A test facility has been developed for in-situ measurement of the thermo-optical and electrical effects of molecular contamination deposited on sensitive spacecraft surfaces. The Contamination Effects Test Facility (CETF) consists of three separate vacuum chambers interconnected by gate valves through which test sample surfaces may be moved as needed by various vacuum manipulators. Deposition of contamination occurs in one chamber, where surface electrical properties can also be measured. In the second chamber, a wide range of thermo-optical properties can be measured by use of a unique ellipsoidal-mirror reflectometer. The third chamber maintains a vacuum environment around the test sample while the chamber is transported to facilities for solar ultraviolet (UV), electron, and proton irradiation of the sample at orbital intensities. By keeping atmosphere away from the contaminated surface at all times during the effects measurement and irradiation stages, the CETF provides a more realistic space simulation that avoids the possible effects of oxygen and water on the thermo-optical or electrical properties of the contaminant deposits. For testing of the volatile species produced by rocket propulsion systems, which are condensible only at cryogenic temperatures, continual vacuum capability precludes rapid icing due to atmospheric water vapor.

Date Published: 1 January 1987
PDF: 11 pages
Proc. SPIE 0777, Optical Systems Contamination: Effects, Measurement, Control, (1 January 1987); doi: 10.1117/12.967079

Published in SPIE Proceedings Vol. 0777:
Optical Systems Contamination: Effects, Measurement, Control
A. Peter M. Glassford, Editor(s)