Crew Systems Design Project

ENAE 483 October 18, 2012 Rebecca Foust, Shimon Gewirtz, Matthew Rich, and Timothy Russell

Mission Itinerary

• • • • Days 1-3: Voyage to moon Days 4-7: On the lunar surface – All three crew members will perform six hours of extra-vehicular activity (EVA) daily Days 8-10: Voyage back to Earth Days 11-13: Contingency period – Plan for all three astronauts to be able to survive inside the spacecraft

Design Constraints

• • • • Spacecraft maximum diameter is 3.57 m Half-cone angle of 25° Wall thickness of 10 cm Mass allocation for crew and crew systems is 1500 kg

95

th

Percentile Male Astronauts

• • • Spacecraft and all crew systems designed to support three 95 th percentile male astronauts Taken under consideration during design of: – Neutral body position chairs – Toilet – – Hatch and ladder for ingress and egress Oxygen supply – Food and water storage – Window placements – Instrument panel placement

Mass of each astronaut: 98.5 kg

Spacesuits

• • • • Astronauts will use the Apollo 15-17 EMU because of its ability to operate at the required 5 psi, 80% O 2 As a soft suit, the EMU also has the advantage of being collapsible and thus requiring less cabin storage space when not in use than would a hard suit

Mass of fully equipped suit: 96.2 kg Volume of collapsed suit: 0.4 m 3

Cabin Atmosphere

• • • • • 80% oxygen, 20% nitrogen, 5 psi, 71 °F (295 K) – Same atmosphere as spacesuits (no denitrogenation or depressurization needed) – – Oxygen density: 0.36 kg/m 3 Nitrogen density: 0.079 kg/m 3 Cabin atmosphere mass is 3.51 kg 1% atmosphere lost daily to leakage – Total 0.08 kg nitrogen lost – Total 0.37 kg oxygen lost 1.11 kg oxygen consumed per person-day – Total 43.3 kg oxygen lost Two options for EVA airlock cycles: – Evacuate all atmosphere for each cycle (“no recycling”) – Try to collect as much atmosphere as possible in storage tank prior to each hatch opening (“recycling”)

No Cabin Atmosphere Recycling

• • 100% atmosphere lost for each airlock cycle – Four airlock cycles – Total 2.52 kg nitrogen lost – Total 11.51 kg oxygen lost Need to supply extra: – 2.6 kg of nitrogen – 55.17 kg of oxygen

No Cabin Atmosphere Recycling

• Gaseous storage of extra oxygen, nitrogen (3000 psi) – Oxygen density: 270 kg/m 3 – Nitrogen density: 236 kg/m 3 – – 2 kg of tank mass for every kg of gas

Total mass (tanks and gas): 177 kg

–

Total volume (tanks and gas): 0.287 m 3

• Liquid storage of extra oxygen, nitrogen (49.7 atm, -119 °C) – Liquid oxygen density: 1140 kg/m 3 – Liquid nitrogen density: 807 kg/m 3 – – 0.3 kg of tank mass for every kg of liquid Vaporizer: 77 kg and 0.238 m 3 – –

Total mass (tanks, liquid and vaporizer): 156 kg Total volume (tanks, liquid and vaporizer): 0.307 m 3

Cabin Atmosphere Recycling

• • • • • 10% atmosphere lost for each airlock cycle 90% atmosphere stored in collection tank as gas (3000 psi) and released after each airlock cycle – Four airlock cycles – 0.25 kg nitrogen lost – 1.15 kg oxygen lost Need to supply extra: – 0.33 kg of nitrogen – 44.8 kg of oxygen Vacuum pump: 26.6 kg, 0.026 m 3 Storage tank: 6.32 kg, 0.016 m 3

Cabin Atmosphere Recycling

• Gaseous storage of extra oxygen, nitrogen (3000 psi) – Oxygen density: 270 kg/m 3 – Nitrogen density: 236 kg/m 3 – – 2 kg of tank mass for every kg of gas

Total mass (tanks and gas): 172 kg

–

Total volume (tanks and gas): 0.265 m 3

• Liquid storage of extra oxygen, nitrogen (49.7 atm, -119 °C) – Liquid oxygen density: 1140 kg/m 3 – Liquid nitrogen density: 807 kg/m 3 – – 0.3 kg of tank mass for every kg of liquid Vaporizer: 77 kg and 0.238 m 3 – –

Total mass (tanks, liquid and vaporizer): 172 kg Total volume (tanks, liquid and vaporizer): 0.333 m 3

200 180 160 140 120 100 80 60 40 20 0 0

Atmosphere Storage Mass Trade Study

2 4 6 8

Mission Duration (days)

10 Gas No Recycle Gas 90% Recycle Liquid No Recycle Liquid 90% Recycle 12 14

0,15 0,1 0,05 0 0 0,35 0,3 0,25 0,2

Atmosphere Storage Volume Trade Study

2 4 6 8

Mission Duration (days)

Gas No Recycle Gas 90% Recycle Liquid No Recycle 10 Liquid 90% Recycle 12 14

Cabin Atmosphere

• Decided on liquid storage and no recycling – Lower mass is more critical than lower volume • •

Total mass (tanks, liquid and vaporizer): 156 kg Total volume (tanks, liquid and vaporizer): 0.307 m 3

Particulate Scrubbing

• • • Placed near entrance of air-treating ducting Activated Charcoal (based on the ISS trace contaminant control system) – Carbon riddled with pores to adsorb particulates while letting air flow through –

Mass: 0.763 kg

–

Volume: 0.260 m 3

Fiberglass Filters – Allows air to flow through while trapping dust – Need four filters to trap over 90% of dust –

Mass (four filters): 1 kg

–

Volume (four filters): 0.00655 m 3

– Chosen because much lower volume for similar mass

Spacesuit Carbon Dioxide Scrubbing

• • • • Total CO 2 produced per astronaut: 1 𝑘𝑔 𝐶𝑂 2 𝑑𝑎𝑦 6 ℎ𝑜𝑢𝑟𝑠 × 24 ℎ𝑜𝑢𝑟𝑠 × 4 𝑑𝑎𝑦𝑠 = 1 𝑘𝑔 𝐶𝑂 2 LiOH canister scrubbing: – Total mass required per astronaut: 2.09 kg – However, the mass of a single canister is 6.4 kg, which is the minimum mass of LiOH that each astronaut can carry in his spacesuit – Total mass for 3 LiOH canisters: 19.2 kg METOX canisters have mass of 14.5 kg each, for a total mass of 43.5 kg for three canisters EMUs will employ LiOH canisters for CO EVA 2 scrubbing during

CO

2

Generation in Cabin

• • • • Each crew member generates 1 kg CO 2 per day On each non-EVA day, crew is in cabin at all times and thus produces: 1 𝑘𝑔 𝐶𝑂 2 𝑝𝑒𝑟𝑠𝑜𝑛 − 𝑑𝑎𝑦 × 3 𝑝𝑒𝑟𝑠𝑜𝑛𝑠 = 3 𝑘𝑔 𝐶𝑂 2 𝑑𝑎𝑦 On each EVA day, crew is in cabin for 18 of 24 hours and thus produces: 3 𝑘𝑔 𝐶𝑂 2 𝑑𝑎𝑦 × 18 ℎ𝑜𝑢𝑟𝑠 24 ℎ𝑜𝑢𝑟𝑠 = 2.25

𝑘𝑔 𝐶𝑂 2 𝑑𝑎𝑦

Total CO 2 produced:

9 𝑛𝑜𝑛 𝐸𝑉𝐴 𝑑𝑎𝑦𝑠 × 3 𝑘𝑔 𝐶𝑂2 𝑛𝑜𝑛−𝐸𝑉𝐴 𝑑𝑎𝑦 + 4 EVA days × 2.25

𝑘𝑔 𝐶𝑂2 𝑑𝑎𝑦 = 𝟑𝟔 𝒌𝒈 𝑪𝑶 𝟐

Cabin CO

2

Scrubbing Options

• • • Disposable LiOH canisters – 2.09 kg for each kg of CO 2 removed Disposable Ca(OH) 2 – canisters 3.05 kg for each kg of CO 2 removed 4-Bed Molecular Sieves (4BMS) – 30 kg for each kg of CO 2 removed per day

120 100 80 60 40 20 0 0 2

CO 2 Scrubbing Trade Study

4 6 8

Mission Duration (days)

10 12 14 LiOH Ca(OH)2 4BMS

Cabin CO

2

Scrubbing Trade Study Results

LiOH (kg)

75.24

Ca(OH)2 (kg)

109.8

4BMS (kg)

90 • • • LiOH canisters require the least mass of the cabin CO 2 scrubbing apparatuses 4BMS is only marginally more massive than LiOH canisters and has the additional benefit of handling humidity control The spacecraft will employ 4BMS for cabin CO 2 scrubbing and cabin humidity control

Four Bed Molecular Sieve

• • • • • • First two beds adsorb water vapor from the air –

Humidity control

– Adsorbed water vented into space Second two beds adsorb carbon dioxide –

Carbon dioxide scrubbing

– Adsorbed carbon dioxide vented into space Need to heat to ~400° C to regenerate

Total mass: 90 kg Total volume: 0.33 m 3

Power draw: 510 W

Cabin Temperature Control

• • • The astronauts and the electrical equipment in the spacecraft generate heat, which must be rejected to maintain a comfortable cabin temperature The spacecraft employs a porous-plate sublimator as its atmospheric temperature control device Porous-plate sublimator operating principle: 1.

Water in the sublimator extracts heat from the warm air 2.

3.

4.

Water seeps through the pores of nickel plates, the opposite ends of which are exposed to the vacuum of space The water forms a layer of ice on the surface of the plate and sublimes The air is chilled via this process of heat extraction and is then recirculated into the cabin

Cabin Atmosphere Conditioning Summary

Pressurized Cabin Air Porous Plate Sublimator 4BMS CO2 H2O Vacuum LOX Vaporizer LN2 Fiberglass Dust Filters

Unpressurized Storage

B A D E F C I G H A. Vaporizer B. N 2 Tank C. O 2 Tank D. Propellant Tank E. Vapor Compression Distillation Unit F. Multifiltration Unit G. Four Bed Molecular Sieve H. Porous Plate Sublimator I. Particulate Filtration Unit

Water Required

Use

Water In Food Food Prep Water Drinking Water EVA Water

Amount of Water Required

1.15 kg/person-day .76 kg/person-day 1.62 kg/person-day 2.1 kg/person-day (4 EVA days) Total Potable Water (for 3 people, 13 days) 167.87 kg

Water Required (cont.)

Use

Hygiene Water Total Hygiene Water (for 3 people, 13 days)

Amount of Water Required

2.84 kg/person-day 110.76 kg

Use

Hygiene Water Potable Water Total

Total Water Required (kg)

110.76 167.87

273.63

System

Multifiltration Distillation Both

Water Recycling

Mass (kg)

2.2

63 65

Volume (m 3 )

0.01

0.32

0.33

Vapor Compression Distillation was chosen because it is low mass and low-wattage, while remaining within the volume constraints. Numbers shown are scaled back to accommodate the maximum water load on the system.

Water Required for Various Recycling Schemes

300 250 200 150 100 50 0 1 2 3 4 5 6

Day

7 8 9 10 11 12 13 None Hygiene Atmospheric Urine Hygiene + Atmospheric Hygiene + Urine Atmospheric+ Urine Hygiene, Atmospheric + Urine

Water Recycling Summary

• • • Hygiene and Atmosphere and Urine water will be recycled through a multi-filtration system for use as hygiene water, then through a distillation system for use as potable water.

The total mass required to support the trip with water recycling decreases to 86 kg, a reduction of 69% from the initial water mass of 274 kg, including the masses of the recycling systems.

This will save an estimated 252 kg of water.

Food

• • • • Expect each crew member to consume 0.674 kg of dry food each day Comprised of rehydratable food and consumable dry food

Total mass of dry food: 26.3 kg Total volume of dry food: 0.1 m 3

Waste Management System

• • • • • • The spacecraft will employ a toilet whose dimensions are derived from those of a squatting male: – 0.5 m wide by 0.526 m deep by 0.615 m tall Urinary and fecal waste will reside in a plastic bag in the base of the toilet until the next cabin depressurization cycle for EVA, at which time the astronauts will empty the bag outside of the spacecraft A plastic seal will be used to secure the closed lid of the toilet when exposed to microgravity Used toilet bags may be removed from the toilet and sealed and placed in stowage as necessary

Toilet mass: 15 kg Toilet volume: 0.16 m 3

Clothes

• • • • • The astronauts will wear disposable clothes rather than reusable clothes to eliminate the need for additional water mass to wash clothes Budget 8 sets of clothing per astronaut over the duration of the mission – 1 set for each day on the moon, when physical exertion is highest (4 sets) – 1 set for every three days spent inside the spacecraft, including contingency period (3 sets) – 1 extra set of clothes if needed Each set of clothes will have nominal mass 3 kg and nominal volume 0.0008 m 3

Total mass of clothing: 72 kg Total volume of clothes: 0.02 m 3

Neutral Body Posture Chair

• The chair is designed so that the astronaut will be on their back in neutral body posture during launch • After launch, the chair can be inclined to a seated position so that it takes up less space during the day, then reclined at night for sleeping. • The chair is molded to the astronaut’s body and includes restraints for sleeping in microgravity.

• Varying sizes can be accommodated by swapping out the chairs. (95 th percentile male chairs shown in slides for maximum volume case)

Radiation Protection

• • We will put a thin layer of gold over the windows for visual protection from Sun – Same protection as space suit visors Aluminum hull provides radiation protection – Assuming the entire hull is 10 cm thick aluminum, areal density of 27 g/cm 2 – Corresponds to a solar maximum radiation exposure of 0.524 Sv (see next slide for regression) – Mild symptoms of radiation poisoning

Radiation Exposure vs. Aluminum Areal Density

0,58 0,57 0,56 0,55 0,54 0,53 0,52 0,51 0,5 0 y = 0,6817x -0,08 R² = 0,9693 5 10 15 20 25

Areal Density (g/cm^2)

30 35 40 45

Floor Plans

Reclined Chair (Launch) Stowed Chairs • • Chairs in neutral body posture on the astronaut’s back Reclined Chair footprint: – 1.82 x .615 m • • • Chairs in sitting position Stowed chair footprint: • .914x.615 m Inclining the chairs recovers .557 m 2

NBP Chairs Toilet

Interior Views

Control Surface Stowed Spacesuits Unpressurized Storage CTS Bags

Cabin Through Hatch

• Hatch Height: 1.7 m • Average Hatch Width: 0.7 m

Line of Sight: Side View

Line of Sight: Top View

Item

Crew Spacesuits Initial Cabin Air

Mass (kg)

295.5

288.6

3.5

O 2 Supply + Tank N 2 Supply + Tank 71.7

3.4

Cryogenic Vaporizer 77 Fiberglass Filters 4BMS Porous Plate Sublimator 1 90 14.5

Mass Table

Item

Toilet + Bags Clothes Neutral Body Posture Chairs Ducting Intake and Supply Duct Fans Cargo Transfer Bags Water + Distiller Dry Food

Total

Design margin

Mass (kg)

15 72 210 20 2 30 86 26.3

1311.5

12.57%

Power Requirements

Item

Intake and Supply Duct Fans Cryogenic Vaporizer 4BMS Water Distiller Water Filter

Total Power Draw (W)

200 6 510 73.5

1.5

791

References

• • • • • • • • John Duncan, “Portable Life Support System”, January 1999 http://www.apollosaturn.com/ascom/Lmnr/p.htm

NASA Lyndon B. Johnson Space Center, “Advanced Life Support Requirements Document”, February 2003 http://www.marsjournal.org/contents/2006/0005/files/Lange2003.pdf

Donald Rapp, “Mars Life Support Systems”, February 2006 http://spaceclimate.net/Mars.Life.Support.combo.pdf

International Academy of Astronautics, “Artificial Gravity Research to Enable Human Space Exploration”, 2009 http://iaaweb.org/iaa/Scientific%20Activity/Study%20Groups/SG%20Commission%202/sg22/sg22finalrep ortr.pdf

MMR Technologies “Introduction to Vacuum Pump Usage” http://www.mmr tech.com/PDFs/VacPumpReq_TSB007.pdf

Paul E. DesRosiers, “Human Waste Studies in an Occupied Civil Defense Shelter”, July 1968 http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0671703 A. J. Hanford, “Advanced Life Support Baseline Values and Assumptions Document”, August 2004 http://ston.jsc.nasa.gov/collections/TRS/_techrep/CR-2004-208941.pdf

J.A. Steele, "Water Management System Evaluation for Space Flights of One Year Duration", NASA-CR 168484, October 1953 http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19820067073_1982067073.pdf