**Update to the Advanced Life Support Research and Technology
Development Metric**

*Note: A more extensive FY01 metric calculation for other current
reference mission scenarios will be posted in January 2002.*

**ALS Systems Modeling and Analysis Project**

**February 19, 2001**

The Advanced Life Support (ALS) Research and Technology Development
metric, originally reported in Drysdale (1999), has been updated and
recalculated for the Concentrated Exploration and Extended Presence
Reference Missions, both for the ALS and International Space Station
(ISS) technology options. Among the changes, a few minor errors were
identified and corrected, but most of the changes in the metric values
have been due to changes in either technology data or requirements
estimates. One change was to the infrastructure equivalency. This would
have second order effects on the metric. Others were related to the
technologies, which would have first order effects. Only the updates and
results are reported here. Please see the original report for more
details.

**Infrastructure Equivalencies.**

The volume equivalency (V~eq~) for Mars Transit was increased from 0.062
to 0.19 m3 per kg, to correspond to the change in the water thickness
estimated for radiation protection during transit. The original estimate
of 19 cm of water was taken from the undated Executive Summary
presentation of the Mars TransHab Study produced by the NASA JSC
Engineering Directorate several years ago. The updated information is
from the Dingel et al (1999), and assumes a 5.7 cm water thickness.

**ISS Technology Updates**

As ISS is developed and installed on orbit, improved data are becoming
available. However, there is still a need for a formal accounting for
ISS capability and logistics support requirements along the lines of the
paper by Carrasquillo et al, 1997. In particular, as-run data needs to
be tracked and documented. Significant updates that have been identified
include the items documented below. There are still some remaining
inadequacies in the data. In particular, the waste assessment is
probably still low, and the mass of water planned to be delivered will
include some contingency, though the magnitude cannot be identified at
this time.

The OGA mass was increased from 65 kg to 386 kg, largely to accommodate
adding a hydrogen containment dome for safety. The resupply estimate was
increased from 13 kg/y to 127 kg/y. (Cloud et al, 1999).

Water processor expendables were reduced by 30% based on estimates of
contaminant loads. (Finger et al, 1999).

Leakage was measured as being less than 0.009 kg/module/d, compared to a
spec of 0.23 kg/day. (Finger et al, 1999).

Crew time requirements were reduced to 1 crew hour/day for the STS/ISS
prepackaged food scenario, based on input from Dr Jean Hunter, Cornell
University.

Resupply water in the amount of 3330 kg was added according to the data
presented by Bagdigian (1999).

**ALS Technology Updates**

ALS updates were made, as identified below. Additional updates are
needed to document other human accommodation systems (HAS) that would
affect ALS functions, notably a dishwasher and other water-system
interfaces. The major general update was that METOX logistics support
was increased slightly. As in the last metric estimate, In-situ resource
utilization (ISRU) was not considered.

For ALS-PC (physical/chemical) technology, 25 kg for waste storage has
been added to make the data consistent with the preliminary results of
the Waste Workshop, Houston, 2000 (Verostko and Alazraki, 2001).

For ALS-BIO (biological) technology, an incinerator was added to recycle
carbon. Data from the Waste Workshop was used. (This is only
cost-effective if there is excess oxygen and the CO2 produced is
needed.)

# Results

The metric value for the two reference missions that were updated both
increased slightly as shown below.

  ------------------ -------------- -- --------- ---------- ------ --------- ---------- ------ ------
                     **ISS             **PC                        **BIO**                     
                     technology**      ALS**                                                   

  **Mission**        **ESM**           **ESM**   **ALS             **ESM**   **ALS             
                                                 metric**                    metric**          

                                                                                               

  **Concentrated**   196,223           109,011   **1.80**          853,912   0.23              

  **Mars base**      399,715           189,050   2.11              181,230   **2.21**          

                                                                                               

                                                                                               

  **Previous                                                                                   
  estimate (from                                                                               
  Drysdale 1999)**                                                                             

  **Concentrated**   227,058           141,226   1.61              783,959   0.29              

  **Mars base**      317,291           164,620   1.93              161,624   1.96              
  ------------------ -------------- -- --------- ---------- ------ --------- ---------- ------ ------

The metric value for the Concentrated Exploration Mission, based on PC
technology, increased from 1.6 to 1.8 and the metric value for the
Extended Presence Mission (i.e. Mars Base) increased from 2.0 to 2.2. It
is too early to verify this increase as a trend, but the metric value
will continue to be updated on a regular basis and results will be
reported to the ALS community when available.

**References**

Bagdigian, R. (1999). ECLSS consumables model, personal communication.

Carrasquillo, R. L., Reuter, J. L., and Philistine, C. L. (1997).
*Summary of resources for the ISS ECLSS*. SAE paper 972332.

Cloud, D., Devin, M., Schneider, S., Roy, R., Bagdigian, R. and
Erickson, R.(1999). ISS *Oxygen Generation Design Status*. ICES 99-2116

Dingell, C. W. Jr., Quintana, C., Hafermalz, D. S., and Keener, J. F.
(1999). *Updated Environmental Control System for the X-38 Crew Return
Vehicle.* ICES paper 99-1935

Drysdale, A. E., et al. (1999). Advanced Life Support Research and
Technology Development Metric -- Baseline. JSC-39503, CTSD-ADV-384,
November 19, 1999.

Finger, B. W., Supra, L. N., DallBauman L. and Pickering, K. D. (1999).
*Development and Testing of Membrane Biological Wastewater Processors*.
ICES 99-2147

Verostko, C., and Alazraki, M. (2001). Report on the Waste Workshop held
in Houston, April 2000. In work.