Patent ID: 7076341

Claim:
An autonomous active manoeuvring method for performing autonomously, in closed loop on-board, a series of fine attitude manoeuvres for a spinning spacecraft, the method comprising: (a) arranging a plurality of thrusters in a predetermined spatial configuration at the spacecraft; (b) controllably generating a series of thruster pulses by means of the thrusters in said predetermined spatial configuration, the magnitude and the phase of the thruster pulses being determined by computation means so as to permit fine attitude reorientation manoeuvring of the spacecraft about its spin axis, the manoeuvring being effected in a time duration less than or equal to half an inertial precession period of the spacecraft about its spin axis; (c) completing the manoeuvring in dependence upon the measured time from the start of the manoeuvre and the measured angular rates associated with the spacecraft nutation; and (d) providing an autonomous attitude determination of the spacecraft between successive manoeuvring steps such that, in operation of the spacecraft, any errors associated with particular manoeuvres can be controllably corrected in subsequent manoeuvres.