The design and the performance of the cryogenic limb array spectrometer (CLAES) aboard the NASA Upper Atmosphere Research Satellite are discussed. CLAES measures altitude profiles of temperature, pressure, O3, H2O, CH4, N2O, NO, NO2, N2O5, HNO3, ClONO2, HCl, CFC 11, CFC 12, and aerosol absorption coefficients for atmospheric layer between 10 and 60 km. Examples of atmospheric spectral emission profiles for a number of constituents are presented as well as responsivity and noise parameters.

The cryogenic limb array etalon spectrometer (CLAES) on UARS: Experiment description and performance

This paper documents the development of the SPIRIT III telescope from the design through its test activities. The SPIRIT III Instrument is the primary infrared instrument on the Mid-Course Space Experiment (MSX). The telescope is an all reflective optical system consisting of twelve mirrors. The nominal collecting apertures is 14 inches. It was designed and built to integrate with a multicolor radiometer and a Michelson interferometer built by the Space Dynamics Laboratory at Utah State University. Key performance features are discussed, and measured test data is presented. The structural/thermal trade-off issues of a satellite-based cryogenic instrument are presented along with a review of the test techniques and test equipment.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

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Development of the SPIRIT III telescope: from design through test

Reflective optical systems have been developed at SSG, Inc. to satisfy a wide range of spaceborne and tactical flight applications. The key mission requirements and performance goals which dictate reflective optical designs include wide spectral coverage for multi-wavelength operation; high straylight rejection; proper exit pupil location to permit a high degree of coldshielding for improved sensitivity; cryogenic operation; and inherent athermalization under harsh flight environments. Eight telescopes that have been designed and fabricated are reviewed. These telescopes have been designed and flown on various launch platforms including rockets, the space shuttle, satellites, and aircraft. This paper will also review the SPIRIT III reflective telescope being developed for the Midcourse Space Experiment for a satellite application. The selection process of the above designs will be reviewed based on mission and sensor requirements.

Design And Fabrication Of Reflective Optical Systems For Space And Tactical Flight Applications

The cleanliness requirements of the Cryogenic Limb Array Etalon Spectrometer (CLAES) are described and the control program is assessed with particular emphasis given to the effects of particulate interference. The use of the CLAES is reviewed, and off-axis scatter from the earth is identified as an important noise source. Since the CLAES altitude of interest causes a low-altitude detection of 0.2 deg above the earth's surface, straylight controls are important in the development of the instrument. The development of off-axis rejection and the particulate-cleanliness level are evaluated in terms of those required for a certain BRDF. The control plan is described, and procedures are outlined including cleaning methods and facilities. The modeling predictions and procedural controls are found to effectively satisfy requirements for low scatter levels and out-of-field view-rejection by maximizing straylight control and allowing a margin against noise-equivalent radiance.

Contamination control of the Cryogenic Limb Array Etalon Spectrometer

This paper documents the engineering design, fabrication, assembly, and test activities at SSG, Inc. that produced the CLAES Telescope Assembly. It includes a brief outline of the optical design as given by Lockheed Palo Alto Research Laboratory. Several major design and assembly areas are reviewed to highlight the driving design and performance constraints of the telescope. These include the dip-brazing process utilized on the structural sub-assemblies, and the fabrication process for the three flight mirrors. The telescope system alignment techniques and processes are reviewed, and include an outline of the verification test plan which covers the optical, structural, and cryogenic test procedures for the telescope. Test data is given and compared to the performance specifications. The last topic is a brief discussion of the lessons-learned from this telescope, and the follow-on diagnostic tests that are currently in process at SSG, Inc.

Bruce Steakley

Papers

Design, Fabrication, Assembly And Test Methods Utilized On The Cryogenic Limb Array Etalon Spectrometer (CLAES) Telescope