Satellites and roll/yaw controls therefor

Claim 1

An arrangement for roll/yaw control of a satellite with pitch momentum bias and arranged for movement on a near polar orbit with the aid of a magnet coil entering into interaction with the earth's magnetic field, characterized in: (a) timing means for dividing the time of the orbit of satellite and producing timing pulses at times representing four successive quadrants P1, P2, P3, and P4, the quadrants being inclined at an angle of 45° to the equator and the quadrants P2 and P4 being polar quadrants and the quadrants P1 and P3 being equator quadrants; (b) a first control units for producing satellite control signals when the satellite is in the polar quadrants P2 and P4 and a second control unit for producing satellite control signals when the satellite is in the equator quadrants P1 and P3; (c) inverting means responsive to the timing means for inverting the sign of the satellite control signals when the timing pulses represent quadrants P3 and P4 and for maintaining the satellite control signals when the timing pulses represent the quadrants P1 and P2; (d) said first control unit being arranged to respond to signals representing roll angles and roll velocity for the formation of the satellite control signal; (e) said second control unit being arranged to respond to signals representing roll angles and roll velocity and having acceleration signal means for producing roll acceleration signals for the formation of the satellite control signal; (f) switching means for switching between the said control units; and (g) transfer means responsive to the inverted and maintained satellite control signals for applying the signals to the coil for controlling the roll/yaw of said satellite.