Thermal Assessment of OSIRIS-REx OVIRS Cryogenic Instrument During Flight System TVAC Test and in Flight



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48th International Conference on Environmental Systems


The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) Visible and Infrared Spectrometer (OVIRS) is a cryogenic instrument. At the Outbound Cruise nominal spacecraft attitude, sunlight impinges on several multilayer insulation blankets on the forward deck. It is reflected or scattered to other components on the deck. This solar illumination adds heat load to the OVIRS, and causes its detector temperature to exceed the 105K maximum operating allowable flight temperature limit by 0.8K. During the flight system thermal vacuum test, the solar simulator beam reflected or scattered from the test fixtures to the OVIRS added non-flight heat load. The detector temperature was 9K warmer than that in flight. At those temperatures, the science data was acceptable, despite its quality was not as high as that of 105K or colder.


Michael Choi, National Aeronautics and Space Administration (NASA), USA
ICES108: Thermal Control of Cryogenic Instruments and Optical Systems
The 48th International Conference on Environmental Systems was held in Albuquerque, New Mexico, USA on 08 July 2018 through 12 July 2018.


OSIRIS-REx, OVIRS, Cryogenic instrument, Parasitic heat load, Reflection or scattering of sunlight, Stray light, Flight system thermal vacuum test, Detector cool down