Shuttle - Compatible High Performance Propulsion Module

The Air Force Space Test Program (STP) seeks a space shuttle (SS) compatible, high performance, propulsion module (PM) to raise the orbit of a small, SS deployed, experimental payload (125 kg), to a 700+ km. Preliminary analysis identified the Busek 200 W Hall thruster fueled by nontoxic xenon propellant as the most promising technology. The Hall thruster based, 56 kg PM which includes, in addition to the main propulsion subsystem, a solar power system, batteries, power management electronics and ACS propulsion can raise a 181 kg spacecraft (PM + payload) to a maximum of 2458 km. The Hall thruster can also deliver discrete impulse bits (< 2 mN sec) and therefore be used for precise spacecraft positioning as envisioned for formation flying systems. In Phase I, Busek refined the mass, power and operational capability of the Hall thruster system in accordance with the requirements for a standardized plug and play module for the Shuttle Rocket for Payload Augmentation (SHERPA). In Phase II, the remaining subsystem of the propulsion module, the power processor unit and digital control interface unit (PPU/DCIU) will be designed and built at the engineering model level, further advancing the system for an eventual flight opportunity.