Space Station Freedom contamination requirements and predictions

Space Station Freedom (SSF) requirements for the induced external gaseous and particulate environment have been defined. They include the Assembly Complete (AC) and the Permanently Manned Capability (PMC) phases which were established since the original configuration was developed. Requirements for both SSF configurations are discussed. Preliminary assessments of the impacts on SSF design and operation indicate that these requirements are both realistic and acceptable to the users with attached payloads.