New radiation-hardened high-speed serial data bus for satellite onboard communication

The NPOESS program has several sensors that produce large amounts of data and require a high-speed data bus architecture. With the demise of the planned AS1773 serial bus, the IPO was forced to quickly determine a replacement. In light of the schedule pressure, the question centered around using an old but established technology such as RS-422 or TAXI or to embrace new network concepts and a modern serial bus technology. After studying four different serial bus alternatives, it was decided, based on capability, complexity, availability, schedule, and expense, that a space qualified high speed serial bus based on IEEE 1394a-2000 was the best option. We discuss some of the highlights of this evaluation, details of IEEE 1394-2000a, its benefits to the hug-term NPOESS program and future space missions that have large amounts of data to move around the spacecraft, and onboard LANs and IP-in-Space.