Experience with an imaging infrared radiometer in a simulated space environment

Abstract

A commercially available imaging infrared radiometer, an Inframetrics 760 system, was subjected to simulated space and Martian environments in JPL's 25 ft and 10 ft space simulators for a total of 108 hours. Initially, the IR camera was integrated with the Satellite Test Assistant Robot (STAR) system which demonstrated successful operation in late 1994. During this initial demonstration, the IR camera experienced 24 hours of a hard vacuum with simulated space temperatures between minus 190 degrees Celsius to plus 25 degrees Celsius. Subsequently, the IR camera was subjected to 12 hours of a simulated space and 72 hours of a simulated Martian environment during the Mars Rover test. Equipped only with thermostatically controlled heaters to prevent undercooling, the IR camera operated continuously during these periods and provided numerous images of the simulator interior, a reference target, and the Mars Rover. The reference target consisted of nine samples of different materials used in typical aerospace thermal designs. The emittance range covered 0.02 to 0.90. The target temperature range was varied from minus 80 degrees Celsius to 55 degrees Celsius. The IR camera was reliable and provided quality images throughout this range but measurement accuracy was a strong function of target temperature and emittance. Best results for high emittance targets were within 12 degrees Celsius at minus 80 degrees Celsius to within 1 degree Celsius at plus 55 degrees Celsius.