STERILIZATION REQUIREMENTS FOR SPACE EXPLORATION1

Abstract

Summary Planetary landing space hardware is required to be sterilized. The probability of obtaining sterile space hardware is enhanced considerably when the level of microbial contamination of the hardware is kept very low prior to terminal sterilization. Such control requires constant and efficient monitoring of the hardware and the intramural environments where flight hardware is assembled, tested, and encapsulated before terminal sterilization. This study demonstrates that the levels and types of microbial contaminants recovered from space hardware, or from test surfaces exposed within assembly areas, depend upon the degree of environmental and personnel control. Operating personnel was the chief source of contamination. However, the intramural environment may become a reservoir of contamination, especially when environmental control measures are inadequate. It appears that one of the best means for maintaining microbial contamination at a low level is by use of vertical laminar flow clean rooms.