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<tbody>
<tr class="odd">
<td colspan="12"><strong>JSC-47787</strong></td>
</tr>
<tr class="even">
<td colspan="12"><p><strong>CREW AND THERMAL SYSTEMS
DIVISION</strong></p>
<p><strong>NASA–LYNDON B. JOHNSON SPACE CENTER</strong></p>
<p><strong>HOUSTON, TEXAS</strong></p></td>
</tr>
<tr class="odd">
<td colspan="2"></td>
<td colspan="8"><p><strong>Advanced Life Support
Research and Technology<br />
Development Metric<br />
‑ Fiscal Year 2001</strong></p>
<p><strong>Document Number</strong> <u>CTSD-ADV-482</u>
<strong>Date</strong> <u>17 January 2002</u></p></td>
<td colspan="2"></td>
</tr>
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<td colspan="12"></td>
</tr>
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<td></td>
<td colspan="3"><strong>PREPARED BY:</strong></td>
<td colspan="7">A. E. Drysdale <em>Original signed by A. E.
Drysdale</em></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td colspan="3"><strong>PREPARED BY:</strong></td>
<td colspan="7">A. J. Hanford <em>Original signed by A. J.
Hanford</em></td>
<td></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3"><strong>APPROVED BY:</strong></td>
<td colspan="7">M. K. Ewert <em>Original signed by K. Ewert</em></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td colspan="3"><strong>APPROVED BY:</strong></td>
<td colspan="7">C. H. Lin <em>Original signed by H. Lin</em></td>
<td></td>
</tr>
<tr class="odd">
<td></td>
<td colspan="3"><strong>APPROVED BY:</strong></td>
<td colspan="7">T. O. Tri <em>Original signed by T. O. Tri</em></td>
<td></td>
</tr>
<tr class="even">
<td></td>
<td colspan="3"><strong>APPROVED BY:</strong></td>
<td colspan="7">D. L. Henninger <em>Original signed by</em></td>
<td></td>
</tr>
<tr class="odd">
<td colspan="12">Number of pages: <u>___26__</u></td>
</tr>
<tr class="even">
<td colspan="12"><strong>REVISIONS</strong></td>
</tr>
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<td colspan="2"></td>
<td colspan="4">APPROVALS</td>
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</tr>
<tr class="even">
<td colspan="3">DATE</td>
<td colspan="2">AUTHOR</td>
<td>SECTION</td>
<td>BRANCH</td>
<td>DIVISION</td>
<td></td>
<td colspan="3">REV. LETTER</td>
</tr>
<tr class="odd">
<td colspan="3"></td>
<td colspan="2"></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td colspan="3"></td>
</tr>
</tbody>
</table>

JSC FORM 151C (Rev Sept 86) NASA-JSC

***Advanced Life Support Research and Technology
Development Metric -- Fiscal Year 2001***

A. E. Drysdale, Ph.D.\
*The Boeing Company\
Kennedy Space Center, Florida 32815*

A. J. Hanford, Ph.D.\
*Lockheed Martin Space Operations\
Houston, Texas 77058*

*January 2002*

Contents

[1 Introduction 1](#introduction)

[1.1 Basic Metric Format 1](#basic-metric-format)

[1.2 Description of Equivalent System Mass
2](#description-of-equivalent-system-mass)

[1.3 Previous Advanced Life Support Metric Computations
2](#previous-advanced-life-support-metric-computations)

[1.4 Control and Contact Information
3](#control-and-contact-information)

[2 Background 3](#background)

[2.1 Supporting Documentation 3](#supporting-documentation)

[2.2 Reference Missions 4](#reference-missions)

[2.2.1 Orbiting Research Facility: International Space Station Upgrade
Mission
4](#orbiting-research-facility-international-space-station-upgrade-mission)

[2.2.2 Independent Exploration Mission: Mars Dual Lander Architecture
4](#independent-exploration-mission-mars-dual-lander-architecture)

[2.3 Metric Assumptions 5](#metric-assumptions)

[2.4 Technology Assumptions 5](#technology-assumptions)

[2.4.1 Orbiting Research Facility: International Space Station Upgrade
Mission
5](#orbiting-research-facility-international-space-station-upgrade-mission-1)

[2.4.2 Independent Exploration Mission: Mars Transit Vehicle
7](#independent-exploration-mission-mars-transit-vehicle)

[2.4.3 Independent Exploration Mission: Mars Descent / Ascent Lander
10](#independent-exploration-mission-mars-descent-ascent-lander)

[2.4.4 Independent Exploration Mission: Surface Habitat Lander
12](#independent-exploration-mission-surface-habitat-lander)

[2.4.5 Infrastructure Costs/Equivalencies
14](#infrastructure-costsequivalencies)

[3 Advanced Life Support Research and Technology Development Metric
15](#advanced-life-support-research-and-technology-development-metric)

[3.1 Subsystem Technology Data 15](#subsystem-technology-data)

[3.2 Advanced Life Support Research and Technology Development Metric
18](#advanced-life-support-research-and-technology-development-metric-1)

[3.3 Metric Reporting Recommendations
21](#metric-reporting-recommendations)

[4 Cautions and Disclaimers 21](#cautions-and-disclaimers)

[5 Special Recognition of Work 21](#special-recognition-of-work)

[6 References 22](#references)

[7 Abbreviations and Acronyms 23](#abbreviations-and-acronyms)

Tables

[Table 1.1 Technology Readiness Levels 1](#__RefHeading___Toc536595023)

[Table 2.1 Advanced Mission Cost Equivalencies
14](#__RefHeading___Toc536595024)

[Table 3.1 Orbiting Research Facility: International Space Station
Upgrade Mission using ISS ECLSS Technologies
15](#__RefHeading___Toc536595025)

[Table 3.2 Orbiting Research Facility: International Space Station
Upgrade Mission using ALS Technologies 15](#__RefHeading___Toc536595026)

[Table 3.3 Independent Exploration Mission: Mars Transit Vehicle
using ISS ECLSS Technologies 16](#__RefHeading___Toc536595027)

[Table 3.4 Independent Exploration Mission: Mars Transit Vehicle
using ALS Technologies 16](#__RefHeading___Toc536595028)

[Table 3.5 Independent Exploration Mission: Mars Descent / Ascent Lander
using ISS ECLSS Technologies 17](#__RefHeading___Toc536595029)

[Table 3.6 Independent Exploration Mission: Mars Descent / Ascent Lander
using ALS Technologies 17](#__RefHeading___Toc536595030)

[Table 3.7 Independent Exploration Mission: Surface Habitat Lander
using ISS ECLSS Technologies 18](#__RefHeading___Toc536595031)

[Table 3.8 Independent Exploration Mission: Surface Habitat Lander
using ALS Technologies 18](#__RefHeading___Toc536595032)

[Table 3.9 Equivalent System Mass and Metric Values for a Range of
Missions and Technologies 19](#__RefHeading___Toc536595033)

Figures

[Figure 3.2.1 Equivalent system mass summary for the Fiscal Year 2001
ALS Research and Technology Development Metric missions and technology
suites. 20](#__RefHeading___Toc536595034)

# Introduction

This document provides the official calculation of the Advanced Life
Support (ALS) Research and Technology Development Metric (the Metric)
for Fiscal Year 2001. As such, the values herein are primarily based on
reviewed and approved Systems Integration, Modeling, and Analysis (SIMA)
Element reference documents.

As the ALS Project continues to evolve, changes in structure and focus
are inevitable, and these changes will likely affect the Metric. Changes
this year include reclassifying life support systems to fit within the
subsystem categories as defined in SIMA reference documents such as
Stafford, *et al.* (2001). Additionally, the National Aeronautics and
Space Administration (NASA) redirected its near-term human exploration
goals towards missions in near-Earth space and, at least temporarily,
away from human missions to Mars. Because the Metric requires a
reference mission, to provide a basis for assessing life support
equipment properties, and an appropriate Lunar mission architecture is
not yet available, the current Metric still assesses a Mars exploration
mission. However, the focus here is strictly on shorter-term Martian
missions that primarily emphasize near-term, physicochemical or
biological technologies. More distant missions, such as Martian bases
with plant growth chambers and regenerative food systems, have been
omitted from the current assessments. The Metric for Fiscal Year 2001
also considers an International Space Station Upgrade reference mission.

## Basic Metric Format

The Metric is one of several measurement devices employed by the NASA to
measure the Agency's progress as mandated by the U. S. Congress and the
Office of Management and Budget. Because any measure must have a
reference point, whether explicitly defined or implied, the Metric is a
comparison between a selected ALS Project life support system and an
equivalently detailed life support system using technology from the
Environmental Control and Life Support System (ECLSS) for the
International Space Station (ISS). More specifically, the Metric is the
ratio defined by the equivalent system mass (ESM) of a life support
system for a specific mission using the ISS ECLSS technologies divided
by the ESM for an equivalent life support system using the "best" ALS
technologies.

[]{#__RefHeading___Toc536595023 .anchor}Table 1.1 Technology Readiness
Levels

  -------------- -----------------------------------------------------------
  **Technology   **Description**
  Readiness      
  Level**        

  1              Basic principles observed and reported.

  2              Technology Concept and/or application formulated.

  3              Analytical and experimental critical function and/or
                 characteristic proof‑of‑concept.

  4              Component and/or breadboard validation in laboratory
                 environment.

  5              Component and/or breadboard validation in relevant
                 environment.

  6              System/subsystem model or prototype demonstration in
                 relevant environment\
                 (ground or space).

  7              System prototype demonstration in a space environment.

  8              Actual system completed and "flight qualified" through test
                 and demonstration.

  9              Actual system "flight proven" through successful mission
                 operations.
  -------------- -----------------------------------------------------------

As defined, the Metric should increase in value as the ALS technologies
become lighter, less power intensive, and require less volume. Here
"best" is defined as the ALS system that, at the time of the Metric
evaluation, provides the Metric with the highest value. This process
theoretically encourages the ALS Project to research more than a single
technology for each life support function and then select the most
appropriate for a particular mission, which is similar to the actual
process used by mission planners. Only technologies of a certain
maturity level, generally of technology readiness level of 5 or higher,
are selected for inclusion in the Metric to avoid assuming too much with
too little data. Some promising advanced technologies at a lower
technology readiness level might appear here, but those selections are
uncommon. See Table 1.1 for a summary of the technology readiness levels
used by NASA (Behrend, *et al.*, 1999). This implies that the Metric
will improve as promising technologies mature within the ALS Project and
become eligible for inclusion in this calculation. Conversely, early
assumptions for some technologies may be overly optimistic, so the
Metric value may decrease in the future as additional research uncovers
higher than expected costs and outdated assumptions are revised.

## Description of Equivalent System Mass

Equivalent system mass (ESM) is the sum of the masses of life support
equipment and supplied commodities, plus the mass penalties for
infrastructure support, notably power and cooling, corrected for crew
time required to operate and maintain the life support system.

Use of ESM reduces the physical quantities describing a system or
subsystem to a single physical parameter; mass. This allows comparison
of two systems with different physical parameters using a single scale,
and avoids the necessity of arbitrary weightings that reflect the
prejudices of the analyst to compare, for example, a lighter subsystem
to one using less power.

Conversion factors or equivalencies are determined for the environment
and infrastructure technologies that are likely to be used for a
mission. For systems requiring power, for example, the power system can
yield an appropriate power-mass penalty by dividing the average power
plant output for user loads by the total mass of the generating power
system. Thus, for a nuclear power system on an independent lander that,
on average, delivers 100 kW of electrical power and has an overall mass
of 8,708 kg, the power mass penalty is 87 kg/kW (0.0115 kW/kg) (Drysdale
and Hanford, 1999a). This power-mass penalty effectively assigns a
fraction of the power system mass to a power-using subsystem in place of
that subsystem's power requirement. In like manner, mass penalties to
account for heat rejection and volume within a pressurized shell are
defined.

Derivation of a crew-time-mass penalty, to convert operations and
maintenance time to mass, is more complex. The approach detailed in
Drysdale and Hanford (1999a), developed by D. Vaccari and J. Levri of
the New Jersey NASA Specialized Center of Research and Training, [^1] is
used. Briefly, an ESM is calculated for a mission without accounting for
the crew time requirements. This ESM is then multiplied by the total
available crew time divided by this total crew time minus the life
support crew time. This approach is adequate when the crew time
requirement is a small percentage of the total crew time available, as
is expected for life support systems.

## Previous Advanced Life Support Metric Computations

Previously released Metric computations, in reverse chronological order,
may be found in the documents listed below. [^2]

Drysdale, A. E. (2001) "Update to the Advanced Life Support Research and
Technology Development Metric," National Aeronautics and Space
Administration, Lyndon B. Johnson Space Center, Houston, Texas,
19 February 2001.

Drysdale, A. E., and Hanford, A. J. (1999) "Advanced Life Support
Research and Technology Development Metric -- Baseline" JSC‑39503
(CTSD‑ADV‑384), National Aeronautics and Space Administration, Lyndon B.
Johnson Space Center, Houston, Texas, 19 November 1999.

Hanford, A. J., and Drysdale, A. E. (1999) "Advanced Life Support
Technology Research and Development Metric -- Initial Draft,"
LMSMSS‑33045, Lockheed Martin Space Mission Systems and Services,
Houston, Texas, 13 January 1999.

## Control and Contact Information

The ALS Project controls the Metric, and SIMA provides the Metric
calculation. Subsequent releases will be made as required. Please
forward comments to:

Mr. M. K. Ewert\
Manager, Systems Integration, Modeling, and Analysis Element\
National Aeronautics and Space Administration\
Lyndon B. Johnson Space Center\
Mail Code EC2\
2101 NASA Road One\
Houston, TX 77058\
E-mail: michael.k.ewert1@jsc.nasa.gov

# Background

## Supporting Documentation

The listed SIMA reference documents provided inputs for the Fiscal Year
2001 Advanced Life Support Research and Technology Development Metric
calculation. [^3]

Drysdale, A. E. and Hanford, A. J. (1999) "Advanced Life Support Systems
Modeling and Analysis Project Baseline Values and Assumptions Document,"
JSC 39317 (CTSD‑ADV‑371), National Aeronautics and Space Administration,
Lyndon B. Johnson Space Center, Houston, Texas.

Stafford, K. W., Jerng, L. T., Drysdale, A. E., Maxwell, S.,
Levri, J. A., Ewert, M. K., and Hanford, A. J. (2001) "Advanced Life
Support Systems Integration, Modeling, and Analysis Reference Missions
Document," JSC‑39502, Revision A, National Aeronautics and Space
Administration, Lyndon B. Johnson Space Center, Houston, Texas.

Carrasquillo, R. L., Reuter, J. L., and Philistine, C. L. (1997)
"Summary of Resources for the International Space Station Environmental
Control and Life Support System," SAE 972332, *27^th^ International
Conference on Environmental Systems*, *Lake Tahoe*, *Nevada*,
*July 14‑17*, *1997*, Society of Automotive Engineers, Inc., Warrendale,
Pennsylvania.

These reference documents provide the primary resources for the values
contained below, and, unless noted otherwise, all values are listed in
or derived from these documents.

For a few input values, the reference documents are incomplete and other
resources provide the necessary values. These resources are listed here
and noted specifically, when applicable, in the text and footnotes
below.

Drysdale, A. E. (2002) Personal communication, The Boeing Company,
Kennedy Space Center, Florida. Electronic message from 05 December 2001.

Hanford, A. J., and Ewert, M. K. (1996) "Advanced Active Thermal Control
Systems Architecture Study Report," NASA‑TM‑104822, National Aeronautics
and Space Administration, Lyndon B. Johnson Space Center, Houston,
Texas.

MacKnight, A. (2001) "Direct Liquid Contact ECS System for Space
Applications", Document 01‑71471, Honeywell International Inc.,
Torrance, California, May 2001. This document is proprietary.

## Reference Missions

The following missions are addressed for Fiscal Year 2001:

-   Orbiting Research Laboratory: International Space Station Upgrade
    Mission, and

-   Independent Exploration Mission: Mars Dual Lander Architecture.

These missions are described briefly below. For additional details, see
Stafford, *et al.* (2001).

The data given applies to nominal operations. Contingency planning,
though extremely important, is not well advanced at this point so
contingencies are excluded from these calculations at this time.

### Orbiting Research Facility: International Space Station Upgrade Mission

The International Space Station (ISS) mission is a ten-year,
six-crewmember [^4] mission in low-Earth orbit. For this assessment, the
specifics of Earth-to-orbit transfers are not considered, nor are ISS
construction operations. Rather this assessment considers just the ESM
for nominal, on-orbit operation of the life support system in the United
States On‑Orbit Segment (USOS) following Phase 3, or at "assembly
complete." Extravehicular activities are assumed to be a small mission
component during the day-to-day operation of the ISS after buildup is
complete.

ISS Upgrade Mission follows the initial utilization phase for the
complete vehicle and assumes that to use ISS for an additional ten-year
mission the entire USOS life support system must be replaced with new
equipment of the same or comparable technologies. The rationale for
extending ISS beyond its initial design life is not addressed here, but
rather significant justification is implicitly assumed. Alternately,
this mission might apply to a new space station of comparable size and
capability that follows ISS in the timeframe indicated. [^5]

The baseline equipment suite assumes an appropriate life support system
for the USOS Phase 3 segment using ISS ECLSS technologies alone. This
system includes newly fabricated equipment and it replaces the original
equipment just prior to the beginning of the ISS Upgrade Mission.

The advanced equipment suite corresponding to the USOS Phase 3 life
support system at completion is the USOS Post Phase 3 life support
system (Stafford, *et al.*, 2001). In essence, the Post Phase 3 mission
describes an upgraded USOS life support system using ALS technologies
with the same capabilities as the ISS ECLSS USOS Phase 3 life support
system.

### Independent Exploration Mission: Mars Dual Lander Architecture

This Mars exploration mission consists of a single trip to one site on
Mars. The analysis assumes a standard mission profile with outbound and
return transit segments of 180 days and a surface phase of 600 days
(Stafford, *et al.*, 2001). Actual missions will vary in duration
according to the year or transportation opportunity, propulsion
capabilities, and mission development decisions.

A Mars Transit Vehicle carries the crew during both interplanetary
segments, remaining dormant in Martian orbit while the crew descends to
Mars for the surface phase. A second vehicle, the Mars Descent / Ascent
Lander, will fly to Mars orbit robotically. The crew will transfer to,
and land in, this second vehicle. A third vehicle, the Surface Habitat
Lander, will fly to Mars and land robotically on the surface. This last
vehicle will provide housing for the crew during the surface segment.
During the surface segment, extravehicular activities will be constant.
Here the extravehicular activities are assumed to occupy two crewmembers
for up to 8 hours per day, five times per week. After completion of the
surface phase, the crew will ascend to Martian orbit in the Mars Descent
/ Ascent Lander and rendezvous with the waiting Mars Transit Vehicle.
This approach assumes each mission lands at a different location on
Mars, so no infrastructure buildup occurs. Finally, vehicles are
optimized for either weightless or fractional gravity, according to the
primary operational environment.

## Metric Assumptions

Most of the assumptions are derived from the reference documentation
above, especially Drysdale and Hanford (1999a). Most vehicles considered
here assume a free habitable volume of 50 m³ per person. The Mars
Descent / Ascent Lander, due to its limited duration, assumes a free
habitable volume of only 10 m³ per person. These costs are primarily
pressure-vessel costs, and there are significant differences between
various technologies.

To minimize the effect of infrastructure assumptions on the Metric
value, similar infrastructures are assumed for each technology option.
The International Space Station Mission employs infrastructure values
characteristic of International Space Station throughout, while the Mars
Independent Exploration Mission assumes mostly advanced technologies and
some inflatable modules.

Crew time is assumed to be 59 hours of payload time per crewmember per
week during transit or on-orbit, and 66 hours per crewmember per week
during surface operations. This arrangement presumes that additional
exercise time to maintain physical conditioning is required during
long-duration operations in microgravity.

Support to extravehicular activities from the life support system, plus
associated airlock operating costs have been included. Extravehicular
mobility units and other extravehicular activity equipment have not been
included.

Finally, some life support system designs naturally recover more water
than the crew needs to just support their basic metabolic and hygiene
requirements. Thus, such a surplus might support extravehicular
activities or experiments, both of which historically consume water.
This, however, has not been included in the official Fiscal Year 2001
calculations.

## Technology Assumptions

### Orbiting Research Facility: International Space Station Upgrade Mission

International Space Station currently uses aluminum modules and nodes
pressurized to 101 kPa. Solar photovoltaic generation with rechargeable
batteries for energy storage provide continuous power. The external
thermal control system uses a single-phase, pumped ammonia loop to
transport thermal energy and rejects the loads using anti-sun tracking
radiators with Z‑93 surface coating. The ISS ECLSS hardware
configuration associated with completion of Phase 3, or "assembly
complete," is the assumed baseline along with an additional mission
duration of ten years.

#### International Space Station Environmental Control and Life Support System Technology Baseline

The ISS ECLSS, for the purposes of this document, is defined based on
the USOS ECLSS scaled for a crew of six. Carrasquillo, *et al.* (1997),
which provides equipment values, includes various amounts of contingency
capacity integral to the life support system. Such contingency capacity
is removed for the purposes of this document, so that differences in
contingency assumptions for the different missions will not influence
these results. While contingency is an important issue, it has not been
explicitly addressed for advanced missions. See Stafford, *et al.*
(2001), for details of the life support system architecture.

This suite of technologies uses physicochemical technologies to
regenerate air and water, while food is supplied as prepackaged
individual entrees. Waste is generally compacted and stored without
reclaiming any products from that waste. Thermal control employs
coldplates and condensing heat exchangers to collect heat loads, a
single-phase fluid to transport heat, and radiators to reject heat.
Clothing is supplied from Earth clean and discarded once it is deemed
too dirty to wear.

##### Air

The ISS ECLSS uses regenerable carbon dioxide removal equipment based on
molecular sieve technology and a catalytic burner for removing trace
combustible gases. However, the absorbed carbon dioxide is dumped
overboard, so oxygen is supplied. The trace gas contaminant system uses
activated carbon, for non-combustible trace gas removal, and bacteria
filter assemblies, for particulate removal, neither of which are
regenerated. Oxygen is supplied both as pressurized gas and as water. In
the second case, water is electrolyzed to supply oxygen while the
associated product hydrogen is dumped overboard. Additional water may
enter ISS directly, such as from the Shuttle's stock of fuel cell water,
or indirectly, as a human metabolic product from the consumption of
supplied food. Nitrogen is supplied from high-pressure gas stocks. A
major constituent analyzer and a fire detection and suppression system
provide monitoring for air contaminants and combustion products.

##### Food

Food is provided in individual entrees from Earth. A mix of fresh,
dehydrated, and full-water preserved, shelf-stable or frozen foods are
used. This system provides significant quantities of water, but also
requires significant quantities of packaging. Nominally, 11.82 MJ/CM‑d
of energy as food is supplied, corresponding to 1.96 kg/CM‑d. [^6]
0.35 kg/CM‑d of disposable packaging is required, bringing the total
food mass to 2.3 kg/CM‑d. 2.1 MJ/CM‑d of additional energy as food is
provided for days with extravehicular activities. Supporting technology
includes freezers and some food preparation equipment.

##### Thermal

Thermal control is divided into two systems here. The internal thermal
control system includes the avionic air assemblies, which provide
air-cooling for equipment, the common cabin air assemblies, which cool
and dehumidify cabin air, condensate storage, and the water flow loops
for heat transport. Coldplates and heat exchangers are assumed part of
other equipment while the external thermal control system is included in
the assessed thermal control cost factor.

##### Waste

Solid waste is compacted, stored, and returned aboard the crew transfer
vehicle or burned upon re‑entry in an expendable resupply vehicle. This
includes trash, fecal material, brine from the urine and water
processing, and used filters and cartridges. Waste processing is also
responsible for the toilet.

##### Water

Urine is processed by vapor compression distillation. 95% water recovery
is claimed. The brine is either returned to Earth or dumped. All grey
water, including hygiene water, effluent from the vapor compression
distillation, and condensate from dehumidification, is processed through
a water processor. The water processor employs two multifiltration
units, a volatile removal assembly, phase separators, and an ion
exchange bed. A process control water quality monitor provides water
quality assurance. Efficiency of recovery is high, but many expendables,
mostly filter cartridges, are needed.

##### Extravehicular Activity Support

The Shuttle extravehicular mobility unit is assumed with some upgrades.
More specifically, the extravehicular mobility unit consumables include
oxygen, for metabolic consumption and suit pressurization, and water,
which is rejected for thermal control. Though not consumed, water also
provides the working fluid for the internal cooling garment. This
extravehicular mobility unit uses metal oxide, or metox, for carbon
dioxide removal. An airlock pump, a compressor, reduces the airlock
internal pressure to about 10 kPa, reducing gas losses during airlock
operations. Because airlock usage impacts the supply of atmospheric
gases, it is included here in the life-support system baseline. It is
assumed that this technology suite does not require any crewtime from
the life support system. Rather, any associated crewtime is assessed to
other vehicle systems.

##### Human Accommodations

Clothing is delivered with the crew at the beginning of an expedition
and returned to Earth with the crew at the end of each expedition. As
above, this interface does not assess any crewtime to the life support
system. Rather, donning, removing, and storing clothing uses crewtime
assessed to other vehicle systems.

#### Advanced Life Support Technology

The ALS technology suite employs both physicochemical and
bioregenerative technologies. Here bioregenerative technologies aide in
water regeneration while the remaining technologies rely on
physicochemical approaches.

##### Air

The ALS suite uses an improved carbon dioxide removal assembly based on
liquid amine technology, a Sabatier carbon dioxide reduction assembly
with a gas stream compressor, and a regenerable trace contaminant
control assembly. The carbon dioxide removal assembly also removes
latent heat and humidity from the air (MacKnight, 2001). Adequate water
is available to avoid a supply penalty for any necessary oxygen and
hydrogen. High efficiency particulate air filters provide particulate
removal. Other aspects of the ALS air suite are identical to the ISS
ECLSS technology suite for air listed in Section 2.4.1.1.1.

##### Food

The ALS suite for food is identical to the ISS ECLSS suite for food in
Section 2.4.1.1.2,except that an ALS technology is assumed for frozen
food storage.

##### Thermal

The ALS suite for thermal control uses the same technologies as the ISS
ECLSS suite for thermal control described in Section 2.4.1.1.3.

##### Waste

The ALS suite for waste combines a dryer with the technologies listed
above for the ISS ECLSS. See Section 2.4.1.1.4. The dryer reclaims water
from trash before it is compacted and disposed.

##### Water

A biological water processor and a nitrifying bioreactor provide primary
water processing for both grey water and urine. Post-treatment
technologies include reverse osmosis and air evaporation, and ion
exchange and a photocatalytic oxidizer provide polishing. As with the
ISS ECLSS, process control water quality monitor provides water quality
assurance. Recovery efficiency with this system is also high, though
compared to the ISS ECLSS the expendables are reduced.

##### Extravehicular Activity Support

The ALS suite for extravehicular activity support is identical to the
ISS ECLSS suite for extravehicular activity support. See
Section 2.4.1.1.6.

##### Human Accommodations

The ALS approach assumes an aqueous laundry. This will significantly
increase the daily grey water load, but reduce the required mass of
clothing compared to the ISS ECLSS approach. The assessed crewtime
supports laundry operations only.

### Independent Exploration Mission: Mars Transit Vehicle

The Mars Transit Vehicle uses inflatable modules with radiation
shielding for interplanetary travel. Power is provided by solar
photovoltaic generation with minimal energy storage. The external
thermal control system uses a single-phase, pumped loop to transport
thermal energy and rejects the loads using radiators (Stafford,
*et al.*, 2001).

#### International Space Station Environmental Control and Life Support System Technology Baseline

The ISS ECLSS technology suite, for the purposes of this document, is
defined based on the USOS ECLSS scaled for a crew of six. See
Carrasquillo, *et al.* (1997), and Stafford, *et al.* (2001), for
details. This suite of technologies uses physicochemical technologies to
regenerate air and water, while food is supplied as prepackaged
individual entrees. Waste is generally compacted and stored without
reclaiming any products from that waste. Thermal control employs
coldplates and condensing heat exchangers to collect heat loads, a
single-phase fluid to transport heat, and radiators to reject heat.
Clothing is supplied from Earth clean and discarded once it is deemed
too dirty to wear.

##### Air

The life support system for the Mars Transit Vehicle using ISS ECLSS
technologies employs regenerable carbon dioxide removal equipment based
on molecular sieve technology and a catalytic burner for removing trace
combustible gases. The absorbed carbon dioxide is dumped overboard and
oxygen is supplied. The trace gas contaminant system uses activated
carbon, for non-combustible trace gas removal, and bacteria filter
assemblies, for particulate removal. These filters are not regenerated.
Oxygen is supplied both as pressurized gas and as water. In the second
case, water is electrolyzed to supply oxygen while the associated
product hydrogen is dumped overboard. Water may enter the life support
system directly, such as from moisture within prepackaged food, or
indirectly, as a human metabolic product from the consumption of the
prepackaged food. Because the Mars Transit Vehicle will be "water rich"
from moisture stored in food and the relatively high rate of water
reclamation from grey water, most oxygen will be generated by
electrolysis. Nitrogen is supplied from high-pressure gas stocks. A
major constituent analyzer and a fire detection and suppression system
provide monitoring for air contaminants and combustion products.

##### Food

Food is provided in individual entrees from Earth. The Mars Transit
Vehicle will rely on a variety of individually packaged, shelf-stable
foods. This system provides significant quantities of water, but also
requires significant quantities of packaging. Nominally, the daily food
mass is 1.82 kg/CM‑d plus 0.23 kg/CM‑d of disposable packaging for a
total packaged food mass to 2.05 kg/CM‑d. Supporting technology includes
some food preparation equipment.

##### Thermal

Thermal control is divided into two systems here. The internal thermal
control system includes the avionic air assemblies, which provide
air-cooling for equipment, the common cabin air assemblies, which cool
and dehumidify cabin air, condensate storage, and the water flow loops
for heat transport. Coldplates and heat exchangers are assumed part of
other equipment while the external thermal control system is included in
the assessed thermal control cost factor.

##### Waste

Solid waste is compacted and stored aboard the Mars Transit Vehicle.
This includes trash, fecal material, brine from the urine and water
processing, and used filters and cartridges. Waste processing is also
responsible for the toilet.

##### Water

Urine is processed by vapor compression distillation. 95% water recovery
is claimed. The brine is dumped or placed in waste storage. All grey
water, including hygiene water, effluent from the vapor compression
distillation, and condensate from dehumidification, is processed through
a water processor. The water processor employs two multifiltration
units, a volatile removal assembly, phase separators, and an ion
exchange bed. A process control water quality monitor provides water
quality assurance. Efficiency of recovery is high, but many expendables,
mostly filter cartridges, are needed.

##### Human Accommodations

Clothing is launched with the crew at the beginning of this mission and
returns to Earth with the crew at the end of this mission.

#### Advanced Life Support Technology

Though similar to the ISS ECLSS approach above, the ALS technology suite
for the Mars Transit Vehicle employs advanced physicochemical
technologies for air and water recovery, and an aqueous laundry recycles
crew clothing. A biomass production chamber also provides salad to
supplement an otherwise prepackaged food system.

##### Air

The ALS suite uses an improved carbon dioxide removal assembly based on
solid amine technology with vacuum desorption, an improved oxygen
generation assembly, and a regenerable trace contaminant control
assembly. Adequate water is available to avoid a supply penalty for any
necessary oxygen and hydrogen. High efficiency particulate air filters
provide particulate removal. Other technologies within the ALS air suite
are identical to those within the ISS ECLSS technology suite for air as
listed in Section 2.4.2.1.1.

##### Biomass

The ALS suite contains a small biomass production chamber, providing
salad crops as a supplement to an otherwise prepackaged food system.
Though the dietary nutrients gained from salad crops are relatively
minor, salad provides a psychological advantage unavailable in a
completely prepackaged food system. Supporting equipment for the biomass
production chamber includes a nutrient solution supply, condensate
storage, and a larger common cabin air assembly to handle the greater
humidity loading.

##### Food

The food system here is identical to the ISS ECLSS suite in
Section 2.4.2.1.2 except that the ALS suite, as noted above, supplements
the diet with fresh salad from a biomass production chamber.

##### Thermal

The ALS suite for thermal control uses the same technologies as the ISS
ECLSS suite for thermal control described in Section 2.4.2.1.3.

##### Waste

The ALS suite for waste management uses the same technologies as the ISS
ECLSS suite for waste management described in Section 2.4.2.1.4.

##### Water

The ALS water system is built around a vapor phase catalytic ammonia
removal assembly to provide primary water processing of both urine and
grey water. Air evaporation reclaims water from the primary processor
brine, allowing almost complete water recovery. Product water from the
air evaporator passes to the primary processor. Product water from the
vapor phase catalytic ammonia removal assembly requires no further
polishing, though a process control water quality monitor provides water
quality assurance. Recovery efficiency with this system is also high
with reduced expendables compared to the ISS ECLSS suite.

##### Human Accommodations

The ALS approach assumes an aqueous laundry. This will significantly
increase the daily grey water load, but reduce the required mass of
clothing compared to the ISS ECLSS approach. The assessed crewtime
supports laundry operations only.

### Independent Exploration Mission: Mars Descent / Ascent Lander

The Mars Descent / Ascent Lander uses rigid aluminum modules per
International Space Station architecture. Power is provided by
oxygen-hydrogen fuel cells. The external thermal control system uses a
single-phase, pumped loop to transport thermal energy and rejects the
thermal loads using radiators.

#### International Space Station Environmental Control and Life Support System Technology Baseline

The ISS ECLSS technology suite, for the purposes of this document, is
defined based on the USOS ECLSS scaled for a crew of six. See
Carrasquillo, *et al.* (1997), and Stafford, *et al.* (2001), for
details. For this application, this suite of technologies provides,
without any regeneration, air, water, clothing, and food from stocks
emplaced aboard the vehicle before departing Earth. Waste is stored.
Thermal control employs coldplates and condensing heat exchangers to
collect heat loads, a single-phase fluid to transport heat, and
radiators to reject heat.

##### Air

The ISS ECLSS air suite for the Mars Descent / Ascent Lander uses
regenerable carbon dioxide removal equipment based on molecular sieve
technology and a catalytic burner for removing trace combustible gases.
The absorbed carbon dioxide is dumped overboard and oxygen is supplied.
The trace gas contaminant system uses activated carbon, for
non-combustible trace gas removal, and bacteria filter assemblies, for
particulate removal. These filters are not regenerated. Oxygen is
supplied only as pressurized gas. A major constituent analyzer and a
fire detection and suppression system provide monitoring for air
contaminants and combustion products.

##### Food

Food is provided in individual entrees prepackaged before the Mars
Descent / Ascent Lander leaves Earth. These entrees are shelf-stable
foods at ambient temperatures, as presented in Section 2.4.2.1.2. As
with other vehicles, supporting technology includes some food
preparation equipment.

##### Thermal

Thermal control for the Mars Descent / Ascent Lander is divided between
two systems here. The internal thermal control system includes the
avionic air assemblies, which provide air-cooling for equipment, the
common cabin air assemblies, which dehumidify cabin air, condensate
storage, and the flow loops. Coldplates and heat exchangers are assumed
part of other equipment while the external thermal control system is
included in the assessed thermal control cost factor.

##### Waste

The waste management system provides only for rudimentary collection and
storage of waste products. Thus, the waste management system includes a
toilet, pretreatment to stabilize urine, and separate storage for human
metabolic wastes and trash.

##### Water

Water is provided in the Mars Descent / Ascent Lander completely from
stocks without any regenerative capability. Water is produced as a
byproduct of the oxygen-hydrogen fuel cells, but any additional potable
water is placed aboard the vehicle before departing from Earth.

##### Extravehicular Activity Support

While extravehicular activities from the Mars Descent / Ascent Lander
are essential to mission success, such activities are expected to be
limited in number. Thus, the entire cabin will function as an airlock
and no effort is made to recover cabin gases before pressurization,
preferring instead to simply repressurize the cabin from gas stocks when
the crew reoccupies the Mars Descent / Ascent Lander en route to
rendezvous with the Mars Transit Vehicle. The life support system is
expected to provide bottled water and oxygen to the extravehicular
mobility units for cooling and crew consumption, and water to charge the
internal liquid cooling loop. Additionally, the extravehicular mobility
units use lithium hydroxide to remove carbon dioxide from the
extravehicular mobility unit atmosphere. It is assumed that this
technology suite does not use any crewtime from the life support system.
Rather, any associated crewtime is assessed to other vehicle systems.

##### Human Accommodations

Clothing is launched with the vehicle before the Mars Descent / Ascent
Lander leaves Earth. This clothing will remain with the vehicle when the
crew departs either for surface operations or upon returning to the Mars
Transit Vehicle. This clothing is not laundered. As above, this
interface does not assess any crewtime to the life support system.
Rather, donning, removing, and storing clothing uses crewtime assessed
to other vehicle systems.

#### Advanced Life Support Technology

The ALS life support suite for the Mars Descent / Ascent Lander is
identical to the ISS ECLSS suite except for several air system
technologies. Because ALS technologies are designed to minimize costs
for long duration missions, their general applicability to
short-duration vehicles is not currently clear.

##### Air

Though similar in structure to the ISS ECLSS air suite, the ALS suite
selects different technologies in several areas. Carbon dioxide removal
is provided by a solid amine technology with vacuum desorption. High
efficiency particulate air filters provide particulate removal, and an
advanced regenerable technology provides trace contaminant control. As
in Section 2.4.3.1.1, oxygen and nitrogen are supplied only as
high-pressure gases.

##### Food

The food system for the ALS life support suite within the Mars Descent
/ Ascent Lander is identical to the technologies described for the ISS
ECLSS food system in Section 2.4.3.1.2.

##### Thermal

The thermal control system for the ALS life support suite within the
Mars Descent / Ascent Lander is identical to the technologies listed for
the ISS ECLSS thermal control system in Section 2.4.3.1.3.

##### Waste

The waste management system for the ALS life support suite within the
Mars Descent / Ascent Lander is identical to the technologies described
for the ISS ECLSS waste management in Section 2.4.3.1.4.

##### Water

The water system for the ALS life support suite within the Mars Descent
/ Ascent Lander is identical to the technologies provided for the ISS
ECLSS water system in Section 2.4.3.1.5.

##### Extravehicular Activity Support

The extravehicular activity support for the ALS life support system
within the Mars Descent / Ascent Lander is identical to the technologies
described for the ISS ECLSS extravehicular activity support suite in
Section 2.4.3.1.6.

##### Human Accommodations

The human accommodations for the ALS life support system within the Mars
Descent / Ascent Lander is identical to the technologies described for
the ISS ECLSS human accommodations suite in Section 2.4.3.1.7.

### Independent Exploration Mission: Surface Habitat Lander

The Surface Habitat Lander utilizes an inflatable module without
radiation protection because, if necessary, regolith and other local
resources can provide this function. Solar photovoltaic panels with
regenerative fuel cells for energy storage provide vehicle power. The
external thermal control system uses a single-phase, pumped loop to
transport thermal energy and rejects the thermal loads using radiators.

#### International Space Station Environmental Control and Life Support System Technology Baseline

The ISS ECLSS technology suite, for the purposes of this document, is
defined based on the USOS ECLSS scaled for a crew of six. See
Carrasquillo, *et al.* (1997), and Stafford, *et al.* (2001), for
details. This suite of technologies uses physicochemical technologies to
regenerate air and water, while food is supplied as prepackaged
individual entrees. Waste is generally compacted and stored without
reclaiming any products from that waste. Thermal control employs
coldplates and condensing heat exchangers to collect heat loads, a
single-phase fluid to transport heat, and radiators to reject heat.
Clothing is supplied from Earth clean and discarded once it is deemed
too dirty to wear.

##### Air

The ISS ECLSS air suite on the Surface Habitat Lander uses regenerable
carbon dioxide removal equipment based on molecular sieve technology
with a catalytic burner to remove trace combustible gases. The absorbed
carbon dioxide is dumped overboard while oxygen is supplied from other
sources. The trace gas contaminant system uses activated carbon, for
non-combustible trace gas removal, and bacteria filter assemblies, for
particulate removal. These filters are not regenerated. Oxygen is
supplied both as pressurized gas and via electrolysis of water. The
second product from electrolysis, hydrogen, is vented to the
environment. Water may enter the life support system directly, such as
from moisture within prepackaged food, or indirectly, as a human
metabolic product from the consumption of the prepackaged food. Nitrogen
is supplied from high-pressure gas stocks. A major constituent analyzer
and a fire detection and suppression system provide monitoring for air
contaminants and combustion products.

##### Food

Food is provided in individual entrees from Earth. A mix of fresh,
dehydrated, and full-water preserved, shelf-stable or frozen foods are
used. Additional food is provided for days with extravehicular
activities. Supporting technology includes freezers and food preparation
equipment.

##### Thermal

Thermal control is divided into two systems. The internal thermal
control system includes the avionic air assemblies, which provide
air-cooling for equipment, the common cabin air assemblies, which cool
and dehumidify cabin air, condensate storage, and the water flow loops
for heat transport. Coldplates and heat exchangers are assumed part of
other equipment while the external thermal control system is included in
the assessed thermal control cost factor.

##### Waste

Solid waste is compacted and stored aboard the Surface Habitat Lander.
This includes trash, fecal material, brine from the urine and water
processing, and used filters and cartridges. Waste processing is also
responsible for the toilet.

##### Water

Urine is processed by vapor compression distillation. 95% water recovery
is claimed. The brine is stored and remains with the vehicle after the
crew departs. All grey water, including hygiene water, effluent from the
vapor compression distillation, and condensate from dehumidification, is
processed through a water processor. The water processor employs two
multifiltration units, a volatile removal assembly, phase separators,
and an ion exchange bed. A process control water quality monitor
provides water quality assurance. Efficiency of recovery is high, but
many expendables, mostly filter cartridges, are needed.

##### Extravehicular Activity Support

The extravehicular mobility unit consumables include oxygen, for
metabolic consumption and suit pressurization, and water, which is
rejected to provide thermal control and consumed by the crew as drinks.
Though not consumed, water also provides the working fluid for the
internal cooling garment. This extravehicular mobility unit uses lithium
hydroxide for carbon dioxide removal. An airlock pump, a compressor,
reduces the airlock internal pressure to about 10 kPa, reducing gas
losses during airlock operations. Because airlock usage impacts the
supply of atmospheric gases, it is included here in the life-support
system baseline. However, this technology suite does not assess any
crewtime to the life support system. Rather, any associated crewtime is
assessed to other vehicle systems.

##### Human Accommodations

Clothing is launched from Earth with the Surface Habitat Lander and
stays with the vehicle at the end of the surface phase. When clothing is
deemed too dirty to wear, it is stowed with the other dirty clothing and
replaced with a clean garment from stores. This interface does not
assess any crewtime to the life support system. Rather, donning,
removing, and storing clothing uses crewtime assessed to other vehicle
systems.

#### Advanced Life Support Technology

Though similar to the ISS ECLSS approach above, the ALS technology suite
for the Surface Habitat Lander employs advanced physicochemical
technologies for air revitalization, an aqueous laundry to recycle crew
clothing, and two approaches to recover water from human waste and
trash. The water recovery system features a biological water processor,
or bioreactor, as the primary processor. As on the Mars Transit Vehicle,
a biomass production chamber again provides salad to supplement an
otherwise prepackaged food system.

##### Air

The ALS air suite within the Surface Habitat Lander uses an improved
carbon dioxide removal assembly based on molecular sieve technology, a
Sabatier carbon dioxide reduction assembly with a gas stream compressor,
and a regenerable trace contaminant control assembly. Oxygen is supplied
from electrolysis of water within an advanced oxygen generation
assembly. Adequate water is available to avoid a supply penalty for any
necessary oxygen and hydrogen. High efficiency particulate air filters
provide particulate removal. Other aspects of the ALS air suite are
identical to the ISS ECLSS technology suite for air listed in
Section 2.4.4.1.1.

##### Biomass

The ALS suite contains a small biomass production chamber, providing
salad crops as a supplement to an otherwise prepackaged food system.
Though the dietary nutrients gained from salad crops are relatively
minor, salad provides a psychological advantage unavailable in
completely a prepackaged food system. Supporting equipment for the
biomass production chamber includes a nutrient solution supply,
condensate storage, and a larger common cabin air assembly to handle the
greater humidity loading.

##### Food

The food system here is identical to the ISS ECLSS suite in
Section 2.4.4.1.2 except that the ALS suite, as noted above, supplements
the diet with fresh salad from a biomass production chamber and
substitutes an ALS freezer.

##### Thermal

The ALS suite for thermal control uses the same technologies as the ISS
ECLSS suite for thermal control described in Section 2.4.4.1.3.

##### Waste

The ALS suite for waste combines a dryer and a lyophilizer with the
technologies listed above for the ISS ECLSS. See Section 2.4.4.1.4. The
dryer reclaims water from trash while the lyophilizer abstracts moisture
from fecal material. Both dried wastes are compacted and stored
following drying, while water returns to the life support system as grey
water.

##### Water

A biological water processor and a nitrifying bioreactor provide primary
water processing for both grey water and urine. Post-treatment
technologies include reverse osmosis and air evaporation, and ion
exchange and a photocatalytic oxidizer provide polishing. As with the
ISS ECLSS, process control water quality monitor provides water quality
assurance. Recovery efficiency with this system is also high, though
compared to the ISS ECLSS the expendables are reduced.

##### Extravehicular Activity Support

The ALS suite for extravehicular activity support is identical to the
ISS ECLSS suite for extravehicular activity support. See
Section 2.4.4.1.6.

##### Human Accommodations

The ALS approach assumes an aqueous laundry. This will significantly
increase the daily grey water load, but reduce the required mass of
clothing compared to the ISS ECLSS approach. The assessed crewtime
supports laundry operations only.

### Infrastructure Costs/Equivalencies

Except as noted, infrastructure equivalencies from Drysdale and Hanford
(1999) are used as shown in Table 2.2 for each mission vehicle. Notably,
the power and cooling values for International Space Station and the
power value for the Mars Descent / Ascent Lander were not available in
the reference document, so these were computed and listed here. The
corresponding infrastructure technologies are noted above with each
mission. As discussed in Drysdale and Hanford (1999), the crew time cost
is based on the equivalent system mass for the life support system
hardware and the crew's available time. The values below result from
those computations and are listed for convenience. Because the same
infrastructure equivalencies apply to both the ISS ECLSS and ALS
technology suites, any variation in the Metric value is due only to
differences in either life support technology or life support system
architecture.

[]{#__RefHeading___Toc536595024 .anchor}Table 2.2 Advanced Mission Cost
Equivalencies

+--------------------------------+--------+--------+--------+--------+
| **Mission**                    | **V    | **     | **Co   | **M    |
|                                | olume\ | Power\ | oling\ | ission |
|                                | \      | \[     | \[k    | or     |
|                                | [kg/m^ | kg/kW~ | g/kW~t | S      |
|                                | 3^\]** | e~\]** | h~\]** | egment |
|                                |        |        |        | Dur    |
|                                |        |        |        | ation\ |
|                                |        |        |        | \      |
|                                |        |        |        | [d\]** |
+--------------------------------+--------+--------+--------+--------+
| **Orbiting Research Facility:  | 66.7   | 476.   | 323.9  | 3,650  |
| International                  |        | 0 [^7] | Error: |        |
| Space Station Update Mission** |        |        | Ref    |        |
|                                |        |        | erence |        |
|                                |        |        | source |        |
|                                |        |        | not    |        |
|                                |        |        | found  |        |
+--------------------------------+--------+--------+--------+--------+
| **Independent Exploration      |        |        |        | \~96   |
| Mission:**                     |        |        |        | 0 [^8] |
+--------------------------------+--------+--------+--------+--------+
| > Mars Transit Vehicle         | 16.1   | 83.3   | 21.1   | 360    |
+--------------------------------+--------+--------+--------+--------+
| > Mars Descent / Ascent Lander | 66.7   | 200.   | 21.1   | 30     |
|                                |        | 0 [^9] |        |        |
+--------------------------------+--------+--------+--------+--------+
| > Surface Habitat Lander       | 2.08   | 175.0  | 66.7   | 600    |
+--------------------------------+--------+--------+--------+--------+

# Advanced Life Support Research and Technology Development Metric

## Subsystem Technology Data

The tables below list overall subsystem attributes for the various
vehicles and missions considered in this Metric computation. These
classifications are consistent with ALS terminology as presented within
Stafford, *et al.* (2001).

[]{#__RefHeading___Toc536595025 .anchor}Table 3.3 Orbiting Research
Facility: International Space Station Upgrade Mission
using ISS ECLSS Technologies

  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- -----------
  **Subsystem      **Mass\     **Volume\    **Power\   **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**   \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                   \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,768       204.13       2.72       2.72         13             430           0.57          0

  Food             3,346       17.08        2.89       2.89         754            4,030         6.39          0

  Thermal          793         2.31         3.02       3.02         0              0             0.00          0

  Waste            99          0.06         0.11       0.11         60             786           0.00          0

  Water            300         1.04         0.44       0.44         20             1,175         2.18          0

  Extravehicular   143         0.31         0.05       0.05         0              23            0.00          1,949
  Activity Support                                                                                             

  Human            0           0.00         0.00       0.00         0              1,277         0.00          0
  Accommodations                                                                                               

  **Totals**       **6,449**   **224.93**   **9.23**   **9.23**     **847**        **7,721**     **9.14**      **1,949**
  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- -----------

The total life support system ESM for the International Space Station
Upgrade Mission using ISS ECLSS technologies is 122,513 kg.

[]{#__RefHeading___Toc536595026 .anchor}Table 3.4 Orbiting Research
Facility: International Space Station Upgrade Mission
using ALS Technologies

  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- -----------
  **Subsystem      **Mass\     **Volume\    **Power\   **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**   \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                   \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,617       204.40       1.57       1.57         11             139           0.22          0

  Food             3,346       17.08        1.74       1.74         754            4,030         6.39          0

  Thermal          793         2.31         3.02       3.02         0              0             0.00          0

  Waste            99          0.06         0.11       0.11         60             786           0.00          0

  Water            250         0.50         1.26       1.26         1              154           0.00          0

  Extravehicular   143         0.31         0.05       0.05         0              23            0.00          1,949
  Activity Support                                                                                             

  Human            142         0.65         0.14       0.14         119            33            0.00          0
  Accommodations                                                                                               

  **Totals**       **6,390**   **225.31**   **7.89**   **7.89**     **945**        **5,165**     **6.61**      **1,949**
  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- -----------

The total life support system ESM for the International Space Station
Upgrade Mission using ALS technologies is 92,866 kg.

[]{#__RefHeading___Toc536595027 .anchor}*Table 3.5 Independent
Exploration Mission: Mars Transit Vehicle using ISS ECLSS Technologies*

  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------
  **Subsystem      **Mass\     **Volume\    **Power\   **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**   \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                   \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,783       306.87       4.03       4.03         17             602           0.75          0

  Biomass          0           0.00         0.00       0.00         0              0             0.00          0

  Food             45          0.00         0.90       0.90         1,132          7,167         8.86          0

  Thermal          793         2.31         3.02       3.02         0              0             0.00          0

  Waste            149         0.09         0.17       0.17         90             1,179         0.00          0

  Water            401         1.43         0.61       0.61         30             1,763         3.27          0

  Extravehicular   0           0.00         0.00       0.00         0              0             0.00          0
  Activity Support                                                                                             

  Human            0           0.00         0.00       0.00         0              6,228         3.00          0
  Accommodations                                                                                               

  **Totals**       **3,171**   **310.70**   **8.73**   **8.73**     **1,269**      **16,939**    **15.88**     **0**
  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------

The total life support system ESM for the Mars Transit Vehicle in the
Independent Exploration Mission using ISS ECLSS technologies is
27,966 kg.

[]{#__RefHeading___Toc536595028 .anchor}Table 3.6 Independent
Exploration Mission: Mars Transit Vehicle using ALS Technologies

  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------
  **Subsystem      **Mass\     **Volume\    **Power\   **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**   \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                   \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,265       302.54       2.40       2.40         17             204           0.34          0

  Biomass          78          0.99         0.34       0.34         0              10            0.00          0

  Food             45          0.00         0.90       0.90         1,132          7,167         8.86          0

  Thermal          780         2.25         3.02       3.02         0              0             0.00          0

  Waste            149         0.09         0.17       0.17         90             1,179         0.00          0

  Water            236         0.65         1.54       1.54         1              24            0.00          0

  Extravehicular   0           0.00         0.00       0.00         0              0             0.00          0
  Activity Support                                                                                             

  Human            652         3.02         1.16       1.16         423            1,056         0.77          0
  Accommodations                                                                                               

  **Totals**       **3,205**   **309.54**   **9.53**   **9.53**     **1,663**      **9,640**     **9.97**      **0**
  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------

The total life support system ESM for the Mars Transit Vehicle in the
Independent Exploration Mission using ALS technologies is 20,711 kg.

[]{#__RefHeading___Toc536595029 .anchor}Table 3.7 Independent
Exploration Mission: Mars Descent / Ascent Lander
using ISS ECLSS Technologies

  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------
  **Subsystem      **Mass\     **Volume\    **Power\   **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**   \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                   \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,832       72.18        1.82       1.82         14             1,476         8.40          0

  Biomass          0           0.00         0.00       0.00         0              0             0.00          0

  Food             45          0.00         0.90       0.90         1,132          7,167         8.86          0

  Thermal          793         2.31         3.02       3.02         0              0             0.00          0

  Waste            116         0.00         0.11       0.11         90             1,175         0.00          0

  Water            1,030       4.13         0.20       0.20         0              0             0.00          0

  Extravehicular   0           0.00         0.00       0.00         0              0             0.00          43
  Activity Support                                                                                             

  Human            0           0.00         0.00       0.00         0              6,228         3.00          0
  Accommodations                                                                                               

  **Totals**       **3,816**   **78.62**    **6.05**   **6.05**     **1,236**      **16,046**    **20.26**     **43**
  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------

The total life support system ESM for the Mars Descent / Ascent Lander
in the Independent Exploration Mission using ISS ECLSS technologies is
12,721 kg.

[]{#__RefHeading___Toc536595030 .anchor}Table 3.8 Independent
Exploration Mission: Mars Descent / Ascent Lander using ALS Technologies

  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------
  **Subsystem      **Mass\     **Volume\    **Power\   **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**   \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                   \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              843         43.08        0.56       0.56         12             186           0.33          0

  Biomass          0           0.00         0.00       0.00         0              0             0.00          0

  Food             45          0.00         0.90       0.90         1,132          7,167         8.86          0

  Thermal          793         2.31         3.02       3.02         0              0             0.00          0

  Waste            116         0.00         0.11       0.11         90             1,175         0.00          0

  Water            1,030       4.13         0.20       0.20         0              0             0.00          0

  Extravehicular   0           0.00         0.00       0.00         0              0             0.00          43
  Activity Support                                                                                             

  Human            0           0.00         0.00       0.00         0              6,228         3.00          0
  Accommodations                                                                                               

  **Totals**       **2,827**   **49.52**    **4.79**   **4.79**     **1,234**      **14,756**    **12.19**     **43**
  ---------------- ----------- ------------ ---------- ------------ -------------- ------------- ------------- ----------

The total life support system ESM for the Mars Descent / Ascent Lander
in the Independent Exploration Mission using ALS technologies is
9,122 kg.

[]{#__RefHeading___Toc536595031 .anchor}Table 3.9 Independent
Exploration Mission: Surface Habitat Lander using ISS ECLSS Technologies

  ---------------- ----------- ------------ ----------- ------------ -------------- ------------- ------------- -----------
  **Subsystem      **Mass\     **Volume\    **Power\    **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**    \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                    \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,738       306.87       4.03        4.03         17             602           0.75          0

  Biomass          0           0.00         0.00        0.00         0              0             0.00          0

  Food             3,361       17.08        3.16        3.16         1,132          9,067         14.39         0

  Thermal          793         2.31         3.02        3.02         0              0             0.00          0

  Waste            149         0.09         0.17        0.17         90             1,179         0.00          0

  Water            401         1.43         0.61        0.61         30             1,763         3.27          0

  Extravehicular   85          0.14         0.01        0.01         0              0             0.00          6,676
  Activity Support                                                                                              

  Human            0           0.00         0.00        0.00         0              6,228         3.00          0
  Accommodations                                                                                                

  **Totals**       **6,572**   **327.92**   **11.00**   **11.00**    **1,269**      **18,839**    **21.41**     **6,676**
  ---------------- ----------- ------------ ----------- ------------ -------------- ------------- ------------- -----------

The total life support system ESM for the Surface Habitat Lander in the
Independent Exploration Mission using ISS ECLSS technologies is
51,961 kg.

[]{#__RefHeading___Toc536595032 .anchor}Table 3.10 Independent
Exploration Mission: Surface Habitat Lander using ALS Technologies

  ---------------- ----------- ------------ ----------- ------------ -------------- ------------- ------------- -----------
  **Subsystem      **Mass\     **Volume\    **Power\    **Cooling\   **Crew Time    **Logistics   **Logistics   **Event\
  / Interface**    \[kg\]**    \[m^3^\]**   \[kW\]**    \[kW\]**     \[CM-h/y\]**   Mass\         Volume        Mass\
                                                                                    \[kg/y\]**    \[m³/y\]**    \[kg\]**

  Air              1,410       302.70       2.75        2.75         17             211           0.34          0

  Biomass          79          0.99         0.34        0.34         0              10            0.00          0

  Food             3,361       17.08        1.65        1.65         1,132          9,067         14.39         0

  Thermal          768         2.20         3.02        3.02         0              0             0.00          0

  Waste            150         0.41         0.73        0.73         151            1,204         231.78        0

  Water            727         1.06         6.37        6.37         1              533           0.00          0

  Extravehicular   85          0.14         0.01        0.01         0              0             0.00          6,676
  Activity Support                                                                                              

  Human            498         2.30         0.48        0.48         420            1,056         0.77          0
  Accommodations                                                                                                

  **Totals**       **7,078**   **326.88**   **15.35**   **15.35**    **1,721**      **12,081**    **247.28**    **6,676**
  ---------------- ----------- ------------ ----------- ------------ -------------- ------------- ------------- -----------

The total life support system ESM for the Surface Habitat Lander in the
Independent Exploration Mission using ALS technologies is 42,377 kg.

## Advanced Life Support Research and Technology Development Metric

Metric values were calculated for each of the mission vehicles described
above. The ESM for each mission segment was estimated separately by
multiplying the time-dependent parameters by mission duration and
applying the appropriate equivalencies or cost factors. The mission
segment ESM values were summed to derive a total vehicle ESM. The
vehicle ESM values were also summed to provide an overall mission ESM.
Metrics were calculated for each vehicle and mission by dividing the ESM
for the life support system using ISS ECLSS technologies by the
corresponding ESM for the life support system using ALS technologies.
Different extravehicular activity models were used for the various
vehicles as applicable. The results are tabulated in Table 3.11.

As noted earlier, the International Space Station mission employs a
single vehicle here, thus the mission and the vehicle are equivalent.
The Mars Independent Exploration mission uses three different vehicles
to place a single crew on Mars and return them safely to Earth. The
overall mission ESM and Metric are listed on the first line, and the
individual vehicle ESM and Metric values are listed on the lines below.

[]{#__RefHeading___Toc536595033 .anchor}Table 3.11 Equivalent System
Mass and Metric Values for a Range of Missions and Technologies

+---------------------------------------+---------+---------+---------+
| > **Mission / Vehicle**               | **ISS   | **ALS   | **ALS\  |
|                                       | ECLSS   | Tec     | R&TD\   |
|                                       | Tec     | hnology | M       |
|                                       | hnology | ESM\    | etric** |
|                                       | ESM\    | \       |         |
|                                       | \       | [kg\]** |         |
|                                       | [kg\]** |         |         |
+---------------------------------------+---------+---------+---------+
| > **Orbiting Research Facility:       | **12    | **9     | *       |
| > Internat                            | 2,513** | 2,866** | *1.32** |
| ional Space Station Upgrade Mission** |         |         |         |
+---------------------------------------+---------+---------+---------+
| > **Independent Exploration           | **9     | **7     | *       |
| > Mission:**                          | 2,648** | 2,210** | *1.28** |
+---------------------------------------+---------+---------+---------+
| > Mars Transit Vehicle                | 27,966  | 20,711  | 1.35    |
+---------------------------------------+---------+---------+---------+
| > Mars Descent / Ascent Lander        | 12,721  | 9,122   | 1.39    |
+---------------------------------------+---------+---------+---------+
| > Surface Habitat Lander              | 51,961  | 42,377  | 1.23    |
+---------------------------------------+---------+---------+---------+

Table 3.11 and Figure 3.2.1 summarize calculations supporting the Fiscal
Year 2001 Advanced Life Support Research and Technology Development
Metric.

Several trends deserve some explanation. Most notably, the Metric for
the Orbiting Research Facility exceeds the Metric for the Independent
Exploration Mission. ALS technologies stress reducing expendable
components often at the expense of greater power consumption compared to
ISS ECLSS technologies. Thus, ALS technologies are more economical for
longer duration missions. Thus, the ALS technologies provide a greater
benefit for the longer duration Orbiting Research Facility than for the
shorter duration Independent Exploration Mission. Further, the Orbiting
Research Facility Upgrade is expected to fly at a later time than the
Independent Exploration Mission so the ALS technologies selected for the
former are possibly more economical than similar ALS technologies for
the Independent Exploration Mission.

Examination of Figure 3.2.1, which provides a graphical breakdown of ESM
by subsystem, reveals that food is generally the most massive subsystem
within the life support system except for extremely short duration
mission segments. As almost all food for each of these scenarios is some
form of prepackaged system, food mass varies linearly with mission
duration. Air is often the second most massive subsystem within the
overall life support system because it includes the free cabin volume
necessary to house the crew. The actual equivalent masses associated
with the air subsystem excluding the free cabin volume are significantly
less.

Some specific trends are also evident in Figure 3.2.1. For example, the
mass for human accommodations is significantly reduced within the ALS
technology suite, compared with the ISS ECLSS technology suite for those
vehicles with a laundry because the laundry recycles clothing at the
expense of increased grey water loads while the ISS ECLSS only cleans
clothing on Earth. Further, the commodity mass to support extravehicular
activities during the surface segment of an Independent Exploration
Mission is significant. Here the extravehicular activity technology is
identical for both life support technology suites, but extravehicular
activity equipment with greater regeneration will significantly reduce
this load on life support.

![](media/image1.png){width="8.994444444444444in"
height="4.655555555555556in"}

[]{#__RefHeading___Toc536595034 .anchor}Figure 3.2.1 Equivalent system
mass summary for the Fiscal Year 2001 ALS Research and Technology
Development Metric missions and technology suites.

## Metric Reporting Recommendations

The Metric can be calculated for a variety of reference missions. It
will differ for each one because ESM depends on many factors including
environment, crew size, and most notably, duration. Calculating the
Metric for a range of increasingly ambitious missions provides an
objective view of progress by the ALS Project to provide improved
technologies for a wide range of possibilities.

It is recommended that the following values of the Advanced Life Support
Research and Technology Development Metric be reported to NASA Code U
for Government Fiscal Year 2001:

> Orbiting Research Facility: 1.32\
> Independent Exploration Mission: 1.28

# Cautions and Disclaimers

Compared with earlier calculations, as detailed in Section 1.3, the
current Metric values are fairly comparable across the various missions
presented. However, several inescapable sources of variation are
uncontrollable in this type of analysis. The first is that these
estimations fail to consider contingency or redundancy and sparing in
any detail. Further, inclusion of contingency capability or redundancy
invariably increases the overall equivalent system mass of all
configurations, although this may have little significant impact on the
overall conclusions and, therefore, the implied direction, above. The
second source of uncertainty resides in the preliminary nature of the
data employed for the ALS equipment. While it is desirable that flight
equipment will be more economical than the values assumed here, it is
possible that real systems may actually be less economical due to
unforeseen difficulties during development. Thirdly, as ALS research and
technology development continues, new technologies and architectural
ideas may drastically change current ideas about providing life support
and this may produce profound savings for future human space vehicles.
Thus, these estimates should be considered as preliminary and not as
definitive, although they provide a measure of where the ALS Project is
today.

# Special Recognition of Work

The authors would like to thank many people, both within and outside of
NASA, for their thoughts and input into both what is presented above and
what has come before. Many metric formulations were considered by a
group of life support analysts and researchers, and it is due to their
excellent input that the Metric now exists in its current form.

Additionally, NASA Research Announcement contract number NAS9-98119
supported this work.

This document is available electronically from the Advanced Life Support
Project at the Lyndon B. Johnson Space Center at:

*http://advlifesupport.jsc.nasa.gov/*

# References

Behrend, A. F., Jr., *et al.* (1999) "Advanced Life Support Project
Plan," JSC 39168 (CTSD‑ADV‑348), Revision B, National Aeronautics and
Space Administration, Lyndon B. Johnson Space Center, Houston, Texas,
30 September 1999.

Carrasquillo, R. L., Reuter, J. L., and Philistine, C. L. (1997)
"Summary of Resources for the International Space Station Environmental
Control and Life Support System," SAE 972332, *27^th^ International
Conference on Environmental Systems*, *Lake Tahoe*, *Nevada*,
*July 14‑17*, *1997*, Society of Automotive Engineers, Inc., Warrendale,
Pennsylvania.

Drysdale, A. E. (2001a) "Update to the Advanced Life Support Research
and Technology Development Metric," National Aeronautics and Space
Administration, Lyndon B. Johnson Space Center, Houston, Texas,
19 February 2001.

Drysdale, A. E. (2001b) Personal communication, The Boeing Company,
Kennedy Space Center, Florida. Electronic message from 05 December 2001.

Drysdale, A. E. and Hanford, A. J. (1999a) "Advanced Life Support
Systems Modeling and Analysis Project Baseline Values and Assumptions
Document," JSC 39317 (CTSD‑ADV‑371), National Aeronautics and Space
Administration, Lyndon B. Johnson Space Center, Houston, Texas,
18 June 1999.

Drysdale, A. E., and Hanford, A. J. (1999b) "Advanced Life Support
Research and Technology Development Metric -- Baseline" JSC‑39503
(CTSD‑ADV‑384), National Aeronautics and Space Administration, Lyndon B.
Johnson Space Center, Houston, Texas, 19 November 1999.

Hanford, A. J. and Drysdale, A. E. (1999) "Advanced Life Support
Technology Research and Development Metric -- Initial Draft,"
LMSMSS‑33045, Lockheed Martin Space Mission Systems and Services,
Houston, Texas, 13 January 1999.

Hanford, A. J., and Ewert, M. K. (1996) "Advanced Active Thermal Control
Systems Architecture Study Report," NASA‑TM‑104822, National Aeronautics
and Space Administration, Lyndon B. Johnson Space Center, Houston,
Texas.

MacKnight, A. (2001) "Direct Liquid Contact ECS System for Space
Applications", Document 01‑71471, Honeywell International Inc.,
Torrance, California, May 2001. This document is proprietary.

Stafford, K. W., Jerng, L. T., Drysdale, A. E., Maxwell, S.,
Levri, J. A., Ewert, M. K., and Hanford, A. J. (2001) "Advanced Life
Support Systems Integration, Modeling, and Analysis Reference Missions
Document," JSC‑39502, Revision A, National Aeronautics and Space
Administration, Lyndon B. Johnson Space Center, Houston, Texas.

# Abbreviations and Acronyms

ALS Advanced Life Support

CM-d crewmember-day (*i.e.*, the time of one crew member for one day.)

CM-h crewmember-hour (*i.e.*, the work of one crew member for one hour.)

CTSD Crew and Thermal Systems Division at Johnson Space Center

ECLSS environmental control and life support system

ESM equivalent system mass

ISS International Space Station

kg kilogram (*i.e.*, units of mass.)

kPa kilo Paschal (*i.e.*, units of pressure.)

kW~e~ kilo Watt, electric\
(*i.e.*, units of electric power.)

kW~th~ kilo Watt, thermal\
(*i.e.*, units of heat.)

m^3^ cubic meters (*i.e.*, units of volume.)

MJ mega Joule (*i.e.*, units of energy.)

NASA National Aeronautics and Space Administration

SIMA Systems Integration, Modeling, and Analysis Project Element

USOS United States On‑Orbit Segment (of the ISS)

y year (*i.e.*, units of time.)

[^1]: The New Jersey NASA Specialized Center of Research and Training is
    comprised of Rutgers, The State University of New Jersey, and
    Stevens Institute of Technology.

[^2]: For electronic copies of these documents, please see
    *http://advlifesupport.jsc.nasa.gov/*

[^3]: For electronic copies of the NASA reference documents, please see
    *http://advlifesupport.jsc.nasa.gov/*

[^4]: A crew of six is defined here not as a policy statement or a
    forward projection for NASA, but rather to make the ISS scenario
    comparable to other exploration missions that propose six
    crewmembers.

[^5]: While the ALS Project supports current NASA missions as requested,
    most ALS technologies under development will provide technological
    solutions for missions that are not yet defined because the
    technology development cycle duration is considerably longer than
    the mission planning cycle duration. Thus, SIMA analyzes probable
    missions even if the specific rationale for a likely mission is not
    completely known.

[^6]: The units here, kilograms per crewmember per day \[kg/CM‑d\],
    denote a per person basis.

[^7]: Source: Computed from Hanford and Ewert (1996).

[^8]: The duration of the total surface element is 600 days and the
    Surface Habitat Lander is sized for the full mission. In reality,
    the crew will probably spend a few days in the Mars Descent / Ascent
    Lander both just after landing and just before liftoff. The total
    duration for this vehicle is 30 days.

[^9]: Source: Drysdale (2001b).