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. 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's BET-300-P passively fed electrospray thrusters have been shown to yield ultra-low levels of thrust noise (predominantly <0.1uN/Hz^1/2 from mHz to kHz frequencies), high dynamic range (<1uN-300uN) and thrust resolution of a few hundred nN. 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. However, the total impulse capability of the BET-300-P must be significantly augmented to meet the 1000's of Ns per axis required for large observatory missions. 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.
The BET-300-P is applicable to the proposed HabEx exoplanet mission and the LISA gravity-wave mission. Additional NASA studies include the BET-300-P for attitude control, formation flight and positioning of small spacecraft. Specific applications include deep-space missions, astronomy, solar-system observations, laser communications and situational awareness. Mission duration are extended by increased wheel desaturation capacity. Improved body pointing augments stability; permitting lower cost/complexity realization of needs and new objectives.
Compact propulsion systems scalable in thrust and ΔV are an enabling technology for all bus sizes and therefore have numerous applications. The virtual elimination of vibration while superseding reaction wheel precision is a competitive advantage. The precision capabilities of the BET300P are otherwise unavailable. Potential customers include international partners, DoD and commercial entities.