In-orbit experiment on the fault-tolerant space computer aboard the satellite Hiten

This paper presents field data from the Hiten onboard computer (OBC) which was launched on January 24 1990, and completed its mission on April 10 1993. The components in the OBC experienced 655 single-event upsets (SEU) caused by cosmic rays; the bursts of SEU were observed after 9 major solar flares. In spite of these SEU, the OBC worked correctly during the mission time, due to the fault tolerance technique, Stepwise Negotiating Voting. The field data reveal a statistical correlation between SEU and solar activities.