The data relay and tracking satellite system: Present status of NASDA

Abstract NASDA is developing the Data Relay and Tracking Satellite System (DRTSS) toward the late 1990's when some Japanese user spacecraft are planed to appear. The DRTSS will include terminals on user spacecraft, two GEO satellites and few ground stations. The DRTSS will be interoperable with NASA and ESA data relay systems. It has two frequency bands for inter orbit link, one is S-band for low data rate transmission, anther is Ka-band for high data rate transmission. This paper presents development status of DRTSS.