The NANOobc on-board computer represents the newcomer in the emerging space market. Its fault tolerance by design provides remarkable reliability and robustness against SEE. Fault tolerance is assured by redundancy on the component level and their flight heritage, latch-up protection by constant current monitoring and several mitigation techniques. The NANOobc is fully compliant with the small foot-print PicoSkyFT™ soft-core processor, which furthermore increases operational reliability and delivers nearly 1 MIPS / MHz. NANOobc features a redundant mass storage and sufficient capacity of non-volatile and volatile program and data memories to assure functionality for the most demanding space applications.