The proposed feed system supports iodine Hall thrusters, ion engines, hollow cathodes, and other plasma generators currently under development for NASA. Possible near term applications include the Iodine Satellite (iSat), Lunar IceCube, and follow-on missions. The Phase II feed system will be ideally sized for a Hall thruster operating at power levels of 100 W to 600 W, and for gridded ion engines operating at similar or lower power levels. These thrusters would be used for orbit raising and interplanetary transfers. Missions of current interest include resource prospecting at the moon, Mars, asteroids, and NEOs. The technology is applicable to spacecraft of all sizes from CubeSats to Asteroid Redirect spacecraft to future MW-class cargo transports supporting human exploration. The ability to flow iodine as a HET propellant is a the game changer. Iodine is efficient, compact, highly storable, and an order of magnitude cheaper than xenon. Full power thruster demonstrations and throttling in space conditions are feasible because iodine is efficiently pumped by liquid nitrogen cooled panels.
The proposed feed system supports many types of plasma generators used in space and on the ground. In the near term, the innovative feed system components are most likely to be used as part of a space propulsion system. Commercial and military applications for iodine propulsion include orbit raising, orbit circularization, inclination changes, station-keeping and repositioning. The next stage for commercial users is an all-electric satellite, where electric propulsion accomplishes all propulsion functions. Beyond stored density and pressure, iodine has many additional benefits with respect to xenon. For instance, a fully-fueled, non-active system may be stored on the ground or on orbit for long periods of time. This reduces the cost of on-orbit spares, and minimizes down-time in the event of a failure. Low pressure on-orbit refueling is also feasible. Due to these and other advantages, iodine may be very attractive for commercial missions such as asteroid mining.