Spin-stabilized spacecraft and methods

Abstract

Spin-stabilized spacecraft are provided which facilitate simple attitude maneuvers and the use of high-gain antennas and efficient solar panels without the need for complex control systems and an excessive number of thrusters. They include a rotor and first and second spacecraft platforms wherein the rotor and the first and second spacecraft platforms are rotatably coupled together and a spin thruster system is arranged to urge and maintain the rotor in a spacecraft-stabilizing spin about the rotor axis. A first rotary-drive mechanism couples the first spacecraft platform to the rotor and a second rotary-drive mechanism couples the second spacecraft platform to the first spacecraft platform. An attitude thruster is spaced from the rotor axis and oriented to generate an axial thrust component in the rotor for synchronous control of the inertial attitude of the rotor axis. A spacecraft of the invention can orbit the earth in an orbital plane and at an orbital rate and be controlled by the steps of (a) spinning the rotor about a rotor axis with a thruster to establish a satellite-stabilizing angular rotor momentum, (b) orienting the rotor axis in an orthogonal relationship with the orbital plane, (c) rotating the first satellite platform substantially at the orbital rate to constantly direct a portion of the first satellite platform at the earth, and (d) counter-rotating the second satellite platform substantially at the orbital rate to constantly direct a portion of the second satellite platform at the sun. The orienting step (b) is simply realized by synchronously generating an axial thrust component in the rotor that is spaced from the rotor axis.