It has long been known that optical surfaces aboard spacecraft and research rockets can suffer irreversible degradation due to various forms of contamination present in the spacecraft environment. Sources of contamination include: outgassing and subsequent deposition of foreign materials (hydrocarbons, silicones, etc.), bombardment by reaction by-products of thruster firings (including potentially reactive chemical etching species), liquid, gaseous and particulate venting emissions and the residual contaminants from ground processing and handling. While detrimental to any experiment employing optical surfaces, experiments operating in the vacuum ultraviolet (VUV) and experiments employing cooled optical surfaces are generally most seriously affected. It is also possible that VUV reflectivities and transmittances of optical components in space flight and space station experiments may go through a condition of temporary degradation in the course of a mission without being noticed by a postflight calibration resulting in erroneous data. In response to this problem, a self-contained, space qualifiable optical contamination monitor has been developed to provide in-flight and/or real time monitoring of VUV reflectivity and transmittance. Time lining measurement results with other spacecraft events will permit, for the first time, the ability to evaluate the direct effects of various spacecraft operations on critical optical surfaces.