Patent ID: 6695262
Filing Date: 2004-02-24
Classification: B64G

Abstract:
A method of enhancing the accuracy of the service attitude of a spacecraft that orbits the earth each solar day wherein an earth-based beacon station radiates a beacon signal and, relative to said spacecraft, moves along a path that defines a beacon-station window, the method comprising the steps of:configuring a beacon-receiving antenna to have a beacon-receiving field-of-view that is substantially smaller than said beacon-station window wherein said beacon-receiving antenna has a beacon-receiving boresight and generates a difference signal that corresponds to a difference angle between said beacon-receiving boresight and a line-of-sight from said spacecraft to said beacon station; successively steering said beacon-receiving boresight to beacon-receiving attitudes, relative to said service attitude, that maintain said beacon station within said beacon-receiving field-of-view over said solar day; receiving said beacon signal with said beacon-receiving antenna; and controlling said service attitude in response to said difference signal; said accuracy enhanced because said beacon-receiving field-of-view is substantially smaller than said beacon-station window.