A novel instrument to measure the optical properties of VUV materials in space

Abstract

The performance of materials used in the space environment continues to be a limiting technology for space missions. The Optical Properties Monitor (OPM) experiment is designed to study the effects of the space environment on optical, thermal control, and other materials. Material samples will be exposed to the space environment and the effects of this exposure measured in-situ with three onboard optical instruments. The OPM is scheduled to be carried aboard the NASA Space Shuttle to the Russian Mir Space Station where it will be deployed on the Mir exterior for approximately nine months. The three instruments onboard the OPM are the Integrating Sphere Reflectometer, the Total Integrated Scatter (TIS) instrument, and the Vacuum Ultra Violet (VUV) spectrometer. While there have been many missions aimed at studying study solar absorptance, there have been fewer missions to study total integrated scatter and fewer still to study UV properties of materials. 1 The VUV experiment is ground-breaki ng science. This paper describes the VUV spectrometer hi terms of the optical and mechanical design, instrument operation and presents experimental results. A novel detection system is also presented which uses a sodiumsalycilate-doped coating over a light pipe.