Lightweight Iodine Thruster Could Help Solve Space Junk Problem

Rocket fuel is one of the most important components of any maneuverable spacecraft.  That is also true for ion thrusters – while they don’t use traditional chemical fuel, they do still need a feed source for their ion engines.  Now, a team from ThrustMe, a spinoff of the École Polytechnique and CNRS, has designed a type of ion thruster using a completely novel propellant – iodine.

Ion thrusters typically use xenon as a propellant, which has several disadvantages when compared to iodine.  Firstly, it is a gas, whereas iodine is a solid at room temperature and pressure.  Iodine also sublimates directly to a gas when heated, allowing for the storage and propulsion systems of a spacecraft to operate with two different states of the material.  

Video describing the operation of an ion thruster.

Iodine is also less expensive, non-toxic, and much easier to handle that the noble gas it aims to replace.  Finally, iodine is also denser than competing technologies, which is particularly useful in space-constrained environments such as small satellites.

That CubeSat market is exactly what ThrustMe is hoping to capture with this novel type of thruster.  Particularly, they hope to use this new, less expensive, and more compact thruster to deal with problems such as deorbiting and space junk.  With more propellant, it would be much easier to control a satellite’s descent at the end of its life, creating less derelict junk in space and ensuring anything entering the atmosphere would not harm anything on the ground.

ThrustMe's system installed on a CubeSat to be tested this year.
A ThrustMe system is installed on the Beihanghongshi-1 CubeSat.
Credit Spacety

The first step toward that dream launched on a mission last November, and the system has been successfully test fired.  ThrustMe now hopes to control the orbit of the satellite it is affixed to as a proof of concept demonstration for future customers.  With their success, there might be some significant interest in iodine for use in space exploration in the not too distant future.

Learn More:
ESA: Iodine thruster could slow space junk accumulation
SciTechDaily: Iodine Thruster Used to Change the Orbit of a Satellite for the First Time Ever
SpaceNews: French startup demonstrates iodine propulsion in potential boost for space debris mitigation efforts

Lead Image: Iodine Thruster under test.
Credit: ThrustMe