2012.C.2.3 High Delta V Propulsion for CubeSats

Author(s)

Vlad Hruby (1), Tom Roy (1), Nathaniel Demmons (1), Kurt Hohman (1) and Mike Tsay (1)

Busek Co. Inc.

Session

C.2 – Propulsion Issues and Launching Capabilities for Interplanetary CubeSat Missions

Keywords

electric, propulsion, electrospray, colloid, ion thruster, resistojet, pulsed plasma thruster

Abstract

Busek Co. Inc. has developed four types of electric propulsion thruster systems for high Delta-V CubeSat missions. These include the electrospray thruster, micro-resistojet and RF ion thruster. Each will be described in the paper along with achievable mission parameters and niche applications.

For 25 years, Busek Co. Inc. has been working with government, academia and industry to develop electric propulsion (EP) for spacecraft, recently culminating in several flight demonstration missions on small satellites. The appeal of EP is that it offers exceptional propellant efficiency (compared to traditional chemical propulsion), which in turn gives spacecraft the capability of performing large delta-V maneuvers at the cost of relatively little propellant. Though developed for small satellites, Busek has been actively miniaturizing its EP systems to mass, volume and power consumption that is relevant to CubeSat applications. This work has resulted in the development of four EP technologies, each of which allows CubeSats to achieve a performance niche previously attainable only in their larger counterparts. Applications range from precision attitude control (10uN-s impulse bits) to large delta-V maneuvers (up to 410m/s in less than 1U volume). Each of the four EP systems – electrospray thruster, micro-resistojet and RF ion thruster – are under 1U volume and include propellant storage and management, as well as power electronics and digital interface to the host CubeSat.

The electrospray thruster is a 1U module ideally suited to provide moderate thrust/high-delta-V primary propulsion to a CubeSat. The 9W unit is capable of delivering 1050N-s impulse and 410m/s delta-V to a 3kg CubeSat. The technology is derived from the only space qualified electrospray propulsion system delivered to JPL for the NASA-ESA LISA Pathfinder mission.

The ammonia micro-resistojet module delivers higher primary (5mN) and warm-gas attitude control propulsion, ideally suited for high thrust / proximity operations. The 10W unit is capable of delivering 300 N-s impulse at 87 m/s total delta-V. The miniature valves are derived from flight valves developed for the LISA Pathfinder mission.

The RF Ion Thruster is a 1U module that is best suited to provide lower thrust and high delta-V primary propulsion to a CubeSat. The 10W unit is capable of delivering 868 N-s and 300m/s delta-V to a 3kg CubeSat. The RF Ion thruster uses miniature valves and propellant-less cathode neutralizer derived from flight units developed for the LISA Pathfinder mission. The unit features a novel high efficiency self-resonating RF power supply.