IN-ORBIT DEPLOYMENT PERFORMANCE OF LARGE SATELLITE ANTENNAS

Engineering Testing Satellite VI has been developed for advanced satel lite communication experiments. It was launched from Tanegashima Space Center in August 1993. It failed to enter geostationary orbit became the apogee engine failed, Hoc-ever, the mission equipment remained ful ly functional, and the two large main reflectors and two small subrefl ectors were deployed successfully The two main reflectors were 3.5 and 2.5 m in diameter, They were stowed against the tower structure durin g launch and deployed by spiral springs. Flight data from acceleration and temperature sensors were obtained, Of particular interest, the ac celeration data agreed with the results of ground deployment and vibra tion testing. The deployment and vibration characteristics of the two large main reflectors are described and compared with the results of g round varification. In-orbit deployment and vibration characteristics are directly compared with the results of ground testing. Fight data o btained by in orbit measurements show that ground validation methods a re feasible and reliable.