ABSTRACT
This paper deals specifically with the particulate contaminants found on Long Duration Exposure Facility (LDEF) and the methods used to characterize them. It illustrates the effects of low earth orbit (LEO) exposure, vacuum, solar ultraviolet light and atomic oxygen, on particulate contaminants. An interpretation of the sources of contamination found on LDEF is provided along with the implications of the effectiveness of contamination control methods used from assembly, through launch, orbit, recovery, and disassembly. An interesting particle population seen on LDEF was that created by micrometeorite or space debris impact. In LEO, ultraviolet light, atomic oxygen erosion, and deposition of molecular films all result in a shadow effect. Cross-contamination from the Shuttle Bay surfaces to the Payload in the Bay has been a concern throughout the life of the Shuttle concept. Light microscopy provides information about particles on surfaces that is not available using any other analytical technique.
