Evaluating Clean Room Products for Aerospace Applications

Abstract

Large aerospace assemblies, such as the Optical Telescope Assembly (OTA) for the Hubble Space Telescope built by Perkin-Elmer, present a unique challenge to anyone evaluating clean room products for use on these programs. Very stringent requirements for molecular and particulate contamination control are often not taken into account by the manufacturers of clean room products. The realization that extractables of plastic products pose a serious contamination threat to optical assemblies is gaining wider recognition, but even so-called "solvent compatible" products may not meet the requirements of all sensitive payloads. A process is described for evaluating, selecting and monitoring products in the most widespread use—garments, gloves, and wipers. Notwithstanding well-trained, conscientious personnel, items such as garments, gloves and wipers can be used in such a variety of ways that their tolerance for misuse without untoward consequences must be considered. The final selection process must therefore consider both compatibility and durability and, as was discovered, a unique choice is not always possible for all applications.