Kate Mitchell Week 2: January 25 th , 2007

1. Kate MitchellWeek 2: January 25th, 2007 Human Factors – Team Lead Habitat (HAB), Crew Transfer Vehicle (CTV) This Week: HAB

2. Definition of HAB Mission • Requirements [2] • 2 HABs on Mars Surface (MS) by the beginning of 4th synodic period • Each HAB support crew of 4 (8 in emergency) • Launch Specifications • HAB 1: 1564 days consumables • HAB 2: 2112 days consumables • Re-supply (RS) 1-5: 1330 days consumables • Re-supplies launched with crews 4-8

3. HAB Conclusions Total Mass/Volume/Power for HAB 2 *Consumable calculations made assuming water recycling system with 90% efficiency, plus the capability to produce all water (9225 kg per synodic period) through ISPP beginning in 7th synodic period. Total Mass/Volume/Power Entire Architecture

4. Backup - Totals Total Mass/Volume/Power for HAB 1 Total Mass/Volume/Power for each re-supply

5. 1st table is a breakdown of all components of crew water consumption 2nd table shows max water that will need to be stored in HAB as well as its volume (based on 2112 days) Backup – Water Calculations Crew Consumption of Water per day[1]

6. Backup – Water Comparison • The following slide contains a comparison of two different plans for water • Plan 1: Launch necessary water, then use recycling system which has efficiency of 90% • Plan 2: Launch necessary water, then use recycling system which has efficiency of 90%, plus produce all water (9225 kg per synodic period) through ISPP beginning in 7th synodic period • Conclusion: Plan 2 cuts the water IMLEO in half • Plan 2 was therefore used in final mass calculations

7. Backup – Water Comparison Plan 1* Plan 2* *Water calculations done in MATLAB code (attached)

8. Backup – Food Consumption Crew Consumption of Food per day • 1st table shows mass and volume of food consumed per crew member per day • 2nd table shows max food that will need to be stored in HAB as well as its volume (based on 2112 days) • 3rd tables shows mass and volume of food to be launched in both HABs as well as re-supply ships, and total food IMLEO *Food calculations done in MATLAB code (attached)

9. Backup – Atmospheric Supply • Atmospheric supply values were based on O2 consumption of 0.835 kg/p/d (1st table) • 2nd table shows max O2 and N2 that will need to be stored in HAB as their tank volumes and masses* (based on 2112 days) *Tank mass/volume calculations in MATLAB code (attached)

10. Backup – Atmospheric Supply Total gases per Launch as well as total IMLEO through entire architecture* *Atmospheric supply calculations in MATLAB code (attached)

11. Backup – Atmospheric Supply • Atmospheric pressure: 101 kPa • Partial pressures: 80 kPa N2 21 kPa O2 • Volume of 1 mole of gas (101 kPa and 298 K): 0.02445 m3/mole • Mass of gas needed to fill the pressurized volume: • Mass of gas needed assuming 0.14% mass per day leakage rate: • Using Sabatier/electrolysis reaction: • Oxygen consumption rate: 0.835 kg/p/d • Total oxygen consumed by crew:

12. Backup – Atmospheric Supply CO2 production rate: 1 kg/p/d Total carbon dioxide produced by crew: Total oxygen reclaimed: Find Mass of O2 Tank (using O2 tankage value of 0.364 kg tank/kg O2 [1] ): Find Mass of N2 Tank (using N2 tankage value of 0.556 kg tank/kg N2 [1] ): Volume of tanks (Assuming density of gases to be 1440 kg/m3):

13. Backup – Life Support Systems Water Recycling System CO2 Removal/Oxygen Generation System

14. Backup – Crew Accommodations [5]

15. Backup – Crew Accommodations

16. Backup – Radiation Shielding • Investigations have suggested that a 50 g/cm2 shield should be sufficient to protect from solar particle events[4]. The Mars atmosphere provides 16 g/cm2 of shielding, which can be subtracted from the 50 g/cm2, making it necessary to provide the crew with 34 g/cm2 of additional shielding. • Safe-room Shielding • By creating a room to protect the crew from SPEs, we reduced the total mass by eliminating the necessity to heavily shield the entire HAB. The room will be 2 x 2 x 2 m (8m3) and will contain crew beds and necessary provisions. The shielding used will be 16 cm Polyethelyne (ρ = 1 g/cm3) and 5 cm Aluminum (ρ = 2.78 g/cm3), making the total shield arial density 29.9 g/cm2. The total surface area of the safe-room is 24 m3, making the total shield mass 7176 kg. • HAB External Shielding • An additional 4 g/cm2 shielding must be provided to meet the 50 g/cm2 shielding requirement. This will be done by shielding the entire habitat with 4 g/cm2 shielding. We will use 1 cm Aluminum and 2 cm Polyethelyne to meet this requirement, giving a HAB external shielding arial density of 4.77 g/cm2. Since the surface area of the HAB is not yet known, a conservative (large) estimate was made: 408 m3 (assuming cylindrical shape with 10m diameter, 8m height). Using this surface area, the total shield mass is 19,462 kg. • The total mass of the required radiation shielding is therefore 26,638 kg.

17. References [1] Hanford, Anthony J., ed. NASA Johnson Space Center. Advanced Life Support Baseline Values and Assumptions Document. Aug. 2004. 1 Feb. 2005. http://ston.jsc.nasa.gov/collections/TRS/_techrep/CR-2004-208941.pdf [2] Landau, Dr. Damon F., “Strategies for the Substained Human Exploration of Mars.” Thesis Submitted to the Faculty of Purdue University, Dec. 2006. [3] Niziolek, Paul, Project Legend - Final Report - Appendix. April 2005. p. 478-480. [4] Reed, Ronald D., and Gary R. Coulter. "Physiology of Spaceflight." Human Spaceflight: Mission Analysis and Design. Ed. Wiley J. Larson and Linda K. Prank. New York: McGraw-Hill, 1999. 113-115. [5] Stilwell, Don, Ramzy Boutros, and Janis H. Connolly. "Crew Accomodations." Human Spaceflight: Mission Analysis and Design. Ed. Wiley J. Larson and Linda K. Prank. New York: McGraw-Hill, 1999. 575-606. [6] Tribble, Alan C. "The Space Environment: Hazards and Effects." Human Spaceflight: Mission Analysis and Design. Ed. Wiley J. Larson and Linda K. Prank. New York: McGraw-Hill, 1999. 65-73.