Star-Planet Activity Research CubeSat (SPARCS) instrument vacuum testing setup

The Star-Planet Activity Research CubeSat (SPARCS) is a small space telescope tasked with monitoring sunspots and flares of M-type stars in near ultra-violet (NUV) and far-ultraviolet (FUV) wavelengths. The SPARCS instrument is approaching its critical design review (CDR), and the team is moving forward with assembly integration and test (AI&T) plans for the payload and spacecraft. This paper focuses on the SPARCS thermal vacuum (TVAC) testing facility and thermal testing plan for the payload. The SPARCS TVAC testing chamber has been developed at Arizona State University (ASU) to provide a clean and relevant thermal environment for testing CubeSats and their payloads. The chamber can perform long-duration bakeouts at +80°C for cleaning and monitoring volatile and condensable contaminants with a thermal quartz crystal microbalance (TQCM) and a residual gas analyzer (RGA). These capabilities allow the SPARCS team to control and monitor the cleanliness of the test environment. An FUV monochromator is mounted to the side of the chamber, providing a calibrated light source to test and calibrate the payload. The SPARCS payload will be the first instrument tested in this chamber and demonstrate the capabilities of the SPARCS TVAC Test Facility. The team will verify the payload’s thermal capabilities, such as heating critical surfaces to expel contaminants and cooling the detectors for imaging. The thermal test plan details thermal cycling, hot/cold dwells, thermal balance, and instrument operations through the test. The SPARCS payload TVAC test aims to verify various performance requirements before integration with the spacecraft.