NASA Tests Powerful Lithium-Fed Thruster Prototype for Potential Deep Space Missions

NASA recently tested a prototype electromagnetic thruster running on lithium metal vapor at the Jet Propulsion Laboratory in Southern California, marking a step in electric propulsion research aimed at potential future crewed missions to Mars and robotic solar system exploration.

On Feb. 24, a team successfully fired the lithium-fed magnetoplasmadynamic (MPD) thruster at power levels reaching up to 120 kilowatts, exceeding previous tests in the United States and surpassing the power levels of electric thrusters on current agency spacecraft. Data from these initial ignitions will inform an upcoming series of tests.

Test Highlights and Operations

• High Power Achievement: The prototype reached up to 120 kilowatts, which is over 25 times the power of the thrusters currently used on NASA's Psyche mission.
• Extreme Temperatures: During five ignitions, the central tungsten electrode reached over 5,000 degrees Fahrenheit (2,800 degrees Celsius).
• Facility Used: Testing took place in JPL’s Electric Propulsion Lab, utilizing the condensable metal propellant vacuum facility.

Technology and Future Goals

Electric propulsion systems generally use significantly less propellant than traditional chemical rockets. While current operational thrusters, such as those on Psyche, rely on solar power, the MPD engine uses high currents interacting with a magnetic field to accelerate lithium plasma electromagnetically.

Researchers note that lithium-fed MPD thrusters have been studied since the 1960s but have not yet flown operationally. The current development effort is led by JPL in collaboration with Princeton University and NASA’s Glenn Research Center, funded by the Space Nuclear Propulsion project under NASA’s Space Technology Mission Directorate.

Practical Implications and Verification

If fully developed and potentially paired with a nuclear power source, high-power MPD thrusters could reduce launch mass and support payloads for deep space exploration. However, significant engineering challenges remain, including proving that components can withstand extreme operating temperatures over thousands of hours. The team aims to reach power levels between 500 kilowatts and 1 megawatt per thruster in coming years.

Readers can verify official announcements, technical papers, and updates by visiting NASA's official website or checking press releases issued by the Jet Propulsion Laboratory.