Space-operating Linux: An Operating System for Computer Vision on Commercial-Grade Equipment in LEO

With recent exponential advances in AI-particularly with respect to the tremendous power and efficiency accessible for data processing-there is now a countless array of applications for aerospace missions and space exploration, even in experimental CubeSats. However, with the large volume of data acquisition required for satellite missions, downlinking presents an increasingly expensive bottleneck that drastically reduces mission efficiency. Hence, there is a skyrocketing demand to perform edge computation on board the payload system, often via a graphics processing unit (GPU). Multiple edge-computing CubeSat missions set to operate in Low Earth Orbit (LEO), including the University of Georgia's Multiview Onboard Computational Imager (MOCI), house an Nvidia Jetson TX2i module to perform onboard computer vision. As is the case for many commercial off-the-shelf (COTS) devices used in CubeSats, the TX2i does not come radiation-hardened, and its most vulnerable component is its eMMC disk. Even with the option of radiation shielding, there is nevertheless a possibility of single event effects (SEEs) reaching the TX2i, calling for software-level mitigation as a final line of defense. The MOCI team and partners at Johns Hopkins University's Applied Physics Lab have developed Space Operating Linux (SOL), a minimized Yocto-based operating system with built-in redundancy designed to handle these environmental pressures. While SOL contains patches that enable real-time scheduling in Linux for time-sensitive reliability in flight, the methodologies of operating system minimization, software-based triple modular redundancy in persistent memory with associated bootloader modifications, and a RAM-based file system allow the device to rely less on its eMMC card and render it less prone to radiation-induced damage. Results from proton SEE tests on the device's chip exhibit lower expected error rates in LEO compared to stock devices. Additionally, the devices tested were less prone to permanent failure under a narrower beam than used in previous tests, confirming that peripherals including flash are the highest contributors to critical failures on the TX2i.