Tamiya Nomura

Usuda deep space station with 64-meter-diameter antenna

Abstract Institute of Space and Astronautical Science (ISAS), Japan, constructed a new deep space ground station with 64-meter-diameter antenna at Usuda-cho, Nagano, in 1984. The station has successfully operated in the tracking of “Sakigake”, the first Japanese interplanetary spacecraft that ISAS launched on January 8, 1985. This paper describes the facilities and the features of the Usuda Station, the results of Sakigake tracking, as well as the features of the softwares for trajectory generation and orbit determination that we have developed for deep space missions.

Dual Speed PN Ranging System for Tracking of Deep Space Probes

A new pseudonoise (PN) ranging system is proposed for trackingof deep space probes, named the dual speed PN ranging system,that transmits two different PN sequences simultaneously through a PSK/PSK (phase-shift keying) dual speed communication channel.The dual speed PN ranging system improves the maximummeasurable range significantly, with no degradation of theacquisition time, when compared with usual PN ranging systems.According to the analysis, the tracking error of this system becomesas small as those of usual PN ranging systems when the inputsignal-to-noise ratio (SNR) is large enough.

Recent development of scientific satellites and their launch vehicles

Abstract The Institute of Space and Aeronautical Science (ISAS), University of Tokyo, has been engaged in the development of scientific satellites and their launch vehicles of Mu series. ISAS has conducted the first flight test of M-3S, the newest version of Mu series, and launched a technology test satellite MS-T4 into an orbit. The objectives were to verify the overall performance of the vehicle and to perform various experiments on the satellite technology to be applied to the following scientific satellites. Technological aspects of M-3S and MS-T4 are reviewed in reference to the recent trend in the scientific satllite program.