ORBITAL DYNAMICS OF LASER-PROPELLED SPACE VEHICLES IN LOW-EARTH ORBIT

摘要

Since the first proposal in the early 1970s, laser-propelled launch vehicles have been considered as one of the candidates offering the potential of thousands of launches to low Earth orbit. Previous papers mainly investigate the ascent trajectory phase utilizing this laser propulsion system, while this paper proposes in-orbit laser propulsion system and investigates the dynamics of a laser-propelled space vehicle around an orbiting station with a laser propulsion capability. The linear rendezvous equations, Clohessy-Wiltshire equations, are used for the analysis. The objective is to investigate the orbital dynamics, orbital control method, and feasibility of laser-propelled system for application to space vehicle orbital transfer. The thrust given by laser system is assumed in the direction from the orbiting laser station to the space vehicle around it. First, a conservative function denoting total energy in the rotating frame is discussed. Then, periodic trajectories around the orbiting laser station are investigated and an approximate analytical solution is given, which provides sufficient description of the laser-propelled orbital dynamics in terms of amplitude and frequency variation. Finally a simple on-off control scheme is proposed to control the size of the orbit around the orbiting laser station.