The proposed feed system supports iodine Hall thrusters, ion engines, hollow cathodes, and other plasma generators currently under development for NASA. Specific applications include iSat, Lunar Cube, and future Game Changing missions. The Phase II feed system will be ideally sized for a Hall thruster operating at 500 to 1000 W. This thruster would be used for orbit raising and interplanetary transfers of spacecraft up to several hundred kg. Missions of current interest include resource prospecting at the moon, Mars, asteroids, and NEOs. The technology is also applicable to much smaller spacecraft, such as CubeSats, and much larger spacecraft, such as future MW-class cargo transports supporting human exploration. The ability to flow iodine as a HET propellant is ultimately 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. The next stage for commercial users is an all-electric satellite, where electric propulsion accomplishes all propulsion functions including orbit raising, orbit circularization, inclination changes, station-keeping and repositioning. 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 its these and other advantages, iodine may be very attractive for commercial missions such as asteroid mining.