Small optical transponder for small satellites

Space optical communications from small satellites need to be developed for the high-data-rate communications link to the ground. The requirements for the onboard resources are discussed with respect to the antenna diameter, the mass, and the consumption power. The development for a small optical transponder has begun and the data rate will be on the order of several ten-Mbps. The mass of the small optical transponder will be about 5 kg, which can be embarked on 50-kg-class small satellites as the piggyback of launch vehicles.