Measurement of surface reactions in the space environment

The Atomic Oxygen Measurement Spacecraft, ATOMS, and a suite of associated instruments, designed to measure the performance of improved atomic-oxygen-resistant materials and coatings in orbit and to telemeter the resulting data and video images to earth at intervals during a one-year mission, have been described in a definition study sponsored by the Langley Research Center under NASA's In-Space Technology Experiments Program. The objective of the program is to work toward an improvement of base materials and surface coatings which will resist the serious degradation experienced by the external surfaces of LEO spacecraft as a result of the ablative effects of atmospheric oxygen, possibly catalyzed by solar UV radiation. This miniature orbiting laboratory includes a radio-frequency mass spectrometer, a set of osmium actinometers, and a scanning optical microscope. The design of these instruments and their use in the overall experiment are discussed.