) traverses, with less suit time.




   HYPOTHESIS ACCEPTED
   HYPOTHESIS ACCEPTED
Comments: SPR performance per EVA hr = 3.4 to 6.1 x greater than UPR
Comments: SPR performance per EVA hr = 3.4 to 6.1 x greater than UPR
          Mean: 4.7 x more productive per EVA hr than UPR
          Mean: 4.7 x more productive per EVA hr than UPR
Hypothesis 3: Subjective assessment of contextual observations from
Hypothesis 3: Subjective assessment of contextual observations from
inside an SPR will be equal to suited contextual observations.
inside an SPR will be equal to suited contextual observations.

Data Collection: Four geologists were allowed up to 20 mins to make
Data Collection: Four geologists were allowed up to 20 mins to make
shirt-sleeve observations of an area of the BPLF. They were then allowed
shirt-sleeve observations of an area of the BPLF. They were then allowed
up to 20 mins to make observations from within the SPR and then rated
up to 20 mins to make observations from within the SPR and then rated
the Geological Observation Quality (scale below) from inside the SPR and
the Geological Observation Quality (scale below) from inside the SPR and
provided other subjective remarks. [100% COMPLETE]
provided other subjective remarks. [100% COMPLETE]
   Hypothesis 3: Subjective assessment of contextual observations from
   Hypothesis 3: Subjective assessment of contextual observations from
   inside an SPR will be equal to suited contextual observations.
   inside an SPR will be equal to suited contextual observations.

   Results:
   Results:
         Average Geological Observation Quality inside SPR = 2.9
         Average Geological Observation Quality inside SPR = 2.9
         Shirt-sleeve Geological Observation Quality
         Shirt-sleeve Geological Observation Quality       = 3.0
                                                           = 3.0
            HYPOTHESIS ACCEPTED
            HYPOTHESIS ACCEPTED

   Comments: Results of this protocol suggest that – for this terrain – the
   Comments: Results of this protocol suggest that – for this terrain – the
   quality of contextual observations from inside the SPR are approximately
   quality of contextual observations from inside the SPR are approximately
   equal to unsuited contextual observations.
   equal to unsuited contextual observations.




Test Area
Suitport Egress
Hypothesis 4: Human interfaces to the SPR suit ports and alignment
Hypothesis 4: Human interfaces to the SPR suit ports and alignment
guides will be acceptable as assessed by human factors metrics.
guides will be acceptable as assessed by human factors metrics.

Data Collection: Suit port human factors data collected from four subjects
Data Collection: Suit port human factors data collected from four subjects
during 5 days of SPR traverses [100% COMPLETE]
during 5 days of SPR traverses [100% COMPLETE]




Results:
Results:
Suit port human factors data are currently being analyzed. Preliminary
Suit port human factors data are currently being analyzed. Preliminary
analysis of data (next slide), including data collected during JSC dry-runs,
analysis of data (next slide), including data collected during JSC dry-runs,
suggests that human factors of the suit ports and alignment guides are
suggests that human factors of the suit ports and alignment guides are
indeed acceptable. Issues have been identified with the latching
indeed acceptable. Issues have been identified with the latching
mechanisms and potential solutions identified.
mechanisms and potential solutions identified.

   HYPOTHESIS ACCEPTED
   HYPOTHESIS ACCEPTED
                                                            Modified Cooper-Harper
                            In
                               te

                                                                                                                         10




                                                    1
                                                        2
                                                            3
                                                                         4
                                                                             5
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                          EV                   s
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                             hu
                                m
                                                                                                                              Suit Port Human Factors




                                   an
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                     at
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                                                                                                      Unacceptable




                              ou
                                 to
                                    fs
                                       ui
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                                             or
                                                t
 Hypothesis 5: The human factors and crew accommodations within the
 Hypothesis 5: The human factors and crew accommodations within the
 SPR will be acceptable to support a 3-day exploration/ mapping/
 SPR will be acceptable to support a 3-day exploration/ mapping/
 geological traverse.
 geological traverse.




                  10
                       Fatigue: Pre- and Post- 1-day Traverses
                  9
                  8

                  7
Average Fatigue




                  6

                  5
                  4

                  3
                  2

                  1
                  0
                       UPR                SPR   UPR                 SPR

                             Pre-Flight               Post-Flight
Hypothesis 5: The human factors and crew accommodations within the
Hypothesis 5: The human factors and crew accommodations within the
SPR will be acceptable to support a 3-day exploration/ mapping/
SPR will be acceptable to support a 3-day exploration/ mapping/
geological traverse.
geological traverse.

Results (cont.d):
Results (cont.d):
                       Fatigue Ratings during 3-day SPR Traverse
           10
                                                                           Subject 1
           9                                                               Subject 2

           8
           7
           6
 Fatigue




           5
           4
           3
           2
           1
           0
                Pre           Post    Pre           Post    Pre            Post
                      Day 1                 Day 2                  Day 3
Base Camp
Base Camp
Base Camp
Base Camp
                                  Combining Field Operational Concept Data with
                                  Laboratory Physiological Data

                             45
                                                                                                                                                                                    450
                                                                                   Earth, unsuited (×)
                             40
                                                                                                                                                                                    400
                                                                                                                                                                                                                                               Earth
                             35




                                                                                                                                             Vertical Ground Reaction Force (lbs)
                                                                                                                                                                                    350
                             30
Metabolic Rate (ml/kg/min)




                                          Moon, suited (■)                                      Metabolic Cost of Suit
                                                                                                                                                                                    300
                             25                                                                                                                                                                                Suited

                                                                                                         Moon, unsuited / weighted (♦)                                              250
                             20



                             15                                                                                                                                                     200

                                                                                                                                                                                           Unsuited weighted
                                                                                                                                                                                                                                            Unsuited
                             10                                                                                                                                                     150
                                                                               Moon, unsuited (Δ)


                             5
                                                                                                                                                                                    100

                             0
                                  1   2           3          4                 5                    6                    7               8
                                                                                                                                                                                     50
                                                                 Speed (mph)                                                                                                           2           2.5          3       3.5        4         4.5       5   5.5   6
                                                                                                                                                                                                                              Speed (mph)




                                                                                                                                                                                                                                                       Base Camp
  Integrated Suit Tests: Test Traceability to Life
  Science Implications


                          Test Traceability to Life Sciences Implications
             Understand the impacts of EVA, from a life sciences perspective, on ______
                                                                      Behavioral
Operations         Bone            Muscle         Cardiovascular       Health &      Human Factors &
Concepts       Maintenance      Maintenance         Maintenance      Performance       Performance                    Test
    X                X                X                  X                                  X          EVA Walkback
    X                X                X                  X                                  X          IST-1




                                                                                                                                    Prior
    X                X                X                  X                                  X          IST-2
    X                                                    X                                             HMP Walkback
    X                                                                                       X          NEEMO 9-13
    X                                                                                       X          NBL
                                                                                                       Desert RATS '08
    X                                                                   X                 X
                                                                                                       (Small Pressurized Rover)
                                                                                                       C-9 Test
                     X                X                                                   X
                                                                                                       (varied mass)
                                                                                                       IST-3
                     X                X                X                                  X




                                                                                                                                    Future
                                                                                                       (shirtsleeve)
                                                                                                       C-9 Test
                     X                X                                                   X
                                                                                                       (varied weight)
                                                                                                       C-9 Test
                     X                X                                                   X
                                                                                                       (varied center of gravity)
                                                                                                       IST-3
                     X                X                X                                  X
                                                                                                       (suited)
Summary of SPR Test Performance
♦ 1-day Traverse Distance:
  1-day                       31% increase
♦ Productivity:                    57% increase
                                   57% increase
♦ Productivity per EVA Hour: 470 % increase
♦ Boots-on-Surface EVA Time: 23% increase
  Boots-on-Surface EVA Time: 23% increase
♦ Total EVA Time:          61% decrease
                                decrease
♦ Crew Fatigue:                    Statistically significant
  decrease
  C     Di      f t        St ti ti ll i ifi       t
      Suit-Induced Trauma

♦ Suit-induced trauma currently occurs with even
  minimal EVA time
   • Long duration missions with three 8hr EVAs per person
     per week
   • Apollo suits were used no more than 3 times
   • Individual crewmembers could perform up to 76 EVAs in
     a 6-month mission
♦ SPRs potentially reduce total EVA time by 50% or
  more - with same boots-on-surface exploration EVA
  time - because long translations are performed in SPR
  shirtsleeve environment and visibility is as good as
  EVA visibility
♦ Less time in EVA suit = less suit-induced trauma
       Improved Nutrition, Hydration and
       Waste Management Options

♦ Rapid ingress/egress capability enables IVA
♦ Rapid ingress/egress capability enables IVA
  solutions for nutrition, hydration and waste
  solutions for nutrition, hydration and waste
  management needs
  management needs
♦ In current design:
♦ In current design:
   •
   •   Flip-up counter reveals food stowage lockers
       Flip-up counter reveals food stowage lockers
   •
   •   Flash water heater access under counter for re-
       Flash water heater access under counter for re-
       hydration of food items
       hydration of food items
       Reduced Decompression Stress

♦ Suit Ports enable crew members to
♦ Suit Ports enable crew members to
  perform multiple short
  perform multiple short
  extravehicular activities (EVAs) at
  extravehicular activities (EVAs) at
  different locations in a single day
  different locations in a single day
  versus a single 8-hr EVA
  versus a single 8-hr EVA

♦ Previous modeling work and
♦ Previous modeling work and
  empirical human and animal data
  empirical human and animal data
  indicate that the intermittent
  indicate that the intermittent
  recompressions between EVA suit
  recompressions between EVA suit                                     9
                                                                                              Recompression
  pressure (≤4.3 psia, 100% O2) and       Cabin
  pressure (≤4.3 psia, 100% O2) and      Pressure
                                                                      8

  cabin pressure (8 psia, 32% O2)
  cabin pressure (8 psia, 32% O2)                                     7

  may reduce decompression stress
  may reduce decompression stress                                     6




                                                    Pressure (psia)
                                                                      5
                                          Suit
                                                                      4               EVA                          EVA
                                        Pressure
                                                                      3

                                                                      2

                                                                      1

                                                                      0
                                                                          0   1   2   3   4    5   6   7   8   9    10   11   12   13 14   15
                                                                                                   Time (hours)
        Reduced Decompression Stress:
        Tissue Bubble Dynamics Model (TBDM)


♦ Decompression stress index based on tissue
♦ Decompression stress index based on tissue
  bubble growth dynamics (Gernhardt, 1991)
  bubble growth dynamics (Gernhardt, 1991)
     • Original statistical analysis of 6437 laboratory
     • Original statistical analysis of 6437 laboratory
       dives (430 DCS cases) compared predictions of
       dives (430 DCS cases) compared predictions of
       the TBDM to Workman M-value and the
       the TBDM to Workman M-value and the
       Hempleman PrT index. TDBM predictions (Bubble
       Hempleman PrT index. TDBM predictions (Bubble
       Growth Index) yielded best log-likelihood and
       Growth Index) yielded best log-likelihood and
       Hosmer-Lemeshow goodness-of-fit test
       Hosmer-Lemeshow goodness-of-fit test
     • Used operationally in more than 25,000 dives with
     • Used operationally in more than 25,000 dives with
       extremely low DCS incidence (< 0.1%)
       extremely low DCS incidence (< 0.1%)




                          r = Bubble Radius (cm)
                          t = Time (sec)
                          a = Gas Solubility ((mL gas)/(mL tissue))
                          D = Diffusion Coefficient (cm2/sec)
                          h(r,t) = Bubble Film Thickness (cm)
                          Pa = Initial Ambient Pressure (dyne/cm2)
                          v = Ascent/Descent Rate (dyne/cm2⋅cm3)
                          g = Surface Tension (dyne/cm)
                          M = Tissue Modulus of Deformability (dyne/cm2⋅cm3)
                          PTotal = Total Inert Gas Tissue Tension (dyne/cm2)
                          Pmetabolic = Total Metabolic Gas Tissue Tension


Gernhardt M.L. Development and Evaluation of a Decompression Stress Index Based on Tissue Bubble Dynamics. Ph.D dissertation, University of
Pennsylvania, UMI #9211935, 1991.
                                     Reduced Decompression Stress:
                                     3 x 2hr EVA at 4.3 psi
                            40

                            35
Bubble Growth Index (BGI)




                            30
                                                      6hr Continuous EVA
                            25
                                                                        0.5hr between 2hr EVAs
                                                                               1hr between 2hr EVAs
                            20
                                                                                         2hr between 2hr EVAs

                            15

                                                                                                3hr between 2hr EVAs
                            10

                             5

                             0
                                 0    1   2   3   4   5   6   7     8      9     10   11   12    13   14   15   16     17
                                                                  Time (hours)
Shuttle Ground Test- Repetitive EVAs from 10.2 psi




     •VGE associated with repetitive EVA from 10.2 psi
     •~28% DCS for single 6 hr. EVA exposure ( n=35)
     •No DCS observed after first EVA exposure ( n=12)
        Pressurized Safe Haven for Treatment of
        Injuries or Decompression Sickness

♦ Crewmembers always within 20 minutes of a
♦ Crewmembers always within 20 minutes of a
  pressurized safe haven
  pressurized safe haven
♦ Enables treatment for decompression sickness
♦ Enables treatment for decompression sickness
  and expedited on-site treatment/medication of
  and expedited on-site treatment/medication of
  injured crewmembers
  injured crewmembers
♦ SPR will carry an expeditionary medical kit
♦ SPR will carry an expeditionary medical kit
♦ Medical capabilities of SPR will match the
♦ Medical capabilities of SPR will match the
  standards of care mandated by NASA
  standards of care mandated by NASA
  requirements based on the duration of the
  requirements based on the duration of the
  expedition and the distance from the outpost
  expedition and the distance from the outpost
♦ Incapacitated crewmembers brought into SPR
♦ Incapacitated crewmembers brought into SPR
  cabin using side hatch
  cabin using side hatch
♦ Two SPRs provides pressurized contingency
♦ Two SPRs provides pressurized contingency
  return capability
  return capability
   • With a single Large Pressurized Rover,
   • With a single Large Pressurized Rover,
     contingency return capability would be provided
     contingency return capability would be provided
     by an Unpressurized Rover, which decreases
     by an Unpressurized Rover, which decreases
     contingency return range
     contingency return range
    Exercise Countermeasures
♦ Time spent inside SPR during long translations may be spent
  exercising
♦ Exercise device being designed to provide cardiovascular (up to 75%
  VO2 peak) and resistive exercise capability
      2
♦ Crewmembers’ mechanical energy during exercise may be converted
  to electrical energy and used to help recharge SPR batteries
       Radiation Protection


♦ Water and polyethylene shield will provide
♦ Water and polyethylene shield will provide
  protection against Solar Particle Events
  protection against Solar Particle Events
  (SPEs)
  (SPEs)
♦ Shielding will vary from 1.3cm to 5.3 cm
♦ Shielding will vary from 1.3cm to 5.3 cm
  (0.5” to 2.4”) with less shielding needed in
  (0.5” to 2.4”) with less shielding needed in
  areas where the central lock is also
  areas where the central lock is also
  shielded by the rest of the SPR structure
  shielded by the rest of the SPR structure
    • Preliminary analysis based on reducing the
    • Preliminary analysis based on reducing the
      effective dose (organ averaged) below
      effective dose (organ averaged) below
      10cSv (Rem) for the historically largest
      10cSv (Rem) for the historically largest
      SPEs
      SPEs

♦ Polyethylene shielding will be used for surfaces where the use of water
  shielding would interfere with interior layout during nominal operations or
  be complicated by other structures e.g. suitport hatches
♦ SPE safe haven in the SPRs should eliminate the need for dedicated
  SPE shielding in either the habitats



                                                                                Page 58
                            SPR Shield Model Views
Shield Panel arrangement forming shelter                       Exploded view of water panels and
                                                                       flexible shielding




                                                                          Starboard crew
                                                                          member water
                                                                          phantom
 Baseline Case utilizes only radiator (ice) and vehicle shielding




  Radiator panel
                                                               Port crew
                                                               member target
                                                               points


                                                                                 Flexible Shield Curtain
                                                                           Option considered to cover suit port
Alternate Configuration “Pancake” V-Node
                                           Cylindrical inflatable
                                           dome:
                                           Height: 5.2m
                                           Volume: 63m3
                                           Diameter: 4.2m
                                           Flr area: 12m2 (129ft2) x2

                                           Inflatable dome is same
                                           diameter as pressure
                                           vessel, so nodes with
                                           domes can be docked
                                           together

                                           Deployable lightweight
                                           metal decking and
                                           supports (assembled
                                           autonomously, or by
                                           crew after inflation)

                                           Minimal node contains
                                           ECLSS, core functions,
                                           plumbing, water wall
                                           shielding, etc.



                                           Pancake V-Node in
                                           Lunarbago mode
                                                                Page 60
      Advantages of early HRP participation in SPR Evolution

♦ In addition to all of the health and safety benefits of the SPR itself, early
♦ In addition to all of the health and safety benefits of the SPR itself, early
  HRP participation provides a better understanding of operational
  HRP participation provides a better understanding of operational
  concepts and vehicle capabilities
  concepts and vehicle capabilities

♦ Head start on
    • Exercise
    • Exercise
      countermeasures
      countermeasures
    • Food packaging
    • Food packaging
      concepts
      concepts
    • Waste management
    • Waste management
      concepts
      concepts
    • Human
    • Human
      factors/ergonomics
      factors/ergonomics
    • Medical treatment
    • Medical treatment
      delivery concepts
      delivery concepts
    • Mitigating potential
    • Mitigating potential
      BHP issues
      BHP issues
                                  #16 - Life Science           #19 - Medical
    • Low entry cost
    • Low entry cost
      opportunities for
      opportunities for
      dedicated life sciences
      dedicated life sciences
      & medical laboratories
      & medical laboratories

				
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