Affiliations: Wireless Communications Department, National Institute of Information and Communications Technology, 4-2-1 Nukui-kita, Koganei, Tokyo 184-8795, Japan E-mail: nisinaga,y-ogawa @nict.go.jp | Office of Space Applications, Japan Aerospace Exploration Agency, 1-1, Sengen 2chome, Tsukuba-city, Ibaraki 305-8505, Japan E-mail: takayama.yoshihisa,takahashi.takashi2@jaxa.jp | Kashima Space Research Center, National Institute of Information and Communications Technology, 893-1 Hirai, Kashima, Ibaraki 314-0012, Japan E-mail: tkubooka,umehara@nict.go.jp
Abstract: It is generally impossible to exchange, repair, or upgrade onboard equipment in orbit, and communications satellites are designed for fifteen or more years of life. Consequently, orbiting communications satellites cannot follow unforeseen changes in terrestrial communications. Moreover, because of long lead times and high costs of satellite development, it is difficult to implement the latest technology at launch. And even if the latest communications technology were implemented at the time of launch, the configuration on orbit has limited capability for configuration change to parallel the endless evolution in terrestrial communications technology. In this paper, we propose a reconfigurable communication satellite system based on formation flying and inter-satellite communications technology. The satellite is composed of a group of satellites. The functions implemented by each satellite are defined by the OSI (Open Systems Interconnection) reference model. The discussion centers on a three satellite constellation or cluster having relatively close spacing; but the concept may be applied to larger clusters and spacings. Satellites implementing higher OSI layers are small and also on a size reducing trend. Replacing or adding small satellite elements might enable the cluster as a whole to keep pace with frequent paradigm shifts of terrestrial networks.
