Abstract: Three-axis spacecraft momentum management is performed for a spacecraft traveling along a trajectory, by an actuator including at least one thruster disposed on a single positioning mechanism. As the spacecraft travels along the trajectory, a desired line of thrust undergoes a substantial rotation in inertial space. When the spacecraft is located at a first location on the trajectory, the single positioning mechanism orients the thruster so as to produce a first torque to manage stored momentum in at least one of a first and a second of the three inertial spacecraft axes. When the spacecraft is located at a second location on the trajectory, the single positioning mechanism orients the thruster so as to produce a second torque to manage stored momentum in at least a third of the three inertial spacecraft axes.

Abstract: Three-axis spacecraft momentum management is performed for a spacecraft traveling along a trajectory, by an actuator including at least one thruster disposed on a single positioning mechanism. As the spacecraft travels along the trajectory, a desired line of thrust undergoes a substantial rotation in inertial space. When the spacecraft is located at a first location on the trajectory, the single positioning mechanism orients the thruster so as to produce a first torque to manage stored momentum in at least one of a first and a second of the three inertial spacecraft axes. When the spacecraft is located at a second location on the trajectory, the single positioning mechanism orients the thruster so as to produce a second torque to manage stored momentum in at least a third of the three inertial spacecraft axes.

Abstract: A spacecraft, such as a geosynchronous weather or communications satellite, is constructed to include a plurality of low thrust thrusters mounted at predetermined locations on at least one of a spacecraft appendage or a spacecraft bus. The plurality of low thrust thrusters are fired in pairs for at least one of removing a disturbance torque or providing fine pointing attitude control. In one embodiment the low thrust thrusters are mounted on a solar array panel, thereby increasing the moment arm and enhancing the thrust output of the low thrust thrusters. In one embodiment a spacecraft has a plurality of low thrust thrusters arranged as at least two sets of two low thrust thrusters, individual ones of the low thrust thrusters of a set being disposed in a V-configuration and mounted at predetermined locations on at least one of a spacecraft appendage or a spacecraft bus. The plurality of low thrust thrusters are selectively fired for achieving control of 3-axes of spacecraft attitude or momentum.

Abstract: A spacecraft includes a plurality of thrusters mounted at predetermined locations on a spacecraft structure, individual ones the plurality of thrusters being fired for generating a torque about a desired axis. The firing of a thruster is partitioned into two firings that are offset in time by an amount .DELTA.t, wherein .DELTA.t=(1/2).times.(1/F).times.SF, where F is a dominant modal frequency, in Hertz, for any particular axis (nominally the 1st mode) of the spacecraft structure, and where SF is a scale factor that is adjustable about the frequency. In a presently preferred embodiment the thruster is a low thrust thruster that is mounted on a solar array panel, and the thrusters are fired in pairs.