Technology status of the 13 m aperture deployment antenna reflectors for engineering test satellite VIII

Large deployable antenna reflectors for Engineering Test Satellite VIII (ETS-VIII) are now stated in the critical design phase. The Fourteen 4.8m modules, which construct a 19.2 m x 16.7 m (13m aperture) antenna reflector, have been fabricated as Engineering Models. Ground testing for the fourteen modules will be performed until next spring. This paper describes results of critical design for the antenna reflectors and their validation plans. Each module consists of a gold-plated molybdenum mesh surface, spacially determined cable network, and a deployable truss structure as a supporting structure. Stowed size is 1 m (diameter) x 4 m (height). In stowed configuration, the lowest eigen frequencies of the antenna reflector are 47 Hz (longitudinal) and 69 Hz (lateral) respectively. The lowest eigen frequency is 0.14 Hz. Solar ray transparency of the reflector structure is designed to be more than 85% to avoid excessive solar pressure torque. Weight of each reflector is expected to be less than 100 kg. In addition, we will perform a piggyback deployment experiment in transfer orbit using the second stage of the first flight I-I-II A vehicle in 2000. Half scale seven modules antenna reflector will be used to validate its deployment reliability. Design, analysis and test results of LDRP are also introduced in this paper. (C) 2000 International Astronautical Federation. Published by Elsevier Science Ltd. AII rights reserved.