NASA-LLIS-0778

Abstract

<strong>Practice:</strong> <br>Each flight project provides requirements for defining and implementing a contamination control program applicable to the hardware for the program. The program consists first in defining the specific cleanliness requirements and setting forth the approaches to meeting them in a Contamination Control Plan. One significant part of the Contamination Control Plan is a comprehensive Materials and Process Program beginning at the design stage of the hardware. This program helps ensure the safety and success of the mission by the appropriate selection, processing, inspection, and testing of the materials employed to meet the operational requirements for the application. The following potential problem areas are considered when selecting materials: radiation effects, thermal cycling, stress corrosion cracking, galvanic corrosion, hydrogen embrittlement, lubrication, contamination of cooled surfaces, composite materials, atomic oxygen, useful life, vacuum outgassing, toxic offgassing, flammability, and fracture toughness. The practice described here for the collection and compilation of vacuum outgassing data is used in conjunction with a number of other processes in the selection of materials. Vacuum outgassing tests are conducted on materials intended for space flight use, and a compilation of outgassing data, Reference 1, is maintained and constantly updated as new materials are tested. This includes materials used in the manufacture of parts intended for space applications.