Home > Proceedings of the 14th International Cryocooler Conference > Durand

Abstract

The Northrop Grumman Space Technology (NGST) Advanced Cryocooler Technology Development Program (ACTDP) cooler features a 5-6 K Joule-Thomson (J-T) cooler precooled by a three-stage Pulse Tube (PT) cryocooler to provide remote cooling in the range of 60 to 70 mW at temperatures ranging from 5 to 6 Kelvin. This cooler was developed under contract with the Jet Propulsion Laboratory to enable active cooling of large space telescopes, with particular focus on the Mid Infrared Instrument (MIRI) of the James Webb Space Telescope (JWST). This paper describes recent progress in the design and performance of the NGST ACTDP cooler applied to the specific requirements of the MIRI application. End-to-end performance of the MIRI Cooler Subsystem is projected by combining separate performance measurements of the J-T cooler and the PT precooler using flight like hardware. Significant improvement in the efficiency of NGST's low temperature three-stage pulse tube cryocooler enables our design to meet the nominal steady state MIRI cooling requirements of 65 mW at < 6.2 K and 77 mW total parasitic load on the 18 Kelvin refrigerant lines for a total bus power of 256 W, against the requirement of 360 W maximum. This paper also addresses the extent to which this design can accommodate changes in the heat load requirements.