New Propellants for Ion Thrusters – Iodine and Other Alternatives

Ion thrusters are nowadays routinely used on satellites for attitude control and for dedicated space missions, such as GOCE and Dawn. The commonly used propellant for ion thrusters is the noble-gas xenon, which comprise some advantages such as high atomic mass, no chemical reactivity, and efficient ionization. One disadvantage of xenon is the high price, which leads to high costs for testing and qualification of thrusters. Potential candidates for alternative propellants are currently under investigation in the electric propulsion community. An interesting material is iodine, which has a high mass, a high ionization efficiency and a high density due to its solid nature at standard temperature. It can be evaporated with moderate heating power and was successfully tested recently at Giessen university with a radiofrequency ion thruster. The talk will present performance results of iodine and gives an overview about alternative propellants in general.