A propulsion bottleneck for small satellites may be loosening
Engineers at MIT have tested a hybrid propulsion system that could make small satellites far more capable by solving an old design tradeoff. The concept combines chemical thrusters, which provide short bursts of strong thrust, with electrospray thrusters, which deliver much more efficient but slower propulsion over long periods. The key advance is that both systems can run on the same fuel.
For CubeSats and other microsatellites, that matters a great deal. Small spacecraft are attractive because they are cheaper and easier to launch than conventional satellites, but their size leaves little room for multiple propulsion systems and separate tanks. If a mission requires both quick orbital maneuvers and gradual deep-space acceleration, fitting those capabilities into one compact platform becomes difficult.
MIT’s result suggests that constraint may not be as fixed as it once seemed. By using a propellant known as ASCENT for both propulsion modes, the team is pointing toward a way for small spacecraft to gain flexibility without carrying incompatible fuel architectures.
Why one fuel changes the equation
Chemical and electric propulsion each solve a different problem. Chemical thrusters burn fuel rapidly and produce powerful thrust, making them useful for fast orbit changes that happen in seconds. Electrospray thrusters are much slower, but they are exceptionally fuel-efficient and well suited to precision adjustments or long-duration acceleration over months or years.
Until now, using both approaches on a very small spacecraft has generally meant accepting added complexity. Different propulsion systems typically require different fuels, storage methods and supporting hardware. On a platform the size of a shoebox or carry-on bag, that is a major penalty.
The breakthrough described in the report comes from the properties of ASCENT, short for Advanced SpaceCraft Energetic Non-Toxic propellant. Developed by the US Air Force as a greener alternative to hydrazine, ASCENT was originally intended for chemical thrusters. But it also has a feature that makes it unusual: it is an ionic liquid.
Ionic liquids are salts that remain liquid even in the vacuum of space, which is rare and useful. That stability makes them suitable for electrospray propulsion, where charged droplets or ions are accelerated to generate thrust. In other words, a propellant created for one mode of space propulsion turned out to have a hidden second life.
Testing the idea in simulated weightlessness
The MIT team used a magnetic levitation thrust stand designed to simulate the weightlessness of space and measure thrust from ASCENT-fueled electrospray thrusters. The report says the engineers successfully tested the hybrid concept, demonstrating that the same fuel can support both the quick-force needs of chemical propulsion and the long-haul efficiency of electric thrust.
The article also notes that four electrospray flight thrusters built by MIT’s Space Propulsion Laboratory are destined for NASA’s upcoming Green Propulsion Dual Mode mission. That point matters because it connects laboratory development to an actual spaceflight path. The work is not only theoretical. It is being prepared for a mission context in which the concept can be assessed more directly.
The report references Lunar Flashlight, a low-cost CubeSat powered by ASCENT green propellant and designed to map ice on the Moon’s south pole. That example reinforces the strategic appeal of green propellants in small missions, where toxicity, handling complexity and mass constraints all matter.
What this could unlock for CubeSats
If a small satellite can carry one fuel and still switch between high-thrust maneuvers and efficient long-duration propulsion, mission designers gain options that have traditionally belonged to larger platforms. A CubeSat could potentially handle orbital insertion tasks more aggressively, then transition to precise corrections or long interplanetary cruises using the same onboard propellant family.
That is why the headline claim in the report is so striking: thumbnail-sized thrusters could eventually help CubeSats reach Mars and beyond. The wording is aspirational, but the logic is clear. Interplanetary missions demand efficiency, while deployment and navigation can still require bursts of stronger thrust. A dual-mode architecture could narrow the gap between what small spacecraft cost and what they can accomplish.
The appeal is not only scientific. Lower-cost spacecraft with more versatile propulsion could expand access for universities, smaller companies and agencies looking to distribute risk across multiple smaller missions rather than one large platform.
Green propellant is part of the story too
ASCENT’s role as a non-toxic alternative to hydrazine is more than a side note. Hydrazine has long been effective but notoriously hazardous to handle. Safer propellants can lower operational burdens and open mission possibilities for organizations that do not want the infrastructure overhead tied to highly toxic fuels.
In that sense, MIT’s work sits at the intersection of two important trends in space systems: miniaturization and greener propulsion. The combination is powerful because it addresses both cost and practicality. Small satellites are only truly transformative if they can do more without inheriting the operational complexity of larger systems.
A technical result with strategic implications
The MIT tests do not mean every CubeSat is suddenly headed for deep space. Flight validation, durability and mission integration still matter, and engineering breakthroughs often take time to move from promising demonstrations to routine deployment. But the concept tackles a real bottleneck with an elegant answer: one fuel, two propulsion regimes, one much more capable class of small spacecraft.
That is why the work stands out. It is not simply another incremental thruster refinement. It is a systems-level simplification that could expand the mission envelope of compact satellites. For an industry pushing toward lower-cost, more distributed space infrastructure, that kind of simplification can matter as much as raw performance.
If the upcoming mission work confirms the promise of the concept, the result could be a new generation of small spacecraft that no longer have to choose so sharply between agility and endurance. For CubeSats, that would be a meaningful upgrade in ambition as well as reach.
This article is based on reporting by New Atlas. Read the original article.
Originally published on newatlas.com
