Design of a Cold-Gas Micropropulsion system for LISA Pathfinder

Astrium Limited, as prime contractor for ESA’s LISA Pathfinder (LPF) spacecraft, is implementing a cold gas micropropulsion system. The micropropulsion system is the primary actuator in the Drag Free Attitude Control System (DFACS), providing the thrusts required to maintain the spacecraft attitude and counter external disturbance forces, primarily solar radiation pressure Since the spacecraft has already been built, the new system must be designed to fit round existing spacecraft units, on unoccupied sections of panel and using only existing electrical interfaces. The micropropulsion system design is an evolution of that developed for the GAIA spacecraft which has been adapted by Astrium and Selex-ES to meet a number of additional requirements particular to LISA Pathfinder such as gravitational field control and low frequency disturbance force noise constraints. A detailed overview of the system constraints is given along with the steps taken to meet them. The overall system architecture is then presented, along with a summary of the expected performance, showing that a cold gas system is able to meet the challenging requirements of this mission to demonstrate gravitational wave detection technologies in space.