ST7-DRS Colloid Thruster System Development and Performance Summary

Abstract

This paper summarizes Busek's five year effort to develop Colloid Micro- Newton Thrusters (CMNT) for the LISA Path Finder (LPF) mission. The LPF is jointly pursued by NASA and ESA as a technology demonstration mission with a planned launch date of 2010. Busek recently delivered two (2) flight CMNT Clusters, each containing four (4) CMNTs, to NASA JPL that sponsored and assisted Busek in the development. Following further integration with additional hardware, JPL will deliver the system to ESA. The LPF and future formation flight/interferometer missions have extraordinary propulsion requirements that proved to be very challenging to meet and to verify by direct measurements. Salient among them is the broadly adjustable thrust from 5 to 30μN that each CMNT must deliver with a step precision better than 0.1mN and thrust noise lower than 0.1mN/root Hertz over a frequency interval of 1m Hz to 4Hz. These specifications required the development of new and pioneering hardware including CMNTs that use novel ionic liquid as a propellant, unique propellant management and storage system with flow controlling microvalves that must regulate propellant flow with nL/min precision, carbon nanotube based field emission neutralizers, and high voltage (0 to 10kV) power processors in compact low mass package. The paper summarizes the system and key component design, the test program, and the salient performance results. Companion papers provide further details.