Development of inter-orbit communications equipment of COMETS/NASDA

The National Space Development Agency of Japan (NASDA) plans to launch the COMmunications and broadcasting Engineering Test Satellite (COMETS) by the H-II launch vehicle in February, 1997. The profiles of COMETS are shown. The aim of COMETS is to develop and to experimentally demonstrate new technologies in the fields of communication and broadcasting using Ka-band equipment; inter-orbit communications equipment (ICE), satellite broadcasting equipment (SBE), and mobile satellite communications equipment (MCE). It is proposed to use ICE to establish communications between user spacecrafts in low Earth orbits, satellites (e.g. ADEOS: ADvanced Earth Observing Satellite), the attached pressured modules of the spacestation-α (e.g. JEM: Japan Experiment Module) and ground terminals via relay satellites in geostationary orbits. Various development tests for the engineering model (EM) of ICE have been executed since 1993 and the characteristics of ICE have been verified; S/Ka-band RF characteristics, environment (impulse, vibration, thermal-vacuum)-proof characteristics, and so on. Therefore, appropriate design and the requirements for the proto-flight-model (PFM) of ICE have been decided. This paper reports the development tests and status for ICE