The Applicability of Pulsed Plasma Thrusters to Rendezvous and Docking of Cubesats

Despite the interest in formation flying and cubesats over something like the last decade or so, close controlled formation flying of two cubesat size spacecraft has not been achieved. Similarly, despite the growing interest in propulsion systems for cubesats, there are very few commercially available and flight ready systems. If these are coupled with the realization that formation flying could be an enabling technology for cubesats [1] enhancing capabilities and opening up possibilities for new types of missions, it seemed timely to revisit the problem of rendezvous and docking for cubesats to examine what might be possible with a pulsed propulsion system based on a pulsed plasma thruster(PPT) that is close to flight qualification [2]. The approach taken was to build on previous work [3,4] which developed a universal adaptive control system for formation flying by adding constraints on the actuators in terms of their pulsed nature and also actual performance characteristics. The formalism and theory to solve this problem has been achieved but due to numerical problems in solving the equations, there are no results as yet. However, another simpler approach has been applied and some preliminary results are presented.