ETS-VIII (Engineering Test Satellite) is to be launched in 2006, with the main purpose of dealing with the increasing demand for digital communications, such as mobile phones and other mobile devices. The satellite, with a gross weight of around three tons and a diameter of 40 meters, has two Large Deployable Antenna Reflectors (LDAR) and two Solar Array paddles. One LDAR, about the size of a tennis court, is one of the world’s largest geostationary satellites. Its size will enable direct communications with a geostationary satellite that covers all of Japan, making mobile communications more reliable. Currently under development are Large Deployable Antenna Reflectors with metal-mesh, high-power transponders, and on-board processors. The technologies used in the development of these LDARs will be applicable to other large space structures. A subscale test of the LDARs was flown as the LDREX experiment.