Technology to Support Human Space Physiology Life Support

ESA Academy | Slide 1Human Space Physiology Training Course 2021

Presented by

Technology to Support Human Space Physiology – Life Support Systems

Dr BERNARD COMET (WITH DR LUCIE CAMPAGNOLO CONTRIBUTION)

MEDES – Institute of Space Medicine and Physiology


A collaboration between


Outline

1. Introduction

2. Keeping humans alive and healthy: Adverse effects & environmental threats

3. Environmental Control and Life Support Systems (ECLSS)

4. Low Earth Orbit, long duration spaceflights and extra-terrestrial habitats

5. Overview of current technologies and associated challenges

6. Focus on environmental control in manned spaceflights

7. Conclusion


INTRODUCTION

Life Support Systems


Live and Work in Space

© Elon Musk - Instagram


Live and Work in Space

© ESA/NASA 2017


KEEPING HUMANS ALIVE AND HEALTHY:

Adverse Effects & Environmental Threats


Leaving the planet is only half the problem

• How to stay alive (and healthy) in a remote and artificial environment?

AIR WATER

FOOD WASTE

EN

VIR

ON

MEN

TAL C

ON

TRO

L


Earth Atmosphere

At Sea Level on Earth:

• 78.1% Nitrogen (N2)

• 20.9 % Oxygen (O2)

• 0.93 % Argon etc.. (Ar)

• Trace of Carbon Dioxide and Water

Total Pressure: 101 kPa

Human can survive in a wide range of atmospheric composition and pressures


Adverse Effects of Atmospheric Changes

Too High Too low

Total Pressure Change in biomolecularconformations and inactivation of critical Enzymes

Decompression SicknessEbullism (vaporization of Body Fluids < 6.27 kPa @37°C )

Oxygen - HyperoxiaInflammation of the bronchus,respiratory disturbances (decrease of lung vital capacity), heart symptoms, blindness, loss of consciousness …

- HypoxiaSleepiness, headache, loss of consciousness

Carbon Dioxide Headache, Nausea, Rapid Breathing, increase heart rate, Convulsion, loss of consciousness

Human Space Physiology Training Course 2021


Oxygen Toxicity (Hyperoxia): Given Example of ISS & EVA


Artificial Atmosphere: Example of ISS

• 79% Nitrogen (N2), 21% Oxygen (O2)

• Carbon dioxide partial pressure with 6 crewmembers:

24hr average exposure: 5.3 mmHg

Peak exposure 7.6 mm Hg

• Trace gases: within SMAC values (spacecraft

maximum allowable concentrations)

• Pressure: 20.7 kPa<P≤103 kPa

• Microbial contamination

< 100 CFU/m3 for bacteria & Fungi


Water on Earth

Earth Standards against microbial and chemical contamination

Water is needed for

• Hydration

• Food and beverage rehydration

• Personal hygiene

• Medical use

etc…

In the US, the average water consumption is ~ 7 786 liter of water per person per day (data varying with methodology…)


Water in Space (ISS)

Manned spaceflights specifications:

• Minimum 4.5 L per crewmember per day

• Microbial contamination:

< 50 CFU/mL for total count and no coliforms in 100 mL

• Chemical contamination:

Table of allowed contaminants quantities (NASA Spacecraft Water Exposure Guidelines (SWEGs))


Other Considerations

• Food

• Cleanliness and waste management

• Crew comfort: temperature, humidity, Ventilation …

• Vibration, acceleration, acoustic etc…

• Protection against radiation


Some Habitats Proposals

1975 – Standford Torus

1987 – Artistic view of a moon base


Some Habitats Proposals

Interstellar fictional spacecraft Endurance

Star Trek fictional spacecraft USS Enterprise


ENVIRONMENTAL CONTROL AND LIFE SUPPORT SYSTEMS (ECLSS)

Sizing and Requirements


How to Design an Artificial Environment?

The Crew

The type of missionDistance

Example of drivers• Crew size• Mission duration• Propulsion costs• Launch / supply capabilities and the re-supply capabilities and

opportunities• Reliability (in relation to the possibility for emergency evacuation

or safe havens)• Size of the habitat• Type / available power supply• Possible in-situ resources utilization and recycling technologies …


ECLSS Requirements

Summary of nominal human

metabolic interface values in

kg/crewmember-day Source: NASA BVAD

Life Support Baseline Values and

Assumptions Document (2018)


ECLSS Requirements: Laundry Necessity for Exploratory Mission

Source: NASA BVAD Life Support Baseline Values and Assumptions Document (2018)


Mission Hypothesis


Mission to MARS – Hypothesis

0 100 200 300 400 500 600 700 800 900 1000

Short Stay

Long-Stay (fast transit)

Long-Stay(Minimum Energy)

Outbound Transit Time at destination Return Transit

Mission duration (days)


Mission to MARS – Short Stay

Consumables & Products Transfer Phases in total 30 Day Stay Phase

Oxygen 2 640 kg 123 kg

Hygiene water 59 400 kg 220 kg

Potable water 7 200 kg 340 kg

Food 6 900 kg 320 kg

Carbon dioxide 3 200 kg 150 kg

Water vapor 7 600 kg 350 kg

Solid waste 4 400 kg 250 kg

Liquid waste 61 700 kg 325 kg


Space Requirements

1. Able to function in microgravity or partial gravity

• Phase separation and Phase transfer (solid, liquid, gas), are not completely understood

• No flow convection

2. Safe & Reliable

• Several failure tolerance• Don’t create a hazard for the crew or for the equipment• Harsh environment (radiations)

3. Sustainable

• ORU (On-orbit replacement units)• Maintenance plans

4. Low mass, volume, power & consumables

• Cost effective


Space Human System Integration Requirements Tree (NASA)


LOW EARTH ORBIT,LONG DURATION SPACEFLIGHTSAND EXTRA-TERRESTRIAL HABITATS

Should we take our environment with us?


Open Loop vs Closed Loop

Open-Loop ECLSS« Everything is supplied »

• Very Simple• Highly reliable• Resources are linearly dependent

on flight time

Closed-Loop ECLSS« Everything is recycled »

• High initial mass• Lower reliability• Low re-supply requirements• Higher resources consumption

(power, thermal..)


Open Loop vs Closed Loop

Open-Loop ECLSS« Everything is supplied »

• Very Simple• Highly reliable• Resources are linearly dependent

on flight time

Closed-Loop ECLSS« Everything is recycled »

• High initial mass• Lower reliability• Low re-supply requirements• Higher resources consumption

(power, thermal..)

ISS –Lunar Base


Starting to close the Loop

Open: all consumables are used in open loop

Physico-chemical: Components based on physical and chemical processes only

Hybrid: Components based on physical, chemical and biological processes

Bioregenerative: Components based on biological processes only


ISS: Starting to close the Loop (updated)

o2

CH4 & H2

+ trace contaminants


Overboard Venting Mainly

CH4 & H2

+ trace contaminants


CURRENT TECHNOLOGIES AND ASSOCIATED CHALLENGES

How close are we to sustaining a human colony?


ISS ECLSS

ISS is a test bench for technology demonstrations towards closed loop systems:

• The current ECLSS for the ISS recovers a significant amount of oxygen and water

• Space vehicle reaches the space station on average every month and 70% of these vehicles accommodate only resupply resources such as water, gas, and food


ISS ECLSS(USOS: United States Orbital Segment)

ISS US Segment (L. Carter et al. 2016)


Atmosphere Control and Supply (USOS)

Provides cabin atmosphere pressure control, overpressure relief, pressure equalization, rapid depressurization detection and response, nitrogen and oxygen distribution.


Atmosphere Control and Supply (ACS)

The current overall ISS air recovery rate is approx. 50%

Oxygen generation

• H2O electrolysis

• Oxygen supply (Cryogenic)

CO2 removal

• 4 beds molecular sieves

(microporous solid allowing O2 and N2) + desiccants

• CO2 dumped overboard

CO2 reduction

• Sabatier reactor (produces H2O and methane)

Forced air flow

• Ventilation system

• Air control and cleaning (trace and microbial contaminant)Oxygen Generation System in ISS



CO2 removal

• 4 beds molecular sieves (microporous solid allowing O2 and N2

and traps CO2 + desiccants)

Credit: Gisella Detrell



The current overall ISS air recovery rate is approx. 50%

Oxygen generation

• H2O electrolysis

• Oxygen supply (Cryogenic)

CO2 removal

• 4 beds molecular sieves

(microporous solid allowing O2 and N2) + desiccants

• CO2 dumped overboard

CO2 reduction

• Sabatier reactor (produces H2O and methane)

Forced air flow

• Ventilation system

• Air control and cleaning (trace and microbial contaminant)Oxygen Generation System in ISS



CO2 reduction

• Sabatier reactor (produces H2O and Methane)



Water Recovery and Management (USOS)

Supplies potable water, hygiene water, and water for payloads, as well as collects humidity condensate


Water Recovery and Management

• The current overall ISS water recovery rate is 88% (Walter F. Schneider et al. 2016), goal for exploration mission is 98% (Walter F. Schneider et al. Oct. 2018)

• On ISS, only Urine and Condensate are treated, urine brine is wasted

Water Tank supply

Water recovery « grey water »

Water Processor Assembly (filtration and high-temperature catalytic reactor)

Water recovery from « yellow water »• To be turned into grey water• Aggressive contaminant (urea can turn into

Ammonia)• Urine brine is not recycled

Urine Processor Assembly (Distillation and centrifuge) + Water Processor Assembly


Water Recovery and Management

Water recovery from « yellow water »

Urine Processor Assembly (Vapor Compression Distillation)



Waste and Food

Waste

• Solid waste is simply trashed in Cargos …

Food

• Food supply via Cargos

Veggie (NASA)

• Proof of concept for growing Lettucesin space



FOCUS ON ENVIRONMENTAL CONTROL

Keep the resources produced safe


Physico–chemical and Microbiological

Physico-chemical

• Temperature• Humidity• Pressure• Fire and

flammability risks • Toxicity

European asset: ANITA (Analysing Interferometer for Ambient Air) monitors 32 potential gaseous contaminants

Based on culture-based techniques (except for coliform detection in water)

Closed loop system cannot work without proper environmental control

Microbiological

• Bacteria & Fungi in Air, Water and on Surfaces

• Coliform detection in Water


Microbial Contamination

Microbial contamination in a confined environment can induce:

• Risk for the crew health

• Risk of biodegradation of the equipment

• Risk of contamination of ECLSS


Current Techniques and Mitigations

Air

Microbial Air Sampler (MAS)

Surface

Surface Sampling Kit (SSK)

MitigationDisinfection Wipes

MitigationFilters /POTOK technology


Current Techniques and Mitigations

Air

Microbial Capture Device (MCD)

Water

Coliform detection bags

MitigationIodine


Promising Technologies / Tech Demo

AquapadPaper-based culture

Microbial Monitoring SystemPCR

Biomolecular Sequencer MiniOn


Conclusion

• ECLSS (Environmental Control and Life Support Systems) have to be optimized with respect to the mission parameters

• Less than 90% of the available water and less than half of the potential oxygen that could be is actually recovered

• The water recovery system on ISS is limited to treating only urine and condensate, which is only about 20% of the potential waste stream on long duration exploration missions

• The reliance on expendable items like filters, and the complexities of the systems themselves, create a dependence on the re-supply of equipment and materials from Earth

• Closed-Loop systems are key issues for long duration spaceflights and exploration

• Closed-Loop systems cannot work without Environmental Control systems

ISS is a pillar to reach ECLSS closed loop objective: it provides a unique research environment to validate new technologies and to define new control strategies


Melissa Project: a bioregenerative closed-loop life support system


Thank You!


Documents

Technology to Support Human Space Physiology Life Support