Life Support for Long-Duration Interplanetary Spacecraft: Contributors: Sarah Atkinson, Mary Williamnson, Jacob Hollister, Jorge Santana, Olga Rodionova, Erin Mastenbrook, Dave Hyland Megan Heard Dept. of Aerospace Engineering Texas A&M University 2 Mission Statement “To expand the domain of humanity beyond the earth for the betterment, preservation, and advancement of all humankind by creating a self-sustaining, mobile habitat that ensures the physical and psychological well-being of its inhabitants.” >24 Month Trip Time 12 Crew Members Capable of Interplanetary Space Travel Cool Screenshot of station in space here 3 Mission Statement “To expand the domain of humanity beyond the earth for the betterment, preservation, and advancement of all humankind by creating a self-sustaining, mobile habitat that ensures the physical and psychological well-being of its inhabitants.” >24 Month Trip Time 12 Crew Members Capable of Interplanetary Space Travel Cool Screenshot of station in space here 4 System Overview – Life Support Goal: Create an environment conducive to healthy human functions with no re-supply for duration of mission Components: Atmospheric Control Oxygen production/re-processing Carbon Dioxide management Nutrition Diet determination and provision of food Water management Waste management Processing and recycling of liquid and solid waste 5 Life Support Over the course of 2 years, 12 people would consume: 7,360 kg oxygen 18,700 kg food 26,300 kg water Recycling is essential for any long term independent space habitation 6 Atmospheric Control 7 Atmospheric Control The Oxygen Generation System (OGS) on the International Space Station uses electrolysis to split water into hydrogen and oxygen The Carbon Dioxide Removal System (CDRS) uses zeolite to filter carbon dioxide out of the air Zeolite is a synthetic rock which captures CO2 but allows oxygen and nitrogen to pass through The hydrogen and carbon dioxide produced by these systems are vented overboard as waste 8 Atmospheric Control This system requires about .95 kg of water and produces about 1.3 kg of waste per person per day To provide for 12 people for 2 years, 8290 kg of water would be used and 11,000 kg of waste would be produced Disposing of waste in this manner is an unsustainable process and limits the duration of space missions 9 Atmospheric Control Photosynthetic algae will be used for O2 production and CO2 elimination 8 m2 of algae can consume enough carbon dioxide and produce enough oxygen for a single person 144 m2 of algae can provide O2 for a crew of 12 with a safety factor of 1.5 10 Atmospheric Control Tanks only need to be 5 cm deep, yielding a volume requirement of 7.2 cubic meters • Total algae system mass is estimated at 7450 kg • The total power requirement is 100 kW for both lighting and tank stirring • Mechanical filtration will be used to remove other impurities from the air 11 Atmospheric Control The algae grown will be arthrospira platensis (Spirolina) Supplement crew member’s diets 57% protein by mass and high in numerous essential vitamins and minerals 12 Atmospheric Control: Secondary • Two OGS (Oxygen Generation System) will be available as a back up in the event of algal disease or death in over 1/3 of the tanks • Water from the affected tanks will be filtered and then used by the OGS • Water from 1/3 of the tanks can produce oxygen for a crew of 12 for 214 days • CO2 scrubbers will be used to manage carbon dioxide levels • H2 and CO2 produced will be stored in pressurized tanks and recycled back into the system once the algae tanks have recovered 13 Atmospheric Control Break-Even Analysis 10000 Water Required (kg) 9000 8000 7000 6000 5000 OGS 4000 Algae Break-Even Point 3000 2000 1000 0 0 5 10 15 20 Mission Duration (months) 25 30 14 Nutrition 15 Nutrition Crew diet is modeled after that of the Greek island Ikaria Reasons: • Longevity of the Ikarians (large number of centenarians) • Mediterranean diet is rich in vegetables and herbs • Wine is high in antioxidants and reduces risk of heart disease • Olive Oil reduces low-density lipoprotein (“bad cholesterol”) • Potatoes contribute heart healthy Potassium, Vitamin B6, and Fiber 16 Nutrition The crew’s diet will be sourced from a combination of stored food and on-board agriculture Produce not immediately consumed will be frozen for later use 17 Nutrition Minimum requirements to sustain 12 people for 2 years Grain: 4355 kg Legumes: 653 kg (grown) Sugar or Honey: 653 kg Powdered Milk: 174 kg Olive Oil: 210 kg Salt: 44 kg Total Storage: 8174 kg and 13 cubic meters Additional Stored Food Fish: 245 kg Meat: 363 kg Dried Fruits: 65 kg Wine: 2014 kg equal to 7.4 barrels The addition of fresh produce from agriculture allows this amount of stored food to sustain the crew for upwards of 3 years 18 NUTRITION Aeroponics will be used for all agriculture Reduces water usage by 98 percent, fertilizer usage by 60 percent compared to traditional crops Up to six crop cycles per year, instead of the traditional one to two crop cycles. 19 Agriculture Tower Gardens® 20 towers each supporting 28 plants Each tower has a height of 1.83 m with a 0.58 m 2 footprint Total footprint of 11.8 m 2 for all 20 towers 76 L of water required per tower 1514 L of water needed for all 20 towers Growth time: 3 weeks for most plants to begin yielding 20 Agriculture Tower Garden Vegetables, Fruits, and Herbs included: Chamomile, cilantro, chives, celery, cumin, dill, Echinacea, parsley, basil, oregano, rosemary, sage, thyme, flax, lavender, fennel, lemon grass, mint Arugula, beans (lima, bush, pole, shell, fava, green), garbanzo beans, broccoli, cauliflower, collards, kale, leeks, melons, okra, peas, tomatoes, cucumbers, peppers (red, green, yellow, Chile, jalapenos), strawberries, lettuce, spinach, Brussels sprouts, squash, eggplant, cabbage Potatoes 6.69 sq. m. Yields 8.17 kg per day Grown on aeroponic shelves instead of tower gardens 21 Agriculture • NASA and Orbital Technologies developed High-Efficiency Lighting With Integrated`Adaptive Control (HELIAC) system Power requirements for HELIAC system: 72kW for the entirety of our agriculture • NASA study finds 80% red, 20% blue LED ratio most efficient for plant growth 22 Gravity & Radiation Requirements The maximum dose of radiation allowed for terrestrial flora is about 0.01 Sv/day. No adverse effects are caused Maintains population level Much higher tolerance than that of humans Low-gravity conditions are beneficial to plant growth Positive gravity allows for correct plant orientation Ease of watering and maintenance Faster growth rates 23 Waste Management 24 Waste Management In order to be sustainable, all nutrients must be recycled into the system Wastewater must be filtered to provide usable drinking water, and solid waste must be composted to provide nutrients for agriculture and algae 25 Waste Management Diluted urine is an effective crop fertilizer Unlike feces, urine is effectively sterile when it leaves the body and does not require composting A no mix toilet will be used to prevent feces from contaminating the urine Urine and solid waste will be processed separately 26 Waste Management Some urine will be used in fertilizer and the rest will be sent to wastewater filtration to recover drinking water The brine leftover from filtration will be used to accelerate the compost of solid waste Non edible portions of plants, leftover food, and any biodegradable trash will be composted 27 Waste Management Hyperthermophilic bacteria will be used to compost solid waste into fertilizer High temperature greatly reduces processing time, helps degrade harder proteins, and kills viruses and bacteria pathogenic to humans 28 Waste Management Heaters will be used to ensure the compost maintains a constant temperature of 80˚ C A rotating fin agitates the compost to enable aerobic decomposition A condenser attached to the air exhaust returns water to the compost to maintain water content A single .01 m3 fermentation vessel can process roughly 3 kg of waste in about a week 10 of these systems will be used for all waste processing 29 Water Management Utilize ECLSS Water Recycling System from the ISS (95% efficient) Able to recycle waste water from Urine Oral hygiene and hand-washing Condensing humidity from the air due to agriculture and humans Steps: Filter removes particles/debris Water passes through filters for organic/inorganic impurities Catalytic oxidation reactor removes volatile compounds/kills bacteria and viruses 30 Water Budgets Purpose Water mass (kg) Human Consumption 5100 Algae 7920 Agriculture 1700 Total: 14,720 Note: This does not include requirements for water ballast 31 Life Support Pods 2 pods with 3 floors each Each floor is 2.67 m in height 55.4 m2 per floor Algae (2 floors+shelves) – 144 m2 Agriculture (1 floor+shelf) – 30 m2 + Tower Gardens Freezer, food, and general storage (2 floors) – ~ 500 m3 32 Agriculture Pod LED’s – 80% Red 20% Blue Storage Agriculture Freezer 33 Life Support Pod Storage Algae 34 Life Support Pod (cont.) Walking space (main floor) Algae Shelves 35 PRACTICALITY ANALYSIS Break Even Points for Regenerative Systems System Months to Break Even Agriculture 21 Photosynthetic Algae 23 Water Recovery 0.5 36 Summary of Life Support Sub-system Power (kW) Mass (kg) Volume (m3) Agriculture 72 2000 30 Algae 100 8170 7.2 OGS 0.016 1360 14 ECLSS 4.42 1782 1.5 Water 4.42 14720 14.5 Food Storage .2 8123 13 Waste Management 4 200 4 185.1 36,360 84.2 Total 37 Questions?