Space engineering
Environmental control and life support (ECLS)
Foreword
This Standard is one of the series of ECSS Standards intended to be applied together for the management, engineering and product assurance in space projects and applications. ECSS is a cooperative effort of the European Space Agency, national space agencies and European industry associations for the purpose of developing and maintaining common standards. Requirements in this Standard are defined in terms of what shall be accomplished, rather than in terms of how to organize and perform the necessary work. This allows existing organizational structures and methods to be applied where they are effective, and for the structures and methods to evolve as necessary without rewriting the standards.
This Standard has been prepared by the ECSS-E-ST-34C Working Group, reviewed by the ECSS Executive Secretariat and approved by the ECSS Technical Authority.
Disclaimer
ECSS does not provide any warranty whatsoever, whether expressed, implied, or statutory, including, but not limited to, any warranty of merchantability or fitness for a particular purpose or any warranty that the contents of the item are error-free. In no respect shall ECSS incur any liability for any damages, including, but not limited to, direct, indirect, special, or consequential damages arising out of, resulting from, or in any way connected to the use of this Standard, whether or not based upon warranty, business agreement, tort, or otherwise; whether or not injury was sustained by persons or property or otherwise; and whether or not loss was sustained from, or arose out of, the results of, the item, or any services that may be provided by ECSS.
Published by: ESA Requirements and Standards Division
ESTEC, ,
2200 AG Noordwijk
The
Copyright: 2008 © by the European Space Agency for the members of ECSS
Change log
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ECSS-E-30 Part 4A
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First issue
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ECSS-E-30 Part 4B
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Never issued
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ECSS-E-ST-34C
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Second issue
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Scope
This Standard addresses the discipline of environmental control and life support (ECLS) and the interfaces to other disciplines of engineering and to the domains of management and product assurance.
It also introduces the structure and applicability of the associated Level 3 Standards.
The environmental control and life support systems (ECLSS) covered in this Standard includes those aspects relating to the assurance of a safe and comfortable environment for human beings undertaking a space mission.
When other forms of life are accommodated on board, the ECLSS also ensures the appropriate environmental conditions for those living organisms.
This Standard applies to all ECLSS for:
all manned space endeavours and manrated space products, and
any other form of life to be maintained on board.
This standard may be tailored for the specific characteristics and constrains of a space project in conformance with ECSS-S-ST-00.
Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this ECSS Standard. For dated references, subsequent amendments to, or revision of any of these publications, do not apply. However, parties to agreements based on this ECSS Standard are encouraged to investigate the possibility of applying the more recent editions of the normative documents indicated below. For undated references, the latest edition of the publication referred to applies.
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ECSSS-ST00-01
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ECSS system— Glossary of terms
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ECSSEST-10-02
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Space engineering — Verification
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Terms, definitions and abbreviated terms
Terms from other standards
For the purpose of this Standard, the terms and definitions from ECSSSST0001 apply.
Terms specific to the present standard
anoxic
gas or atmosphere containing no oxygen
closedloop ECLSS
ECLSS based on recycling, regeneration, and recovery of materials or elements
The closedloop ECLSS implies that the use of significant expendables and consumables is excluded from the processes.
compression
EVA related action to increase total pressure
decompression
EVA related action to reduce the total pressure
depressurization
action to reduce the total pressure
environmental control and life support (ECLS)
engineering discipline dealing with the physical, chemical and biological functions to provide humans and other life forms with suitable environmental conditions
The objective of ECLS is to create a suitable environment by controlling the environmental parameters, providing resources, and managing waste products.
environmental control and life support system (ECLSS)
system that includes the hardware and software to perform ECLS functions
hypoxic
gas or atmosphere containing oxygen that provides a partial pressure of oxygen below the specified range of oxygen partial pressure in the atmosphere of habitable volumes
openloop ECLSS
ECLSS based on external resupply of resources
partial pressure
participation of one of the constituents of a gas mixture or an atmosphere in the total pressure
- 1 Examples include:
- PCO2, stands for partial pressure of carbon dioxide,
- PH2O, stands for water vapour partial pressure.
- 2 To calculate a partial pressure, the fraction of the constituent is multiplied by the total pressure. For example, the partial pressure of oxygen on Earth is: PO2 = 0,21 1,013 106 Pa = 0,213 106
- 3 Abbreviation for partial pressure is P followed by the chemical formula of the constituent.
pressurization
action to increase the total pressure
recompression
<EVA>
EVA related action to restore the total pressure after decompression or to treat decompression illness
recompression
<Other than EVA>
action to restore the total pressure after depressurization
repressurization
action to restore the total pressure after depressurization
safe haven
facility capable of sustaining human life under emergency conditions as a minimum, in the case of a life threatening situation
Abbreviated terms
For the purpose of this Standard, the abbreviated terms from ECSSSST0001 and the following apply:
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Abbreviation
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Meaning
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CFU
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colony forming unit
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DCI
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decompression illness
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ECSL
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environmental control and life support
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ECLSS
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ECLS system
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EM
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engineering model
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EMC
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electromagnetic compatibility
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EMU
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EVA mobility unit
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EVA
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extravehicular activity
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FDIR
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failure detection, isolation and recovery
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FM
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flight model
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FOV
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field of view
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GSE
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ground support equipment
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ICD
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interface control document
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ISS
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International Space Station
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IVA
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intravehicular activity
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multig
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more than 1g acceleration situation
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QM
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qualification model
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SMAC
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spacecraft maximum allowable concentration
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TCS
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thermal control system
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Requirements
Overview
Requirements defined in this Standard are specific to ECLSS, including requirements for functional objectives of the system or requirements for the safety of life.
Requirements are not quantified with values for the parameters. Quantified specifications are established on a casebycase basis for project dependent items. Examples of parameters to be specified are listed in Annex A
and system
General
The ECLSS shall be designed for a specific mission and all phases within that mission as defined in 4.2.2, up to the end of the operational lifetime.
Overview
Basic requirements on the ECLSS vary according to the mission scenarios and the mission phases of the selected mission. The most important parameters affecting the requirements are the mission duration, the size of the crew, the type and quantity of living organisms, the availability of a source of resupply (e.g. Earth and space cargo) and the feasibility or duration of any saving, rescue or evacuation procedure.
The longer the mission duration and the larger the distance from the source of resupply (e.g. Earth) are the more difficult the rescue becomes and the higher the dependence is on ECLSS closed loops.
Identification of requirements
ECLSS requirements related to each mission phase shall be identified in project Phase A.
For project phases and planning, see ECSSMST10.
phases
The applicable conditions for the following mission phases shall be included in the ECLSS definition:
- ground and prelaunch operations;
- storage, transport;
- functional check out;
- waiting on launch pad.
- launch and ascent;
- launch time;
- external environment;
- specific requirements during multig phases;
- impact of depressurization and repressurization (IVA);
- launch abort situation.
- planetary orbital phase;
- transfer phase;
- docking, docked and separation phases, rendezvous and parking;
- extravehicular activity: prebreathing
- planetary phase;
- landing, mission on planet;
- planetary walk;
- excursion, rover, supported excursion.
- return to Earth, descent, reentry and landing;
- post landing phases, quarantine.
Manned and unmanned phases can be part of a given mission.
The storage and transport conditions for supplies shall be specified.
External environmental conditions, both on ground and in space shall be taken into account.
System
MultiECLSS phases
Applicability
The requirements in 4.2.3.1.2 apply to each of the several pressurized volumes that can be involved in a given mission, each with its own ECLSS to work independently during some phases of the mission, for the duration of the independent operations (example EVA suit).
Requirements
Interfaces shall be defined for the period of time when several pressurized volumes having independent ECLSSs are mated.
When an ECLSS is not in operation during a given phase of the mission, standby mode conditions shall be defined.
When docking to another spacecraft, the various ECLSSs involved shall be compatible.
Reusable systems
When a vehicle is used for several missions, the following issues shall be addressed during the design phase (project Phase B):
- standby, storage and parking conditions between missions;
- recommissioning procedure before next mission.
General
Forms of life
Humans
The ECLSS can be designed for a mixed or an unmixed crew.
For human factors such as metabolism and anthropometrics, see ECSSEST1011.
Forms of life other than humans
Metabolism
Requirements for energy and for overall intake and output of consumables shall be defined at the beginning of the ECLSS development programme (project Phase A).
Environmental conditions
Environmental conditions for the formsoflife to support shall be defined at the beginning of the programme (project Phase A).
It is important to define such environmental condition because it is usually form of life dependent.
ECLSS engineering
Humans
In engineering of the ECLSS for human missions, the following system modes of operation shall be defined:
- nominal,
- degraded, and
- emergency.
Environmental conditions for each mode are based on the threshold limit values of the concerned parameters.
In the case that, in emergency mode, the mission cannot be aborted to ensure a safe return to Earth, the crew shall have the capability to restore (at least) the state of degraded mode without external resources for the remaining duration of the mission eventually by entering safe haven.
Some missions can include low orbital flights where abortion of the mission is a feasible scenario for emergency rescue.
Forms of life other than humans
For forms of life other than human, requirements shall
- define the environment suitable for the forms of life to be supported, and
- take into account the potential interference with the human mission requirements.
Environmental condition
The variation in the parameters defining the human natural and imposed environment, shall be taken into account during project Phase A.
Examples of such parameters are gravity, pressure, atmosphere composition and ionizing radiation.
Functional
Overview
The functions defined in this clause 4.4 are part of the general tailoring of the ECLSS requirements for a given project.
The functional requirements defined in 4.4.2 to 4.4.6 are applicable to human missions. For other forms of life, relevant requirements can be obtained by tailoring them.
Maintain environment
General
To support and maintain health, safety and well being, the ECLSS shall maintain the nominal environmental conditions in the pressurized volume.
Classification of pressurized volume is given in Table 41.
Table 41: Classification of pressurized volume
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Nonaccessible volume
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Accessible volume
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Habitable volume
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Nonhabitable volume
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Definition
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Volume that humans cannot enter, even with dismounting operations
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Volume that humans can freely enter
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Volume that humans can enter, only with preventive dismounting operations.
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Examples
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Within a component
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CabinCrew quarter
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Behind racks, panels, floor or ceiling which can be removed
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Control atmosphere total pressure
Total atmospheric pressure
The nominal value and the limit values for the total atmospheric pressure in the pressurized volume shall be specified.
Monitor atmosphere total pressure
The range and the accuracy to monitor the atmosphere total pressure in the pressurized volume shall be specified.
Means for adjusting pressure
Means for adjusting pressure at the selected value (up or down) inside the specified range applicable for each type of pressurized volume shall be provided.
Prevent overpressurization
Overpressurization shall be prevented.
Equalize atmosphere pressure
The capability to equalize the maximum pressure differential, as defined by the pressure control range, between adjacent, isolated pressurized volumes shall be provided.
Add inert diluent gas to atmosphere
Addition of inert diluent gas (for example nitrogen) into the pressurized volume shall be provided at a rate capable of maintaining the atmospheric pressure within the control range.
Addition of inert diluent gas (for example nitrogen) into the atmosphere shall be provided at a rate capable of atmospheric restoration after decompression of the habitable volume.
When adding inert diluent gas (for example nitrogen) into the atmosphere the levels of anoxic or hypoxic zones in the accessible volume shall be specified.
The limits for pressure adjustments, decompression, compression and recompression shall be specified.
Means to manage pressure change rates within the specified limits shall be provided.
Add oxygen to atmosphere
Addition of gaseous oxygen into the atmosphere shall be provided at a rate capable of maintaining the oxygen partial pressure in the accessible volume within the specified range.
Addition of gaseous oxygen into the atmosphere shall be provided at a rate capable of restoring the atmospheric condition after decompression of the accessible volume.
Addition of oxygen shall not create risk of fire.
Control thermal nominal condition
Maintain thermal nominal condition:
The limits of the atmosphere effective temperature in the habitable volume shall be specified.
The atmosphere effective temperature is a combination of dry bulb temperature, wet bulb temperature and ventilation.
Maintain temperature
The atmosphere dry bulb temperature in the habitable volume shall be selectable within the operational range.
The accuracy for the stabilized dry bulb temperature in the habitable volume shall be specified.
Removal of excess sensible heat from the atmosphere or addition of sensible heat into the atmosphere shall be provided at a rate capable of maintaining the atmosphere temperature within the specified range.
The points of measurement for the dry bulb temperature shall be representative for the habitable volume situation.
Maintain atmosphere humidity
The range for the atmosphere relative humidity in the habitable volume shall be specified.
The range for the atmosphere dew point in the pressurized volume shall be specified.
Relative humidity is in relation to human comfort evaluation; dew point limits are intended to prevent condensation. Both measurements indicate the water vapour content of the atmosphere.
Monitor atmosphere humidity
The range and the accuracy to monitor the atmosphere relative humidity in the habitable volumes shall be specified.
The range and accuracy of the atmosphere dew point temperature to be monitored in the pressurized volumes shall be specified.
Water vapour shall be removed from or added to the pressurized volume atmosphere at a rate capable of maintaining the specified range.
Circulate atmosphere
Ventilate habitable volume: atmosphere velocities in the habitable volume shall be maintained within the specified air velocity ranges, adapted to total atmospheric pressure situation.
Gas velocity ranges can differ between habitable and nonhabitable volume.
Exchange of atmosphere between pressurized volumes: atmosphere exchange between connected pressurized volumes shall be specified.
Monitor ventilation and atmosphere exchange: Location of ventilation and atmosphere exchange monitoring shall be specified.
Since atmosphere circulation in the habitable volume is intended to maintain thermal nominal condition and atmospheric composition, the previous requirements are included to control of atmosphere circulation.
Control oxygen partial pressure
Maintain oxygen partial pressure
The limits for the oxygen partial pressure in the atmosphere of habitable volume shall be specified.
Monitor oxygen partial pressure
The range and accuracy to monitor the atmosphere oxygen partial pressure shall be specified.
Add oxygen into the atmosphere
For adding oxygen into the atmosphere, requirements in 4.4.2.2.7 shall apply.
Control carbon dioxide partial pressure
Maintain low carbon dioxide partial pressure
The threshold values for the carbon dioxide partial pressure in the atmosphere of habitable volume shall be specified.
Remove carbon dioxide from atmosphere
Removal of carbon dioxide from the atmosphere shall be provided at a rate capable of maintaining the carbon dioxide partial pressure below the specified threshold value.
Monitor carbon dioxide partial pressure
The range and accuracy for the monitoring of the atmosphere carbon dioxide partial pressure shall be specified.
Control carbon monoxide partial pressure
Maintain low carbon monoxide partial pressure
The threshold values for the carbon monoxide partial pressure in the atmosphere of the accessible volume shall be specified.
Remove carbon monoxide from atmosphere
Removal of carbon monoxide from the atmosphere shall be provided at a rate capable of maintaining the carbon monoxide partial pressure below the specified threshold value.
Monitor carbon monoxide partial pressure
The range and accuracy for monitoring the atmosphere’s carbon monoxide partial pressure shall be specified.
Control trace gases and odour
Maintain low trace gases partial pressures and odour
The partial pressure of trace gases in the atmosphere of the accessible volume shall be maintained below a specified SMAC values for various exposure periods.
The threshold values for the odour in the atmosphere shall be specified.
Remove trace gas and odour from atmosphere
Removal of trace gases from the atmosphere shall be provided at a rate capable of maintaining the trace gases partial pressures and odour below specified threshold values.
Trace gases arise from equipment offgassing, systems failures and human (or any other form of life) metabolism.
Monitor trace gases in atmosphere
The detection limits and the accuracy for monitoring the trace gases in the habitable volume atmosphere shall be specified.
Trace gases to be monitored are project dependant.
Control airborne particles
Maintain low level of airborne particles
The threshold values for the concentration of airborne particles in the atmosphere of the habitable volume shall be specified.
Remove airborne particles from atmosphere
Removal of airborne particles from the atmosphere shall be provided at a rate capable of maintaining the particle concentration below the specified threshold values.
Monitor airborne particles in atmosphere
The detection limit and accuracy for the monitoring of the airborne particles in the atmosphere shall be specified.
Control microorganisms
Maintain low level of airborne microorganisms
The threshold values for the concentration of airborne microorganisms in the pressurized volume atmosphere shall be specified.
Remove airborne microorganisms from atmosphere
Removal of airborne microorganisms from the atmosphere shall be provided at a rate capable of maintaining the microbial concentration below the specified threshold value.
Monitor airborne microorganisms in atmosphere
The detection limit and accuracy for the monitoring of airborne microorganisms in the atmosphere shall be specified.
Monitor surface microorganisms
The capability to monitor microbial contamination of surfaces shall be provided in the accessible volume.
Support ionizing radiation control
Monitoring
The capability to monitor the ionizing radiation environment both inside and outside the accessible volume shall be provided.
Shielding
Ionizing radiation limits shall be specified.
The capability to provide shielding to maintain the ionizing radiation below the specified limits shall be provided.
Support nonionizing radiation control
Nonionizing radiation limits should be specified.
Respond to environmental contingencies
Respond to uncontrolled depressurization
Detect uncontrolled depressurization
An uncontrolled depressurization event shall be detected in the following cases:
- when the rate of depressurization is higher than a specified value;
- prior to the habitable volume total pressure decreases below a threshold limit value.
Recover from uncontrolled depressurization
The time limits for recovering depressurization shall be specified.
The capability to recover from an uncontrolled depressurization shall be provided, as follows:
- repressurize to total pressure specified values and with the gases specified in 4.4.2, within the specified time limits;
- restore atmosphere composition, at least to degraded conditions;
- provide means to treat humans from hypoxia, decompression illness or both.
Respond to uncontrolled pressurization
Detect uncontrolled pressurization
An uncontrolled pressurization event shall be detected when the rate of pressurization is higher than a specified value.
An uncontrolled pressurization event shall be detected prior to the accessible volume total pressure increasing above a threshold limit value.
Recover from uncontrolled pressurization
The time limits for the decompression back to nominal total pressure value shall be specified.
The capability to recover from an uncontrolled pressurization shall be provided as follows:
- decompress to total pressure level specified in 4.4.2, within specified time limits;
- restore atmosphere composition, at least to degraded conditions;
- provide means to handle overpressurization consequences for the humans, including the risk of decompression illness.
Respond to fire
Detect fire, smoke, smouldering
Fire shall be detected in enclosed locations and in the pressurized volume.
Isolate fire
Fire events shall be isolated in the affected location.
Suppress fire
The capability to suppress a fire shall be provided.
Recover from fire
Means of restoration of a habitable environment shall be provided, at least to reach degraded conditions.
This includes removal of combustion products from the atmosphere.
Respond to hazardous radiation exposure
Detect hazardous radiation levels
Real-time ionizing radiation levels both inside and outside the accessible volume shall be provided with an alarm system.
Provide human protection from radiation
Means to provide human protection from radiation (e.g. shelter or safe haven) shall be provided.
Detect radiation level normalization
Means to detect the radiation level normalization (e.g. dosimeters) shall be provided.
Inform humans that they can move out from protection
Means to inform humans that they can move out from protection shall be provided.
Respond to hazardous atmosphere
Detect hazardous atmosphere
The hazardous airborne contaminants to be detected, and the detection limits, accuracy and response time, shall be specified.
Provide human protection
Means for protecting humans from hazardous atmospheres (e.g. IVA, isolating the hazardous atmosphere, or breathing from masks) shall be provided.
Restore an acceptable atmosphere
The functionality to restore atmosphere quality at least to degraded mode shall be provided.
Recover from hazardous atmosphere
The functionality to recover from a hazardous atmosphere shall be provided.
Recovery options can include venting of the habitable volume atmosphere and subsequent atmosphere restoration. Additional recovery options can include throttling up of the existing contaminant removal system, and activation of a secondary contaminant removal system coupled with an emergency source of breathable air.
Provide resources
Provide inert diluent gas
Supply inert diluent gases
An inert diluent gas, as for example nitrogen, shall be supplied to points of use in conformance with the interface specifications for gas temperature, pressure and flow rate.
An example of diluent gas is Nitrogen.
Store inert diluent gas
Inert diluent gas usage and contingency needs, including pressurized volumes repressurization, shall be specified.
Storage of inert diluent gas shall be provided with the capacity to meet usage and contingency needs specified in 4.4.4.1.2a.
Monitor inert diluent gas storage
The quantity of stored inert diluent gas, shall be monitored.
Accept external inert diluent gas
Resupply of inert diluent gas shall be accepted in conformance with the interface specifications.
Provide oxygen
Oxygen needs
The amount of oxygen to support human metabolic needs shall be specified.
Oxygen shall be provided to support human metabolic needs specified in 4.4.4.2.1a
Oxygen shall be provided for EMU recharging to support nominal human metabolic needs, as specified in 1. above.
An EVA suit flush procedure shall be specified.
Oxygen shall be provided for breathing during denitrogenation process and the EVA suit flush procedure specified in 4.4.4.2.1d.
Oxygen shall be provided to make up for atmosphere leakage.
Oxygen shall be provided to make up for airlock losses during EVA exit and reentry.
Oxygen shall be provided to restore the accessible volume atmosphere in the event of loss of pressure.
Oxygen shall be provided to support portable and umbilical supplied emergency oxygen breathing equipment.
Supply oxygen
Oxygen shall be supplied to points of use in conformance with the interface specifications for gas temperature, pressure and flow rate.
Store oxygen
Oxygen usage and contingency needs, including the accessible volume’s atmosphere restoration, shall be specified.
Storage of oxygen or oxygen generating resources shall be provided with the capacity to meet the usage and contingency needs specified in 4.4.4.2.3a.
Generate or recycle oxygen
Oxygen shall be generated and recycled at a rate capable of maintaining at least the specified minimum oxygen storage specified in 4.4.4.2.3b.
Oxygen generation and recycling can include plant or algae photosynthesis and water electrolysis.
Monitor oxygen consumption and oxygen storage
The quantity of stored oxygen shall be monitored.
Accept external oxygen
Resupplied oxygen shall be accepted in conformance with the interface specifications.
Provide breathing gases for specific situations
Overview
Requirements on supply of specified breathing gases (e.g. composition, quality, and quantities) are intended to support nominal or degraded situations (e.g. breathing on masks, safe haven, and treatment of decompression illness).
Requirements
Breathing gases shall be supplied to points of use in conformance with the applicable interface specifications for gas temperature, pressure and flow rate.
Storage breathing gases capacity shall be specified.
When mixing or recycling of gases takes place onboard, the quality of the produced gases shall be specified.
The quantity of stored breathing gases shall be monitored.
Resupplied external breathing gases shall be accepted in conformance with the interface specifications.
Provide water
Water needs
Potable water needs, including water for drinking, oral hygiene, and food preparation (e.g. rehydration), shall be specified.
Hygiene water needs, including water for personal hygiene, laundry and dishwashing, shall be specified.
Water needs for medical purposes (e.g. sterile water and medicine reconstitution) shall be specified.
Water to meet the water needs specified in 4.4.4.4.1a, b and c shall be provided.
Other needs can include housekeeping, preparation of hydroponic solutions, food processing, and water quality sampling.
Water quality
For each use, the water quality shall be specified using the following criteria:
- Organoleptic parameters, such as colour, turbidity and taste.
- Physical parameters, such as temperature, conductivity and particle size.
- Chemical parameters, such as pH, dissolved gases, minerals, total hardness and undesirable substances.
- Toxic substances.
- Microbiological parameters, such as bacteria, viruses, yeast and moulds.
- Radiological parameters.
Supply water
Water shall be supplied to points of use in conformance with the interface specifications for water temperature, pressure, flow rate and quality.
Store water
The water peak usage and contingency needs shall be specified.
Storage of water shall be provided with the capacity and flow rate to meet the peak usage demand specified in 4.4.4.4.4a.
The quantity of stored potable water shall meet the contingency needs specified in 4.4.4.4.4a.
Monitor water in storage
The quantity of stored potable and hygiene water shall be monitored.
Generate and regenerate water
Water shall be regenerated at a rate capable of maintaining at least the minimum water storage specified in 4.4.4.4.5a.
The conditions to use generated water shall be specified.
Water regeneration can include waste water purification and water recovering from combustion of hydrocarbon wastes.
Accept external water
Resupplied water shall be accepted in conformance with the interface specifications.
Resupply can include water obtained from in situ resources.
Provide food
Supply food and food ingredients
Nutritional requirements shall be specified.
Food shall be provided for human consumption in conformance with the nutritional requirements specified in 4.4.4.5.1a.
The food provided shall take into account the physiological changes in the human being in his adaptation to a new gravitational environment and his return to a 1g environment, and the extra needs related to eventual EVA.
Prior to consumption, food shall meet specified food safety requirements.
The choice of food shall meet food related psychological needs, that is:
- The choice of food accommodates foods for special events.
- The fraction of mass and calories of recreational foods to be included in the choice of food is specified.
- The variety of foods to be included in the choice of food is specified.
- The diet is composed of palatable food and shall be made of similar ingredients to those used by the crew members on Earth.
- The meals take into account ethnic and cultural food pattern differences between crew members.
Requirements in this clause 4.4.4.5.1 are provided in order to supply food according to a daily individual diet of a crewmember consistent with human physiological requirements.
Store food
Food usage and contingency needs shall be specified.
Storage of food and food ingredients shall be provided with the capacity to meet the usage and contingency needs specified in 4.4.4.5.2a.
The storage conditions to keep the nutritional and palatability characteristics of the food intact and to prevent any contamination or degradation, either of physicochemical or biological origin, shall be specified.
Produce food
- When food production is specified, it shall be produced in conformance with crew needs, following food requirements specified in 4.4.4.5.1.
- Produced food quality shall be controlled.
- The food production expendable by products shall be specified.
Monitor food
- Food quality, quantity and palatability shall be monitored.
- The diet and food intake of each individual shall be monitored.
Process food
- Raw materials and ingredients shall be processed into readytoeat foods and food ingredients at a rate capable to meet current usage needs and storage requirements specified in 4.4.4.5.2.
- Means for food processing, serving as well as utensil and restraints and mobility aids, shall be provided.
- Food trash shall be avoided in term of mass and volume.
Monitor food and food ingredients in stock
- Stored food and food ingredients shall be listed in an explicit inventory providing its quantity, status data, its availability, localisation and its end of date limit.
- The quantity of food in production shall be monitored.
- The requirements for monitoring the quality of food and food ingredients shall be specified .
Generate food and food ingredients
Food and food ingredients shall be produced at a rate capable to maintain at least the minimum food storage requirements specified in 4.4.4.5.2.
Food regeneration can include for example growth of food crops, harvesting, plants, animal growth, eggs, aquaculture and chemical food production.
Accept external food and food ingredients
Resupplied food and food ingredients shall be accepted in conformance with the interface specifications.
Manage waste
Manage carbon dioxide
Accept carbon dioxide
Carbon dioxide shall be accepted from points of collection in conformance with interface specifications.
Carbon dioxide includes metabolically produced carbon dioxide and carbon dioxide produced by combustion of wastes.
Store carbon dioxide
Carbon dioxide peak recovery rate and storage contingencies shall be specified.
Storage contingencies include temporary loss of downstream processing capability.
Storage of carbon dioxide shall be provided with the capacity to meet the peak recovery rate and storage contingencies specified in 4.4.5.1.2a.
Monitor carbon dioxide waste
The requirements for monitoring the quantity and quality of stored carbon dioxide shall be specified.
Process carbon dioxide
For long duration missions the capability for recovering oxygen or any product from carbon dioxide shall be specified.
Dispose excess carbon dioxide
The capability to dispose excess carbon dioxide shall be provided.
Manage waste water
Collect and accept waste water
Waste water shall be collected and accepted in conformance with the interface specifications.
Store waste water
Storage of waste water shall be provided taking into account the capacity to meet peak recovery rate and storage contingency needs.
Storage contingencies include temporary loss of downstream processing capability.
Monitor waste water
The requirements for monitoring the quality and quantity of waste water shall be specified.
Process waste water
Waste water shall be processed to recover potable and hygiene water .
Processing can include chemical stabilization and water recovery.
Processed waste water shall meet specified quality requirements for further use.
Other uses can include hydroponic solutions preparation.
Dispose excess waste water
The capability to dispose excess water shall be provided.
Disposal includes overboard dumping and transfer to a returning vehicle. This requirement is mission or design dependent.
Manage gas, solid and concentrated liquid wastes
Collect and accept gas, solid and concentrated liquid wastes
Gas, solid and concentrated liquid wastes shall be accepted from points of collection in conformance with the interface specifications.
To prevent atmosphere contamination, the gas from breathing systems, including the collection of expired gas from breathing masks (e.g. prebreathing for EVA and medical treatment gases), shall not be released into the atmosphere.
- 1 Waste gas originates mainly from breathing systems and experiments.
- 2 Concentrated liquid waste is mainly the residuals of waste water processing but not only water soluble liquids (oil and organic liquids can be present).
Waste water includes biological and used hygiene water.
Biological waste water includes:
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urine,
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condensate from human and plants expiration and perspiration,
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faecal water,
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vomit, and
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menses.
Waste water from general hygiene processes include: -
shower water and condensate from shower,
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water from washing and maintenance, and
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food preparation water.
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3 Solid waste is mainly composed of solid elements which are not usable in their chemical or physical form by humans.
Source of solid waste are of biological and physicochemical nature and originate from the general hygiene processes and food trash.
Biological solid waste includes:
-
faeces,
-
nonconsumable solids from food production storage management systems,
-
solid residues from food preparation (cooking),
-
solid residue from non eaten food, and
-
medical waste.
Nonbiological solid waste includes all the degraded, nonusable solid elements used on board, as -
in hygiene,
-
food production and preparation,
-
clothes,
-
maintenance byproducts,
-
disposable parts and conditioning materials, and
-
waste water processor residual.
Store gas, solid and concentrated liquid wastes
Peak and contingency needs for unprocessed gas, solid and concentrated liquid waste shall be specified.
Contingencies include temporary loss of downstream processing capability.
Temporary storage of unprocessed gas, solid and concentrated liquid wastes shall be provided with the capacity to meet the peak and contingency needs specified in 4.4.5.3.2a.
Long-term storage shall be provided for residuals and nonrecycled wastes.
Residuals are wastes from which no further useful resources can be recovered. Nonrecycled wastes are wastes that can contain useful resources, but for which processing is not attempted.
Long term storage of waste shall not increase the risk of biological, chemical or particulate contamination.
Monitor gas, solid and concentrated liquid wastes
Waste management shall keep records of the stored wastes status.
The quantity of stored wastes shall be monitored.
The requirements for monitoring of the physical, chemical and biological quality of wastes shall be specified.
Process gas, solid and concentrated liquid wastes
Solid and concentrated liquid wastes shall be processed to recover water, carbon dioxide, and other useful products such as nitrogen, methane, nutrients.
Dispose gas, solid and concentrated liquid wastes
The capability to dispose of nonrecovered wastes and process residuals in conformity with the specified safety and environmental standards shall be provided.
Disposal includes overboard dumping and transfer to a returning vehicle. This requirement is mission and design dependent.
When recovery cannot be performed, storage and stabilization of wastes shall specify means for safe and effective disinfection, sanitization and containment.
Support EVA operations
Support EMU servicing and check out
Oxygen, consumable filtering material and potable water shall be provided for EMU servicing.
Removal of waste water from EMU shall be implemented.
Some projects also specify the removal of waste carbon dioxide.
Cleaning and drying procedures of the spacesuit shall be established and corresponding equipment specified.
Support denitrogenation procedure
Prebreathe procedures shall be established and corresponding equipment specified.
This requirement is equivalent to the ISS requirement.
Support decompression for egress
Decompression of the airlock from the habitable volume pressure to the external pressure shall be supported at a specified rate.
The minimum percentage of the airlock atmosphere to be recovered during decompression under nominal (nonemergency) EVA operations shall be specified.
Support recompression for ingress
Recompression procedure of the airlock for a crew member from the external ambient pressure to the habitable volume pressure shall be supported at a specified nominal rate.
Support contaminant detection and decontamination
Contaminant detection and decontamination of the EVA equipment and of the person shall be supported following an EVA.
The decontamination levels shall be specified.
Support decompression illness management
Procedure and corresponding equipment for managing DCI cases by treatment or evacuation shall be provided.
Support EVA radiation monitoring
Realtime monitoring of the ionizing radiation environment of the space suit, and of the accumulated total doses inside the spacesuit, shall be supported during an EVA.
Support IVA
IVA operations shall be supported.
Support rover operations
Rover operations shall be supported.
Safe haven operation
Safe haven operations shall be supported.
Provide health related services
Provide health monitoring
Requirements for providing health monitoring shall be specified.
Provide medical assistance on board
Support first aid
Requirements on support of first aid shall be specified.
Provide medical equipment for diagnostic and treatment purposes
Requirements for providing medical equipment for diagnostic and treatment purposes shall be specified.
This can include means to treat cases of decompression illness.
Provide drugs
Requirements shall be specified to
- store drugs,
- monitor quantity and quality of drugs,
- dispose drug waste, and
- dispose drugs.
Provide access to telemedicine services
Requirements to provide access to telemedicine services shall be specified.
Provide means of sanitary evacuation
Requirements to provide means of sanitary evacuation shall be specified.
Depending on the mission, evacuation can be a scenario in case of medical problem.
Support time (day and night) control
Requirements on supporting time (day and night) control shall be specified.
Support gravity counter measures
The requirements to support reduced gravity counter measures shall be specified.
The requirements to support increased gravity counter measures (launch and reentry) shall be specified.
Design
Overview
Introduction
Design requirements cover the requirements on ECLSS hardware and software to ensure that the flight system fulfils the objectives of the ECLSS in terms of mission requirements (see clause 4.2) and functional requirements (see clause 4.4)
ECLSS is not a standalone subsystem, and therefore is designed to conform to interface requirements with other subsystems (see clause 4.6) aiming to minimize constraints on other subsystems or systems.
Structural and mechanical
For structural and mechanical requirements, see ECSSEST-32, ECSSEST3301, and ECSSEST-32-08.
Thermal
For thermal requirements applicable to ECLSS, see ECSSEST-31.
Electrical and electromagnetic compatibility (EMC)
For electrical and electromagnetic compatibility requirements applicable to ECLSS, see ECSSEST-20.
Operations and logistics
For operations and logistics requirements applicable to ECLSS, see ECSSEST70 and ECSSETM-10-10.
Failure detection, isolation and recovery
For requirements on FDIR applicable to ECLSS, see ECSSQST-3002.
Human factors
The design of all ECLS hardware and their mounting inside the pressurized volume cannot be done without taking into consideration that hardware is functioning with, for and under the control of humans. That implies the complete apprehension and application of ergonomics, psychological and cognitive factors and constraints.
For requirements on human factors, see ECSSEST-10-11.
Data management control
The ECLSS shall include:
- the sensors and control components for monitoring each ECLSS process and subsystem functions;
- interface with the onboard data management system, and with ground base support;
- visual and acoustic warning and alarm indications;
- manual override control system.
Interface
General
The ECLSS design shall take into account the ECLSS hardware and software functional interfaces with:
- other ECLSS in multiple ECLSS missions;
- nonECLSS hardware and software;
- the humans for direct control in normal operation or override in case of emergency.
Ground support equipment (GSE)
Interfaces of the ECLSS with ground support shall be provided.
The GSE requirements shall be specified.
interfaces
Flight system
Requirements on mission interfaces for flight system shall be specified.
Software, data systems, interface
The ECLSS shall conform to the specified data handling and software.
Thermal control interface
Being part of the overall environmental control system (ECS) of the vehicle, ECLSS design shall conform to interface requirements with TCS.
The objective of this requirement is to reduce to a minimum the constraints on TCS subsystem.
Biological interface
As nonwanted forms of life can be present onboard, for example microbiological species, the ECLSS shall, as part of their functional requirements:
- monitor potential unwanted forms of life,
- prevent dissemination of such form of life from ECLSS, and
- control any unwanted form live developing on board.
Mechanical and structural interface
Pressurized volume configuration and layout
ECLSS shall take into account the overall configuration and layout, together with the following information provided for each item from the applicable ICD:
- dimension and mass;
- fixation and mounting techniques;
- contact area;
- surface characteristics, e.g. treatment, and roughness;
- alignment requirements;
- connectors locations;
- available area for fixation of ECLSS hardware;
- spacecraft harness;
- accessibility.
Mechanical load
The ECLSS shall conform to the mechanical load during the mission phases.
The internaltoexternal differential pressure in the pressurized volume shall be prevented from exceeding the maximum design pressure.
Stability requirements
Exported vibrations from ECLSS shall be specified.
microgravity disturbances shall be specified.
Hardware configuration
ECLSS design shall define the ECLSS hardware configuration and layout and provide the inputs for the ICD.
Forbidden zones
The requirements on ECLSS specific forbidden zones shall be specified at project Phase C (ECLSS design phase).
Forbidden zones include outside FOV, and operational range of mechanisms.
Fracture control
Fracture control procedures shall be applied to ECLSS.
For requirements on fracture control, see ECSSEST-3201.
Electric power
The requirements for electric power supply to ECLSS shall be specified.
For example, peak and average electric power, duty cycles, and backup electric power.
Environment for onboard equipment
The requirements for payload in the pressurized volume shall be specified.
Human interface
The dedicated human time allocation for operation and maintenance on ground and on board shall:
- be specified (in manyear per mission), and
- not exceed the value specified in conformance with 1. above.
To prevent too frequent human interventions on board and actions from the personnel on the ground in order to replace consumable or dispose waste, maintainability issues are given a particular importance in ECLS design.
The need for direct human actions for the operation and maintenance of ECLSS shall be tradedoff against automatic systems.
ECLSS specification shall define the training, qualification of the human for operation, maintenance, and control of ECLSS for:
- nominal modes of operation, and
- degraded modes of operation.
Verification
General
Verification shall demonstrate that the ECLSS design conforms to specified performance requirements.
For verification, refer to ECSSEST-10-02.
A verification programme shall be established and submitted to the customer for approval.
Conformance of the ECLSS design to its requirements shall be demonstrated by satisfactory completion of the ECLSS verification programme specified in 4.7.1b.
Verification activities shall be carried out on each level, i.e. component, subassembly and assembly.
Verification activities related to inspection and testing shall be performed under product assurance (PA) control.
Requirements on PA can be found in ECSSQST20.
During project Phase A, a complete and coherent verification plan and matrix shall be established clearly indicating for each item and level the intended verification approach.
Verification by similarity
When verification by similarity is performed, similarity between the two items shall exist with respect to:
- functional design,
- hardware used,
- mission requirements, and
- life time.
Verification by inspection
No physical contact with the hardware shall take place during an inspection.
If 4.7.3a is not met, the physical contact shall be planned and approved as part of the verification plan and inspection procedure in conformance with ECSSE-ST-10-02.
Verification by analysis
Verification by analysis shall be performed for all cases where representative testing cannot be carried out, such as limitation of test facilities (e.g. environmental, dimensional and behaviour of ECLSS items under reduced or increased gravity).
Product assurance and safety
Product assurance and safety provisions shall apply to design, production manufacturing testing and utilization of ECLSS.
For product assurance and safety, refer to the Qbranch of the ECSS Standards.
Automated safety functions shall be implemented.
In case of failure, the very capability of the humans can be directly degraded from the resulting environmental conditions, and therefore they can be unable to access or to operate any of the recommended safety actions.
Product assurance and safety provisions shall apply to ECLS ground support equipment.
Deliverables
Hardware
The hardware to be delivered in the course of a project shall be specified during project Phase A.
Since the ECLSS can consist of several functional subunits, for each subunit integration procedures and interfaces shall be defined during project Phase B.
Examples of the hardware to be delivered include
- ECLSS hardware for different models (e.g. EM, QM and FM),
- hardware for sample test,
- spare, tools and repair hardware, and
- integration and support hardware.
Documentation
The organization responsible for the ECLSS shall issue the specification to lowerlevel suppliers for the procurement of ECLSS subunits.
ANNEX(informative) Parameters specification and monitoring
Specification of parameters
Table A-1 lists the parameters to be specified, and refers to the provisions where these parameters are specified.
Table: List of parameters to be specified
|
Clause
|
Parameter
|
|
4.2.2.2 Identification of requirements, and
|
For each mission phase, specific ECLS requirements
|
|
4.4.2.2 Control atmosphere total pressure
|
Nominal and limit values for total atmospheric pressure
|
|
4.4.2.3 Control thermal nominal condition
|
Limits for effective temperature in habitable volumes
|
|
4.4.2.4Control oxygen partial pressure
|
Limits for PO2 in habitable volumes
|
|
4.4.2.5 Control carbon dioxide partial pressure
|
Limits for PCO2 value in habitable volumes
|
|
4.4.2.6 Control carbon monoxide partial pressure
|
Maximum PCO value in habitable volumes
|
|
4.4.2.7 Control trace gases and odour
|
Threshold values for odours in habitable volumes
|
|
4.4.2.8 Control airborne particles
|
Threshold limit values for air borne particles
|
|
4.4.2.9 Control microorganisms
|
Threshold limit values for air born microorganisms
|
|
4.4.2.10 Support ionizing radiation control
|
Ionizing radiations limits
|
|
4.4.2.11 Support nonionizing radiation control
|
Nonionizing radiation limits
|
|
4.4.3.11 Respond to uncontrolled depressurization
|
Maximum depressurization rate
|
|
4.4.3.2 Respond to uncontrolled pressurization
|
Time limits for recovery from depressurization
|
|
4.4.3.5 Respond to hazardous atmosphere
|
Hazardous airborne contaminants detection criteria
|
|
4.4.4.1 Provide inert diluent gas
|
Inert diluent gas usage and contingency needs, including pressurized volumes repressurization
|
|
4.4.4.2 Provide oxygen
|
Amount of oxygen to support human metabolic needs
|
|
4.4.4.3 Provide breathing gases for specific situations
|
Composition, quality and quantity of breathing gases
|
|
4.4.4.4 Provide water
|
Water qualities for each usage
|
|
4.4.4.5 Provide food
|
Nutritional requirements
|
|
4.4.5.1 Manage carbon dioxide
|
Carbon dioxide peak recovery rate and storage contingencies
|
|
4.4.5.2 Manage waste water
|
Stored waste water monitoring requirements
|
|
4.4.5.3 Manage gas, solid and concentrated liquid wastes
|
Monitoring of physical, chemical and biological wastes requirements
|
|
4.4.6 Support EVA operations
|
Equipment to clean and dry space suits
|
|
4.6.2 Ground support equipment (GSE)
|
GSE requirements
|
|
4.6.3.2 Software, data systems, interface
|
ECLSS data handling and software requirements
|
|
4.6.3.5 Mechanical and structural interface
|
Stability requirements
|
|
4.6.3.6 Electric power
|
Electric power requirements
|
|
4.8 Product assurance and safety
|
PA and safety policy
|
|
4.9.1 Hardware
|
All products for delivery
|
Monitoring of parameters
Table A-2 lists the parameters to be monitored, and refers to the provisions where these parameters are specified.
Table: List of parameters to be monitored
|
Clause
|
Parameter
|
|
4.4.2 Maintain environment
|
Total pressure
|
|
4.4.4 Provide resources
|
Nitrogen or other inert gas
|
|
4.4.5 Manage waste
|
Carbon dioxide
|
|
4.4.7 Provide health related services
|
Drugs
|
ANNEX(informative) Reference information for parameters
Previous flight data
In order to provide the designers with basic information on the values which can be used for dimensioning the systems, the data from previous flights and the reference values of ISS are listed in Table B-1 to Table B-5.
Table: Previous flight data
|
Parameter
|
Earth a
|
Skylab (19734) b
|
MIR (1986) c
|
SSF (1992) d
|
STD3000 (1995) e
|
ISS (1996) f
|
|
|
|
84 day max. stay
|
365 day max. stay
|
90+ day design stay
|
|
90+ day design stay
|
|
Total pressure, kPa
|
101,3
|
34,5
|
88,0114,7
|
100,0102,7
|
100,0102,7
|
97,9102,7
|
|
O2 partial pressure, kPa
|
21,0
|
22,826,9
|
20,026,7
|
19,523,1
|
19,523,1
|
19,523,1
|
|
CO2 partial pressure, Pa
|
31100
|
670 (nominal)
|
800
|
400
|
400
|
Average < 707, peak < 1 013
|
|
Diluent gas
|
N2/Ar
|
N2
|
N2
|
N2
|
N2
|
N2
|
|
Temperature, K
|
292,5300,5
|
285,9305,4
|
291,1301,1
|
291,5299,8
|
291,5299,8
|
291,5302,6
|
|
Dew point, K
|
274,9289,9
|
280,9288,7
|
|
277,6288,7
|
277,6288,7
|
277,6288,7
|
|
Relative humidity, %
|
2085
|
2585
|
3070 g
|
2570
|
2570
|
2570
|
|
Ventilation, m/s
|
< 0,1
|
|
0,20,5
|
0,0760,203
|
0,0760,203
|
0,0510,203
|
|
Particles (> 0,5 m), particles/m3
|
|
|
|
< 3,5E6
|
3,5E6
|
Average < 3,5E6, peak < 7,1E7
|
|
Particles (> 0,5 m), g/m3
|
89(nominal)
|
|
|
|
|
Average < 50, peak < 1 000
|
|
Microorganisms h,
|
200600
|
|
|
1 000
|
500
|
Average < 1 000
|
|
Trace contaminants
|
Variable
|
|
see ref. (c)
|
SMAC i
|
SMAC i
|
SMAC i
|
|
a Total pressure, O2 partial pressure and lower bound on CO2 partial pressure are based on ambient, sealevel conditions (Lide, 1995). Upper bound on CO2 partial pressure is considered a nominaltohigh indoor value based on the ASHRAE standard for indooroutdoor air exchange (ASHRAE, 1989) (indoor values as high as 300 Pa are reported). Temperature, dew point, relative humidity, and ventilation ranges are based on bounds of the ASHRAE indoor comfort zones (ASHRAE, 1989). Particulate levels are indoor values (for particulates > 2,5 m) reported by Liu, et al. (1991). Microorganism levels are indoor values (for manufacturing areas) reported in the ISS ECLS requirements document (D6841050814, 1996).
| ||||||
|
NOTE: For additional references, see Annex C .
| ||||||
Table: American programmes Requirements
|
Programme
|
MERCURY
|
GEMINI
|
APOLLO
|
APOLLO
|
SKYLAB
|
ORBITER
|
SPACELAB a
|
|
Operational period
|
1961 – 1963
|
1965 – 1966
|
1968 - 1972
|
1968 - 1972
|
1973 - 1974
|
1980’s
|
1983
|
|
duration, days
|
< 1 to 1,5
|
< 1 to 14
|
6 to 13
|
1 to 4
|
28 to 84
|
7
|
Cf orbiter
|
|
Crew size (men)
|
1
|
2
|
3
|
2
|
3
|
4 to 7
|
0 – 4
|
|
Power : generation type
|
battery
|
fuel cells + battery
|
fuel cells
|
|
solar power
|
fuel cells
|
|
|
Output, kW
|
|
|
4
|
|
23
|
21
|
from orbiter
|
|
Atmosphere type
|
oxygen
|
oxygen
|
oxygen
|
oxygen
|
oxygen
|
oxygen
|
oxygen
|
|
Total cabin Pressure, hPa
|
345
|
345
|
345
|
345
|
345
|
1 013
|
1 013
|
|
O2 partial pressure, hPa
|
345
|
345
|
345
|
345
|
250
|
220
|
220
|
|
CO2 partial pressure (max), hPa
|
10,6
|
10,1
|
10,1
|
|
7,3
|
6,6 - 10,1
|
6,6 – 10,1
|
|
Temperature, C
|
15 - 22
|
15 - 22
|
25
|
|
18 – 24
|
21
|
18 – 27
|
|
Humidity, %
|
|
|
|
|
|
|
50
|
|
a European contribution
| |||||||
|
NOTE: For references see Annex C .
| |||||||
Table: American programmes Functions
|
Programme
|
MERCURY
|
GEMINI
|
APOLLOCOMMAND MODULE
|
APOLLOLUNAR MODULE
|
SKYLAB
|
ORBITER
|
SPACELAB a
|
|
Operational period
|
1961 – 1963
|
1965 – 1966
|
1968 - 1972
|
1968 - 1972
|
1973 - 1974
|
1980’s
|
1983
|
|
Oxygen supply
|
Stored
|
Stored
|
Stored (cryo)
|
Stored + cryo
|
Stored (cryo)
|
Stored + cryo
|
From orbiter
|
|
Nitrogen supply
|
N/A
|
N/A
|
N/A
|
N/A
|
Stored
|
Stored
|
Stored
|
|
CO2 control
|
LiOH
|
LiOH
|
LiOH
|
LiOH
|
R
|
LiOH
|
LiOH
|
|
CO control
|
none
|
none
|
none
|
none
|
None
|
none
|
none
|
|
Humidity control
|
CHX
|
CHX
|
CHX
|
Suit cooling
|
CHX
|
CHX
|
CHX
|
|
Trace contaminant monitoring
|
|
|
no
|
no
|
No
|
|
no
|
|
Trace contaminant control
|
Charcoal + leak
|
Charcoal + leak
|
Charcoal + leak
|
Charcoal + leak
|
Charcoal + leak
|
Charcoal + leak
|
Charcoal + leak
|
|
Gas recovery / Regeneration
|
none
|
none
|
none
|
none
|
none
|
none
|
none
|
|
Gas storage
|
O2 (500 bar)
|
O2 cryo
|
O2 cryo
|
O2 186 b cryo
|
O2 N2 (200 b)
|
O2 N2 (230 b)
|
N2 (230 b)
|
|
Fire detection
|
Crew sense
|
Crew sense
|
Crew sense
|
Crew sense
|
UV detector
|
Ionis. smoke
|
Ionis. smoke
|
|
Fire suppressant
|
Water spray
|
Water spray
|
Water gel
|
Water gel
|
Water gel
|
Halon
|
Halon
|
|
a European contribution
| |||||||
|
NOTE: For references see Annex C .
| |||||||
Table: Russian programmes Requirements
|
Programme
|
VOSTOCK
|
VOSKHOD
|
SOYUZ, T and TM
|
SALYUT
|
MIR
|
|
Operational period
|
1961 – 1963
|
1964 – 1965
|
Soyuz 1967 – 1981T 1980 – 1986T M ? - 1987
|
1971 – 1986
|
1986 - 2002
|
|
duration, days
|
1 to 5
|
1
|
1 to 17
|
Max. 236
|
Max. 366
|
|
Crew size (men)
|
1
|
2 (V2) and 3 (V1)
|
1 to 3
|
2 to 6
|
2 to 6
|
|
Atmosphere type
|
Air
|
Air
|
O2 / N2 (N2 : 70-80 %)
|
O2 / N2
|
O2 / N2 Max 78 % N2
|
|
Total cabin pressure, hPa
|
1 013
|
1 013
|
1013 (3)
|
1013
|
600 - 1280
|
|
O2 partial pressure, hPa
|
|
|
Max. 304
|
210 - 317
|
Max. 470
|
|
CO2 partial pressure (max.), hPa
|
|
|
|
|
Max. 30
|
|
Temperature, C
|
12 - 25
|
12 - 25
|
12 – 25
|
12 - 25
|
20 comfort (18-28)
|
|
Humidity, %
|
30 - 70
|
30 - 70
|
30 – 70
|
|
20 – 70 (for T = 20 C)
|
|
NOTE: For references see Annex C .
| |||||
Table: Russian programmes Functions
|
Programme
|
VOSTOCK
|
VOSKHOD
|
SOYUZ, T, and TM
|
SALYUT
|
MIR
|
|
Operational period
|
1961 – 1963
|
1964 - 1965
|
Soyuz 1967 – 1981T 1980 – 1986; TM ? - 1987
|
1971 - 1986
|
1986 - 2002
|
|
Oxygen supply
|
KO2
|
KO2
|
KO2
|
KO2
|
KO2
|
|
Nitrogen supply
|
Air storage
|
Air storage
|
|
Air storage
|
Air storage
|
|
CO2 control
|
KO2
|
KO2
|
KO2
|
KO2 + LiOH
|
KO2 + LiOH
|
|
CO control
|
|
|
|
|
|
|
Humidity control
|
KO2 + Silicagel + LiCl
|
KO2 + charcoal
|
KO2 + charcoal
|
|
|
|
Trace contaminant monitoring
|
|
|
|
|
|
|
Air flow, m/s
|
fan
|
fan
|
fan
|
adjust. 0,1 – 0,8
|
fan + air ducts
|
|
Gas monitoring
|
O2 CO2 only
|
O2 CO2 only
|
O2 CO2 only
|
O2 CO2 only
|
O2 CO2 only
|
|
Trace contaminant control
|
KO2 + charcoal
|
KO2 + charcoal
|
KO2 + charcoal
|
KO2 + charcoal
|
KO2 + charcoal
|
|
Gas recovery / Regeneration
|
|
|
|
|
Electrolysis
|
|
Gas storage
|
Comp. air + KO2
|
Comp. air + KO2
|
KO2
|
Comp. air + KO2
|
Compressed air + KO2
|
|
Fire detection
|
none
|
|
|
CO2 detectors
|
|
|
Fire suppressant
|
|
|
|
|
|
|
NOTE: For references see Annex C .
| |||||
ISS data
Atmosphere
Table B-6 lists the atmosphere data from existing programs.
Table: Atmosphere data
|
Parameter
|
US ECLS Requirements
|
Russian ECLS requirements
|
|
Range
|
Range
| |
|
Total pressure
|
97,9 kPa to 102,7 kPa
|
79,9 kPa to 114,4 kPa
|
|
Total pressure monitoring
|
0 to 110,6 kPa
|
1 kPa to 131,58 kPa
|
|
PCO2 a
|
0,705 kPa to 1,011 kPa
|
0,69 kPa up to 3 people
|
|
PCO2 Monitoring
|
0 to 2,0 kPa
|
0 to 3,33 kPa
|
|
PO2
|
19,5 kPa to 23,1 kPa
|
19,5 kPa to 23,1 kPa
|
|
PO2 monitoring
|
0 to 40 kPa
|
|
|
PN2
|
< 80 kPa
|
< 80 kPa
|
|
Relative humidity
|
25 % to 70 %
|
30 % to 70 %
|
|
Relative humidity monitoring
|
Not monitored
|
1 kPa to 4,6 kPa ( 0,2 kPa accuracy)
|
|
Atmospheric temperature b
|
17,8 C to 26,7 C
|
18 C to 28 C
|
|
Atmospheric temperature Monitoring
|
15,6 C to 32,2 C ( 1,8 C)
|
|
|
Dew point temperature
|
4,4 C to 15,6 C
|
4,4 C to 15,6 C
|
|
Intramodule air circulation
|
0,051 m/s to 0,20 m/s
|
0,05 m/s to 2,0 m/s
|
|
Intramodule air flow
|
(66 2,4) l/s
|
(60 to 70) l/s
|
|
Fire suppression PO2 level
|
10,5 %
|
|
|
Particulate concentration
|
Average < 0,05 mg/m3
|
< 0,15 mg/m3
|
|
Temperature of surfaces
|
4 C < Touch temperature < 45 C
|
> dew point
|
|
Atmospheric leakage c per module
|
Max. of 0,23 kg/day at 101,3 kPa
|
< 0,02 kg/day
|
|
a During crew ex changes the maximum daily average PCO2 is 1,01 kPa, with a peak of up to 1,33 kPa.
| ||
|
NOTE: For references see Annex C .
| ||
ECLS loads
Table B-7 lists the metabolic loads from existing programs.
Table: Metabolic loads
|
Parameter
|
ECLS loads
|
Russian ERCLS loads
| ||
|
Standard value
|
Range
|
Standard value
|
Range
| |
|
Crew O2 consumption(kg/person/day)
|
0,84
|
0,49 to 1,25
|
0,86
|
|
|
Experiment O2 consumption(g/day)
|
120
|
|
|
|
|
Animal O2 consumption(kg/day)
|
1,08
|
|
|
|
|
Crew heat loads(W/person)
|
137
|
|
|
|
|
Experimental animals heat loads a(W)
|
6
|
|
|
|
|
Animalgenerated moisture
|
136 g
|
TBD
|
2,5 l/day/animal
|
|
|
Crew water consumption(kg/day/person)
|
2,8
|
Up to 5,15
|
|
|
|
Crew hygiene water usage(kg/day/person)
|
6,8
|
Up to 7,3
|
1,1 (ISS service module only)
|
|
|
Crew urine production(kg/day/person)
|
1,56
|
Up to 2,0
|
1,2
|
|
|
Microbial generation rate(CFU/person/day)
|
3,0
|
N/A
|
|
|
|
Particles generation rate(pcs/person/day)
|
1 109
|
N/A
|
|
|
|
Crew CO2 generation rate b(kg/person/day)
|
1,00
|
0,52 to 1,50
|
1,00
|
|
|
Animal CO2 generation rate(g/day)
|
136
|
|
|
|
|
a These values are for rodents. Up to 72 rodents (or an equivalent metabolic load) can be accommodated.
| ||||
|
NOTE: For references see Annex C .
| ||||
Water quality
Table B-8 lists the water quality specifications from existing programs.
Table: Water quality specifications
|
Parameters b
|
Potable water specifications
|
Parameters b
|
Potable water specifications
|
|
Physical
|
100 mg/l
|
Inorganic constituents
|
0,5
|
|
Aesthetics
|
15 mg/l | ||
|
Microbial
|
100 CFM/100 ml
| ||
|
Organic parameters
|
500 g/l
|
Bactericide
|
1
|
|
a No detectable gas using a volumetric gas versus fluid measurement systemexcludes CO2 used for aesthetic purposes.
| |||
|
NOTE: For references see Annex C .
| |||
Radiation doses
The limit dose values for the ISS crew exposure are given in the following tables:
Consensus dose limits for the international partners of the ISS are listed in Table B-9 and Table B-10.
Crew exposures are managed in conformance with the ALARA (as low as reasonably achievable) principle. Current career limits for each agency are documented in the AMERD (JSC 24834).
If nuclear generator systems are employed, the effects of radiation from them on crew and systems are carefully assessed.
Table B-9 and Table B-10 show the current astronaut exposure limits based on recommendations by the National Council on Radiological Protection and Measurements (NCRP). Exposure to large solar flares or longterm exposure to cosmic rays can exceed these limits. Note that these limits are considerably above those for nonspace workers.
Table B-11 shows the current career exposure limits.
These limits are expressed in effective dose. The career depth equivalent dose limit is based upon a maximum 3% lifetime excess risk of cancer mortality and has additional components of detriment associated with it, namely the risk of heritable effects (0,6%) and of nonfatal cancer (also 0,6%) for a total detriment of 4,2%. These nominal risks are as given in ICRP (1991a) and NCRP (1993a). The total equivalent dose yielding this risk depends on sex and age at the start of exposure.
Table: Current ionizing radiation equivalent dose limits
|
Organ specific equivalent dose limits
| |
|
Exposure interval
|
BFO (Sv)
|
|
30 days
|
0,25
|
|
Annual
|
0,50
|
|
For references, see Annex C .
| |
Table: Organ dose limits for deterministic effects (all ages)
|
Exposure interval
|
Bone marrow (Sv)
|
Eye(Sv)
|
Skin(Sv)
|
|
30 days
|
0,25
|
1,0
|
1,5
|
|
Annual
|
0,50
|
2,0
|
3,0
|
|
Career
|
|
4,0
|
6,0
|
|
For references, see Annex C .
| |||
Table: Current career exposure limits
|
Sex
|
Age of exposure
| |||
|
25
|
35
|
45
|
55
| |
|
Male
|
0,7
|
1,0
|
1,5
|
3,0
|
|
Female
|
0,4
|
0,6
|
0,9
|
1,7
|
|
NOTE 1: Based on 3% excess lifetime risk on fatal cancer in Sv.
| ||||
ANNEX(informative)References
Additional data for ECLS can be found in the following documents:
ESAPSS0340 Issue 1, 1992: Environmental control and life support
ESAPSS03401 Issue 1, 1992: Atmosphere quality standards in manned space vehicles
ESAPSS03402 Issue 1, 1994: Water quality standards in manned space vehicles
ESAPSS0370 Issue 1, 1994: Human factors Volume 1 and 2
NASA STD 3000 ManSystems Integration Standards, 2002 : Volumes I and II JSCARDOHAB\SFINTRA\MSISReview\DOC files
NASA/TM1998206956/Vol1: Living together in Space : The design and operation of the Life Support System on the ISS.
NASA/CTSDADV245 (REV A) 1998: Advanced Life Support Program – Requirements Definition and Design Considerations. JSC 38571.
NASA/CTSDADV371 1999: Advanced Life Support – Systems Modeling and Analysis Project Baseline and Assumptions Document. JSC 39317.
Bibliography
The publications listed below were used in the preparation of this standard, and contain background information relating to the subject addressed.
|
ECSS-S-ST-00
|
ECSS System – Description , implementation and general requirements
|
|
ECSS-E-ST-10-03
|
Space engineering — Testing
|
|
ECSS-E-ST-10-11
|
Space engineering – Human factors engineering
|
|
ECSS-E-ST-20
|
Space engineering – Electrical and electronic
|
|
ECSS-E-ST-31
|
Space engineering – Thermal control general requirements
|
|
ECSS-E-ST-32
|
Space engineering – Structural general requirements
|
|
ECSS-E-ST-32-01
|
Space engineering – Fracture control
|
|
ECSS-E-ST-32-08
|
Space engineering – Materials
|
|
ECSS-E-ST-33-01
|
Space engineering – Mechanisms
|
|
ECSS-E-TM-10-10
|
Space engineering – Logistics engineering
|
|
ECSS-M-ST-10
|
Space project management – Project planning and implementation
|
|
ECSS-Q-ST-20
|
Space product assurance — Quality assurance
|
|
ECSS-Q-ST-3002
|
Space product assurance – Failure modes, effects (and criticality) analysis (FMEA/FMECA)
|