ISS ECLS System Analysis Software Tools - An Overview and Assessment 2002-01-2343
There have been many software programs that have provided simulations for the performance and operation of the Environmental Control and Life Support Subsystems (ECLSS) in the International Space Station (ISS) and in the Space Shuttle. These programs have been applied for purposes in system analysis, flight analysis, and ECLSS studies. Flight and system analysis tasks are deemed important. Therefore, more manpower and resources added for such work is considered beneficial.
System analysis covers design and trouble-shooting, the validation of Flight Rules, and the contingency analysis. During the engineering design phase, ECLSS modelers predict the performance and interaction of units in a process train. Simulation results can be useful in estimating equipment sizes and costs. This article has also used two examples to illustrate that many Flight Rules need to be validated using properly selected integrated programs. In addition, contingency analysis using computerized tools is suggested for current ISS ECLS operations.
Flight analysis is normally performed during periods of pre-flight, real-time, and post-flight. The IPS RUPSM ECLSS program has been recommended after updating equipment data and validation of several subroutines have been completed. ARPCS2AT2 program has been applied successfully to two ISS missions. An ISS integrated SINDAFLUINT model has produced reports in many pre-flight and post-flight analysis in the last two years.
Many standing-alone models have been identified in this article. These models that simulated single equipment or subsystems are: LIOH, 4BMS, OGA, WRA, Vozdukh, etc. The Carbon Dioxide Removal Assembly (CDRA) has been modeled by at NASA JSC in recent years, and is now integrated with ASPEN. There is a current effort to incorporate updated CDRA and Vozdukh subroutines into ARPCS2AT2_STATION.
Evaluation of current tools such as ISS integrated SINDAFLUINT program is included in this article also. Two emerging integrated technologies, HYSYS-CFX and ASPEN-FLUENT are considered second-generation programs, which have potentials in simultaneous simulation of ARS subsystem performance and the local air properties in the spacecraft cabins.