The thruster uses lithium metal vapor as propellant, accelerated by high currents and magnetic fields to create plasma. In contrast, current electric thrusters, such as those on NASA's Psyche mission, use solar power to accelerate propellants. The MPD thruster achieved power levels over 25 times that of Psyche's thrusters, which are the highest-power electric thrusters on any NASA spacecraft to date. The tungsten electrode reached temperatures exceeding 5,000 degrees Fahrenheit (2,800 degrees Celsius), NASA officials said. Electric propulsion uses up to 90% less propellant than traditional chemical rockets, offering significant mass savings.
The test was conducted in JPL's Electric Propulsion Lab, which features a vacuum facility designed for metal vapor propellants. NASA Administrator Jared Isaacman said the successful test demonstrates real progress toward sending an American astronaut to Mars. James Polk, senior research scientist at JPL, noted that the team hit their target power levels and now have a good testbed for scaling up the technology. The thruster could potentially propel crewed missions to Mars and robotic spacecraft throughout the solar system, though specific timelines and challenges to scaling remain unclear.