For an onboard switching, serious decline in the reliability is induced by the harsh space radiation environment. In this paper, a 3-stage Clos-network supporting fully distributed scheduling and a Fully Distributed Fault Tolerant(FDFT) scheduling algorithm are proposed to improve fault-tolerant ability of an onboard switching. Combined input and output queued architecture is employed in the central and output stages of the proposed Clos-network to support fully distributed scheduling in both the network an...