Cryocooler Electromagnetic Compatibility

Abstract

The Jet Propulsion Laboratory, under joint Ballistic Missile and Defense Organization (BMDO)/Air Force and NASA/Eos Atmospheric Infrared Sounder (AIRS) sponsorship, is conducting extensive space cryocooler characterization to provide a reliable and accurate data base on cryocooler performance for use by the space community. As the number of cryocoolers taken through the characterization program increases, it is possible to synthesize the test results to allow performance trends and similarities and differences among the coolers to be observed.

One of the important characteristics of the space cryocooler is the cryocooler’s electromagnetic compatibility with the cooled imaging detector, payload instruments, and host spacecraft. Quantification of the cryocooler radiated magnetic and electric field emissions and the conducted power line emissions back onto the spacecraft power bus is extremely important. Data on these attributes is required to determine the degree of shielding or filtering required to insure that the cryocooler electromagnetic signature does not cause malfunction or performance degradation to anything within the spacecraft.

This paper presents typical EMI test results drawn from measurements made on a variety of representative space cryocoolers. The data are presented in comparison with various MIL-STD-461C requirements as a measure of the suitability of the coolers for application aboard sensitive spacecraft.