A sealed sample of Concordia University’s kerosene gel stayed visibly unchanged for more than a year, while becoming about 100 times less viscous when pushed harder. That unusual mix of steadiness and flow could help researchers tackle a basic problem in space travel: how to keep fuel still in storage but move it reliably into an engine when needed.
The gel was developed by researchers in Montreal using kerosene, lecithin and a small amount of calcium chloride. Lecithin is a naturally derived substance that can burn. The team designed the mixture to address limits found in both liquid and gel fuels. Liquid fuel can slosh around inside a tank, making a spacecraft harder to control. Gel fuel may stay in place, but some gels are difficult to pump and spray into an engine so they can burn.
The new material changes its behavior depending on the force applied to it. At rest, it acts more like a soft solid, which could help limit unwanted movement and leakage. When more force is applied, its viscosity—the measure of how much a liquid resists flowing—falls by about 100 times. That shift could make the gel easier to move through a fuel system and inject into an engine.
The researchers also tested how the material responded to temperature and chemical changes. In sealed containers, samples showed no visible separation after more than a year. The gel is transparent, too, giving researchers a way to watch how fuel moves and burns as they study its behavior. Together, these tests offer a detailed picture of how the mixture responds under different conditions and point to properties that may matter for dependable fuel storage and delivery.
The findings are a promising starting point, not proof that the gel is ready to power a spacecraft. The research has not yet established how it performs in an actual propulsion system. Engine tests will be needed to find out whether the material can be pumped, sprayed and burned reliably in real operating conditions, and whether its storage and flow advantages hold up in a spaceflight setting.
The study was carried out by researcher Pranay Mudaliar and Jerin John, an associate professor of Mechanical, Industrial and Aerospace Engineering at Concordia. Their paper, “Rheology and Thermal Characterization of Lecithin-Based Kerosene Gels for In-Space Propulsion,” appeared in the journal Langmuir in 2026. By showing that a fuel can behave like a soft solid at rest and flow much more easily under force, the work gives future testing a clear question to answer: can that balance make spacecraft fuel systems easier to control?