Compact High Impulse Electrospray Thrusters for Large Observatory Precision Pointing

Busek proposes to develop a versatile, high-impulse precision pointing attitude-control actuator evolved from now flight-proven electrospray propulsion technology. The proposed system would support unprecedented thrust dynamic range while virtually eliminating reaction wheel vibrational jitter and associated complications.nbsp;Numerous past and upcoming precision observatory missions have recognized the improved stability and other benefits afforded by microthruster based control; including the completed Gravity Probe B, GAIA, LISA Pathfinder missions and upcoming LISA, HabEx and Euclid mission concepts. Busek#39;s BET-300-P passively fed electrospray thrusters have been shown to yield ultra-low levels of thrust noise (predominantly lt;0.1uN/Hz^1/2 from mHz to kHz frequencies), high dynamic range (lt;1uN-300uN) and thrust resolution of a few hundred nN.nbsp;These features are well suited to proposed mission concepts like HabEx; offering both expanded capabilities and reduced propellant mass over the state-of-the-art Colloid Micro Newton Thruster recently demonstrated aboard the LISA Pathfinder Mission.nbsp; However, the total impulse capability of the BET-300-P must be significantly augmented to meet the 1000#39;s of Ns per axis required for large observatory missions.nbsp; To meet this need, the proposed Phase I comprises a sequence of modelling, experimental and development tasks designed to expand knowledge of life-limiting physical and logistical mechanisms and investigate new means to overcome them.