Shuttle/Payload Contamination Evaluation program (SPACE computer program): Further model refinement and pre-mission contamination assessment

摘要

This report summarizes the results of the Shuttle Payload Contamination Evaluation (SPACE) Program Further Model Development and Refinement Program conducted for JSC under contract NAS9-15826. The SPACE computer program was developed to provide the user with a flexible and consistent analytical tool with which to predict the external self-induced molecular contaminant environment of a spacecraft during its on-orbit operations. The SPACE computer program mathematically synthesizes the induced environment for major contaminant sources of the Shuttle Orbiter. It predicts direct flux surface deposition, return flux on surfaces with up to 2(pi) steradian fields-of-view and molecular column densities for any modeled line-of-sight. From its inception under NASA Contract NAS8-30452 to its delivery to JSC under the NAS9-14767 contract and updated under contract NAS9-15826, the primary goal of the SPACE computer program was to evaluate the molecular environments induced by the Space Transportation System (STS) Shuttle Orbiter and key Spacelab configurations for compliance with program contamination control requirements. These requirements have in part dictated the format and present capabilities of the SPACE program. As the STS Program approached its operational phase, an important need existed to be able to evaluate the external self-induced molecular contaminant environment on an operational basis for a number of Shuttle Orbiter missions -- in particular, the Orbital Flight Test (OFT) series that involves the Induced Environment Contamination Monitor (IECM). In order to meet these needs, the JSC SPACE Program required further improvements, utility, and flexibility in its code. The end product of these model improvement activities is the second version of the SPACE Program denoted as SPACE 2. The purpose of the activity reported herein was to complete further identified improvements and create greater utility and flexibility in the SPACE Program code delivered to NASA JSC under previous contract and to conduct pre-mission contamination analyses of the early OFT/IECM Shuttle missions.