JPL Team Ignites High-Power Lithium-Fed Electric Thruster Aimed at Human Mars Flights

by Clarence Oxford
Los Angeles CA (SPX) Apr 29, 2026
A prototype lithium-fed magnetoplasmadynamic thruster was fired for the first time in years at NASA's Jet Propulsion Laboratory in Southern California, reaching power levels higher than any previous electric thruster test conducted in the United States and marking a significant step toward nuclear electric propulsion systems capable of carrying humans to Mars.

The test took place on Feb. 24 inside JPL's condensable metal propellant (CoMeT) vacuum facility, a 26-foot-long (8-meter-long) water-cooled vacuum chamber designed to safely handle metal-vapor propellants at up to megawatt-class power levels. During five ignitions, the thruster's tungsten center electrode glowed white-hot, exceeding 5,000 degrees Fahrenheit (2,800 degrees Celsius), while the nozzle-shaped outer electrode emitted a vibrant red plume visible through a small portal into the chamber.

The prototype achieved power levels of up to 120 kilowatts - more than 25 times the output of the electric thrusters aboard NASA's Psyche spacecraft, which currently operates the highest-power electric propulsion system of any NASA mission. Psyche's thrusters, powered by solar energy, accelerate the spacecraft to 124,000 mph through low, continuous thrust accumulated over time.

"At NASA, we work on many things at once, and we haven't lost sight of Mars. The successful performance of our thruster in this test demonstrates real progress toward sending an American astronaut to set foot on the Red Planet," said NASA Administrator Jared Isaacman. "This marks the first time in the United States that an electric propulsion system has operated at power levels this high, reaching up to 120 kilowatts. We will continue to make strategic investments that will propel that next giant leap."

The magnetoplasmadynamic (MPD) thruster concept has been studied since the 1960s but has never flown operationally. Unlike conventional electric thrusters that use electric fields to accelerate ionized propellant, an MPD engine applies high electrical currents interacting with a magnetic field to electromagnetically accelerate lithium plasma, enabling substantially higher thrust and power density than currently flying designs.

Electric propulsion systems in general consume up to 90 percent less propellant than traditional chemical rockets, making them attractive for long-duration deep-space missions. The lithium-fed MPD variant offers additional advantages in thrust-to-power ratio when scaled to megawatt-class operation.

"Designing and building these thrusters over the last couple of years has been a long lead-up to this first test," said James Polk, senior research scientist at JPL, who has studied lithium-fed MPD thrusters for decades and previously contributed to NASA's Dawn mission and Deep Space 1, the first demonstration of electric propulsion beyond Earth orbit. "It's a huge moment for us because we not only showed the thruster works, but we also hit the power levels we were targeting. And we know we have a good testbed to begin addressing the challenges to scaling up."

The team's near-term goal is to reach power levels between 500 kilowatts and 1 megawatt per thruster within the coming years. A crewed Mars mission is estimated to require 2 to 4 megawatts of total propulsion power, necessitating multiple MPD thrusters operating in parallel for more than 23,000 hours. Demonstrating that thruster components can withstand the extreme operating temperatures over extended test campaigns is identified as a primary engineering challenge.

Fully developed and paired with a nuclear power source, the technology could significantly reduce launch mass requirements and enable the large payloads that human Mars missions demand. Data gathered during the February firing will feed into an upcoming series of higher-power tests.

The MPD thruster program has been in development for approximately two and a half years and is led by JPL in collaboration with Princeton University and NASA's Glenn Research Center in Cleveland. Funding comes from NASA's Space Nuclear Propulsion project, which in 2020 launched a megawatt-class nuclear electric propulsion initiative focused on five critical technology elements for human Mars missions. The project is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, under the agency's Space Technology Mission Directorate.