integrating life sciences, engineering & operations

Integrating Life Sciences, Engineering & Operations Research to Optimize Human Safety

and Performance in Planetary Exploration

Mike GernhardtAugust 20, 2009Mike GernhardtAugust 20, 2009

The Challenge of Moving Past Apollo

Apollo was a remarkable human achievement, however fewer than 20 total program EVAs

Both surface crew performed EVA, but a maximum of 3 EVAs per mission

Up to 2000 EVAs (8 hrs/EVA) without LER, up to 10,000 EVAs (shorter duration) with LER

Limited mobility, dexterity, center of gravity and other features of the suit required significant crew compensation to accomplish the objectives. It would not be feasible to perform the Constellation EVAs using Apollo vintage designs

The vision is to develop an EVA system that is low overhead and results in close to (or better than) 1g shirt sleeve performance i.e. “

A suit that is a pleasure to work in, one that you would want to go out and explore in on your day off”

Lunar EVA will be very different from Earth orbit EVA –

a significant change in design and operational philosophies will be required to optimize suited human performance in lunar gravity

Unlike Shuttle & ISS, all CxP

crewmembers must be able to perform EVA –

and suits must be built to accommodate and optimize performance for all crew

Apollo was a remarkable human achievement, however fewer than 20 total program EVAs

Both surface crew performed EVA, but a maximum of 3 EVAs per mission

Up to 2000 EVAs (8 hrs/EVA) without LER, up to 10,000 EVAs (shorter duration) with LER

Limited mobility, dexterity, center of gravity and other features of the suit required significant crew compensation to accomplish the objectives. It would not be feasible to perform the Constellation EVAs using Apollo vintage designs

The vision is to develop an EVA system that is low overhead and results in close to (or better than) 1g shirt sleeve performance i.e. “

A suit that is a pleasure to work in, one that you would want to go out and explore in on your day off”

Lunar EVA will be very different from Earth orbit EVA –

a significant change in design and operational philosophies will be required to optimize suited human performance in lunar gravity

Unlike Shuttle & ISS, all CxP

crewmembers must be able to perform EVA –

and suits must be built to accommodate and optimize performance for all crew

Biomedical & Technological Challenges of EVA

•

Decompression (denitrogenation

required to work in low pressure suit (4.3 psi)) *separate proposed risk*

•

Thermoregulation (-120oC to + 120oC)

•

Nutrition (200 kcal/hr requirement)

•

Hydration (1 liter/EVA)

•

Waste Management

•

Radiation

•

Micrometeoroids and Orbital Debris

•

Suit Trauma

•

Mobility/Dexterity: current pressurized suits reduce mobility and dexterity

•

Visibility

Human & EVA System Relationships

Biomechanics

Human Factors

Suit Trauma/Injury Prevention

Thermal & Metabolic

Space Medicine

Sensorimotor

Radiation Protection

DCS Protection

Nutrition

Bone & Muscle

Exercise Physiology

Recommendations for:

Optimal Suit Weight, Mass, Pressure, CG and Kinematics

Suit Trauma Countermeasures

Contingency Reponses (Walkback, Suit Leak, Degrade Cooling)

Consumables, Usage & Management

Biomedical Sensors and algorithms

Validated Prebreathe

Protocols

Nutrition & Hydration Systems

Waste Management System

Exercise Countermeasureof EVA

HRP/EPSP: Provides medical expertise on what the human requires

EVA System: Working with HRP, determines what the system shall provide for the human

Challenges for EVA on the Moon

Dealing with risk and consequences of a significant Solar Particle Event (SPE)

Long duration missions with three 8hr EVAs

per person per week

Apollo suits were used no more than 3 times

Individual crewmembers might perform up to 76 EVAs

in a 6-month mission

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 and 10 km walkback

constraint

Science/geology community input that optimal scientific return within this range could be accomplished within ~ 30 days of EVA

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

Increased Decompression Sickness (DCS) risk and prebreathe

requirements associated with 8 psi 32% O2

cabin pressure versus Apollo with 5 psi 100% O2

The high frequency EVA associated with the projected lunar architectures will require significant increases in EVA work efficiency (EVA time/prep time)

Dealing with risk and consequences of a significant Solar Particle Event (SPE)

Long duration missions with three 8hr EVAs

per person per week

Apollo suits were used no more than 3 times

Individual crewmembers might perform up to 76 EVAs

in a 6-month mission

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 and 10 km walkback

constraint

Science/geology community input that optimal scientific return within this range could be accomplished within ~ 30 days of EVA

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

Increased Decompression Sickness (DCS) risk and prebreathe

requirements associated with 8 psi 32% O2

cabin pressure versus Apollo with 5 psi 100% O2

The high frequency EVA associated with the projected lunar architectures will require significant increases in EVA work efficiency (EVA time/prep time)

“The Wall of EVA”

ISS Construction

GeminiApollo/Skylab

Pre-ChallengerShuttle Shuttle

“The Wall”

“The Mountain of EVA”

0

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Year

EV

A H

ours

ISS Construction (projected)

Available Lunar EVA Hours (LAT-2 Option 2) –

based on Three 8 hour EVAs

per week using Unpressurized Rovers Need to extend range well beyond 10 km

Gemini

Apollo/Skylab Pre-ChallengerShuttle

Shuttle

“The Wall”

“The Mountain”

Systems Engineering Approach to Optimizing Human Safety & Performance in Planetary Exploration

‘Contributing Factors’ in RMAT

Systems Engineering Approach to Optimizing Human Safety & Performance in Planetary Exploration

Suit Design Parameters: Risks to Crew Health

Suit-Induced Trauma

Comprehensive review of musculoskeletal injuries/minor trauma sustained throughout U.S. space program (Scheuring

et al., 2009)

219 in-flight injuries, of which 50 were from wearing EVA suit

Incidence rate of 0.26 injuries per EVA (3 injuries per week based on LAT2 model)

Nine of the 219 in-flight injuries were sustained by Apollo astronauts who were performing lunar

surface EVAs.

One wrist laceration from the suit wrist ring while working with

drilling equipment

One account of wrist soreness due to the suit sleeve rubbing repeatedly

One shoulder injury while attempting to complete multiple surface activities on a tight mission timeline.

During Apollo Medical Operations Project summit, Apollo astronauts were adamant that the glove flexibility, dexterity, and fit be improved. (Scheuring

et al., 2007)

86 astronaut-subjects evaluated during 770 suited NBL test sessions.

Symptoms reported in 352, or 45.7%, of the sessions. Of these injuries, 47% involved hands; 21% shoulders; 11% feet; 6% each involved arms, legs, and

neck; and 3% involved the trunk

Strauss S. (2004) Extravehicular mobility unit training suit symptom study report. TP-2004-212075. NASA Lyndon B. Johnson Space Center, Houston.Scheuring RA, Jones JA, Polk JD, Gillis DB, Schmid JF, Duncan JM, Davis JR. (2007) The Apollo Medical Operations Project: recommendations to improve crew health

and performance for future exploration missions and lunar surface operations. TM-2007-214755. NASA Johnson Space Center, Houston. Scheuring RA, Mathers CH, Jones JA, Wear ML, Djojonegoro BM. (2009) Aviat. Space Environ. Med., 80(2):117-124.

Suit-Induced Trauma

Comprehensive review of musculoskeletal injuries/minor trauma sustained throughout U.S. space program (Scheuring

et al., 2009)

219 in-flight injuries, of which 50 were from wearing EVA suit

Incidence rate of 0.26 injuries per EVA (3 injuries per week based on LAT2 model)

Nine of the 219 in-flight injuries were sustained by Apollo astronauts who were performing lunar

surface EVAs.

One wrist laceration from the suit wrist ring while working with

drilling equipment

One account of wrist soreness due to the suit sleeve rubbing repeatedly

One shoulder injury while attempting to complete multiple surface activities on a tight mission timeline.

During Apollo Medical Operations Project summit, Apollo astronauts were adamant that the glove flexibility, dexterity, and fit be improved. (Scheuring

et al., 2007)

86 astronaut-subjects evaluated during 770 suited NBL test sessions.

Symptoms reported in 352, or 45.7%, of the sessions. Of these injuries, 47% involved hands; 21% shoulders; 11% feet; 6% each involved arms, legs, and

neck; and 3% involved the trunk

Strauss S. (2004) Extravehicular mobility unit training suit symptom study report. TP-2004-212075. NASA Lyndon B. Johnson Space Center, Houston.Scheuring RA, Jones JA, Polk JD, Gillis DB, Schmid JF, Duncan JM, Davis JR. (2007) The Apollo Medical Operations Project: recommendations to improve crew health

and performance for future exploration missions and lunar surface operations. TM-2007-214755. NASA Johnson Space Center, Houston.Scheuring RA, Mathers CH, Jones JA, Wear ML, Djojonegoro BM. (2009) Aviat. Space Environ. Med., 80(2):117-124.

Suit Induced Trauma

Mechanisms of Injury & Countermeasures for EVA Associated with Finger Pressure in EVA Gloves Study

Results:

The pressure bulb compression test resulted in 50% and 45% decreased blood flow at 100 mmHg and 200 mmHg, respectively (top right).

Contact forces during the bulb task were highest in the palmar

side of the finger, followed by the palm.

Blood flow decreased more than 60% during pressing tasks, more rapidly for finger pad compression (4 N) than for finger tip compression (10 N) (middle right)

Significant reactive hyperemia occurred upon release of axial compression (bottom right); this rapid return of blood flow to capillaries may be source of microvascular

damage that contributes to fingernail delamination. This needs to be further understood.

Future Work:

Pilot study to compare EVA astronauts with-

and without documented finger injury begins Sept 2009

Results will help understand compression-induced fingertip blood flow changes and drive follow-on studies to include non-

astronaut population, refinement of techniques to identify root cause(s) of fingertip injury

Results:

The pressure bulb compression test resulted in 50% and 45% decreased blood flow at 100 mmHg and 200 mmHg, respectively (top right).

Contact forces during the bulb task were highest in the palmar

side of the finger, followed by the palm.

Blood flow decreased more than 60% during pressing tasks, more rapidly for finger pad compression (4 N) than for finger tip compression (10 N) (middle right)

Significant reactive hyperemia occurred upon release of axial compression (bottom right); this rapid return of blood flow to capillaries may be source of microvascular

damage that contributes to fingernail delamination. This needs to be further understood.

Future Work:

Pilot study to compare EVA astronauts with-

and without documented finger injury begins Sept 2009

Results will help understand compression-induced fingertip blood flow changes and drive follow-on studies to include non-

astronaut population, refinement of techniques to identify root cause(s) of fingertip injury

Skin Blood Flow (%)

Human Performance Testing Series Objectives & Measurements

Human Performance Measurements Collected:

•

Metabolic Rate• CO2

and humidity produced

•

Body heat production & storage

•

Human kinematics (range of motion, cycles)

•

Gait parameters•

Subjective measurements of perceived exertion, comfort, and

•

Ground Reaction Forces (from surface contact)

Human Performance Measurements Collected:

•

Metabolic Rate•

CO2

and humidity produced

•

Body heat production & storage

•

Human kinematics (range of motion, cycles)

•

Gait parameters•

Subjective measurements of perceived exertion, comfort, and

•

Ground Reaction Forces (from surface contact)

Identify the relative contributions of weight, pressure, and suit kinematics to the overall metabolic cost of the MKIII suit in its POGO configuration in lunar gravity

To quantify the effects of varied gravity, varied mass, varied pressure, varied cg, and suit kinematic constraints on human performance

To develop predictive models of metabolic rate, subjective assessments, and suit kinematics based on measurable suit, task, and subject parameters

Initial Metabolic Data –

Lunar

Gravity

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8

Speed (mph)

VO

2 (m

l/min

/kg) Moon, suited (■)

Earth, unsuited ()

Moon, unsuited / weighted ()

Moon, unsuited (Δ)

Total Metabolic Cost of Suit

Weight Factors

Inertial MassKinematics

Pressure

50

100

150

200

250

300

350

400

450

500

1 2 3 4 5 6 7 8

Speed (mph)

Tra

nspo

rt C

ost (

ml/k

g/km

)

Moon, suited

Moon, unsuited weighted

Earth, unsuited

Moon, unsuited

Transport Cost

Metabolic Cost

Exploration Task Metabolic Cost Varied Weight

0

1

2

3

4

5

6

7

0 50 100 150 200 250 300 3501-g Equivalent Suit Weight (kg)

Tota

l O2 -

l/ta

sk (B

usy

Boa

rd &

Roc

k Tr

ansf

er)

0

20

40

60

80

100

120

140

VO2 -

ml/k

g ro

ck (S

hove

ling)Rock

Transfer

Busy Board

Shoveling

Exploration Task Metabolic Costs Varied Pressure

0

1

2

3

4

5

6

7

8

0 5 10 15 20 25 30 35Suit Pressure (kPa)

Tota

l O2 -

l/ta

sk (B

usy

Boa

rd, R

ock

Tran

sfer

)

0

10

20

30

40

50

60

70

80

VO2 -

ml/k

g ro

ck (S

hove

ling)Shoveling

Busy Board

RockTransfer

Inclined Walking Results

0

5

10

15

20

25

30

35

40

45

50

0% 5% 10% 15% 20% 25% 30% 35%

Treadmill Incline (%grade)

VO2 (

ml*k

g-1*m

in-1

)

Lunar Shirt Sleeve

Lunar SS Weight-Matched

Lunar Suited

1-g Shirt Sleeve

Lowest walking speed used

(1.4 –

2.2 mph)3 min per grade

Lowest walking speed used(1.4 –

2.2 mph)3 min per grade

Metabolic cost of weight increased with grade

Metabolic costs unrelated to weight decrease with grade•

Indicates energy recovery from suit

Metabolic cost of weight increased with grade

Metabolic costs unrelated to weight decrease with grade•

Indicates energy recovery from suit

Contributions of Weight, Pressure & Other Factors to Metabolic Cost of MKIII, Pogo Configuration in 1/6 Gravity

Baseline, 34%Baseline, 55%

Baseline, 37%

Weight, -37% Weight, -40% Weight, -46%

Pressure, 9%

Pressure, 2%

Pressure, -1%

Other Factors, 93%Other Factors, 83%

Other Factors, 110%

-50%

-25%

0%

25%

50%

75%

100%

125%

150%Busy Board Rock Transfer Shoveling

% M

etab

olic

Cos

t

Baseline, 50% Baseline, 51% Baseline, 55%

Weight, 11% Weight, 31%Weight, 39%

Pressure, 15%

Pressure, 10%

Pressure, 5%

Other Factors, 24%

Other Factors, 8%

Other Factors, 0%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

10% 20% 30%

Treadmill Incline (% Grade)

% M

etab

olic

Cos

t

Exploration Tasks

Ambulation

*Data for weight only,not mass-matched

Predicted Metabolic Rate Algorithm

Preliminary linear regression model

Uses the following combination of variables to predict normalized metabolic rates during locomotion in the MKIII EVA suit:

MR = b0 + (b1·Vlocomotion

· Wtotal

) + (b2·Mbody

) + (b3·(Wtotal

·Lleg

)) + (b4·Psuit

) where MR

= metabolic rate expressed as normalized VO2 (ml·kg-1·min-1)Vlocomotion

= locomotion speed (km/h)Wtotal

= total weight of EVA suit plus astronaut (N)Mbody

= body mass of unsuited astronaut (kg)Lleg

= leg length of astronaut (cm)Psuit

= suit pressure (kPa)

Preliminary linear regression model

Uses the following combination of variables to predict normalized metabolic rates during locomotion in the MKIII EVA suit:

MR = b0 + (b1·Vlocomotion

· Wtotal

) + (b2·Mbody

) + (b3·(Wtotal

·Lleg

)) + (b4·Psuit

) where MR

= metabolic rate expressed as normalized VO2 (ml·kg-1·min-1)Vlocomotion

= locomotion speed (km/h)Wtotal

= total weight of EVA suit plus astronaut (N)Mbody

= body mass of unsuited astronaut (kg)Lleg

= leg length of astronaut (cm)Psuit

= suit pressure (kPa)

R2 = 1

R2 = 0.8464

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0

Measured VO2 (ml·kg-1·min-1)

Mod

el P

redi

cted

VO

2 (m

l·kg-1

·min

-1)

Root mean square error = 2.52 ml·kg-1·min-1 (< 3.5 ml·kg-1·min-1)

-7.0

-3.5

0.0

3.5

7.0

10.5

14.0

17.5

0 1 2 3 4 5 6 7 8 9 10 11

Speed (km·h-1)

Δ V

O2 (

ml·k

g-1·m

in-1

)

Intrasite Translation

Site to SiteWalkback

63 kg

186 kg

247 kg

308 kg

121 kg Baseline

± 3.5 ml·kg-1·min-1

Translation

Predicted effect of suit weight on metabolic rate (operational concepts)

Center of Gravity Studies

Background:•

Center of Gravity (CG) is likely to be an important variable in astronaut performance during partial gravity EVA

•

The Apollo lunar EVA experience revealed challenges with suit stability and control

•

Likely a combination of mobility and center of gravity factors

CG Studies conducted in several environments:

NBL (2007)

NEEMO (Missions 9-13)

Pogo (Integrated Suit Test 3)

C-9 Parabolic Aircraft

Initial testing focused on 6 different CG locations that included the baseline PLSS design and the extremes of what was considered a realistic PLSS mass distribution

After initial testing, PLSS packaging was refined resulting in two new configurations (fanny pack, flex pack). Additionally the Apollo PLSS, and a true 0,0 CG location were evaluated

Background:•

Center of Gravity (CG) is likely to be an important variable in astronaut performance during partial gravity EVA

•

The Apollo lunar EVA experience revealed challenges with suit stability and control

•

Likely a combination of mobility and center of gravity factors

CG Studies conducted in several environments:

NBL (2007)

NEEMO (Missions 9-13)

Pogo (Integrated Suit Test 3)

C-9 Parabolic Aircraft

Initial testing focused on 6 different CG locations that included the baseline PLSS design and the extremes of what was considered a realistic PLSS mass distribution

After initial testing, PLSS packaging was refined resulting in two new configurations (fanny pack, flex pack). Additionally the Apollo PLSS, and a true 0,0 CG location were evaluated

Underwater CG Study Results

Modified Cooper-Harper Ratings for Varied CG Configuration Ambulation vs. Exploration Tasks

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

Ideal Low Forward High Aft Baseline Flex.Backpack

Flex. FannyPack

Apollo 0,0,0

CG Configuration

Mod

ified

C-H

Rat

ing

Average C-H(ambulation)

Average C-H(exploration)

Task Performance Adequate w/o hardware improvement

Initial 6 CG configs Refined CG configs,

plus Apollo

Modified Cooper-Harper Ratings for Varied CG Configuration Ambulation vs. Exploration Tasks

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

Ideal Low Forward High Aft Baseline Flex.Backpack

Flex. FannyPack

Apollo 0,0,0

CG Configuration

Mod

ified

C-H

Rat

ing

Average C-H(ambulation)

Average C-H(exploration)

Task Performance Adequate w/o hardware improvement

Initial 6 CG configs Refined CG configs,

plus Apollo

•

Forward•

Ideal•

Low•

High•

Baseline•

Aft

Rank Order (Best to Worst)Ambulation

•

Forward•

Ideal•

Low•

Baseline•

High•

Aft

Exploration Tasks•

Forward•

Ideal•

Low•

High•

Baseline•

Aft

Incline•

Forward•

Ideal•

Low•

Baseline•

High•

Aft

Decline

NEEMO/NBL GCPS (C-H) Probabilities vs. CG Location

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

-8.0 -6.0 -4.0 -2.0 0.0 2.0

Aft (in) Forward (in)

Low

(in)

H

igh

(in)

HIGH

CTSD 2005BASELINE

APOLLO

AFT

LOW

FANNYPACK

BACKPACK

IDEAL

0,0,0 CH=1-3

CH=4-6

CH=7-10

PROBABILITY OF:

MODIFIED COOPER-HARPER PROBABILITY VS. CG LOCATION

Exploration Tasks

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

-8.0 -6.0 -4.0 -2.0 0.0 2.0

Aft (in) Forward (in)

Low

(in)

H

igh

(in)

HIGH

CTSD 2005BASELINE

APOLLO

AFT

LOW

FANNYPACK

BACKPACK

IDEAL

0,0,0 CH=1-3

CH=4-6

CH=7-10

PROBABILITY OF:

MODIFIED COOPER-HARPER PROBABILITY VS. CG LOCATION

Level Ambulation Tasks

RPE CH RPE CH RPE CH RPE CH RPE CH RPE CHBackpack 8 3 9 3 12 5 10 4 12 4 12 3

CTSD 8 4 9 4 12 4 10 4 12 4 12 4POGO 9 5 11 6 12 5 11 5 11 4 12 4

Backpack 8 3 9 2 11 4 10 5 12 5 9 3CTSD 8 4 9 4 12 4 10 4 12 4 12 3POGO 8 5 11 5 13 6 10 6 12 5 13 5




Shoveling

19074

29.3

Walking

Kneel/ Recover (down)Kneel/ Recover (up)

Rock Pickup

PHASE II DATA Subject ID2080 2501 1051 1459 7068 6678

2874.529.3

16269

28.471

29.1Task CG

1607328

14869

215 173

C9 –

CG Comparison Modified CH & RPE Preliminary Data

C9 data at suit/rig mass of 400 lb; NEEMO/NBL at 195 lb

3-7 CHvariabilityacrosssubjects

Subject Variability

Earth Shirt-Sleeve Performance Index (ESSPI)

Earth Shirt-sleeve Performance Index = MET RATE X

MET RATE earth shirt-sleeved

Ambulation

Exploration Tasks

where x = condition being tested (1/6g suited, etc.))

ESSPI is an index which relates metabolic rate for a given condition of interest to metabolic rate during the same task in the reference 1g shirt-

sleeved condition

10 km Walkback

Summary10 km Walkback Summary Data

(averaged across entire 10 km unless noted)

MEAN SD

Avg walkback velocity (mph) 3.9 0.5

Time to complete 10 km (min) 95.8 13

Avg %VO2 pk 50.8% 6.1%

Avg met rate (BTU/hr) 2374 303.9

Max. 15-min-avg met rate (BTU/hr) 2617 315

Total energy expenditure (kcal) 944.2 70.5

RPE 11.8 1.6

Cooper-Harper 3.5 1.4

Water used for drinking (oz) ~24-32 N/A

Planning / PLSS Sizing Data Walkback Apollo

O2 Usage 0.4 lbs/hr 0.15 lbs/hr

BTU average 2374 BTU/hr 933 BTU/hr

Cooling water 3.1 lbs/hr 0.98 lbs/hr

Energy expenditure 599 kcal/hr 233 kcal/hr

1

2

3

4

5

6

0 20 40 60 80 100 120

Time (min)

Spee

d (m

ph)

100

150

200

250

300

350

400

0 1 2 3 4 5 6 7

Speed (mph)

Tran

spor

t Cos

t (m

l/kg/

km)

1000

1500

2000

2500

3000

3500

Hea

t Pro

duct

ion

(BTU

/hr)

Transport cost,Moon suited (□)

Heat Production ( ) Cooling Limit ofApollo & STS

Suits

Faster speeds provide improved efficiency, but require higher metabolic cost and associated heat production

Cooling is a limiting factor

Implications for Walkback

HMP: Effects of Terrain and Navigation

↑

VO2

by 56% on average(range 41-67%)

↑

Distance by 7% (up to 21%)

↑

VO2

by 56% on average(range 41-67%)

↑

Distance by 7% (up to 21%)

10.18 9.8410.30

9.79 9.57 9.81 9.91 9.89 9.89

0.690.42

1.24

0.520.27

2.06

0.35 0.37 0.48

0.00

2.00

4.00

6.00

8.00

10.00

12.00

1 2 3 1 2 3 1 2 3

Route and Subject

Stra

ight

Lin

e D

ista

nce

(km

)

Radial 17Radial 00 Radial 23

0

5

10

15

20

25

30

35

40

45

50

0 20 40 60 80 100 120

Time

VO2 (

ml/m

in/k

g)

JSCHMPDelta VO2

Summary (n=3) HMP JSCJSC ΔVO2

AvgAvg

VOVO

22

((mLmL··kgkg--11··minmin--11))

26.9 ±

6.4

17.1 17.1 ±±

4.94.9

9.8 ±

3.8

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)

Suitports: allows suit donning and vehicle egress in < 10min with minimal gas loss

Work Package Interface: allows attachment of modular work packages e.g. winch, cable reel, backhoe, crane

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 ice vs. evaporating water to vacuum.

Aft Driving Station: enables crew to drive rover while EVA

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

Radiator on Roof: allows refreezing of fusible heat sink water on extended sorties

Small Pressurized Rover Design Features (Slide 2 of 2)

Modular Design:

pressurized module is transported using Mobility Chassis. Pressurized module and chassis may be delivered on separate landers

or pre-integrated on same lander.

Docking Hatch: allows pressurized crew transfer from Rover-to-Habitat, Rover-to-Ascent Module and/or Rover-to-Rover

Dome windows:

provide visibility as good, or better than, EVA suit visibility

Pivoting Wheels:

enables crab-

style driving for docking

Cantilevered cockpit:

Mobility Chassis does not obstruct visibility

Exercise ergometer

(inside):

allows crew to exercise during translations

Two Pressurized Rovers: low mass, low volume design enables two pressurized vehicles, greatly extending contingency return (and thus exploration) range

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

Mate/de-mate from Hab/Lander: ≤

10mins and ≤

0.03kg gas losses

Nominal velocity: 10kph

Driving naked-eye visibility should be comparable to walking in suit i.e. eyes

at same level, similar Field-of-View

Augmented by multi-spectral cameras/instruments

Visual accessibility to geological targets comparable to EVA observations i.e. naked eyes ≤

1m of targets

Possibility of magnification optics providing superior capability than EVA observations

Suit don and Egress/Egress

≤

10mins

≤

0.03kg gas losses per person

≥

2 independent methods of ingress/egress

Vehicle Mass (not incl. mobility chassis) ≤

2400kg

Habitable volume: ~10 m3

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

PLSS recharge time ≤

30mins

Crewmembers ≤

20mins

from ice-shielded lock SPE protection (incl. translation to Small Pressurized Rovers and ingress)

Heat and humidity rejection provided by airflow through ice-shielded lock and condensing heat exchanger

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

Nominal velocity: 10kph

Driving naked-eye visibility should be comparable to walking in suit i.e. eyes

at same level, similar Field-of-View

Augmented by multi-spectral cameras/instruments

Visual accessibility to geological targets comparable to EVA observations i.e. naked eyes ≤

1m of targets

Possibility of magnification optics providing superior capability than EVA observations

Suit don and Egress/Egress

≤

10mins

≤

0.03kg gas losses per person

≥

2 independent methods of ingress/egress

Vehicle Mass (not incl. mobility chassis) ≤

2400kg

Habitable volume: ~10 m3

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

PLSS recharge time ≤

30mins

Crewmembers ≤

20mins

from ice-shielded lock SPE protection (incl. translation to Small Pressurized Rovers and ingress)

Heat and humidity rejection provided by airflow through ice-shielded lock and condensing heat exchanger

Black Point Lava Flow, Arizona

October 18-31, 2008

Preliminary Results of Small Pressurized Rover Testing

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 traverses using the Small Pressurized Rover (SPR) will be equal to or greater the performance achieved during Unpressurized Rover (UPR) traverses, with less suit time.

2.

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

3.

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

4.

Human interfaces to the SPR suit ports and alignment guides will

be acceptable as assessed by human factors metrics.

5.

The human factors and crew accommodations within the SPR will be

acceptable to support a 3-day exploration/mapping/geological traverse.

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-

person EVA from the SPR or UPR, with less EVA suit time.

1.

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

2.

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

3.


4.

Human interfaces to the SPR suit ports and alignment guides will

be acceptable as assessed by human factors metrics.

5.

The human factors and crew accommodations within the SPR will be

acceptable to support a 3-day exploration/mapping/geological traverse.

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-

person EVA from the SPR or UPR, with less EVA suit time.

Study Design

Two 2-person EVA crews

One astronaut per crew

One field geologist per crew

Only one crew performed the 3-day SPR traverse

For the purpose of UPR-SPR comparisons, practically significant differences in metrics were prospectively defined for the testing of study hypotheses

10% difference in time, range and productivity metrics

Categorical difference in subjective human factors metrics

Two 2-person EVA crews

One astronaut per crew

One field geologist per crew

Only one crew performed the 3-day SPR traverse

For the purpose of UPR-SPR comparisons, practically significant differences in metrics were prospectively defined for the testing of study hypotheses

10% difference in time, range and productivity metrics

Categorical difference in subjective human factors metrics

36

11--dayday 33--dayday

Crew ACrew A UPRUPR SPRSPR SPRSPRTraverse UPR1ATraverse UPR1A Traverse SPR1ATraverse SPR1A Traverse SPR3ATraverse SPR3A

Crew BCrew B SPRSPR UPRUPRTraverse UPR1BTraverse UPR1B Traverse SPR1BTraverse SPR1B

UPR 1-day Traverse Timeline

SPR 1-day Traverse Timeline

SPR 3-day Traverse Plan

SPR 3-day Traverse Plan

Performance Metric

Value of Traverse Objectives pre-assigned by Science Team

Data Quality scores assigned post-traverse by science team consensus

Unique Performance Data Sheets created for each traverse based on pre-

defined traverse objectives

Hypothesis 1:

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

Data Collection:

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

Results:

HYPOTHESIS ACCEPTED

Hypothesis 1:

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

Data Collection:

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

Results:

HYPOTHESIS ACCEPTED

EVA Time Performance

61% less EVA Time61% less EVA Time 57% greater Performance57% greater Performance

Hypothesis 1:

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

HYPOTHESIS ACCEPTEDComments: 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

Hypothesis 1:

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

HYPOTHESIS ACCEPTEDComments: Comments: SPR performance per EVA hr = 3.4 to 6.1 x greater than UPRSPR performance per EVA hr = 3.4 to 6.1 x greater than UPR

Mean: 4.7 x more productive per EVA hr than UPRMean: 4.7 x more productive per EVA hr than UPR

Hypothesis 3:


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 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 provided other subjective remarks. [100% COMPLETE]

Hypothesis 3:


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 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 provided other subjective remarks. [100% COMPLETE]

Hypothesis 3:


Results:

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

Comments: Results of this protocol suggest that –

for this terrain –

the quality of contextual observations from inside the SPR are approximately equal to unsuited

contextual observations.

Hypothesis 3:


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

Comments: Results of this protocol suggest that –

for this terrain –

the quality of contextual observations from inside the SPR are approximately equal to unsuited

contextual observations.

Test Area

Suitport

Egress

Hypothesis 4:

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

Data Collection:

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

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

HYPOTHESIS ACCEPTED

Hypothesis 4:

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

Data Collection:

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

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

HYPOTHESIS ACCEPTED

Suit Port Human Factors

1

2

3

4

5

6

7

8

9

10

Intern

al ac

cess

Interi

or ha

nd ho

lds

Genera

l IVA op

eratio

nsExte

rnal a

cces

sExte

rnal h

and h

olds

Genera

l EVA op

eratio

ns

Overal

l hum

an fa

ctors

Donnin

g

Doffing

Interi

or ve

hicle

volum

e for

donn

ing

Interi

or ve

hicle

volum

e for

doffin

g

Transla

tion i

nto su

it port

Transla

tion o

ut of

suit p

ortM

odifi

ed C

oope

r-H

arpe

r

Unacceptable

Acceptable

Borderline

Hypothesis 5:

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

Hypothesis 5:


0

1

2

3

4

5

6

7

8

9

10

UPR SPR UPR SPR

Pre-Flight Post-Flight

Ave

rage

Fat

igue

Fatigue: Pre-

and Post-

1-day Traverses

Hypothesis 5:


Results (cont.d):

Hypothesis 5:


Results (cont.d):

Fatigue Ratings during 3-day SPR Traverse

0

1

2

3

4

5

6

7

8

9

10

Pre Post Pre Post Pre Post

Day 1 Day 2 Day 3

Fatig

ue

Subject 1Subject 2

Base CampBase Camp

Base CampBase Camp

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8

Speed (mph)

Met

abol

ic R

ate

(ml/k

g/m

in)

Moon, suited (■)

Earth, unsuited ()

Moon, unsuited / weighted ()

Moon, unsuited (Δ)

Metabolic Cost of Suit

2 2.5 3 3.5 4 4.5 5 5.5 650

100

150

200

250

300

350

400

450

Speed (mph)

Ver

tical

Gro

und

Rea

ctio

n Fo

rce

(lbs)

Earth

Suited

UnsuitedUnsuited weighted

Combining Field Operational Concept Data with Laboratory Physiological Data

Integrated Suit Tests: Test Traceability to Life Science Implications

Operations Concepts

Bone Maintenance

Muscle Maintenance

Cardiovascular Maintenance

Behavioral Health &

PerformanceHuman Factors &

PerformanceX X X X X EVA WalkbackX X X X X IST-1X X X X X IST-2X X HMP WalkbackX X NEEMO 9-13X X NBL

X X X Desert RATS '08(Small Pressurized Rover)

X X X C-9 Test(varied mass)

X X X X IST-3(shirtsleeve)

X X X C-9 Test(varied weight)

X X X C-9 Test(varied center of gravity)

X X X X IST-3(suited)

Test Traceability to Life Sciences ImplicationsUnderstand the impacts of EVA, from a life sciences perspective, on ______

Prio

rFu

ture

Test

Summary of SPR Test Performance1‐day Traverse Distance: 31% increase

Productivity:

57% increase

Productivity per EVA Hour: 470 % increase

Boots‐on‐Surface EVA Time: 23% increase

Total EVA Time:

61% decrease

Crew Fatigue:

Statistically significant decrease

Crew Discomfort:

Statistically significant decrease

Summary of SPR Test PerformanceSummary of SPR Test Performance 11‐‐day Traverse Distance: 31% increaseday Traverse Distance: 31% increase

Productivity: Productivity:

57% increase57% increase

Productivity per EVA Hour: 470 % increaseProductivity per EVA Hour: 470 % increase

BootsBoots‐‐onon‐‐Surface EVA Time: 23% increaseSurface EVA Time: 23% increase

Total EVA Time:Total EVA Time:

61% decrease61% decrease

Crew Fatigue: Crew Fatigue:

Statistically significant decreaseStatistically significant decrease

Crew Discomfort: Crew Discomfort:

Statistically significant decreaseStatistically significant decrease

Reduced Decompression Stress (DCS)

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

Intermittent Recompressions (IR) during saturation decompression previously proposed as a method for decreasing decompression stress and time (Gernhardt,1988)

Gas bubbles respond to changes in hydrostatic pressure on a time scale much faster than the tissues

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

Intermittent Recompressions (IR) during saturation decompression previously proposed as a method for decreasing decompression stress and time (Gernhardt,1988)

Gas bubbles respond to changes in hydrostatic pressure on a time scale much faster than the tissues

0

1

2

3

4

5

6

7

8

9

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Time (hours)

Pres

sure

(psi

a)EVA EVA

Cabin Pressure

Recompression

Suit Pressure

IR has been shown to decrease decompression stress in humans and animals (Pilmanis

et al. 2002, Møllerløkken

et al. 2007)

Tissue Bubble Dynamics Model (TBDM)-

Provides Significant Prediction and Fit of Diving and Altitude DCS Data

Decompression stress index based on tissue bubble growth dynamics (Gernhardt, 1991)

Diving: n = 6437 laboratory (430 DCS cases)

Logistic Regression Analysis: p <0.01

Hosmer-Lemeshow Goodness of Fit = 0.77

Altitude: n = 345 (57 DCS, 143 VGE)

Logistic Regression Analysis (DCS): p <0.01

Logistic Regression Analysis (VGE): p <0.01

Hosmer-Lemeshow Goodness of Fit (DCS): p = 0.35

Hosmer-Lemeshow Goodness of Fit (VGE): p = 0.55

Decompression stress index based on tissue bubble growth dynamics (Gernhardt, 1991)

Diving: n = 6437 laboratory (430 DCS cases)

Logistic Regression Analysis: p <0.01

Hosmer-Lemeshow Goodness of Fit = 0.77

Altitude: n = 345 (57 DCS, 143 VGE)

Logistic Regression Analysis (DCS): p <0.01

Logistic Regression Analysis (VGE): p <0.01

Hosmer-Lemeshow Goodness of Fit (DCS): p = 0.35

Hosmer-Lemeshow Goodness of Fit (VGE): p = 0.55

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/cm2cm3)g = Surface Tension (dyne/cm)M = Tissue Modulus of Deformability (dyne/cm2cm3)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

0

5

10

15

20

25

30

35

40

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Time (hours)

Bub

ble

Gro

wth

Inde

x (B

GI)

3hr between 2hr EVAs

0.5hr between 2hr EVAs1hr between 2hr EVAs

2hr between 2hr EVAs

6hr Continuous EVA

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)

2 2.5 3 3.5 4 4.5 5 5.5 650

100

150

200

250

300

350

400

450

Speed (mph)

Ver

tical

Gro

und

Rea

ctio

n Fo

rce

(lbs)

Earth

Suited

UnsuitedUnsuited weighted

Lunar Ground Reaction Forces: Implications for Prebreath

and Exercise Countermeasures

0

20

40

60

80

Ambulatory Non-Amb.%

DCS

2/203/21

10/20

1/21

Legs (p=0.0008)

95% CI

Arms (NS)

Duke, NASA micro-gravity simulation (non ambulation-3.5 hr prebreathe)

Background: Background: Abbreviated Suit Purge Abbreviated Suit Purge ––

Mass and Time SavingsMass and Time Savings

EVA suits are purged of N2

prior to depressurization to achieve ≥

95% O2

Purge requires ~ 8 minutes and uses 0.65 lb gas per purge per suit

In an airlock, most of this gas is reclaimed but with a suit port this gas is vented to vacuum Shortening the purge will expedite vehicle egress & save gas

A 2 min purge saves ~0.48 lb gas and 6 minutes of crew time per person per egress compared with a standard 8 min purge

EVA suits are purged of N2

prior to depressurization to achieve ≥

95% O2

Purge requires ~ 8 minutes and uses 0.65 lb gas per purge per suit

In an airlock, most of this gas is reclaimed but with a suit port this gas is vented to vacuum Shortening the purge will expedite vehicle egress & save gas

A 2 min purge saves ~0.48 lb gas and 6 minutes of crew time per person per egress compared with a standard 8 min purge 6 month mission, 4 crew, 3 egresses /day,

6 days/week:

900 lb gas + tankage

= 1800 lb (819 kg)

Over 31 hours

of crew time saved

0.16lb

0.32lb

0.81lb

0.65lb

Cumulative Gas and Crew Time Saved by Abbreviated Purge

Background: Abbreviated Suit Purge –

Decreased Off-Gassing Gradient

An abbreviated purge saves gas and crew time, but decreases the tissue N2

off-gassing gradient because suit O2

reaches only 80% compared with 95% O2

achieved during an 8 minute purge

However, the benefit of 95% O2

vs. 80% O2

for denitrogenation

is reduced when initial saturation pressure is 8 PSI, 32% O2

(LER) vs. 14.7 PSI 21% O2

(ISS) as there is a smaller change in off-gassing gradient

An abbreviated purge saves gas and crew time, but decreases the tissue N2

off-gassing gradient because suit O2

reaches only 80% compared with 95% O2

achieved during an 8 minute purge

However, the benefit of 95% O2

vs. 80% O2

for denitrogenation

is reduced when initial saturation pressure is 8 PSI, 32% O2

(LER) vs. 14.7 PSI 21% O2

(ISS) as there is a smaller change in off-gassing gradient

Approximate. Based on 1.5ft3

floodable volume @ 8 PSI

Pressurized Safe Haven for Treatment of Injuries or Decompression Sickness

Crewmembers always within 20 minutes of a pressurized safe haven

Enables treatment for decompression sickness and expedited on-site treatment/medication of injured crewmembers

SPR will carry an expeditionary medical kit

Medical capabilities of SPR will match the standards of care mandated by NASA requirements based on the duration of the expedition and the distance from the outpost

Incapacitated crewmembers brought into SPR cabin using side hatch

Two SPRs

provides pressurized contingency return capability

With a single Large Pressurized Rover, contingency return capability would be provided by an Unpressurized Rover, which decreases contingency return range

Crewmembers always within 20 minutes of a pressurized safe haven

Enables treatment for decompression sickness and expedited on-site treatment/medication of injured crewmembers

SPR will carry an expeditionary medical kit

Medical capabilities of SPR will match the standards of care mandated by NASA requirements based on the duration of the expedition and the distance from the outpost

Incapacitated crewmembers brought into SPR cabin using side hatch

Two SPRs

provides pressurized contingency return capability

With a single Large Pressurized Rover, contingency return capability would be provided by an Unpressurized Rover, which decreases 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 Crewmembers’

mechanical energy during exercise may be converted to electrical energy and used to help recharge SPR batteries

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 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 protection against Solar Particle Events (SPEs)

Shielding will vary from 1.3cm to 5.3 cm (0.5”

to 2.4”) with less shielding needed in areas where the central lock is also shielded by the rest of the SPR structure

Preliminary analysis based on reducing the effective dose (organ averaged) below 10cSv (Rem) for the historically largest SPE

Water and polyethylene shield will provide protection against Solar Particle Events (SPEs)

Shielding will vary from 1.3cm to 5.3 cm (0.5”

to 2.4”) with less shielding needed in areas where the central lock is also shielded by the rest of the SPR structure

Preliminary analysis based on reducing the effective dose (organ averaged) below 10cSv (Rem) for the historically largest SPE

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

Alternate Configuration “Pancake”

V-NodeCylindrical inflatable dome:Height: 5.2mVolume: 63m3

Diameter: 4.2mFlr

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

modePage 81

Advantages of early HRP participation in SPR Evolution

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

concepts and vehicle capabilities

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

concepts and vehicle capabilities

#19 -

Medical#16 -

Life Science

Head start on

Exercise countermeasures

Food packaging concepts

Waste management concepts

Human factors/ergonomics

Medical treatment delivery concepts

Mitigating potential BHP issues

Low entry cost opportunities for dedicated life sciences & medical laboratories

Head start on

Exercise countermeasures

Food packaging concepts

Waste management concepts

Human factors/ergonomics

Medical treatment delivery concepts

Mitigating potential BHP issues

Low entry cost opportunities for dedicated life sciences & medical laboratories

Exploration:•

Exploration range of up to 1000km (vs. 240km w/ large pressurized rover)

•

Shirt-sleeve envnmt

with visibility as good as suited EVAs•

Multi-spectral sensors & instruments always available•

Single-person EVA capability

Exploration:•

Exploration range of up to 1000km (vs. 240km w/ large pressurized rover)

•

Shirt-sleeve envnmt

with visibility as good as suited EVAs•

Multi-spectral sensors & instruments always available•

Single-person EVA capability

Operational / Engineering:•

Potential for transfer under pressure from Ascent Module and/or hab

(PLSSs

kept in controlled envnmnt

for re-use)

•

Reduced cycles on suit

•

Uses suit PLSS for life support

•

Potential for 4hr (lighter weight) PLSS-

Mars forward

•

Potential to achieve Work Efficiency Index (WEI) of up to 9.0 for individual EVA excursions

•

Reduces suit nutrition, hydration and waste mgmnt

needs

•

Eliminates need for contingency walkback, decreasing design reqts

for suit

•

>50% reduction in EVA time for equal or greater productivity and

increased range

Health & Safety:•

SPE protection within 20mins•

Pressurized safe-haven within 20mins •

DCS treatment within 20mins•

Expedited on-site treatment and/or medication of injured crewmember

•

Reduces suit induced trauma•

Better options for nutrition, hydration, waste management•

Increased DCS safety, decreased prebreathe

reqts

through intermittent recompression (would allow 3.5psi suit)

•

Provides resistive and cardiovascular exercise (75% VO2 peak) during otherwise unproductive translation time

•

Better background radiation shielding vs. EVA suit•

Dust control through use of suit port

Health & Safety:•

SPE protection within 20mins•

Pressurized safe-haven within 20mins •

DCS treatment within 20mins•

Expedited on-site treatment and/or medication of injured crewmember

•

Reduces suit induced trauma•

Better options for nutrition, hydration, waste management•

Increased DCS safety, decreased prebreathe

reqts

through intermittent recompression (would allow 3.5psi suit)

•

Provides resistive and cardiovascular exercise (75% VO2 peak) during otherwise unproductive translation time

•

Better background radiation shielding vs. EVA suit•

Dust control through use of suit port

Architectural: •

2 Pressurized Rovers weigh less than single large pressurized rover

–

Enables earlier delivery, possibly on crewed landers•

Up to 12,000 kg H2

O mass savings (with Rover and PLSS Heat Sink)

•

1000kg+ O2

and N2

mass savings and up to 144 days

less depress time using suit port vs. suitlock

–

Earlier long-duration crew missions–

Aggressive development of Hab

ECLSS less important•

“Gods-eye view”

capability (highly desirable for public outreach)•

Vehicle design and required technologies highly relevant to Mars

missions

•

No major cost burden for early SPRs

-

majority of DDT&E for critical components needed early anyway

Architectural: •

2 Pressurized Rovers weigh less than single large pressurized rover–

Enables earlier delivery, possibly on crewed landers•

Up to 12,000 kg H2

O mass savings (with Rover and PLSS Heat Sink)

•

1000kg+ O2

and N2

mass savings and up to 144 days

less depress time using suit port vs. suitlock–

Earlier long-duration crew missions–

Aggressive development of Hab

ECLSS less important•

“Gods-eye view”

capability (highly desirable for public outreach)•

Vehicle design and required technologies highly relevant to Mars

missions•

No major cost burden for early SPRs

-

majority of DDT&E for critical components needed early anyway

Advantages of Lunar Electric Rover

Floating Through the Terminator in the Sea Space Continuum

Slide Title

integrating life sciences, engineering & operations

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