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Crew Systems Design Project ENAE 788D, Fall 2012

University of Maryland Block, Henninger, Rotunda

Crew Systems and Life Support

Establishing a Recurring Human Presence on the Moon

Preliminary Design Review



Overview

• Preliminary Design Review of Crew Systems / Life Support aboard low-cost lunar lander – Atmosphere / O2

– Water

– Food

– Waste Management

• Human Factors and Habitability – Seating

– Control Stations and Windows

– Stowage and Placement

– Ingress / Egress



Requirements

• 3 Crew Members

• 10 day mission (+3 contingency days) – 3 days transit

– 4 days on lunar surface

– 3 days return to Earth

– Plan for 13 days total (includes 3 contingency days)

• Crew will occupy Crew Vehicle for duration of mission (launch to landing) – Exit Crew Vehicle only during EVAs on lunar surface

– Cannot receive / transfer supplies



Requirements

• Max diameter 3.57 m (at bottom of spacecraft)

• Half-cone angle of 25°

• Wall thickness 10 cm

• Maximum allowed mass: 1500 kg

– Includes crew systems, life support, crew members, spacesuits, chairs

– Does Not include ladder, avionics, control stations



Air System Assumptions

• Each EVA 5 hours, airlock remains open, all atmosphere lost each EVA

• CO2 canisters are usable for both cabin and suits

• EMU suit volume is maximum (0.153 m3) and has own dehumidification/heat exchange system

• EMU can be “recharged” with O2/N2 upon return



Cabin Atmosphere Trade

100

150

200

250

300

350

400

5.6 6.6 7.6 8.6 9.6 10.6

Tan

k M

ass

(kg)

Interior Volume (m3)

Total Tank Mass at Select Spacecraft Volumes

5psi, Heavy Respiration

10 psi, Heavy Respiration

5psi, Light Respiration

10 psi, Light Respiration

APOLLO CM APOLLO LM SPACEX DRAGONLAB [1]



Pressure / O2 content for Interior Cockpit

Total Pressure (psia)

Normoxic Partial Pressure (psia-O2)

Normoxic Concentrations (percentage of O2)

3.7 3.7 100 4 3.62 90.5 5 3.45 69 6 3.36 56 7 3.29 47 8 3.24 40 9 3.2 35.5 10 3.17 31.7 14.7 3.08 21

Table acquired from [3]



Final Tank Masses

Atm. Pressure @Light Resp Rate (5psi) (10 psi) O2 mass for consumption, cabin and suit (kg) 118.47 117.64 Tank and gas total (kg) 201.40 199.98 Tank Volume (m3) 0.073 0.072 N2 mass for consumption, cabin and suit (kg) 14.58 27.93 Tank and gas total (kg) 24.79 47.48 Tank Volume (m3) 0.182 0.349

Total mass of tanks (for cabin) (kg) 226.20 247.47 Total Energy Req. (MJ) 28.255 30.733



Humidity Removal at Low Pressures

• Incredibly large systems required for humidity/distillation process reuse

• Dessicant Requires 266.63 kg + 10% wt packaging [5], Unsuitable

• Dehumidification system suitable for small volume (6.7 m3), allows for condensate removal and relative constant humidity(~40%) based on parameter controls

• Mass 16 kg and 33 x 48 x 25 cm, 410 W power [6]

• May be redundant if heat exchange system is optimized for condensate removal



Water Accumulated in Module over Time

0

5

10

15

20

25

30

0 2 4 6 8 10 12 14

Lite

rs W

ate

r A

ccu

mu

late

d

Mission Days

Water Produced

0.28 Leftover

.275 Leftover

0.25 Leftover

0.2 Leftover

0.1 Leftover

Rates in L/hr, constant rate of water production at 0.285 L/hr



Apollo Environmental Control System

Photos via [4]



CO2 Level During Mission - Light Resp. Rate

0 2 4 6 8 10 12 14

0

10000

20000

30000

40000

50000

60000

Carbon Dioxide Levels During Mission

EVA Airlock Jettison Inclusion

Mission Days Elapsed

Gra

ms

Ca

rbo

n D

ioxi

de

/ C

ub

ed

Me

ter

SMAC limit [2] (23 g/m3)



CO2 Removal Comparisons

Mass (kg) CO2 to remove 43.44 KO2

Used for CO2 and O2 Production in Combination with Liq O2 KO2 140.12 Generates O2 53.25 Total Mass 672.60

LiOH CO2 Removal (ExtendAir® LiOH Absorbent Curtains) LiOH (0.794 kg CO2

/ kg LiOH) 54.71 Packaging (.7 kg/4.6 kg gross mass canister) 9.82 Total Mass 64.53 KO2

Used Only for O2 Production (CO2 Removed with Surplus) KO2 311.77 Generates O2 118.47 Total Mass 1496.50

Infeasible

Option Chosen



Atmospheric Conclusions

• 5 psi Atmosphere chosen (lowest tank mass, No denitrification needed [R=0.69]) – Advantage in no pre-breathe, but material

flammability can be a concern as well as crew comfort

– Light Respiration rate chosen (slightly larger than ALS Baseline Values Assumptions)

• LO2/LN2 and LiOH systems optimal for mass reduction

• Air purification system (3.3 kg, 51 W) based on readily obtainable products (25.4 x 25.4 x 38.4 cm) [7]



Water System Requirements

• Nominal usage for each mission day (10 days) – 2 kg (2 L) drinking water / CM day

– 0.5 kg (0.5 L) hygiene water / CM day

• Minimal usage for each contingency day (3 days) – 2 kg (2 L) drinking water / CM day

– 0 kg (0 L) hygiene water / CM day

• Total 93 kg water required

Note: / CM day = per crew member per day



Water Recycling Trades • 15 kg hygiene water reclaimable

– Hygiene water treatment technologies:

• 58 kg urine reclaimable (1.5 kg / CM day) – Urine treatment technologies:

• Mass of recycling systems exceeds amount reclaimable – No Water Recycling System will be used

Mass (kg) Volume (m3)

Reverse Osmosis / Ultrafiltration 214 0.35

MilliQ Absorption Bed 108 0.06

Mass (kg) Volume (m3)

Air Evaporation System 75 0.3

Vapor Compression Distillation 144 0.49



Water System Specifics

• Water tank will be flexible bladder contained in non-pressurized section

• Water will be moved through a flexible tube using a small pump up to an accessible location

• No heating / cooling of water. Water will be ambient temperature

• Water tank will be filled before launch • NASA requirement: Water supply must be free of micro-

organisms – Water will be supplied with 12 mg iodine / liter of water – This will ensure minimum of 0.5 mg iodine / liter for duration of

mission

• Taste and odor of iodine in water could be negative factor • Total mass: 112 kg (assuming 20% of water mass for tank mass)



Food System Requirements

• Nominal Activity Metabolic Load: – 11820 kJ / CM day

– Extra 2100 kJ / CM per EVA day

– Total: 486,000 kJ required

• 42 pre-packaged meals provided – 14 days of food / CM

– Total: 496,000 kJ (10,000 kJ more than required)

– Extra meals can be opened as needed for EVA days or for higher metabolic loads



Food System Specifics

• All meals contained in a food locker – Dimensions: 0.5 m x 0.5 m x 0.8 m = 0.2 m3

– Full locker mass: 74 kg

– Empty locker mass: 6.4 kg

– Similar to food locker used on Space Shuttle

• Pre-packaged meals with individually sealed food items

• Food will contain 42% water (no rehydration required)

• Food will be consumed as-is – No rehydration system / oven / refrigeration / freezing

available



Waste Management

• Derived from the Apollo missions

• Urine collection – Based on Urine Receptacle Assembly (URA)

– Further testing/development required for: • Consumables minimization/flow performance

• Improved hygiene standards

• Crew comfort

• Female astronaut compatibility

– Additional collection/transfer assembly worn under spacesuit for launches, EVA’s and emergencies



Waste Management

• Fecal collection

– No positive means for removal of feces

– Adopted Apollo fecal collection assembly

• Fecal Bag with adhering flange

• Sanitary wipes

• Germicide pouch

– Fecal Containment System (FCS), an absorbent undergarment, will be worn under the spacesuit as a safeguard during launches, EVA’s and emergencies



Waste Management

• Waste disposal

– Urine system contains a purge valve that allows the waste to be selectively released into the vacuum of space

– Feces will be stored

• Production rate : 1.00 x 10-3 m3 per person per day

• Required volume : 0.0975 m3 (Safety Factor = 2.5)



Waste Management

Figure 1: URA Figure 2: Urine Transfer Assembly

Figure 3: Fecal Bag Assembly Figure 4: FCS



Overall Design - Exterior

Front Rear

Windows (3x)

EVA Hatch

25°



Overall Design - Interior

Parachute

Collapsible Seats (3x)

Pressurized Volume

Unpressurized Storage



Overall Design – Interior (Collapsed Seats)

O2 Tank

N2 Tank

Air Filter / Dehumidifier

Water Storage

Food Storage

Landing Controls / Avionics

Waste Management



Overall Design - Landing

Lunar Surface

Ingress / Egress

Sight Lines (3 windows evenly spaced around SC)

41.9°

Exterior Height: 3.98 m Interior Height: 2.37 m

Exterior Diameter: 3.57 m Interior Diameter: 3.13 m

Hatch Diameter: 1.0 m



Launch and Landing

• Earth Launch and Landing

– All crew members will occupy seats in a horizontal position for greater G force tolerance

• Lunar Launch and Landing

– Seats are folded down to the deck

– Pilot will stand at center window / control panel

– Co-pilots will occupy side windows for greater overall visibility



Lunar Surface Operations

• Seats will remain folded down for duration of lunar surface operations

• Crew members can stand up in middle section for donning / removing spacesuits

• During EVA: – All crew members don spacesuits – Entire cabin depressurized – Two crew members exit, one remains aboard – Exterior hatch remains open for duration of EVA – EVA concludes with enough time to repressurize cabin

• Crew members will eat, sleep, work on cabin floor • After final EVA, ladder and all consumable / disposable

items will be left on lunar surface



Stowage and Placement

• Unpressurized bottom section – O2 and N2 tanks – Water tank – Air filter / dehumidifier

• Under legs of side seats – Food locker – Waste management system – Additional stowage

• Cabin sides – Spacesuits – Avionics

• Unpressurized top section – Parachute



Mass Budget

Component Mass (kg)

O2, N2 tanks 226

CO2 , H2O removal canisters 80

Water tank / system 112

Food (full locker) 74

Waste system 25

3 x 95th percentile males 296

3 x Orlan spacesuits (MK model) 360

3 x Launch seats 150

Total 1323

• 177 kg available for extra storage / components • 12% mass margin



Power Budget

Component Power (kW)

O2, H2 tanks .025

CO2 scrubber/Air Filtration .452

Water pump 0.02

Total 0.497



Mission Support Conclusions

• Crew System / Life Support achieves mission – 3 crew members to lunar surface for 4 days

– 4 EVAs in support of recurring human presence on the moon

• Design does not support crew comfort or convenience – 10 day mission is short enough in duration that crew

morale is not a factor

• If crew is stranded on lunar surface – Minimal contingency supplies

– Rescue mission must be launched immediately

– Additional supplies can be pre-staged on lunar surface during cargo mission



References • [1] “SpaceX DragonLab Datasheet” Available Online:

http://www.spacex.com/downloads/dragonlab-datasheet.pdf

• [2] J. James, Spacecraft Maximum Allowable Concentrations for Airborne Contaminants. JSC 20584: NASA Johnson Space Centre, Houston, TX, Feb. 1995

• [3]A. Hanford, Advanced Life Support Baseline Values and Assumptions Document

NASA/CR—2004–208941 : Lockheed Martin Space Operations, Houston, TX,

Aug. 2004

• [4]http://www.spaceaholic.com/apollo_artifacts.htm

• [5] “AGM Product Specifications Sheet” AGM Container Controls, Inc. Tucson, AZ. Available Online: http://www.agmcontainer.com/desiccantcity/pdfs/bulkDesSpecifications/920007Specs.pdf

• [6] “Soleus Air Product Review” Available Online: http://www.soleusaircentral.com/product/45-pint-dehumidifier-sg-deh-45-1

• [7]”Honeywell Central Product Review” Available Online: http://www.honeywellcentral.com/product/honeywell-enviracaire-true-hepa-air-purifier-n




http://www.agmcontainer.com/desiccantcity/desiccant_faqs.htm

http://www.agmcontainer.com/desiccantcity/pdfs/bulkDesSpecifications/920007Specs.pdf




http://www.soleusaircentral.com/product/45-pint-dehumidifier-sg-deh-45-1














http://www.honeywellcentral.com/product/honeywell-enviracaire-true-hepa-air-purifier-n
















References • [9] International Space Station Flight Crew Integration Standard (NASA–

STD–3000/T) - SSP 50005, Rev. C - Space Station Program Office, NASA Johnson Space Center, December 15,1999.

• [10] R. Sauer , G. Jorgensen, “Waste Management System” in Biomedical Results of Apollo Washington, D.C.: NASA, 1974, Ch. 2, Sec. VI. Available Online: http://lsda.jsc.nasa.gov/books/apollo/s6ch2.htm

• [11] R. Sauer , D. Calley, “Potable Water Supply” in Biomedical Results of Apollo Washington, D.C.: NASA, 1974, Ch. 4, Sec. VI. Available Online: http://lsda.jsc.nasa.gov/books/apollo/s6ch4.htm

• [12] A. J. Hanford, “Advanced Life Support Baseline Values and Assumptions Document” NASA/CR—2004–208941, August 2004.

• [13] B. E. Duffield, “Advanced Life Support Requirements Document” JSC-38571C/CTSDADV-245C, February 2003.

• [14] Allen, C. S., et. al., “Guidelines and Capabilities for Designing Human Missions” NASA Exploration Team, Human Subsystems Working Group, March 2002.

• [15] ECLSS Subsystem. (2012). http://www.colorado.edu

http://lsda.jsc.nasa.gov/books/apollo/s6ch2.htm




http://www.colorado.edu/

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