NASA Tests Powerful Lithium-Fed Thruster That Could Change Deep-Space Travel

NASA is testing a high-power lithium-fed magnetoplasmadynamic thruster at its Jet Propulsion Laboratory as part of efforts to develop faster, more fuel-efficient propulsion for deep-space missions. The prototype reached up to 120 kilowatts during a February 2026 ground test—more than 25 times the power of the electric thrusters currently operating on NASA’s Psyche spacecraft. The technology is still experimental, but NASA says future versions paired with nuclear electric power could support robotic missions across the solar system and potentially help enable crewed missions to Mars.

NASA Is Testing a Different Way to Reach Deep Space

Getting to Mars is not simply a matter of building a more powerful rocket.

Chemical rockets provide enormous thrust during launch, but carrying enough propellant to continuously accelerate a spacecraft through deep space becomes increasingly demanding. Electric propulsion takes the opposite approach: it produces much less thrust, but can accelerate a spacecraft continuously for long periods while using propellant far more efficiently.

NASA has spent decades developing electric propulsion for deep-space missions. The agency’s ion and Hall thrusters have already demonstrated that electrically accelerated plasma can provide sustained propulsion over thousands of hours.

The latest experiment at NASA’s Jet Propulsion Laboratory is aimed at pushing that technology into a much higher-power regime.

In February 2026, engineers fired a prototype lithium-fed magnetoplasmadynamic (MPD) thruster at JPL’s Electric Propulsion Laboratory. During five ignitions, the system reached power levels of up to 120 kilowatts. NASA described this as the highest power level reached by an electric propulsion system in a U.S. test at the time.

The test does not mean a lithium-powered engine is ready to propel astronauts to Mars. Instead, it represents an important ground demonstration of a technology NASA hopes could eventually become part of a much larger nuclear electric propulsion system.

How a Lithium-Fed MPD Thruster Works

The propulsion system tested by NASA belongs to the magnetoplasmadynamic, or MPD, class of electric thrusters.

The basic idea is to turn propellant into plasma and then use electromagnetic forces to accelerate that plasma out of the engine.

In the JPL prototype, lithium metal is converted into vapor and ionized. Electrical current passing through the resulting plasma interacts with a magnetic field, generating electromagnetic forces that accelerate the plasma away from the thruster.

The spacecraft receives an equal and opposite reaction, producing thrust.

This is different from a conventional chemical rocket, where combustion generates expanding gases that are expelled through a nozzle.

It is also important to distinguish this technology from the conventional ion thrusters already flying on NASA missions. NASA’s lithium-fed system is an MPD thruster, although both technologies belong to the broader family of electric propulsion systems.

The attraction is power.

Existing spacecraft electric thrusters typically operate at much lower power levels. NASA says the lithium-fed MPD prototype reached 120 kilowatts, more than 25 times the power of the electric thrusters currently operating on the Psyche spacecraft.

Why Lithium Is Being Considered

Lithium offers several properties that make it interesting as a high-power electric-propulsion propellant.

The metal can be converted into vapor and ionized for use in an electromagnetic propulsion system. NASA’s research is exploring whether lithium can support the combination of high power, efficient propellant use and higher thrust that future deep-space missions may require.

The objective is not simply to make an electric engine more powerful.

A spacecraft traveling through deep space needs to balance propulsion performance against the mass of its power system, propellant and supporting hardware.

A propulsion system capable of producing greater thrust at high efficiency could allow a spacecraft to accelerate more strongly while still retaining the propellant advantages associated with electric propulsion.

NASA says electric propulsion can use up to 90% less propellant than traditional high-thrust chemical propulsion, although the systems produce much lower thrust and generally require long periods of operation.

The 120-Kilowatt Test Is Only the Beginning

The February test was deliberately an early step.

NASA’s JPL team is targeting significantly higher power levels in future development, with a goal of reaching 500 kilowatts to 1 megawatt per thruster.

That jump is substantial.

A 1-megawatt electric propulsion system requires not only a more powerful thruster but also power generation, thermal management, electrical control and structural systems capable of operating under extreme conditions.

The thruster’s components must also survive prolonged exposure to very high temperatures.

During the recent test, the central tungsten electrode reached temperatures above 2,800 degrees Celsius. NASA says demonstrating that the hardware can survive high-temperature operation for thousands of hours will be one of the major challenges ahead.

The current experiment therefore answers one important question—whether the prototype can reach the targeted power range—but leaves many engineering questions still unresolved.

Why Nuclear Power Could Be the Missing Piece

There is a fundamental limitation to high-power electric propulsion: the spacecraft needs a large amount of electricity.

Solar arrays can provide substantial power near the Sun, but available sunlight decreases with distance. Large solar-electric systems also require significant array area and supporting hardware.

For missions deep into the solar system, nuclear electric propulsion offers another possibility.

A nuclear power system could generate electricity independently of sunlight and feed that power into high-performance electric thrusters.

NASA’s Space Nuclear Propulsion project has been developing technologies for a potential megawatt-class nuclear electric propulsion system, with the electric propulsion subsystem being one of several critical technologies.

The lithium-fed MPD thruster is being developed within this broader effort.

NASA’s longer-term target is particularly ambitious: a human Mars mission could require approximately 2 to 4 megawatts of propulsion power, potentially requiring multiple high-power thrusters operating for more than 23,000 hours.

That illustrates the scale of the challenge.

A single 120-kilowatt ground test is an important demonstration, but a Mars-class propulsion system would require orders of magnitude more sustained power and much greater operational endurance.

How Electric Propulsion Could Reduce Deep-Space Travel Times

The key advantage of high-power electric propulsion is not explosive thrust.

It is continuous acceleration.

A chemical rocket delivers a large amount of thrust over a relatively short period. Electric propulsion can provide a much smaller force continuously, allowing the spacecraft to build up velocity over time.

The result can be particularly useful for missions where a spacecraft spends months or years traveling through space.

NASA’s existing electric-propulsion systems demonstrate this principle. The Psyche spacecraft uses solar electric propulsion, and NASA says its thrusters can gradually accelerate the spacecraft to very high velocities despite producing relatively gentle thrust.

Increasing electric-propulsion power could allow future spacecraft to accelerate more strongly while maintaining the propellant-efficiency advantage.

That is why high-power systems are being studied for missions involving large robotic spacecraft, cargo and eventually human exploration.

Mars Is One of the Major Targets

Mars is particularly demanding because a crewed mission would require transporting people, life-support equipment, supplies and other hardware across interplanetary space.

Reducing the amount of propellant needed for propulsion could potentially free mass for other mission requirements.

NASA says lithium-fed MPD thrusters could eventually provide significantly greater thrust than currently flying electric thrusters while retaining high propellant efficiency. If combined with a nuclear power source, the technology could potentially support the payload requirements of human Mars missions.

But that remains a future possibility.

NASA has not demonstrated a complete nuclear-electric Mars transportation system using this technology, and the current thruster is not a flight-ready Mars engine.

The path from a laboratory prototype to a human-rated propulsion system involves years of testing, reliability demonstrations and integration with a complete spacecraft architecture.

Robotic Missions Could Benefit Earlier

Human missions attract the most attention, but high-power electric propulsion could have applications well before astronauts travel to Mars.

Robotic spacecraft could use such systems to transport large scientific instruments, cargo or other equipment through the solar system.

NASA’s technology programmes have long considered high-power electric propulsion for deep-space science missions because the combination of high specific impulse and sustained acceleration can reduce the propellant burden associated with long-duration exploration.

The possibilities extend beyond Mars.

A sufficiently powerful and efficient electric propulsion system could eventually support missions to the outer planets and other destinations where travel time, spacecraft mass and propellant efficiency become major design constraints.

NASA’s earlier lithium-fueled ion-thruster research has even explored extremely high specific impulse concepts for ambitious precursor missions, including potential missions toward the outer solar system.

These concepts remain research projects rather than operational spacecraft technologies.

The Biggest Challenge Is Endurance

Producing high power for a few minutes is not the same as operating an engine reliably for years.

That is one of the most important challenges facing high-power electric propulsion.

NASA’s current development programme ultimately needs to establish that the thruster can survive sustained operation at much higher power levels.

Thermal stress, electrode erosion, material degradation and other effects can become increasingly important as power rises.

The JPL team therefore plans additional testing after the initial 120-kilowatt demonstration. NASA says future work will focus on scaling the technology while addressing the challenges associated with long-duration, high-power operation.

For a human Mars mission, the required endurance would be particularly demanding.

The agency estimates that multiple MPD thrusters could need to operate for more than 23,000 hours for such a mission architecture.

That is why the present test should be viewed as a technology milestone rather than a finished propulsion solution.

A New Generation of Deep-Space Propulsion

NASA’s lithium-fed MPD experiment represents a broader shift in space propulsion research.

For decades, electric propulsion has been valued for efficiency but constrained by relatively low thrust and available electrical power. Researchers are now attempting to push electric propulsion toward hundreds of kilowatts and eventually megawatt-class systems.

The combination of high-power electric thrusters and nuclear electricity could change the way future spacecraft are designed.

Instead of relying primarily on short bursts of chemical propulsion followed by long periods of coasting, spacecraft could potentially accelerate for much longer portions of their journeys.

That does not make interplanetary travel instantaneous. Nor does it mean astronauts are about to fly to Mars using the new thruster.

What NASA’s latest test demonstrates is something more practical: engineers are beginning to prove the individual technologies needed for a radically different approach to deep-space transportation.

The next challenge is to make that technology powerful, durable and efficient enough to leave the vacuum chamber and operate reliably in space.

MOST SEARCHED FAQ

What is NASA’s lithium-fed thruster?
It is a prototype magnetoplasmadynamic (MPD) electric thruster that uses lithium metal vapor as its propellant. NASA’s Jet Propulsion Laboratory tested the system at power levels of up to 120 kilowatts in February 2026.

How does a lithium-fed MPD thruster work?
The system converts lithium into vapor and ionizes it into plasma. Electrical current interacts with a magnetic field to accelerate the plasma out of the thruster, producing thrust.

How powerful is NASA’s lithium-fed thruster?
The prototype reached up to 120 kilowatts during its February 2026 test. NASA says this was more than 25 times the power of the electric thrusters currently operating on the Psyche spacecraft.

Could NASA’s lithium thruster reduce travel time to Mars?
Potentially, if the technology can be scaled to much higher power and operated reliably for long periods. NASA is targeting future systems in the 500-kilowatt-to-1-megawatt range, and has studied nuclear electric propulsion architectures for human Mars missions.

Is NASA’s lithium-fed thruster ready for a Mars mission?
No. The current system is an experimental ground-tested prototype. NASA says substantial additional development is required, particularly to demonstrate long-duration operation at much higher power levels before the technology could support a Mars mission.