I’m not a rocket scientist and I didn’t go to Princeton, but I’m interested in going to Mars if the trip was a lot shorter. That’s why the news of a Princeton physicist developing an engine based on the same principle as solar flares (which travel at the speed of light) that would shorten a trip to Mars by at least an order of magnitude, I was interested – even if I wasn’t able to understand how it worked. Fortunately, Princeton Plasma Physics Laboratory (PPPL) physicist Fatima Ebrahimi is also good at putting things in simple terms.
“I’ve been cooking this concept for a while. I had the idea in 2017 while sitting on a deck and thinking about the similarities between a car’s exhaust and the high-velocity exhaust particles created by PPPL’s National Spherical Torus Experiment (NSTX). During its operation, this tokamak produces magnetic bubbles called plasmoids that move at around 20 kilometers per second, which seemed to me a lot like thrust.”
OK, I had to look up “tokamak” (a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle – a donut or bagel shape) but the rest was relatable … especially the part about sitting on the deck and thinking about car exhaust (mine faces a neighbor’s garage). And 20 km/sec is about 44738 mph, which is definitely a lot of thrust when compared to current rockets which top out at about 17,000 mph. Ebrahimi ran computer simulations on PPPL computers and at the National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory in Berkeley, California, and it showed this new plasma thruster concept can generate exhaust with velocities 10 times faster than those of other plasma thrusters.
“By using more electromagnets and more magnetic fields, you can in effect turn a knob to fine-tune the velocity.”
Turning a knob to speed up? I could handle that on the trip to Mars. The Princeton press release on Ebrahimi’s study, published in the Journal of Plasma Physics, explains other ways that Ebrahimi’s thruster concept is better. It produces movement by ejecting both plasma particles and magnetic bubbles known as plasmoids, which no other thruster uses for additional power. Also, replacing electric fields (used in current plasma thrusters) with magnetic fields allows rocket developers to use any kind of gas they want for different kinds of thrust.
“This work was inspired by past fusion work and this is the first time that plasmoids and reconnection have been proposed for space propulsion. The next step is building a prototype!”
That exclamation point indicates not only that it’s feasible, but prototype development can begin immediately since it’s based on fusion work that has already been done.
The line starts here to buy your tickets to Mars on the plasma thruster rocket. Just remember – I get to turn the knob.