Closed-loop control of close orbits around asteroids

Abstract

The purpose of this workis to developa simple control lawtoperform orbit transfer about a small rotating celestial body. The celestial body is assumed to be rotating about a principal axis, with constant rotational velocity along the largest momentof inertia.Ananalysisof the spacecraft natural trajectories is performed in the body-fixed coordinate system. A three-dimensional closed-loop guidance law is defined and analyzed, enabling the determination of the guidance constants to assure convergence to any desired orbit about the irregular celestial body. The particular case of synchronous orbits is further studied, enabling determination of the required guidance constants to implement stable synchronous orbits. Numerical results are presented for representative cases.