Human Life Support Requirements:
Inputs
Life Support Concepts
for Space Travel
Outputs
Daily
Rqmt.
Oxygen
Food
Water
(% total
mass)
0.83 kg
0.62 kg
3.56 kg
Daily
2.7%
2.0%
11.4%
Carbon 1.00 kg
dioxide
Metabolic 0.11 kg
solids
Water
29.95 kg
(drink and
food prep.)
Raymond M. Wheeler
Biological Sciences Branch
Kennedy Space Center, FL
Water
26.0 kg
(% total
mass)
83.9%
(hygiene, flush
laundry, dishes)
(metabolic / urine
(hygiene / flush
(laundry / dish
(latent
3.2%
0.35%
96.5%
12.3%)
24.7%)
55.7%)
3.6%)
TOTAL 31.0 kg
TOTAL 31.0 kg
Source: NASA SPP 30262 Space Station ECLSS Architectural Control Document
Food assumed to be dry except for chemically-bound water.
Life Support Approaches for Space
Physico-Chemical (PC)
Food
Oxygen
CO2 Removal
CO2 Reduction
Liquid Wastes
Solid Wastes
PHYSICO-CHEMICAL (PC) TECHNOLOGIES -CLOSING THE AIR LOOP
LEADING OPTIONS
Biological
OO2 GENERATION
2 GENERATION
¾Static
¾StaticFeed
FeedWater
WaterElectrolysis
Electrolysis
Stowage and Resupply
Photosynthesis
Electrolysis
Photosynthesis
Chlorate Candles
LiOH
Photosynthesis
Regenerable Amines
Molecular Sieves
Bosch / Sabatier
Photosynthesis
CO2 Electrolysis
Multi-Filtration
Microbiological
Evaporation
Transpiration
Vap. Compr. Distillation
Vap. Phase Cat. NH3 Removal
Incineration
Microbiological
Supercritical Oxidation
Lyophilization
ITALIC = International Space Station
¾¾Solid
SolidPolymer
PolymerElectrolysis
Electrolysis- -Liquid
LiquidAnode
AnodeFeed
Feed
¾¾CO
Electrolysis
CO22Electrolysis
¾¾Water
WaterVapor
VaporElectrolysis
Electrolysis
¾¾Bioregeneration
Bioregeneration
CO
CO22REDUCTION
REDUCTION
CO
CO22REMOVAL
REMOVAL
¾Four
¾FourBed
BedMolecular
MolecularSieve
Sieve
¾¾Solid
SolidSolid
SolidAmine
AmineWater
WaterDesorbed
Desorbed
¾Sabatier
¾SabatierReactor
Reactor
¾¾Electrochemical
ElectrochemicalDepolarized
DepolarizedConcentrator
Concentrator
¾¾Air
AirPolarized
PolarizedConcentrator
Concentrator
¾Bosch
¾BoschReactor
Reactor
¾¾Two-Bed
Two-BedMolecular
MolecularSieve
Sieve
¾Advanced
¾AdvancedCarbon
CarbonReactor
Reactor
¾¾Lithium
LithiumHydroxide
Hydroxide(LiOH)
(LiOH)
¾CO
Electrolysis
¾CO22Electrolysis
¾¾Bioregeneration
Bioregeneration
¾Bioregeneration
¾Bioregeneration
Source: Mark Kliss, NASA ARC
ISS Allowable Cabin Air Total Pressure and ppO2
15.5
Max O2
Partial
Pressure
Max. Total Pressure
x
Ma
N2
r
Pa
lP
tia
1 .6
e1
Normal Range
Min. Total Pressure
13.5
2
2.5
3
3.5
Oxygen Partial Pressure (psia)
Source: Jim Reuter, NASA MSFC
•
Oxygen Partial Pressure Control Plan:
¾ Intent is to also utilize Shuttle to raise ppO2 as high as
practical prior to undocking.
¾ Normal O2 introduction is via water electrolysis O2
generator.
¾ Can be ~constant introduction of O2 through day to achieve
fairly stable O2 cabin concentrations.
¾ Strict adherence to RRD ppO2 limits would restrict
operational flexibility.
i
ps
Off-Nominal
Range
14
Total Pressure Control Plan:
¾ Intent is to utilize Shuttle to raise ISS pressure as high as
practical within allowable range prior to undocking.
¾ Decay to lower end of control band over time, then utilize
on-orbit gas storage to maintain pressure.
2
14.5
ur
ss
re
•
24.1
%
15
Max
O
Total Pressure (psia)
Min O2
Partial
Pressure
ISS Total Pressure and PPO2 Control
4
Source: Jim Reuter, NASA MSFC
1
ATMOSPHERE REVITALIZATION
Space Station Strategy
CO2 Removal Performance (for ISS) - Development Testing
Impact of Varying Airflow Rate
Four Bed Molecular Sieve ⇒ CO2 Removal
Trap
CO2
SABATIER
REACTOR
¾
¾ 4BMS
4BMS composed
composed of
of two
two sets
sets of
of identical
identical beds
beds operating
operating in
in parallel
parallel ---- one
one set
set is
is for
for
adsorbing,
adsorbing, the
the other
other for
for desorbing
desorbing
•• Dessicant
Dessicant bed
bed for
for water
water vapor
vapor removal
removal
•• Zeolite
Zeolite molecular
molecular sieve
sieve bed
bed for
for trapping
trapping CO
CO22
¾
¾ Beds
Beds trade
trade functions
functions when
when adsorbing
adsorbing beds
beds reach
reach storage
storage capacity
capacity
CO2 Removal Rate
(lb/hr per mmHg)
FOUR BED
MOLECULAR
SIEVE
CO2
FROM
CABIN AIR
0.22
0.2
0.18
0.16
0.14
Flight Unit Performance
¾
¾ Beds
Beds are
are heated
heated to
to desorb
desorb water
water to
to the
the cabin
cabin and
and CO
CO22 to
to Sabatier
Sabatier Reactor
Reactor
0.12
16
¾
¾ Adsorption
Adsorption efficiency
efficiency is
is highest
highest at
at low
low temperatures,
temperatures, requiring
requiring that
that warm
warm cabin
cabin air
air
pass
pass through
through an
an air-liquid
air-liquid heat
heat exchanger
exchanger before
before entering
entering adsorbing
adsorbing beds.
beds.
18
20
22
24
26
Flowrate (cfm)
Source: Jim Reuter, NASA MSFC
Source: Mark Kliss, NASA ARC
Closed Hatch ECLS Test CO2 Removal Performance
PC TECHNOLOGIES CLOSING THE WATER LOOP
LEADING OPTIONS
5.0
ITALIC = International Space Station
ppCO2 (mmHg)
4.5
6 person crew load
4.0
3.5
POTABLE WATER RECYCLING
¾ Multifiltration (and Sabatier)
4 person crew load
3.0
3 person crew load
2.5
2.0
¾ Reverse Osmosis
¾ Electrodeionization
¾ Bioregeneration
1.5
HYGIENE WATER RECYCLING
¾ Multifiltration
¾ Reverse Osmosis
1.0
0.5
URINE RECYCLING
120:15:00
121:07:00
121:14:15
121:21:30
122:12:30
122:17:00
122:19:30
122:23:15
123:01:30
123:03:15
123:06:30
123:13:30
123:17:00
123:21:00
124:00:00
124:05:00
124:16:00
124:19:30
124:22:00
124:23:40
125:02:00
125:05:30
125:08:00
125:10:30
125:13:00
125:14:45
125:16:00
125:17:37
125:18:47
125:21:00
125:23:00
126:01:30
126:03:00
126:05:30
126:07:45
126:08:45
126:10:15
126:11:30
0.0
¾ Bioregeneration
¾ Vapor Compression Distillation
¾ Thermoelectric Integrated Membrane
Evaporation
¾ Air Evaporation
GMT
¾ Vapor Phase Catalytic Ammonia Removal
Source: Mark Kliss, NASA ARC
Source: Jim Reuter, NASA MSFC
WATER RECOVERY MANAGEMENT
Space Station Strategy
MULTIFILTRATION ⇒ (SABATIER) ⇒ POTABLE
WATER RECOVERY MANAGEMENT
Space Station Strategy (Evolutionary)
MULTIFILTRATION ⇒ (SABATIER) ⇒ POTABLE
MULTIFILTRATION (MF)
SABATIER REACTOR
¾¾POTABLE
POTABLEWATER
WATERisisobtained
obtainedthrough
throughMULTIFILTRATION
MULTIFILTRATIONofof
condensate
condensatefrom
fromthe
theTemperature
Temperatureand
andHumidity
HumidityControl
ControlSystem,
System,and
and
eventually
eventuallyalso
alsofrom
fromwater
waterformed
formedininthe
theSabatier
SabatierReactor
Reactorduring
duringthe
the
CO
reduction
process.
CO2 reduction process.
2
¾¾MF
MFconsists
consistsofofaaparticulate
particulatefilter
filterupstream
upstreamofofsix
sixunibeds
unibedsininseries.
series.
Each
Eachunibed
unibedisiscomposed
composedofofan
anadsorption
adsorptionbed
bed(activated
(activatedcarbon)
carbon)and
and
ion
exchange
resin
bed.
ion exchange resin bed.
—
— Particulates
Particulatesare
areremoved
removedby
byfiltration
filtration
—
— Suspended
Suspendedorganics
organicsare
areremoved
removedby
byadsorption
adsorptionbeds
beds
—
— Inorganic
Inorganicsalts
saltsare
areremoved
removedby
byion
ionexchange
exchangeresin
resinbeds
beds
Source: Mark Kliss, NASA ARC
CO2 + 4H2 = 2H2O + CH4 + heat
¾ CO2 is reacted with H2 at high temperature (180-530 °C) in the presence of
a ruthenium catalyst on a granular substrate.
¾ This produces water and methane for the potable supply.
¾ A single pass through the Sabatier reactor reduces greater than 98% of the
input CO2.
¾ CO2 conversion is incomplete (resupply penalty) and methane will likely be
vented (interferes with astronomical instrumentation observations).
Source: Mark Kliss, NASA ARC
2
Principal Life Support Hardware Distribution
ISS Atmospheric Contaminant Control Methods
Source: Jim Reuter, NASA MSFC
•
Passive Control
Atmosphere Gas Bottles
¾ Materials selection and control process
¾ Payload materials and processes screening
¾ Hardware design
•
Service Module
Node 2
Node 1
P
CAM (Zenith)
Not Shown
Node 3
UDM
Carbon Dioxide Removal
ATV
Trace Contaminant Control
P/H
Full Body
Cleanser
Sabatier
(scar)
Water Storage
Nitrogen Storage
Water Processing
(P=Potable; H=Hygiene)
Source: Jim Reuter, NASA MSFC
ESA
COF
CRV (not shown)
Oxygen Storage
Urine Processing
O2 Compressor
Personal Hygiene
Facility
Air Save Compressor
LEGEND
Primary Temperature
and Humidity Control
Vacuum System
Pressure Control Assembly
Galley
Miscellaneous Equip:
Fans, Valves, Filters,
Smoke Detectors, Portable
Fire Extinguishers
Plants and Bioregenerative Life Support
Metabolic
Energy
HUMANS
Energy Requirements
System Mass
System Volume
Crew Time
System Reliability
Habitation Module
DSM
Major Constituent Analyzer
Constraints (“Economics”) of Life
Support in Space:
•
•
•
•
•
JEM
PM
Laboratory Module
Functional Cargo
Module (FGB)
Oxygen Generation
Incidental Control
Overboard leakage
Absorption by humidity condensate
Human respiration
Dilution via atmosphere replenishment
Carbon dioxide removal assembly
Node 3 Nadir
Metal Oxide
¾ Mir: Expendable and regenerable charcoal for volatile trace gas
control and ambient temperature catalyst for CO control
¾ ISS U.S. Segment: Expendable charcoal for volatile trace gas control
and high temperature catalytic oxidation for CO and methane control
¾ ISS Russian Segment: Same system used onboard Mir
¾
¾
¾
¾
¾
HTV
Airlock
Progress Module
Active Control
•
MPLM
Atmosphere and
User Gas Bottles
food
(CH2O) + O2
CO2 + H2O
Clean Water
Waste Water
These apply for all Life
Support Technologies
Light
food
(CH2O) + O2*+ H2O
CO2 + 2H2O*
Clean Water
Waste Water
PLANTS
Testing with Plants and Algae for Life Support
1980
1960
Plants
as a
“Life Support
Machines”
2000
US Air Force
USSR Air Force
Inst. for Biomedical Problems (Moscow)
Inst. of Biophysics (Krasnoyarsk, Siberia)
NASA
NASA (CELSS)
NASA (ALS)
Natl. Aerospace Lab (Japan) Inst. Env. Sci. (IES)
CEN, Cadarache, FR
MELISSA / ESA
Guelph / CSA
University Studies (US, Europe, Japan, Canada)
3
NASA Testing with Plants for Life Support
1990
1980
2000
CELSS Program
ALS Program
Universities
Wheat (Utah State)
Gas / Ex (Utah State)
Sweetpotato / Peanut (Tuskegee)
Potato (Wisconsin)
Soybean (NC State)
New Jersey
NSCORT
N-Nutrition (UC Davis)
Lettuce (Purdue)
NASA
Centers
ARC
Algae
Closed
Systems
KSC
Purdue
NSCORT
Large, Closed System NFT Lighting
Joseph Priestley (1772) *
• “…a sprig of mint in a glass jar continued growing
for some months, I found that the air would
neither extinguish a candle, nor was it at all
inconvenient to a mouse”
• “plants thrive particularly well in air made obnoxious
by the exhalations of animals (and humans)”
Salad Machine
JSC
Plants and Life Support: Some Background
Waste Recycling
Solid Media Pressure Human/Integration
* Abstracted from E.I. Rabinowitch. 1945. Photosynthesis and Related
Processes. Interscience Publ. Inc. NY.
Early Bioregenerative Studies Focused on
Algae and Cyanobacteria (1950s and 1960s)
• Chlorella pyrenoidosa TX71105 (thermotolerant 39°C)
• Other species of Chlorella, Anacystis, Synechocystis,
Scenedesmus, Synechococcus, Spirulina were studied
• Development of culture systems (chemostats, turbidostats)
• Studies with animals (e.g., mice, monkeys) and humans
• Interest in Assimilation and Respiration Quotients (AQ
and RQ)
¾“…a general misconception in the scientific community is that
success of the bioregenerative approach depends on development
of a biologically and chemically closed ecology with complete
material balance. While this may be the ultimate goal, few consider
it possible if indeed necessary” (Miller and Ward, 1966)
Photosynthesis in Space
Observations from Algae Studies:
• Positives
– high photosynthetic efficiency
– good volume efficiency
– good energy efficiency--minimum wastage of light
• Negatives
–
–
–
–
–
difficulties with food processing / palatability
long-term, sustained production challenges
gas / liquid phase issues for µ-gravity
no transpiration advantage for water purification
not convenient for point source lamps
Bioregenerative Life Support for Space:
Reviews of Work in 1950s and 1960s:
• Eley, J.H. and J. Myers. 1963. A study of a photosynthetic
gas exchanger. A quantitative repetition of the Priestley
Experiment. Texas J. Sci. 16:296-333.
• Miller, R.L. and C.H. Ward. 1966. Algal bioregenerative
systems. In K. Kammermeyer (ed.) Atmosphere in Space
Cabins and Closed Environments. Appleton-Century-Croft,
NY.
• Taub, F.B. 1974. Closed ecological systems. In: R.F.
Johnston, P.W. Frank, and C.D. Michener (eds.) Annual
review of Ecology and Systematics. 5; 139-160.
C.H.Ward, S.S. Wilks, and H.L. Craft. 1970.
Dev. Indust. Microbiol. 11:276-295
4