Life Support for Human Spaceflight
Water Recovery, Waste Management, and Plant Growth Systems
Karen D. Pickering, Ph.D. NASA Johnson Space Center Crew and Thermal Systems Division
Agenda • Life Support – a brief refresher
• Water Reclamation Systems
• Solid Waste Management
• Bioregenerative Life Support
April 18, 2013 Karen D. Pickering
Life Support – an overview
April 18, 2013 Karen D. Pickering
General classes of life support systems • Regenerative/Closed
Loop • Recycling of resources
(low consumable/resupply) • Minimized overboard
losses • Increased power, thermal,
and initial mass • Lower reliability due to
complexity • Usually about 3 months of
duration required to make the trade off beneficial
• Non Regenerative/Open Loop
• Backpacking mission (high consumables/resupply)
• Simple, reliable • Resources are linearly
dependent on flight time
Open-loop life support system resupply mass 12,000 kg/person-year
(26,500 lbs/person-year)
Systems Maintenance 2.1%
Gases lost to space 2.1%
Crew Supplies 2.1%
Food (dry) 2.2%
Oxygen 2.5%
Water 89%
10,680 kg (23,545 lbs)
(2827 gallons)
Human life support requirements
Mass balance
WATER RECLAMATION SYSTEMS
April 18, 2013 Karen D. Pickering
Spacecraft water cycle
• Water requirements vary as exploration missions mature
• Wastewater characteristics change
Water requirements change as mission matures
The Spacecraft Water Cycle
• Stages of the water recovery process: • Stabilization • Wastewater Storage • Primary Processing • Brine Water Recovery • Post-processing • Disinfection • Potable Water Storage
Shuttle
Shuttle • Water generated through fuel cell reaction
• Excess water and wastewater dumped overboard or transferred to ISS
• Water dumps are propulsive!
• Vent lines must be heated!
International Space Station
International Space Station • Recycle urine and
humidity condensate
• Distillation
• Adsorption
• Ion exchange
• Catalytic oxidation
ISS Life Support Systems
15
Stored Water • Contingency Water
Containers (CWC) • Originally intended for
“contingency” use • Laminated polymer
bladder with a Nomex restraint
• Silver ions used as disinfectant
• 45 liter capacity
Stored Water • Contingency
Water Containers – Iodine (CWC-I)
• Approximately 150 onboard ISS
• FEP bladder with Nomex restraint
• Iodine used as disinfectant
• 22 liter capacity
CWC-I
The Spacecraft Water Cycle • Stages of the water
recovery process: • Stabilization • Wastewater Storage • Primary Processing • Brine Water Recovery • Post-processing • Disinfection • Potable Water Storage
Wastewater Storage & Stabilization • Some water recovery systems
rely on minimal microbial growth and prevention of urea breakdown to ammonia
• Stabilization typically involves the addition of strong acids/oxidizers
• The goal of current stabilization studies is to find alternatives to hazardous acids/oxidizers (alternate chemicals or biological stabilization).
Urine and Bronopol samples showing no microbial growth.
Bacterial growth in imidazolidinyl
urea.
What happens when you DON’T stabilize
April 18, 2013 Karen D. Pickering
Distillation systems • Planetary missions:
simple evaporation
• Microgravity missions: forced to use rotary, vacuum driven distillation process
• Recovery is limited by solubility
Urine and solubility
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Urine solids on orbit
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Membrane systems • Membrane systems are ideal for
removal of inorganic solids downstream of a biological water process
• Forward osmosis: low fouling potential and high rejection of contaminants
• Ultrafiltration: high flux, rejection of large contaminants
• Reverse osmosis systems produce near potable quality water
• Electrodialysis has potential for calcium scale prevention
Forward osmosis / reverse osmosis
Biological Water Processors • Low energy, regenerable
treatment process
• Key questions include reliability, rapid startup, and scalability
JSC 2001 JSC 2004 TTU 2011
Alternative water processor
April 18, 2013 Karen D. Pickering
Brine Water Recovery • Membrane and
distillation technologies all produce brines
• Approximately 15% of daily wastewater is lost as brine
• Solids handling is greatest challenge to development
• There is currently no brine recovery system in flight.
Bladder Assembly, prior to installation
into Restraint.
June 1, 2012 Burst Test 61.53 psig
Temporary Brine and Urine Storage System
Integrated treatment systems Feed Pump
FO Membrane Contactor
Bioreactor
RO Module
s
Product Water Tank
Osmotic Agent Loop
Wastewater Feed • Quantify consumables,
power requirements • Demonstrate water quality of produced water • Define integration issues for future system developme
exploration habitats
Alternative water processor integrated test
April 18, 2013 Karen D. Pickering
WRS Interfaces
Water Recovery
Air Revitalization
Food Production
Crop Production
Habitability
Solid Waste
Recovered Solid Waste Water ISRU / EVA
Insitu Water EVA waste
EVA supply Wastewater
or intermediate water
SOLID WASTE MANAGEMENT
April 18, 2013 Karen D. Pickering
Function of solid waste management • Trash management
• Fecal disposal
• Reduce, reuse, recycle!
• (and stabilize too)
April 18, 2013 Karen D. Pickering
Stabilization • Prevent bacterial growth and odors
from wet trash
• Shuttle • Wet trash stored below floor
• Vented to vacuum
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Compaction Drying
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Technology options • Drying
• Freeze drying
• Heat melt compaction
• Disposal • Pyrolysis
• Incineratin
• Biological treatment
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BIOREGENERATIVE LIFE SUPPORT
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What types of plants would be needed? • Crops--high yielding and nutritious
• High harvest index (edible / total biomass)
• Horticultural considerations • planting, harvesting, pollination, propagation
• Environmental considerations • photoperiod, temperature, mineral nutrition
• Processing requirements
• Dwarf or low growing types
Cultivar Comparisons and Crop Breeding
← Utah State: Super Dwarf Wheat Apogee Wheat Perigee Wheat Super Dwarf Rice
Dwarf Pepper ↑ and Tomato ↓
Recirculating Hydroponics with Crops • Conserve Water &
Nutrients • Eliminate Water Stress • Optimize Mineral Nutrition • Facilitate Harvesting
Wheat / Utah State
Soybean KSC Sweetpotato
Tuskegee
Root Zone Crops in Nutrient Film Technique (NFT)
Wheeler et al., 1990. Amer. Potato J. 67:177-187; Mackowiak et al. 1998. HortScience 33:650-651
Watering Systems for Weightlessness
Wright et al. 1988. Trans. ASAE 31:440-446; Dreschel and Sager. 1989. HortScience 24:944-947.
Porous Ceramic Tubes to Contain the Water
High Yields from High Light and CO2 Enrichment
Wheat - 3-4 x World Record Potato - 2 x World Record
Lettuce-Exceeded Commercial Yield Models
Utah State Univ.
Wisconsin Biotron
NASA Kennedy Space Center
• Bubgee, B.G. and F.B. Salisbury. 1988. Plant Physiol. 88:869-878. • Wheeler, R.M., T.W. Tibbitts, A.H. Fitzpatrick. 1991. Crop Science 31:1209-1213.
Ethylene in Closed Systems
Epinastic Potato Leaves
at ~40 ppb
Epinastic Wheat Leaves at ~120 ppb
Electric Lighting Systems
High-Pressure Sodium
LEDs
Microwave Sulfur
Fluorescent
LED for Plant Growth
Red...photosynthesis Blue...photomorphogenesis Green...human vision
John Sager, KSC, Testing Prototype Flight Plant Chambers with LEDs
Light, Productivity, & Crop Area Requirements
0 10 20 30 40 50 60 70 80
Light (mol m-2 day-1)
Area
Req
uire
d (m
2 / p
erso
n)
0
5
10
15
20
25
30
Prod
uctiv
ity (g
m-2
day
-1) Productivity Area
0
20
40
60
80
100
120
140
Bright Sunny Day on Mars
Capture and Delivery of Solar Light for Plants
Space Life Sciences Laboratory Kennedy Space Center, FL
Surface Deployable Greenhouse Concepts →
• Inflatable, low mass, easy stowage
• Might be covered at night • Operated at low pressure
One Human and 11 m2 of Wheat !
Nigel Packham, NASA Johnson Space Center
Contact and acknowledgements Karen D. Pickering
EC3
Life Support Systems Branch
NASA Johnson Space Center
Houston, TX 77058
Thank you to:
KSC / Dr. Ray Wheeler
ARC / John Fisher and Wiggy Wignarajah
April 18, 2013 Karen D. Pickering