SmallSats use predominantly commercial electronics and specialized custom miniaturized subsystems out of the primary need to fit volumetric constraints and meet tough power efficiency targets. Using commercial electronics poses a major challenge as the radiation performance of commercial electronics is generally unknown and long-term reliability at elevated temperatures is not guaranteed. To make matters worse, compressed development schedules and customarily low budgets makes a thorough analysis of each part and circuit impossible. Yet, the combination of educated part selection approaches, part and circuit level mitigations, architectural considerations and operational changes can achieve a high level of reliability even if the individual components don’t meet the typical space grade pedigree. Such mitigation approaches are only cost effective if employed early in the concept and design phase before even minor design changes have the potential to trigger system wide redesigns. For this reason, JPL has developed design and part selection guidelines that reduce the overall part test program.