Trying to understand ion thrusters a little, I started looking at https://en.wikipedia.org/wiki/Ion_thruster#Propellants where I saw:

The CubeSat Ambipolar Thruster (CAT) used on the Mars Array of Ionospheric Research Satellites Using the CubeSat Ambipolar Thruster (MARS-CAT) mission proposes to use solid Iodine as the propellant to minimize storage volume.[42]

Reference [42] says:

"MARS-CAT Mission Implementation". www.marscat.space. University of Houston College of Natural Sciences and Mathematics. Retrieved June 25, 2015.

But that link doesn't go anywhere for me.

Question: What is a Cubesat Ambipolar Thruster and how does it work? Is this thrust to get the cubesat to Mars, or to maneuver in Mars' ionosphere after getting there, or both?

edit: CAT is definitely written about, a quick search already gives




So how close is it to seeing a real cubesat mission to Mars?


1 Answer 1


The Cubesat Ambipolar Thruster (CAT) is currently being designed and tested by Phase Four, a company that formed from the University of Michigan team that originally came up with the idea. Here's the website page describing CAT: http://www.phasefour.io/cat-engine.html.

The operational concept is explained really well in the technology section of their website: A radio helix antenna is used to pump RF energy into the equivalent of a combustion chamber on a chemical rocket engine. The resultant plasma is then accelerated out the back by focusing the beam with a "magnetic nozzle" created by a permanent magnet.

I know from talking with people in the Cubesat community that Phase Four is working with multiple entities with the intent of getting CAT to fly on a Cubesat within the next two years. I haven't heard of any concrete plans to use CAT on a Mars mission yet, but a LEO demonstration mission is definitely the first step.

  • $\begingroup$ Great! Thanks for the concise summary. The old U. Houston link seems to be related to people moving around, and this company seems to have some Kickstarter and Angel activity as well as the U. Michigan connection. $\endgroup$
    – uhoh
    Jun 14, 2016 at 1:14

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