NASA Space Cryocooler Programs—An Overview

Abstract

Mechanical cryocoolers represent a significant enabling technology for NASA's Earth and Space Science missions. An overview is presented of ongoing cryocooler activities within NASA in support of current flight projects, near-term flight instruments, and long-term technology development. NASA programs in Earth and space science observe a wide range of phenomena, from crop dynamics to stellar birth. Many of the instruments require cryogenic refrigeration to improve dynamic range, extend wavelength coverage, and enable the use of advanced detectors. Although, the largest utilization of coolers over the last decade has been for instruments operating at medium to high cryogenic temperatures (55 to 150 K), reflecting the relative maturity of the technology at these temperatures, important new developments are now focusing at the lower temperature range from 4 to 20 K in support of studies of the origin of the universe and the search for planets around distant stars. NASA's development of a 20K cryocooler for the European Planck spacecraft and its new Advanced Cryocooler Technology Development Program (ACTDP) for 6-18 K coolers are examples of the thrust to provide low temperature cooling for this class of missions. COOLERS ON NEAR-TERM EARTH AND SPACE SCIENCE MISSIONSIn spring 2002 three new cryocooler systems were launched into space to support NASA missions. Two of the three were based at least partially on the Oxford cooler technology that first flew on the Improved Stratospheric and Mesospheric Sounder (ISAMS) instrument in 1991; this type of cooler has demonstrated multi-year lifetime in orbit, and has been adopted by many long-life instruments to enable new and improved science. The third cooler, the NICMOS cooler, was the first space application of a long-life turbo-Brayton cooler.These recently launched coolers, which are reviewed below, have each now achieved over a year of successful operation in space, adding to the growing number of long-life space coolers enabling the acquisition of important new space-science data. These recent applications build upon the coolers of earlier NASA missions, such as those on the MOPITT, ASTER and Hyperion instruments that have achieved over two years of space operation at this point. 2 Additional coolers, such as the Northrup Grumman (TRW) pulse tube coolers on the TES instrument and the Ball Aerospace Stirling cooler on the HIRDLS instrument, are in the queue for launch aboard NASA missions in early 2004 and are also described below. RHESSI Gamma-Ray SpectrometerLaunched in February 2002, the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) uses an array of nine large germanium gamma-ray detectors to observe solar flares from 3 keV to 25 GeV. The detector

Line emission mapper microcalorimeter spectrometer

“…The LMS cryocooler designed by Lockheed Martin is based on another cryocooler that was developed as part of advanced cryocooler technology development program (ACTDP). 69 The ACTDP cryocooler has since been tested and qualified for a Balloon flight 70 by ASTHROS, 71 which will be launched in 2023. Table 6 provides a summary of the expected cryocooler heat loads from thermal modeling of the LMS design, and the power needed to operate this cryocooler is 626 W. Because the CADR heat load already incorporates 100% cooling power margin at 40 mK and 50% at 350 mK, there is no need to double-count the margin with additional margin specifically at the cryocooler level from the CADR.…”

“…Cooling is needed at 4.0 K primarily to remove the heat generated by the CADR and the FPA and also to remove conducted heat loads from the signal-chain harness and structural support of the whole 4.0 K core as well as some other minor headload sources. The LMS cryocooler designed by Lockheed Martin is based on another cryocooler that was developed as part of advanced cryocooler technology development program (ACTDP) 69 . The ACTDP cryocooler has since been tested and qualified for a Balloon flight 70 by ASTHROS, 71 which will be launched in 2023.…”

A Review on Advancements and Characteristics of Cryogenic Propulsion Rocket Engine

“…The passive insulation systems that meet these requirements includes multi-layer insulations and active heat removal systems such as Cryocoolers, Thermodynamic Venting System (TVS) can manage and reduce the fluid temperature and heat leaks respectively 74) . Since the early space programs (which began in the 1950s) and after the development of 80K Stirling long life coolers, used in the Improved Stratospheric and Mesospheric Sounder (ISAMS) and Along-Track Scanning Radiometer (ATSR-1) instruments 75,76) , countless experiments have been performed to come up with a feasible state of the art technique. However, maintaining the temperature of the cryo-fuels as low as possible while still holding the Zero Boil Off (Zero Boil Off) point was extremely difficult.…”

Cooling large space telescopes to 4 kelvin

“…To reach temperatures below 4 K, the working fluid will be changed from 4 He to 3 He, which has a lower critical temperature. The lower the operating temperature, the worse the thermodynamic efficiency of these cryocoolers.…”