NASA has dusted off a 1960s-era idea and turned it into a very modern test rig: a lithium-fueled magnetic plasma thruster that hit 120 kW in its first firing. The agency says the prototype could eventually help send astronauts to Mars and push robotic probes deeper into the Solar System, but the immediate headline is simpler: the hardware actually survived its first run.
The test took place on 24 February 2026 at NASA’s Jet Propulsion Laboratory, using the CoMeT vacuum facility. That matters because plasma engines are easy to admire on paper and far less charming when their electrodes start cooking themselves into scrap metal.
How the MPD thruster works
The device is a magnetoplasmadynamic, or MPD, accelerator. Instead of relying on the same kind of ionized gas used by many electric thrusters, it uses extreme electric currents and magnetic fields to hurl plasma made from evaporated metal, such as lithium. In theory, that gives the exhaust far more energy and much higher thrust than conventional electric propulsion.
NASA says the prototype used a tungsten electrode that climbed above 2800 °C during testing. That is less a triumphal number than a warning label: the real challenge is not making the engine fire once, but keeping it alive for tens of thousands of hours in space.
Mars missions need far more power
The agency says the test engine delivered more than 25 times the power of the thrusters on NASA’s Psyche spacecraft. That is a useful benchmark, but Mars-bound crewed missions would need far more still: NASA estimates 2 MW to 4 MW per mission, with several engines running reliably for more than 23,000 hours.
That is why this story is less about a single firing and more about the long road from laboratory success to flight hardware. Other space agencies and private players are chasing higher-efficiency propulsion too, but nuclear power supply, thermal management, and materials durability remain the real gates through which every ambitious deep-space engine must pass.
Lithium is the awkward part
NASA’s target is a 500 kW to 1 MW engine, developed with Princeton University and NASA’s Glenn Research Center. But the fuel choice may be the least elegant part of the concept. Lithium is a scarce element, and the article notes that a Mars mission could require 100 or more tons of it. That is a lot of promise, and a lot of logistics.
So the next question is not whether MPD propulsion can outperform chemical rockets in efficiency – it can – but whether NASA can build a power system, likely nuclear, that can feed these engines long enough without melting the whole idea down first.