Preliminary Design Review - University of Maryland

Preliminary Design Review 

Dylan Carter 

Vera Klimchenko 

Calvin Nwachuku 

Michelle Sultzman 

Crew Systems Preliminary Design Review 

ENAE 483/788D - Principles of Space Systems Design

Mission Overview 

• Design a crewed spacecraft for a low-cost mission to 

the Moon 

• Support a crew of three for a 10 day mission with 3 

days of contingency 

• Maximum spacecraft diameter: 3.57 m 

• Half cone angle: 25° < θ < 32.5° 

• Wall thickness: 10 cm 

• Total mass allocation for crew and crew systems: 

1500 kg 



Choosing Optimal Half-Cone Angle 



Choosing Optimal Half-Cone Angle 

25 degree half-cone angle: 

• Provides most cabin volume (13.86 m 3 ) 

• Provides large height (need at least 2 m clearance 

for cabin alone) 

• Cabin volume is scarce here 



Heat Shield Radius 

• Standard sphere-cone heat shields have halfangles 

around 70° 

• Chose radius of curvature that best approximated 

this shape 

• R = 2.777 m 



Atmosphere 

Constraints on Cabin Conditions: 

• R < 1.6 to reduce risk of DCS 

• Ambient O2 < 30% to reduce risk of fire 

• Stay within hypoxic and toxic boundaries 

Our Design: 

• Pressure = 9.5 psi 

• Ambient O2 = 29% 

• Reduces DCS risk as much as possible while 

avoiding flammability and hypoxia 



Atmosphere 



Denitrogenation 

Comparative DCS risk estimated using R value 

• Based on 60 minutes of prebreathe 

• R defined for 360-minute tissue 

Our Design: R = 1.20 (about 1.5% risk) 

• Compare to Shuttle: R = 1.10 (0.5% risk) 

• Large tissue choice makes this a very conservative estimate 

o For 200-minute model (next largest): R = 1.096 

o For 5-minute model (smallest): R = 0.0003 



Gasses Lost and Consumed 

Assume 10% of gas lost during depressurization 

4 days on surface: total 4 EVAs 

Cabin Interior: 13.86 m 3 

• Lost Gasses: 0.723 kg N 2, 0.338 kg O 2 

Oxygen Consumption: 1.11 kg O 2/day 

For 3 people over 13 days: 

• Consumed O 2: 43.29 kg O 2 



Oxygen Supply 

O 2 Consumed and Lost: 43.63 kg O 2 

Many options for oxygen production: 

• Open Loop (Non-regenerative) 

o O 2 tanks (gaseous or liquid) 

o Lithium Perchlorate (LiClO 4) 

o Lithium Superoxide (LiO 2) 

o Potassium Superoxide (KO 2) 

• Regenerative 

o Sabatier Reaction (requires some H 2 resupply) 



Oxygen Supply 



Oxygen Supply 

Gaseous and Liquid Storage are lightest 

• Gaseous requires no power 

• Liquid: 210 kJ/kg O 2 (8.16 W - very little) for 

vaporization 

Our Design: Open Loop with liquid O 2 

• Lowest mass and volume 

• Comparatively little power draw 

Liquid will also be used to store N 2 



Resupply Tank Properties 

Tank Mass: 0.7 kg/kg O 2, 0.8 kg/kg N 2 

• O 2 Tank Mass: 30.54 kg 

• N 2 Tank Mass: 0.579 kg 

Liquid O 2 Density: 1141 kg/m 3 

Liquid N 2 Density: 807 kg/m 3 

• O 2 Tank Volume: 0.0382 m 3 

• N 2 Tank Volume: 0.000896 m 3 

• Volume of tank material is negligible 



Depressurization Tank 

During cabin depressurization, ambient air is 

pumped into storage tank: 

• Stored at 3000 psi, 300 K 

• Masses: 10.61 kg air, 2 kg tank/kg O 2 

Depressurization Tank (and Pump, estimated): 

• Mass: 23.28 kg tank, 8.6 kg pump 

• Volume: 0.0439m 3 tank, 0.0093m 3 pump 



CO 2 Scrubbing 

95th percentile males produce 1.306 kg CO 2 

• 3.918 kg CO 2/day, 50.93 kg CO 2 total 

Options available for CO 2 removal: 

• LiOH Canisters 

• METOX Canisters w/ Oven 

• 4-Bed Molecular Sieves 

• Solid Amine Water Desorption 

• Sabatier Reaction 



CO 2 Scrubbing - Mass 



CO 2 Scrubbing - Power 




METOX vs LiOH 

• METOX system lighter by about 10 kg 

• LiOH requires no power; METOX draws 1 kW 

• LiOH is smaller and more portable 

Our Design: Non-regenerable LiOH canisters 

• Difference in weight is outweighed by additional 

battery and portability 




LiOH Canisters for CO 2 Scrubbing 

• 2.1 kg material/kg CO 2 

• 106.9 kg material minimum 

• Each canister is 6.4 kg: 17 total canisters 

17 canisters for total mass 108.8 kg 



Atmosphere Design Summary 

Cabin Conditions: 9.5 psi, 30% O 2, 70% N 2 

• Mass (air, tank, pump): 42.49 kg 

Supplementary O 2: Cryogenic liquid storage 

• Mass (O 2 and tank): 74.17 kg 

Supplementary N 2: Cryogenic liquid storage 

• Mass (N 2 and tank): 1.31 kg 

CO 2 Scrubbing: Expendable LiOH canisters 

• Mass (canisters): 108.8 kg 



Water 

Possible Options: 

Open-Loop System 

• Bring all necessary water in tanks 

without plan of recycling 

• Only extra mass is from pump 

• 48 W of power needed 

Recycling System 

• Vapor Compression Distillation 

System; bring less water and 

recycle 95% of water used daily. 

• Extra mass includes pump and 

distillation hardware 

• 648 W of power needed 



Water 

• Open-loop system requires more water. 

However, the most plausible water recycling 

system is very massive and large. It will also 

requires much more power. 



Water 



Water 

Chosen Water System: Open Loop 

o Less total mass for a short-term mission 

o More power, mass, and volume efficient 

Mass Breakdown: 

Water Mass: Potable Water - 2L/crew-day * 3 members * 13 days 

Total Water Mass = 190 kg 

Tank Mass =53 kg 

Hygiene Water - 2.84L/crew-day * 3 members * 10 days (nominal) 

Pump Mass = 8 kg 

Total Water System Mass: 251 kg 

+ 2.84L/crew-day * 3 members * 3 days (contingency) 



Food 

Using values from previous space shuttle missions, 

baseline requirements for the food system were 

determined: 



Food 

Using these baseline requirements, food and 

packaging mass over the duration of the mission 

was calculated: 



Food 

Cargo Transfer Bags (CTBs) will be used to stow 

food 

• To hold 58.67 kg need equivalent of 5 half-sized 

CTBs (0.12 m 3 ) 

• Using two single-size CTBs for meals and snacks 

and one half-sized CTB for beverages 



Food 

No Thermostablized Meals 

• Eliminates mass and volume requirements of 

oven 

• Over mission duration of 13 days will not cause 

morale or nutritional issues 



Other Food System Related Masses 

Food locker mass: 13.65 kg 

Trays and utensils: ~ 1 kg 

Hydration Station: ~ 15 kg 

Total Food System Mass: ~ 90 kg 



Waste Management 

• All of the waste produced during the mission will be 

collected, stabilized and stored 

• Recycling the waste products does not prove to be 

optimal for this short term mission due to the mass, 

power and space constraint 

• Human solid waste will go into the fecal bags and then 

into the fecal bag compartment 

• Urine and grey water will go into the Urine Collection 

and Transfer Device 



Breakdown of Waste 

Waste [kg/CM-d] [kg/3CM-13d] Storage 

Urine 1.562 60.9 Liquid Waste Tank 

Feces 0.123 4.8 Fecal Bag Collection 

Hygiene Water 

2.84 

110.8 Liquid Waste Tank 

Urine Flush Water 0.5 19.5 Liquid Waste Tank 

Food Packaging 0.324 12.6 Trash Bag 

Wet Wipes 0.051 1.9 Trash Bag 

Toilet Paper 0.028 1.09 Trash Bag 

Total Waste Mass (kg) 5.4 211.6 ***The food package, wet wipes and toilet paper 

mass will not be included in the final mass estimation 

because mass is already allocated for them in 

previous sections 



Human Solid Waste 

• Fecal matter will be collected into special fecal bags, similar to 

the ones used on Apollo module. 

• After the fecal matter is thoroughly mashed and compressed, the 

fecal bag will be treated with germicide and sealed. After all the 

procedures, it will be placed into a designated shoot leading to 

the fecal bag compartment. 



Human Solid Waste 

The fecal bag is able to hold about 0.0408 kg/bag. 

# of Bags= (0.123[kg/CM-d])*(3CM)*(13d)/(0.0408kg/bag)=118 

bags 

Assuming the density of water: 

Total Volume of the Bags=(118*0.0408)/1000=0.0048m 3 

The volume of the fecal bag compartment will be 

larger than the total volume of the bags by 

0.0002m 3 for storage space. 

FECAL BAG 

COMPARTMENT 

Aluminum Square Tank 

M=67 kg 

Side=.168 m 



Human Urine and Grey Water Collection 

Flush Water 

0.5 [kg/CM-d] 

6.5 [kg/CM-13d] 

Total Mass: 19.5 kg 

Total Volume=0.0195m 3 

Liquid Waste Tank 

Material: Aluminum 

Capacity: 0.0956m 3 

Wall Thickness: 2cm 

Used Hygiene Water 

2.84 [kg/CM-d] 

36.92[kg/CM-13d] 

Total Mass:110.8 kg 

Total Volume=0.1108 m 3 

Human urine and grey water will 

be collected in one spherical tank. 

Urine 

1.562 [kg/CM-d] 

20.31 [kg/CM-13d] 

Total Mass:60.9kg 

Total Volume: 0.0609 m 3 

2 Spherical Tanks 

Wall Thickness: 2cm 

Rinner=0.284m 

Router=0.304m 

Mass=60.48kg 



Trash 

• Wet wipes, food packaging and other 

consumables will be stowed away in wet and dry 

trash bags below the the first deck or above the 

first deck. 

• The food packaging might contain food leftovers 

and should be stowed away in durable wet bags 

that will not let out moisture or smells. 



Exterior Design 



Interior Layout 

Upper Level 

Launch and Re-entry 

Control Console 

Launch Seats 

Crew/Space Suits 

Window 

Lunar Landing 

Control Console 

Tanks (Water, 

Waste, O 2, N 2, 

etc.) 



Interior Layout 

• Space suits will be worn during launch and stored in 

launch seats while not in use 

• Hammocks will be provided for crew to hang across 

cabin for sleeping arrangements 

• Upper level is provided as additional space for stowage 

• Bathroom area will be off to the side opposite the airlock 

• Hammocks can be used as curtains during operational 

hours to provide privacy for bathroom area 

• Clothing, food, and other CTBs can be stored on shelving 

provided under lunar landing control console

Sight Line Analysis 



Ingress/Egress 

• A platform with a retractable ladder will sit just 

inside the airlock to be deployed when leaving the 

spacecraft. 

• There will be 4 EVAs during the missions, 

maximum of 8 hours each. One on each day spent 

on the moon. All the crew members will 

participate. 



Power Requirements 

O 2 and N 2 Vaporization: 8.3 W 

Vacuum Pump: 249 W 

Water Pump: 48 W 

Water Heater: 100 W 

Solid Waste Management Equipment: 16 W 

Max Power Draw: 421.3 W 



Total Mass 

Mass (kg) 

Initial Mass Estimate 1500 

Atmosphere Management 226.8 

Water Storage and Distribution 251 

Food Supplies 90 

Waste Management 190 

Equipment and Misc. Supplies 

Space Suits 300 

Clothing 43 

Crew 240 

Total Mass 1340.8 

Mass Margin (%) 10.61 



References 

• Advanced Life Support Baseline Values and Assumptions Document - 

NASA/CR—2004–208941 – NASA JSC, Aug. 2004 

• Advanced Life Support Baseline Values and Assumptions Document – 

JSC-47804 – JSC Crew and Thermal Systems Division, May 2002 

• Advanced Life Support Systems Requirements Document - JSC-38571, 

rev.B - JSC Crew and Thermal Systems Division, Sept. 2002 

• Akin, David L. "ECLIPSE: Design of a Minimum Functional Habitat for 

Initial Lunar Exploration.“ AIAA Space 2009 Conf. & Exposition (2009): 

n. pag. Print. 

• Akin, David. (2011) Habitability and Human Factors [PDF]. Retrieved 

from 

http://spacecraft.ssl.umd.edu/academics/483F12/483F12L12.hufac/483F12 

L12.hufacx.pdf 



References 

• Akin, David. (2012) Introduction to Space Life Support [PDF]. Retrieved from 

http://spacecraft.ssl.umd.edu/academics/483F12/483F12L11.life_support/483F 

12L11.life_support.pdf 

• Akin, David. (2012) Aerospace Physiology [PDF]. Retrieved from 

http://spacecraft.ssl.umd.edu/academics/483F12/483F12L10.physiology/483F1 

2L10.physiology.pdf 

• Bienhoff, Dallas G., Russell F. Graves, and Greg J. Gentry. "Lunar Habitat: 

Minimum Functionality to Outpost Capable." AIAA Space 2009 Conf. & 

Exposition (2009): n. pag. Print. 

• Jorgensen, Catherine A. Baseline Design. N.p.: n.p., 2000. Print. Vol. 1 of 

Intern 

• Howe, Scott A., and Robert Howard. Duel Use of Packaging on the Moon: 

Logistics-2-Living. Rept. no. 6049. N.p.: AIAA, 2010. Print.ational Space 

Station Evolution Data Book. 



References 

• Human Integration Design Handbook (HIDH). WASHINGTON, DC: 

NASA, 2010. Print. NASA/SP-2010-3407. 

• Lin, John K. Lunar Surface Systems Concept Study: Minimum 

Functionality Habitat Element. N.p.: n.p., n.d. Print. 

• NASA. Advanced Life Support Research and Technology Development 

Metric. By Anthony J. Hanford. Technical rept. no. 213694. Houston: 

NASA, 2006. Print. 

• Rapp, Donald, “A Review of: Advanced Life Support Systems Integration, 

Mondeling, and Analysis Reference Missions Document.” Retrieved from 

http://spaceclimate.net/JSC.DRM.life.support.pdf 

• Rudisill, Mirianee, et al. Lunar Architecture Team-Phase 2 Habitat Volume 

Estimation "Caution When Using Analogs." Technical rept. N.p.: n.p., n.d. 

Print. 



References 

• Scheuring et. al, "Risk Assessment of Physiological Effects of Atmospheric 

Composition and Pressure in Constellation Vehicles" 16th Annual Humans in 

Space, Beijing, China, May 2007 

• Shull, Sarah, Raul Polit-Casillas, and Scott A. Howe. "NASA Advanced 

Exploration Systems: Concepts for Logistics to Living." AIAA Space 2012 

Conf. & Exposition (2012): 1-10. Print. 

• Strayer, Richard F., Mary E. Hummerick, and Jeffrey T. Richards. 

Characterization of Volume F Trash from Four Recent STS Missions. N.p.: 

n.p., n.d. Print. 

• United Space Alliance. Final Report on the 3-Month Alternate Access to 

Station Performance Requirements Study. Research rept. N.p.: n.p., 2002. 

Print. 

• University of Maryland. Space Systems Laboratory. Minimum Functionality 

Lunar Habitat Element. By David L. Akin. N.p.: n.p., 2009. Print. 



References 

• Vacuum Pump XE-225. 2012. Retrieved from http://www.made-inchina.com/showroom/ningboaux0574/productdetailNMLxmoITquVn/China-Vacuum-Pump-XE-225-.html

Preliminary Design Review - University of Maryland

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?