The Rosetta Propulsion System

Rosetta is the European Space Agency's mission which is aimed to comet Churyumov-Gerasimenko to perform a close inspection of its nucleus and of its coma. Its propulsion system is a bi-propellant system capable of providing both functions of attitude control and of V manoeuvring. The system is capable to deliver pure torques and pure forces for manoeuvring around the comet with a very weak gravitational field. The system operates mainly in blow-down mode, but it can be re- pressurised in flight twice for delivering with high efficiency and constant performance a total V of 2,300 m/s. This large V is required to rendezvous the comet and be inserted into its orbit. The wide range of operating conditions presented technical challenges from the standpoint of thrusters design as well as system configuration. In addition to the technical aspects, the programme presented also very challenging AIT aspects due to the one-year launch delay that imposed a re-scheduling of the entire mission.