AIRS PFM Pulse Tube Cooler System-Level Performance

Abstract

JPL’s Atmospheric Infrared Sounder (AIRS) instrument is being built to make precision measurements of air temperature over the surface of the Earth as a function of elevation; the flight instrument is in the final stages of assembly and checkout at this time, and uses a pair of TRW pulse tube cryocoolers operating at 55 K to cool its sensitive IR focal plane.

The cryocooler development activity is a highly collaborative effort involving cooler design and fabrication at TRW, cooler characterization and qualification testing at TRW and JPL, and system-level performance characterization and instrument integration at LMIRIS. During the past few months the Engineering Model AIRS cooler has been integrated with the instrument focal plane assembly and measurements have been made on the overall thermal and operational performance of the cryosystem including vibration compatibility, AT from cooler to focal plane, and temperature control stability. At the same time the AIRS flight (PFM) coolers have undergone qualification and characterization testing at JPL prior to shipment to LMIRIS in January 1998, where they are now undergoing integration and system-level testing with the AIRS flight instrument.

This paper presents the measured system-level performance of the AIRS flight coolers including detailed thermal, vibration, and temperature control performance with the EM and flight instrument boundary conditions.