Abstract
Under the current development of mid-to-large size satellites, the high reliability is mandatory to avoid failures and their development cost increases enormously to achieve the high reliability. On the other hand, several universities develop and launch nano-satellites with low cost for the purpose of education from around 2000. To generate new market for satellite utilization, low cost and fast development are key points. The balance of cost and reliability is one of the very important points to realize the markets. The theoretical research toward the balance of cost and reliability is being conducted through the governmental first program "New Space Development and Utilization Paradigm by Nano-satellites Introducing Japan-oriented Reasonable Reliable Systems Engineering". This paper presents the concept of the way to realize the reasonably reliable systems engineering. Current reliability is based on the assumption that there is no miss-design and it only depends on the random failure of parts. However, many of real on-orbit failures were caused by design errors. We propose the new reliability which includes design error and the definition of the reasonably reliable Systems Engineering. The realization concept consists of re-use of design, reduction of complexity, functional redundancy and simple organization to develop nano-satellites.
