A deployable .015 inch diameter wire antenna

Abstract

This mechanism was developed to dispense a small diameter wire which serves as a receiving antenna for electric field measurements on an Earth orbiting satellite. The antenna is deployed radially from a spinning satellite. A brushless dc motor drives a storage spool to dispense the wire at a controlled rate. Centrifugal force, acting on a mass attached to the end of the wire, keeps the wire in the radial position. The mechanism design, testing, and performance characteristics are discussed. Finally, operational data of the mechanism while in orbit are presented.