Deployment Performance and Reliability Prediction of Large Deployable Antenna for Satellite Use.

A method to predict the deployment performance and reliability of satellite antennas is proposed. The gravity cancellation method is selected to minimize gravitational effect on deployment performance. Unwanted torque about the hinge axis is calculated using measured misalignment data in ground deployment testing. Parameters of the equation of deployment motion are identified by curve fitting of measured angle-time or angular velocity-time relationship. The comparison between calculated unwanted torque and the identified one shows good agreement. Therefore, in-orbit deployment performance can be predicted by deleting effects unique to ground testing. The deployment reliability prediction method is based on driving and resistive torque generated by constituent parts of deployment mechanisms. Torque measurements show that each part torque distribution can be fitted to the normal distribution. Deployment reliability can be calculated as a probability that driving torque distribution is greater than resistive torque distribution. Prediction methods are applied to the deployable antennas for Engineering Test SatelliteVI (ETS-VI), scheduled for launch in 1994.