Orbit transfer with a variable thrust Hall thruster under drag

The performance capabilities of an experimental Hall thruster were obtained experimentally for both variable and constant thrust modes at low power levels in order to enable orbit transfer under the influence of air drag with small satellites. For this purpose the measured thruster performance was employed in calculations of transfer trajectories. As a result, by applying optimal thrust acceleration control the required propellant mass for a given low-Earth-orbit transfer was reduced by 15-17% as compared to that required for spacecraft operation with a constant thrust to power ratio. For this purpose a Hall thruster with a movable anode is needed. In addition, the operation of an array of thrusters enables the increase of a factor of variations of the thrust acceleration during the flight time.