The Origins Space Telescope Cryo-Thermal Architecture

The Origins Space Telescope (OST) is studied as a future Mid- and Far-Infrared flagship-class observatory. OST will cover the wavelength range from 6 to 600 microns. To reach the sky background for 200-micron wavelengths temperatures of 4 degrees Kelvin or lower are required. To achieve this low temperature active cooling is required, along with passive shielding and passive radiation to deep space. Currently two concepts are being studied: Concept 1 with a 9-meter-diameter primary and a suite of 5 extremely capable instruments providing both imaging and spectroscopy over the entire wavelength range. Concept 2 is a more modest sized telescope with a collecting area equivalent to a 5-meter primary, fewer deployments and 3 or 4 instruments also covering the entire wavelength range for imaging and spectroscopy, although with somewhat reduced spectroscopic resolution, and somewhat slower mapping speed. This paper will describe OST Concept 2's cryogenic thermal architecture and thermal model results.