초록 ▼

A method and apparatus for satellite station keeping is disclosed in which six thrusters are mounted on the anti-nadir face of a satellite with their direction of thrust passing through the center of mass (CM) of the satellite. The thrust lines of the north trio of thrusters and the south trio of th

A method and apparatus for satellite station keeping is disclosed in which six thrusters are mounted on the anti-nadir face of a satellite with their direction of thrust passing through the center of mass (CM) of the satellite. The thrust lines of the north trio of thrusters and the south trio of thrusters make an angle .theta. with the satellite north-south axis in a northern and southern direction, respectively. The four outer thrusters are laterally separated and slewed by an angle .alpha. about the north-south axis. Each outer thruster produces three components of .DELTA.V, i.e. normal, tangential and radial (toward the Earth), thereby providing complete control of the three orbit vectors, inclination, eccentricity and mean motion. The north and south center thrusters are positioned in the Local-Vertical North-South plane and produce only normal and radial .DELTA.V components, providing control for momentum dumping and, in the event of failure, inclination control. In the event of a thruster failure where one of the pairs of thrusters is shut down, four thrusters remain to maintain station keeping.

대표청구항 ▼

[ What is claimed is:] [1.] A station keeping system for a three-axis stabilized satellite, comprising:six thrusters mounted in two rows of three each on an anti-nadir face of the satellite, each of the thrusters having a line of thrust which passes through the center of mass (CM) of the satellite,

[ What is claimed is:] [1.] A station keeping system for a three-axis stabilized satellite, comprising:six thrusters mounted in two rows of three each on an anti-nadir face of the satellite, each of the thrusters having a line of thrust which passes through the center of mass (CM) of the satellite, the six thrusters including a northwest thruster, a north center thruster, a northeast thruster, a southwest thruster, a south center thruster, and a southeast thruster, the north thrusters being canted away from the anti-nadir face in a north direction with respect to a north-south axis which passes through the center of mass of the satellite, the south thrusters being canted away from the anti-nadir face in a south direction with respect to the north-south axis, the northeast and the southeast thrusters being slewed in an east direction about the north-south axis, the northwest and southwest thrusters being slewed in a west direction about the north-south axis, the north center and south center thrusters positioned in a plane defined by the north-south axis and a local vertical axis which passes through the center of mass of the satellite in a nadir direction;wherein firing the northwest and northeast thrusters near an orbit ascending node and the southwest and southeast thrusters near an orbit descending node in accordance with predetermined firing time durations produces normal, radial and tangential orthogonal .DELTA.V acceleration components for on-orbit control of the satellite and firing of the north center thruster near an orbit ascending node and firing of the south center thruster near an orbit descending node produce normal and radial orthoginal .DELTA.V components to provide momentum dumping and, in the event of failure, inclination control.