Characterizing COTS IMU Performance in High Vacuum

Using CubeSat/nanosat missions as technology demonstrators requires minimizing sources of potential failures from standard spacecraft bus components. Attitude determination and control is a critical component of most nanosat architectures, with angular rates and pointing of the craft being essential to telecommunications and often for the payload instruments as well. The lack of compact star sensors forces a reliance on Inertial Measurement Units (IMUs) for attitude determination and control. This research evaluated the UM7-LT COTS IMU performance by testing in low and high vacuum (milli-Torr and micro-Torr pressure) conditions. This device was not rated by manufacturers for usage in space environment. The performances of the accelerometers, gyroscopes, and magnetometers are characterized in these conditions, evaluating parameters of bias due to thermal effects. Additionally, Raspberry Pi 0W temperature data is evaluated in low and high vacuum. The analysis of thermal data at different vacuum levels using simple lumped capacitance method, allows to estimate the effective heat transfer coefficient and design the on-orbit duty-cycle to avoid overheating