Design and performance of the cryogenic subsystem for the orbiting carbon observatory

The Space Dynamics Laboratory, under contract to Hamilton Sundstrand and NASA's Jet Propulsion Laboratory, designed, manufactured, and tested the cryogenic subsystem for the three focal plane assemblies of the Orbiting Carbon Observatory instrument. The Orbiting Carbon Observatory is a NASA-sponsored Earth System Science Pathfinder program. During its two-year lifetime, the OCO mission will collect space-based measurements of carbon dioxide. OCO's three focal plane assemblies are mounted to the cryogenic subsystem, which thermally isolate the focal planes from the instrument and provide a low-impedance thermal interface to the cryocooler. The hardware meets stringent requirements for stability, temperature, heat flow, contamination, mass, and volume. This paper describes design and performance characteristics, and reports test results of the cryogenic subsystem.