The Hall effect thruster (HET) was designed for long-duration operation with gaseous iodine as the propellant. Iodine is an alternative to the state-of-the-art propellant xenon. Compared to xenon, iodine stores as a solid at much higher density and at a much lower pressure. Because iodine is a halogen, it is reactive with some of the materials with which a Hall thruster is typically constructed. Through research and testing, the new method allows for the HET to be used with iodine propellant for long periods of time.
The thruster is distinguished from the nominal commercial thruster by the materials of construction, the geometry of the anode, and the presence of iodine-resistant coatings. The anode and gas flow lines are made from a non-magnetic, iodine-resistant alloy. The propellant voltage isolator is made from iodine-resistant metals and brazes. The gas distributor was also completely redesigned to allow the use of multiple materials, and for it to be disassembled.