A reliability driven mission for Space Station

The repair of the Hubble Space Telescope has validated the feasibility of repair in space. This paper proposes that the International Space Station be used as a repair base for the many communication, scientific and military satellites, in low Earth orbit, and that the Space Shuttle be used to retrieve such satellites. It is shown that the lifetime of such a satellite is primarily limited by the amount of propellant provided. Other major systems such as batteries and solar panels are designed so that there is a small probability of them failing before the satellite lifetime is reached. The primary components which fail infrequently before the end of design lifetime are the electromechanical components of the attitude control system. The electronics are shown to have a decreasing failure rate and a low probability of failure within the lifetime. It is proposed that the shuttle, (or in the future a space tug), be used to move any repairable satellite at the end of its mission to the Space Station. The cost for operating a satellite for one lifetime plus replenishment of propellant and replacement of electromechanical attitude control components, batteries and solar panels for a second lifetime is considerably less then launch of one satellite and launch of a replacement satellite. The cost per year of operation for replenishment/replacement can in the limit approach one half of the cost per year for the initial orbit boost plus a replacement orbit boost.