Progressive Radiation Hardness Assurance for COTS SmallSat Avionics Beyond LEO

As European SmallSat missions increasingly target higher orbits such as medium Earth orbit (MEO) and geostationary orbit (GEO), radiation hardness assurance (RHA) requires substantially greater attention than in low Earth orbit (LEO) applications due to the more severe radiation environments. SmallSat avionics architectures frequently rely on commercial off-the-shelf (COTS) components, for which radiation mitigation is implemented primarily at system level rather than through fully radiation-hardened parts. This work synthesizes experience from the application of RHA to COTS-based SmallSat avionics, emphasizing progressive validation for early risk identification across component and system levels.

Insights from radiation test campaigns conducted at multiple facilities are discussed, covering heavy-ion, proton, and gamma irradiation. These activities revealed design-relevant sensitivities across multiple subsystems and informed subsequent mitigation and architectural considerations. Performed early in the design cycle, the screening approach supported informed design trade-offs prior to committing to costly qualification campaigns.

Beyond component-level testing, a hardware-in-the-loop laboratory platform supports system-level fault injection and fault propagation analysis during ongoing design iterations. This enables early evaluation of mitigation approaches under representative operational conditions prior to flight hardware commitment.