Lockheed Martin's Advanced Technology Center (LM-ATC) has delivered a flight model cryocooler system for NASA's Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS). This system was developed as a New Millennium Program to demonstrate technologies, which enable revolutionary science. One of the new technologies for future generation remote sensors is the two-stage pulse tube cryocooler. This cooler is presently being integrated with the spectrometer at Space Dynamics Laboratory (SDL) in preparation for system tests.
In addition, a similar two-stage Engineering Model cryocooler was developed for a different program. LM-ATC's pulse tube cryocoolers employ a unique staging arrangement, resulting in high power efficiency, compact and efficient packaging, and interfacing and excellent reliability. They are robust and simple, consisting of a two-stage coldhead with no moving parts, driven by a moving magnet compressor and powered by a high-efficiency electronic controller that includes ripple suppression and vibration cancellation. The design is a "split" system in which the compressor and cold head are separated by a transfer line. The approach allows on orbit adjustment of the relative cooling loads and temperatures of the two stages.
These two stage cryocoolers are developed for simultaneous cooling of the focal plane and the optics at two different temperatures. The electronic controller provides precise temperature control of the focal plane and also provides a vibration reduction loop. The total mass of these systems, including electronics, is approximately 9 Kg.
This paper presents the performance and characteristics of these systems.