MARS-CAT; What is a Cubesat Ambipolar Thruster and how does it work?

Question

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

http://pepl.engin.umich.edu/thrusters/CAT.html

http://pepl.engin.umich.edu/pdf/IEPC-2015-243.pdf

http://www.phasefour.io/cat-engine.html

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

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.