Abstract: A spin-stabilized spacecraft has a pair of three-axis accelerometers (A, C) mounted on the spacecraft rotor (10) to provide for self-aligning, enduring and sophisticated navigational capability. A second pair of accelerometers (B, D) is added for redundancy and added sensitivity. Each pair of accelerometers are disposed at diametrically opposed positions on the rotor and respective axes are co-aligned. The orientation of spacecraft angular momentum h is determined by star and planet sensors.Radial alignment of each accelerometer relative to the spacecraft angular momentum is attained by zeroing non-radial accelerometer readings during spacecraft quiescence. Axial alignment is attained during periods of substantially axial thrust by isolating axial translational acceleration by summing readings across an accelerometer pair to cancel rotational, spin-periodic contributions to the readings and time-averaging or otherwise filtering to cancel other non-axial periodic contributions to the readings.

Abstract: The torque from differential solar pressure acting on a spinning spacecraft body and tending to tilt the spacecraft about an axis transverse to the spin axis, is reduced or eliminated by shifting the center of gravity of the spacecraft axially or longitudinally of the spin axis in a direction toward the center of solar pressure.

Abstract: A method for remotely determining the dynamic imbalance of and for changing the spin rate and center of gravity of a spinning spacecraft which utilizes the communications channel between the spacecraft and the receiving terminal, the master index pulse generator on the spacecraft, and the spacecraft axial thrusters. To measure the dynamic imbalance, the variation in the received signal strength is plotted relative to the master index pulse. The peak-to-peak variation in the received signal strength is proportional to twice the magnitude of the wobble angle of the spacecraft created by the dynamic imbalance. The phase of the wobble angle relative to the master index pulse (MIP) is proportional to the time interval between the occurrence of an MIP and either a peak or a trough in the received signal strength. To be able to change the spin rate, the spinning body must also include a means for dynamically balancing the spinning body.