Advanced Communications Technology Satellite (ACTS)

Abstract

The NASA Advanced Communications Technology Satellite (ACTS) provides high risk technologies having the potential to dramatically enhance the capabilities of the satellite communications industry. This experimental satellite, which will be launched by NASA in 1992, will furnish the technology necessary for providing a range of services. Utilizing the ACTS very high gain hopping spot beam antennas with on-board routing and processing, Very Small Aperture Terminal (VSAT) digital networks which provide on-demand, full mesh connectivity, 1.544 Mbps services with only a single hop can be established. Each individual 64 kbps voice or data circuit from a VSAT is routed by the satellite to any location on the network. Secondly, the high gain spot beams make possible voice and data aeronautical communication in the large frequency bandwidth which exists at 30 20 GHz. The high gain spot beams also make feasible personal communications for low data rate services utilizing Ultra Small Aperture Terminals (USAT). Finally, the high gain spot beam antenna at Ka-band permits wide area, flexible networks providing 1 Gbps services between modest-size Earth terminals. This service is being considered in the U.S. for such applications as interconnecting supercomputers. This paper provides an overview of the ACTS and discusses the value of its technology for these communication applications including the spacecraft ( S C ) weight per unit circuit for providing these services by ACTS technologies as compared to present-day satellites. For some of these services, the ACTS technologies may have more immediate application internationally rather than within the U.S.