Orbital operation of Cryogenic Limb Array Etalon Spectrometer (CLAES) cryostat

Abstract

The Cryogenic Limb Array Etalon Spectrometer (CLAES) is one of nine instruments aboard the Upper Atmospheric Research Satellite (UARS). UARS was developed by the NASA Goddard Space Flight Center for the purpose of understanding the physics of the upper atmosphere. In support of this mission, the CLAES instrument was designed to provide the detailed spectroscopic measurements of trace species and atmospheric constituents that are critical to our understanding into the photochemistry of the upper atmosphere. UARS was launched into low earth orbit on 12 September 1991 on STS-48. Three days later, the UARS was deployed from the cargo bay and after several days of (satellite) outgassing, the CLAES aperture door was opened. The instrument remained operational for over 19.8 months before the open-cycle cryogenic cooler was depleted. The CLAES instrument drew upon the synergistic talents of the Lockheed Palo Alto Research Laboratory in that the principle investigator, as well as the sensor, electronics and cryostat design, development and testing team were all members of the research laboratory. The significant scientific contributions derived from the CLAES instrument and the sensor design have been well documented. This paper discusses the design, test and orbital performance of the dual stage solid neon/CO 2 cryostat used to cool the sensor.