Microsat Constellation Control Techniques

The first air-launched constellation of seven small experimental communications satellites into an unexpectedly low earth orbit (246 nmi X 192 nmi) resulted in a set of tough flight control demands. In the abbreviated demonstration mission the flight operations team was challenged in rapidly propelling the spacecraft into a useful uniform distribution about the orbit plane and in maintaining the "stations" under adverse conditions. The constellation was injected in perfect order and began mission operations immediately. However, each spacecraft's attitude control system coupled with the force of heavy atmospheric drag to produce variable in-plane phase drifts that required constant observation and correction. The satellite UHF transponder payloads were operational until splashdown 190 days from launch.