Cold Gas Micro Propulsion System for Scientific Satellites fine pointing: Review of Development and Qualification activities at Thales Alenia Space Italia

A Cold Gas Micro Propulsion System (MPS) has been developed by TAS-I, under ESA/EADS Astrium GmbH (ASD) Contract, for generating the throttleable micro-thrust necessary for the compensation of environmental disturbances on GAIA satellite. The MPS includes a Micro Propulsion Feed Module (MPFM), provided by EADS/Astrium UK (ASU), a Micro Thruster Assemby (MTA) encompassing a set of Micro Thrusters (MT), and a Micro Propulsion Electronics (MPE). The key element of the MPS is the MT, based on a Low Pressure Regulation and Insulation Valve with Nozzle (used as the proportional thrust actuator ) and on a Mass Flow Sensor (used for measuring the actual gas mass flow rate and provide the control signal for the closed loop thrust actuation control ). The MPE and MT EQM have been manufactured and assembled and are currently being qualified at unit level versus GAIA requirements, through a suitable test campaign encompassing functional/performance evaluation, leak/proof/burst tests, thrust characterization, thermal vacuum cycling, mechanical environmental tests and MPE+MT coupled tests. The paper presents the MPS EQM units and e review of status on the currently ongoing qualification activities.