https://ntrs.nasa.gov/search.jsp?R=20090007922 2019-07-06T19:28:06+00:00Z

Extravehicular Activity Testing in Analog Environments: Evaluating the Effects of Center of Gravity and Environment on Human Performance

Steve Chappell, Ph.D. Michael L. Gernhardt, Ph.D. - Principal Investigator

Human Research Program, EVA Physiology Systems & Performance (EPSP) Project

| Human Research Program Investigator Workshop | Feb. 2-4, 2009 1 Background

• 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 – The EVA Physiology, Systems and Performance Project (EPSP) in conjunction with the Constellation EVA Systems Project Office have developed plans to systematically understand the role of suit weight, CG and suit pressure on astronaut performance in partial gravity environments

• CG Study Objectives – To understand the impact of a varied CG on human performance in lunar gravity

| Human Research Program Investigator Workshop | Feb. 2-4, 2009 2 Simulation Environments & Studies • Test series – EVA Walkback Test (EWT) Parabolic Partial Gravity – Integrated Suit Test 1 (IST-1) Flight – Integrated Suit Test 2 (IST-2) Field – Haughton Mars Project (HMP) Walkback Test NASA Analogs – Integrated Suit Test 3 (IST-3) Neutral Extreme Buoyancy Environmen – NBL CG Lab t Mission – NEEMO 9 – 13 (NBL) Operations – Integrated Parabolic Flight Test 1 (NEEMO) – Integrated Parabolic Flight Test 2 Simulation Environments Simulation Characteristics 1. 2. 3. 4. 5. Parabolic POGO NBL NEEMO Field flight Wt. relief Analogs Suit kinematics / pressure volume + + + - + Mass distribution / dynamics + - + + - Unlimited time duration - + + + + 6 DOF motion throughout work envelope + - + + + True operational environment - - - + + Drag and buoyancy effect + + - - +

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 3 Center of Gravity Studies – NEEMO/NBL • Total Apollo EVA suit & PLSS earth weight - 88.6 kg (195 lb) • Level walk/jog/run – Suit 27.2 kg (60 lbs) – Walk 20 feet (one foot – PLSS 61.2 kg (135 lbs) always on the ground) • CG location based on 182.9 cm (6 ft), 81.8 kg (180 lb) male – Jog 20 feet (slowest speed with both feet • 21 subjects weighed to result in 1/6 g static ground reaction off the ground) force (GRF) – Run 20 feet – Preferred ambulation Clearance for hoses • Ramp incline / decline – 6 CGs (ideal, low, forward, high, aft, baseline) – 30 , 25 , 20 , 15 , 10 • Exploration tasks – Kneel & recovery Adjustable – Fall & recovery shoulder (forward) strap Quick attach – Shoveling activity ReleasesPadding points adjustable – Rock pickup to any – Ladder climb position

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 4 NEEMO/NBL Cooper-Harper Probabilities vs. CG Location

MODIFIED COOPER-HARPER PROBABILITY VS. CG LOCATION MODIFIED COOPER-HARPER PROBABILITY VS. CG LOCATION 12.0 12.0

HIGH HIGH 10.0 10.0

Level Ambulation Tasks Exploration Tasks 8.0 8.0

6.0 CTSD 2005 6.0 CTSD 2005 BASELINE BASELINE

APOLLO APOLLO 4.0 4.0

IDEAL IDEAL 2.0 2.0

BACKPACK PROBABILITY OF: BACKPACK PROBABILITY OF: AFT 0,0,0 CH=1-3 AFT 0,0,0 CH=1-3 0.0 CH=4-6 0.0 CH=4-6 CH=7-10 CH=7-10 Low (in) High (in) (in) High (in) Low Low (in) High (in) (in) High (in) Low FANNYPACK FANNYPACK -2.0 -2.0

LOW LOW

-4.0 -4.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 -8.0 -6.0 -4.0 -2.0 0.0 2.0 Aft (in) Forward (in) Aft (in) Forward (in)

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 5 Recent/Ongoing Tests • Shirt-sleeve IST-3 – CG test on POGO to validate NEEMO/NBL results

• Integrated Parabolic Flight Test 1 – Suited MKIII test varying mass and weight for comparison to POGO results

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 6 Integrated Studies - Center of Gravity Locations IST-3 Shirt-Sleeve rig CG locations Previously Tested Cases at NEEMO/NBL 2005 Baseline 2.98” aft / 5.65” high (330, 400 lbs) Flex Pack Backpack 1.90” aft / 0.40” high (400 lbs) 10 8 6 4 2 0 2 4 6 0,0 0.0” aft / 0.0” high

Previously Tested Cases at EWT/IST-1

12 12 Pogo System 4.41” aft / 7.93” high (330, 400 lbs) 10 10 8 8 Other achievable CG’s: 6 6 Mk III w/ PLSS mockup, 4 4 2 2 C9 CG rig, stowed arms, no lead weights 3.53” aft / 5.84” high (265 lbs) 0 0 Mk III (Al HUT/hatch) 0.3” aft / 2.9” high (155 lbs) 2 2 Mk III w/ PLSS mockup 1.5” aft / 4.7” high (195 lbs) 4 4

0,0 These CG locations are being 10 8 6 4 2 0 2 4 6 assessed in parabolic flight tests

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 7 C-9 Study Design

Trial 1 Trial 2 Trial 3 Suit Mass 195 lb 265 lb 400 lb Gravity 0.17g 0.17g 0.17g Varied Mass Testing 1g Suit Weight 195 lb 265 lb 400 lb CG CTSD (almost) CTSD/POGO CTSD Suit Mass 265 lb 265 lb 265 lb Gravity 0.1g 0.17g 0.3g Varied Weight Testing 1g Suit Weight ~ 87 lb 265 lb ~ 620 lb CG CTSD/POGO CTSD/POGO CTSD/POGO Suit Mass 400 lb 400 lb 400 lb Gravity 0.17g 0.17g 0.17g Varied CG Testing 1g Suit Weight 400 lb 400 lb 400 lb CG Backpack CTSD POGO

} Denotes same condition across tests

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 8 Preliminary IST-3 Shirt-Sleeve Results

9

8

7

6 1G 5 0,0 Backpack 4 CTSD POGO 3 Modified Cooper-Harper

2

1

0 1.5 3 4.5 6 7.5 9 Speed (km/h)

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 9 Integrated Tests Next Steps

• Integrated Parabolic Flight Test 2 – Run added mass trials w/ Mk-III – Perform modified CG trials • Complete exploration trials of shirt-sleeve IST-3 on POGO • Compare results across environments • Other follow-on tests in planning stages – Rear-Entry I (REI) suit testing parabolic flight to test effects of a different suit – REI suit testing on POGO/ARGOS (Active Response Gravity Offload System) – Other suited and unsuited testing on ARGOS – NEEMO 14 – Desert RATS 2009 • Make requirements recommendations for achieving desired suited performance

| Human Research Program Investigators Workshop | Feb. 2-4, 2009 10