JAXA's optical data relay satellite programme

After 13 years successful operation of Japanese first data relay satellite “KODAMA,” JAXA has initiated a new data relay satellite programme which adapts optical communication in the inter-orbit link. The programme includes development of a data relay satellite and optical terminals both for GEO (i.e. the data relay satellite) and LEO, Ka feeder link system to communicate between the data relay satellite and ground stations and has data-relay service capability up to 1.8 Gbps. Targets launch year is 2019 in Japanese fiscal year. In the paper, the authors outline the plan of the programme and its technology.