You could have a lot more flexibility to do a lot more things.
For decades, the dream of sending small satellites on ambitious journeys has been constrained by a fundamental tension: the fuel that moves fast is not the fuel that moves far. A team at MIT has resolved this tension by discovering that a single ionic liquid propellant can feed two entirely different kinds of engines, granting tiny CubeSats both the agility of chemical thrust and the endurance of electric propulsion. In doing so, they have not merely solved an engineering problem — they have quietly expanded the boundary of where humanity's smallest eyes in space might one day look.
- CubeSats have long been trapped between two propulsion worlds — fast or far, but never both — leaving deep-space ambitions out of reach for small, affordable spacecraft.
- MIT researchers discovered that a single Air Force-developed propellant, ASCENT, can simultaneously power chemical thrusters for rapid bursts and electrospray thrusters the size of a dime for slow, precise long-distance travel.
- Vacuum chamber tests — including 100-hour continuous runs on magnetically levitated satellites — confirmed the dual-mode system performs on par with conventional propulsion, turning theory into demonstrated hardware.
- NASA's Green Propulsion Dual Mode CubeSat mission, launching November 2026, will put this unified fuel system to its first real test in orbit, carrying one chemical and four electrospray thrusters from a single shared tank.
- If the mission succeeds, CubeSats could realistically navigate to Mars and the asteroid belt, reshaping the economics and reach of planetary science for a fraction of traditional mission costs.
A team at MIT has solved a long-standing dilemma in small satellite design: how to give a spacecraft both the speed for rapid maneuvers and the efficiency for long-distance travel. The answer turned out to be a single fuel powering two entirely different engines.
Traditionally, chemical and electric propulsion systems each demand their own fuel supply, plumbing, and mass — a serious burden for CubeSats, where every gram is precious. Researcher Amelia Bruno and her colleagues discovered that ASCENT, an ionic liquid propellant originally developed by the U.S. Air Force as a safer alternative to toxic hydrazine, could also drive miniature electrospray thrusters. These dime-sized devices use electric fields to expel charged particles, offering quiet, fuel-efficient thrust ideal for long journeys. Chemical thrusters, by contrast, deliver powerful short bursts for quick repositioning. Fed from one shared tank, the two systems together give a small satellite a flexibility it has never had before.
To validate the concept, the team loaded gram-sized reservoirs of ASCENT onto a CubeSat, levitated it magnetically inside a vacuum chamber, and fired the electrospray thrusters at varying voltages. The satellite spun freely, some tests running for 100 continuous hours. ASCENT proved comparable to conventional electric propulsion fuels, confirming the system was ready for the next step.
Co-author Paulo Lozano envisions applications well beyond deep space — from storm observation to climate monitoring — anywhere a satellite might need to shift fluidly between speed and endurance. The technology also promises simpler designs and lower launch costs. The first true test arrives in November 2026, when NASA's Green Propulsion Dual Mode CubeSat lifts off carrying both thruster types on a single propellant tank. Success would mark the opening of a new era for small spacecraft — one capable of reaching Mars, the asteroid belt, and serious science on platforms once considered too modest for such ambitions.
A team at MIT has cracked a problem that has long constrained the ambitions of small satellites: how to give them both the punch to move fast and the efficiency to travel far. The solution is elegantly simple—a single fuel that powers two entirely different kinds of engines.
Traditionally, spacecraft that need rapid maneuvers carry chemical thrusters, while those designed for long journeys rely on electric propulsion. Each requires its own fuel supply, its own plumbing, its own weight and volume. For tiny satellites called CubeSats—roughly the size of a briefcase—every gram matters. The MIT researchers, led by Amelia Bruno, a former postdoctoral researcher in the Department of Aeronautics and Astronautics, found that a new ionic liquid propellant developed by the U.S. Air Force could do both jobs. The fuel, called ASCENT (Advanced SpaceCraft Energetic Non-Toxic propellant), was originally designed as a safer alternative to hydrazine, a toxic chemical used in traditional spacecraft propulsion. But Bruno and her colleagues realized it had another property: it could also power miniature electrospray thrusters, which are roughly the size of a dime and work by using electrical fields to charge particles in liquid propellant, then expelling them into space.
The implications are substantial. Chemical thrusters generate enormous force for short bursts—perfect for rapid course corrections or quick accelerations. Electrospray thrusters are far more fuel-efficient and excel at slow, precise maneuvers over long distances. By combining both in a single system fed from one tank, small satellites gain flexibility that was previously impossible. A CubeSat could drift slowly across the solar system using its electric thrusters, then fire its chemical engines to quickly reposition itself to observe an interesting feature on an asteroid or in the Martian landscape.
To prove the concept worked, the team conducted extensive tests. They filled tiny reservoirs—each about the size of a LEGO brick—with one gram of ASCENT and mounted electrospray thrusters on opposite sides of a CubeSat. Inside a vacuum chamber, they magnetically levitated the satellite and applied different voltage levels to the thrusters. The resulting sprays generated enough force to spin the satellite like a floating top. Some tests ran continuously for as long as 100 hours. The results showed that ASCENT performed comparably to conventional ionic liquids already used in electric propulsion systems, proving the concept was viable.
Paulo Lozano, the Miguel Alemán Velasco Professor of Aeronautics and Astronautics at MIT and a co-author of the study published in the Journal of Propulsion and Power, sees the potential extending far beyond Mars missions. Weather monitoring, climate research, rapid deployment of satellite constellations to observe storms—all become more flexible and affordable when a single spacecraft can choose whether to move quickly or slowly depending on the mission's needs. The technology could also simplify design and reduce launch costs, since smaller, lighter satellites are cheaper to put into orbit.
The real test comes this November, when NASA launches the Green Propulsion Dual Mode mission—a CubeSat carrying one chemical thruster and four electrospray thrusters all fed from a shared propellant tank. It will be the first time a satellite has flown with this kind of unified fuel system. If it succeeds, the door opens for a new generation of small spacecraft capable of reaching the asteroid belt, Mars, and beyond—doing serious science on platforms that are smaller, cheaper, and far more flexible than anyone thought possible.
Notable Quotes
If you can have chemical and electrical propulsion in one small package, it's the best of both worlds. 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.— Amelia Bruno, MIT researcher
We could send CubeSats to Mars, or the asteroid belt, where they could make the journey slowly, using electrospray thrusters. You could then use your chemical thrusters to quickly move to look at interesting features.— Paulo Lozano, MIT professor
The Hearth Conversation Another angle on the story
Why does it matter that both thrusters can use the same fuel? Couldn't you just carry two separate tanks?
You could, but every kilogram matters on a small satellite. A shared tank means less plumbing, less weight, less volume. On a CubeSat, that's the difference between fitting in a launch slot and not fitting at all.
So the ASCENT propellant was designed for something else entirely?
Yes—the Air Force developed it as a safer alternative to hydrazine, which is toxic and dangerous to handle. But it turns out ASCENT is an ionic liquid, which is exactly what electrospray thrusters need. Sometimes the best solutions come from unexpected places.
What can a CubeSat actually do with this system that it couldn't do before?
Imagine a CubeSat heading to Mars. It can drift slowly and efficiently using its electric thrusters to save fuel. But when it reaches an interesting crater or rock formation, it can fire its chemical thrusters to quickly move into position for detailed observations. Before, you had to choose: be fast or be efficient. Now you can be both.
How small are these electrospray thrusters?
About the size of a dime. The whole reservoir holding the propellant is roughly the size of a LEGO brick. That's the engineering challenge—making something powerful enough to move a spacecraft while keeping it small enough to fit on something you can hold in your hand.
What happens in November when NASA launches this mission?
That's the first real test in space. Everything so far has been in laboratories and vacuum chambers. If the dual-mode system works as expected in actual spaceflight, it changes what's possible for small satellite missions. If there are problems, we learn what needs fixing before the next attempt.
Could this technology work for missions closer to Earth?
Absolutely. Imagine a storm forming and you need to quickly position a constellation of small satellites to observe it. With dual-mode propulsion, you can send them fast or slow depending on what you need. That flexibility is valuable for weather monitoring and climate research—things that matter to people right now.