Precise orientation of multibeam satellite

The Intelsat V satellite is a multibeam/multiantenna RF satellite, 3 axis, stabilized in orbit. The primary references for the attitude control system is an earth sensor for pitch and roll and a combination of sun sensors for yaw. This paper describes the geometric relationship between the attitude control sensors and all the different RF antennas and the methods used to align each of the elements. The second part of the paper describes the actual testing used in a 1 g environment to get as close as possible to an end-to-end verification of the alignment methods. The final section of the paper gives the initial onorbit results and their correlation with the ground-based measurements. Initial results of this data seem to indicate that the overall onground tests, in most cases, present a rather pessimistic performance prediction.