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The engine for future interplanetary missions has passed a key test.
A trip to Mars has long been dependent not only on rockets but also on an engine capable of sustainably and efficiently propelling a heavy spacecraft through deep space. Now, NASA has significant cause for cautious optimism. At the Jet Propulsion Laboratory (JPL) in California, engineers have conducted the first U.S. test of an electromagnetic engine powered by metallic lithium vapor in many years, achieving a record-breaking power output for the country.
The JPL team fired a prototype lithium magnetoplasmadynamic thruster, or MPD thruster. During a series of five firings, the system reached a power output of up to 120 kilowatts. This exceeded the output of all electric thrusters currently powering the agency's active spacecraft. The data obtained will help prepare the next series of tests and understand how to further scale up the design.
NASA Administrator Jared Isaacman stated that the agency is not losing sight of a manned mission to Mars, and the successful test demonstrates real progress toward landing an American astronaut on the Red Planet. According to Isaacman, an electric propulsion system in the United States has never operated at such a high power. The test facility was able to reach 120 kilowatts, and NASA intends to continue investing in this type of research.
Electric propulsion has long been considered one of the most promising options for long-range missions. Unlike chemical rockets, electric engines consume much less propellant, with savings reaching 90 percent. Instead of a powerful, short burst of thrust, these systems generate a weak but constant thrust and gradually accelerate the vehicle to very high speeds. This is the principle used, for example, by the Psyche mission. Its engines are currently considered the most powerful of all electric engines on NASA's existing spacecraft, but the new JPL prototype has already exceeded Psyche's performance by more than 25 times.
The main difference between the MPD thruster and conventional electric systems is its operating principle. Conventional systems use electricity to accelerate gas ions. The lithium MPD thruster accelerates plasma electromagnetically: a strong current interacts with a magnetic field, ejecting a plasma stream outward. This concept has been studied since the 1960s, but the technology has never reached the point of actual space use.
The tests took place in JPL's Electrical Laboratory, home to a unique vacuum facility for safely handling condensable metal propellants. During the test, the tungsten electrode in the center of the engine glowed white-hot, exceeding 5,000 degrees Fahrenheit, or approximately 2,800 degrees Celsius. The project manager, JPL Senior Scientist James Polk, observed the launch through a small window in the 8-meter-long, water-cooled vacuum chamber. Inside the chamber, the engine glowed brightly, and a deep red plume erupted from the nozzle.
For Polk, the test was a particularly important moment. The researcher has been working on lithium MPD thrusters for decades and previously worked on the Dawn mission, as well as Deep Space 1, the first NASA project to demonstrate electric propulsion beyond low-Earth orbit. According to Polk, years of design and assembly work finally led to the first full-scale test, which confirmed the thruster's functionality and the target power level.
The next goal is far more ambitious. The JPL team expects to increase a single engine's output to between 500 kilowatts and 1 megawatt in the coming years. This is no longer a question of launch alone, but rather a question of materials endurance. At such temperatures, engineers must prove that engine components can withstand many hours of continuous operation without failure. NASA estimates that a manned mission to Mars would require between 2 and 4 megawatts of power. Such a spacecraft would likely need multiple MPD engines, with a combined operating time of over 23,000 hours.
If the technology reaches a mature stage and is powered by a nuclear power source, the advantages will be significant. Lithium MPD engines can combine high power, low propellant consumption, and greater thrust than current space electrical systems. In practical terms, such a setup promises to reduce the launch mass of an interplanetary spacecraft and simplify the delivery of the payload needed for a manned mission to Mars. While this is still just a prototype and initial testing, for a project of this scale, even one successful launch represents a significant step forward.
A trip to Mars has long been dependent not only on rockets but also on an engine capable of sustainably and efficiently propelling a heavy spacecraft through deep space. Now, NASA has significant cause for cautious optimism. At the Jet Propulsion Laboratory (JPL) in California, engineers have conducted the first U.S. test of an electromagnetic engine powered by metallic lithium vapor in many years, achieving a record-breaking power output for the country.
The JPL team fired a prototype lithium magnetoplasmadynamic thruster, or MPD thruster. During a series of five firings, the system reached a power output of up to 120 kilowatts. This exceeded the output of all electric thrusters currently powering the agency's active spacecraft. The data obtained will help prepare the next series of tests and understand how to further scale up the design.
NASA Administrator Jared Isaacman stated that the agency is not losing sight of a manned mission to Mars, and the successful test demonstrates real progress toward landing an American astronaut on the Red Planet. According to Isaacman, an electric propulsion system in the United States has never operated at such a high power. The test facility was able to reach 120 kilowatts, and NASA intends to continue investing in this type of research.
Electric propulsion has long been considered one of the most promising options for long-range missions. Unlike chemical rockets, electric engines consume much less propellant, with savings reaching 90 percent. Instead of a powerful, short burst of thrust, these systems generate a weak but constant thrust and gradually accelerate the vehicle to very high speeds. This is the principle used, for example, by the Psyche mission. Its engines are currently considered the most powerful of all electric engines on NASA's existing spacecraft, but the new JPL prototype has already exceeded Psyche's performance by more than 25 times.
The main difference between the MPD thruster and conventional electric systems is its operating principle. Conventional systems use electricity to accelerate gas ions. The lithium MPD thruster accelerates plasma electromagnetically: a strong current interacts with a magnetic field, ejecting a plasma stream outward. This concept has been studied since the 1960s, but the technology has never reached the point of actual space use.
The tests took place in JPL's Electrical Laboratory, home to a unique vacuum facility for safely handling condensable metal propellants. During the test, the tungsten electrode in the center of the engine glowed white-hot, exceeding 5,000 degrees Fahrenheit, or approximately 2,800 degrees Celsius. The project manager, JPL Senior Scientist James Polk, observed the launch through a small window in the 8-meter-long, water-cooled vacuum chamber. Inside the chamber, the engine glowed brightly, and a deep red plume erupted from the nozzle.
For Polk, the test was a particularly important moment. The researcher has been working on lithium MPD thrusters for decades and previously worked on the Dawn mission, as well as Deep Space 1, the first NASA project to demonstrate electric propulsion beyond low-Earth orbit. According to Polk, years of design and assembly work finally led to the first full-scale test, which confirmed the thruster's functionality and the target power level.
The next goal is far more ambitious. The JPL team expects to increase a single engine's output to between 500 kilowatts and 1 megawatt in the coming years. This is no longer a question of launch alone, but rather a question of materials endurance. At such temperatures, engineers must prove that engine components can withstand many hours of continuous operation without failure. NASA estimates that a manned mission to Mars would require between 2 and 4 megawatts of power. Such a spacecraft would likely need multiple MPD engines, with a combined operating time of over 23,000 hours.
If the technology reaches a mature stage and is powered by a nuclear power source, the advantages will be significant. Lithium MPD engines can combine high power, low propellant consumption, and greater thrust than current space electrical systems. In practical terms, such a setup promises to reduce the launch mass of an interplanetary spacecraft and simplify the delivery of the payload needed for a manned mission to Mars. While this is still just a prototype and initial testing, for a project of this scale, even one successful launch represents a significant step forward.
