On-board management of multiple processor spacecraft system

The Korea Multipurpose Satellite (KOMPSAT) is a three-processor distributed spacecraft system. These three on-board processors are interfaced through a MIL-STD-1553B data bus for basic communication and data transfer between them. In this paper, the on-board management of a multiple processor spacecraft system is addressed, based on the experience of KOMPSAT spacecraft system design and on-orbit flight operation. Unlike a single processor system, one major design issue of the multiple processor system is the management of the multiple processor in such a way that all of the processors must be controlled and operated properly during a transient state, such as system initialization or hardware switching via redundancy management. This paper covers the following aspects: a technique to synchronize and initialize three processors; communication and data handling management of the 1553B data bus; and the onboard fault and recovery management technique. This paper shows that the difficulties of using multiple-processor systems are manageable by proper design implementation and flight operation.