In-orbit deployment characteristics of large deployable antenna reflector onboard Engineering Test Satellite VIII

This paper describes design, ground testing, an in-orbit experiment, and a novel in-orbit operation for large deployable antenna reflectors (LDRs). Two LDRs (TX-LDR for transmitting and RX-LDR for receiving) are installed on Engineering Test Satellite VIII (ETS-VIII). The reflector design features that the antenna reflector whose aperture is 13 m in diameter (the mechanical dimension is 19m×17m) consists of 14 basic modules, and each basic module consists of a gold-plated molybdenum mesh, a system of cables, and a deployable frame structures. Several ground tests had been performed using a modular nature to advantage. Prior to the launch of ETS-VIII, we performed an in-orbit deployment experiment using LDREX-2 which consists of seven half-scale modules of LDR, to confirm evaluation accuracy. The LDREX-2 was launched by ARIANE 5 launch vehicle as a piggy-back payload. Deployment characteristics were measured to evaluate the accuracy of analytical prediction obtained by ground deployment testing. ETS-VIII was launched by H-IIA launch vehicle on 18 December 2006. After the successful injection into Geo Synchronous Orbit, the RX-LDR and the TX-LDR were successfully deployed on December 25th and 26th, respectively. We confirmed adequacy of the proposed design and ground verification methodology.