Development and fabrication of a custom vacuum bakeout system for the Far-UV CubeSat SPRITE

The Supernova remnants Proxies for reIonization Testbed Experiment (SPRITE) CubeSat is designed to map shock emission in supernova remnants and determine the escape fraction of hydrogen ionizing radiation in star-forming galaxies. As a secondary objective, SPRITE will track the stability of new advanced ‘eLiF’ mirror coatings and Micro Channel Plate (MCP) detector over the mission’s lifetime as they are sensitive to molecular contamination, especially from organic compounds, silicones, as well as exposure to water vapor. As a result, a thorough cleaning procedure was created to prepare the components for flight assembly. This system contains two ovens that are able to operate independently of one another. One operates at approximately 3 torr with a nitrogen purge, while the other operates at 10-6 torr and funnels contaminants into a liquid nitrogen cold trap. Typically, parts are baked in the low-vacuum oven for three to four days before being transferred to the high-vacuum oven to bake for an additional three to four days where the liquid nitrogen and Residual Gas Analyzer (RGA) measurements are checked daily. This process allows parts to outgas in a controlled environment, rather than exposing the optics to molecular contaminants during integration and while on-orbit (throughout the mission lifetime). This paper will detail the fabrication of the custom vacuum bakeout system and the associated procedures used to bake components at high vacuum. This vacuum bakeout setup is inexpensive and sufficient to meet the contamination control needs of sensitive missions like SPRITE, within the limited budgets of CubeSat and SmallSat missions.