Teruo Fujiwara

A high assurance on-line recovery technology for a space on-board computer

A high-assurance online recovery technology for a space on-board computer that can be realized using commercial devices is proposed whereby a faulty processor node confirms its normality and then recovers without affecting the other processor nodes in operation. Also, the result of an evaluation test using the breadboard model (BBM) implementing this technology is reported. Because this technology enables simple and assured recovery of a faulty processor node regardless of its degree of redundancy, it can be applied to various applications, such as a launch vehicle, a satellite or a reusable space vehicle. As a result, decreasing the cost of an on-board computer is possible while maintaining its high reliability.

A high assurance on-board computer system for use on spacecraft

A high-assurance on-board computer system that overcomes the weaknesses of conventional fault-tolerance technology is proposed. The system is designed so that its performance can be easily tested and verified. It is also designed to be flexible, which means that inexpensive and highly reliable on-board computers can be used not only now but also in the future, as the mission requirements change or technology advances.

A high assurance space on-board distributed computer system

This paper verifies the assurance required of highly reliable, low cost, highly functional and high performance space on-board computers that use commercial parts, and proposes an architecture and technology that realize the necessary assurance. With such technology, the on-board computer attains not only fault tolerance but also high versatility that allows it to be applied to any space vehicle and space application as well as enabling easy testing and verification. This is demonstrated through a functional verification test and radiation test using a breadboard model (BBM).

A high assurance timing synchronization technology for space on-board distributed computer systems

The system requirements of space on-board computer necessary to realize not only high reliability but also low cost are discussed. An architecture and high assurance timing synchronization technology that meet the requirements are proposed.

Verification of assurance of space on-board distributed computer system

This paper verifies the assurance required of highly reliable, low cost, highly functional and high performance space on-board computers that use commercial parts, and proposes an architecture and technology that realize the necessary assurance. With such technology, the on-board computer attains not only fault tolerance but also high versatility that allows it to be applied to any space vehicle and space application as well as enabling easy testing and verification. This is demonstrated through a functional verification test and radiation test using a breadboard model (BBM).