A team of researchers at MIT has demonstrated a propulsion technology that could dramatically expand the capabilities of small satellites, potentially allowing compact spacecraft to travel to destinations as distant as Mars and the asteroid belt. The breakthrough, reported in the Journal of Propulsion and Power, combines two fundamentally different propulsion methods into a single system powered by one shared fuel source. If successfully demonstrated in orbit, the innovation could redefine what low-cost CubeSats are capable of accomplishing beyond Earth.
A Single System That Combines The Best Of Two Propulsion Worlds
For decades, spacecraft designers have faced a trade-off when choosing propulsion systems. Chemical rockets provide powerful bursts of thrust that allow spacecraft to maneuver rapidly, change trajectories, and react quickly to mission demands. Electric propulsion systems, by contrast, generate much lower thrust but are exceptionally efficient, allowing spacecraft to travel vast distances while consuming minimal fuel.
MIT researchers believe they have found a way to combine these strengths without requiring separate fuel systems. Their dual-mode architecture uses a single propellant capable of powering both chemical and electric thrusters. The result is a compact package that can fit aboard small satellites while offering a level of operational flexibility previously associated with much larger spacecraft.
“If you can have chemical and electrical propulsion in one small package, it’s the best of both worlds,” says Amelia Bruno, a former postdoctoral researcher in MIT’s Department of Aeronautics and Astronautics (AeroAstro). “This opens the door for small satellites to do even more science, more observations, and more interesting missions, all on a smaller and cheaper platform.”
The concept addresses one of the biggest limitations facing CubeSats today. These spacecraft are inexpensive to launch and increasingly capable, yet their small size restricts the amount of hardware they can carry. By eliminating the need for multiple propellant systems, engineers can free up valuable volume and mass for scientific instruments, communications equipment, or additional mission capabilities.
How Electrospray Thrusters Could Carry CubeSats Across Deep Space
At the center of the MIT effort is a miniature electric propulsion technology known as an electrospray thruster. These tiny devices use electric fields to charge particles within a liquid propellant and then accelerate those charged particles into space, generating thrust. Although the force produced is small, the efficiency is remarkable.
Over time, this steady acceleration allows spacecraft to travel enormous distances while consuming very little fuel. That characteristic makes electrospray systems particularly attractive for deep-space exploration missions where efficiency is often more important than raw power.
The technology developed by MIT’s Space Propulsion Laboratory is remarkably compact. Individual thrusters are roughly the size of a thumbnail, making them suitable for CubeSats and other small spacecraft platforms. Despite their size, these systems can operate continuously for extended periods, gradually building velocity over months or years.
According to the research team, ionic liquids play a critical role in making this possible. These materials remain liquid under conditions where many conventional fluids would fail, including the harsh environment of space.
“Ionic liquids are very stable and can even remain a liquid in space, which not a lot of materials can do,” Bruno says. “And it’s basically a sea of ions, which is why we base our technology around it, so we can pull those ions out into an electrospray.”
This stability gives engineers a reliable medium for generating electric propulsion while maintaining long operational lifetimes, a key requirement for future interplanetary missions.
The ASCENT Fuel That Made The Breakthrough Possible
The foundation of MIT’s dual-mode concept is a propellant known as ASCENT, short for Advanced SpaceCraft Energetic Non-Toxic propellant. Originally developed by the U.S. Air Force as an alternative to toxic hydrazine fuel, ASCENT was designed primarily for chemical propulsion systems.
Researchers soon realized the propellant possessed characteristics that made it potentially compatible with electrospray propulsion as well. Since ASCENT is itself an ionic liquid mixture, it appeared capable of serving both propulsion modes simultaneously.
“ASCENT happens to be an ionic liquid mixture,” Bruno says. “And we said, hey, that’s the stuff we typically use. Theoretically, this should work. Let’s go figure out how.”
To test the idea, the team conducted extensive laboratory experiments using electrospray thrusters fueled with ASCENT. Engineers mounted the systems on a specialized magnetic levitation platform inside a vacuum chamber that simulated space conditions. During testing, the thrusters generated enough force to rotate a CubeSat-like structure while operating continuously for periods reaching 100 hours.
The results showed that ASCENT performed comparably to conventional electrospray propellants while retaining its usefulness for chemical propulsion. This outcome validated the central premise of the dual-mode architecture and opened the door to practical mission designs based on a shared propellant supply.
The findings were published in the Journal of Propulsion and Power, providing one of the strongest demonstrations yet that a single fuel can effectively support both high-thrust chemical maneuvers and highly efficient electric propulsion.
Why This Technology Could Open A Path To Mars And The Asteroid Belt
The implications extend far beyond improved satellite efficiency. Researchers envision future CubeSats using electrospray propulsion for long-duration interplanetary travel before switching to chemical propulsion when rapid maneuvering becomes necessary near scientific targets.
“We could send CubeSats to Mars, or the asteroid belt, where they could make the journey slowly, using electrospray thrusters,” says study co-author Paulo Lozano, the Miguel Alemán Velasco Professor of Aeronautics and Astronautics at MIT. “You could then use your chemical thrusters to quickly move to look at interesting features. You could have a lot more flexibility to do a lot more things.”
This flexibility is particularly attractive for missions operating on tight budgets. Traditionally, deep-space exploration has required large spacecraft carrying substantial amounts of fuel and expensive propulsion hardware. A successful dual-mode system could allow smaller, cheaper spacecraft to perform meaningful scientific investigations across the solar system.
Scientists could deploy swarms of CubeSats rather than relying on a single large spacecraft. Such missions could collect data from multiple locations simultaneously, increasing scientific return while reducing costs and risk.
NASA’s Upcoming Mission Will Put The Concept To The Test
The next major milestone will come through NASA’s Green Propulsion Dual Mode mission, which aims to provide the first in-space demonstration of the technology. The CubeSat mission will carry one chemical thruster and four electrospray thrusters connected to a shared fuel tank containing ASCENT propellant.
The mission represents a significant step because no satellite has previously operated with this type of integrated propulsion architecture.
“This will be the first time that a satellite will have a shared propellant tank,” says Lozano.
Researchers believe the benefits could extend well beyond planetary exploration. Earth-observation missions may gain the ability to reposition satellites quickly when immediate data collection is needed while retaining efficient long-term station-keeping capabilities.
“Say there’s a storm coming, and you’d want to deploy your constellation of small satellites to observe over one location,” he says. “You could choose to send them quickly or slowly depending on the nature of the observation. And the only way to do that is if you have two propulsion systems, which is now possible.”
The Next Chapter For Small Satellite Exploration
Testing also revealed that ASCENT performs at levels comparable to established electrospray fuels, giving researchers confidence that further optimization could unlock even greater capabilities.
“Compared to our normal electrospray propellants, ASCENT can provide similar performance in terms of thrust,” Bruno says. “Now that we know our thrusters work with ASCENT, we can start thinking of all the ways we can make them even better.”
As launch costs continue to fall and small satellites become increasingly sophisticated, propulsion remains one of the most important factors determining mission capability. MIT’s dual-mode system offers a new approach that combines efficiency, flexibility, and simplicity within an exceptionally compact package. If the upcoming NASA demonstration succeeds, the technology could help transform CubeSats from Earth-orbiting instruments into capable explorers of the wider solar system.