UF engineering team tackles spaceflight fuel challenge in zero-gravity experiment
A University of Florida engineering research team led by Jacob Chung, Ph.D., a professor in the Department of Mechanical and Aerospace Engineering and member of the Astraeus Space Institute, has successfully completed a zero-gravity flight experiment testing a breakthrough method to reduce fuel loss in space.
The work — funded by NASA’s Flight Opportunities program — aims to solve one of the most pressing technical challenges in deep space exploration: preventing the boil-off of cryogenic rocket fuels during long missions. Without efficient thermal management, the supercooled propellants essential to future moon and Mars missions can gradually evaporate, rendering them unusable.
“Propellant loss due to boiling and evaporation in storage tanks during long-term space missions is one of the most important considerations in tank design,” Chung said. “Once cryogenic liquid turns to vapor, it can no longer be used as propellant. Our research is focused on providing a technology to minimize or even eliminate that boil-off loss.”
Flying aboard a zero-G parabolic flight on May 2 and May 5, the UF team tested four advanced coating materials applied to the inside of cryogenic propellant tanks. These coatings are designed to suppress the boiling of liquid fuels in reduced gravity conditions, using two materials based on aluminum and stainless steel that emulate common spacecraft tank designs.
“The thin-film coatings we tested are fundamentally different from conventional insulation,” Chung said. “Existing solutions rely on adding heavy thermal insulation layers. Our coatings are extremely lightweight and actively reduce boil-off, offering a promising alternative for spacecraft fuel tank design.”
UF researchers collected heat transfer data during four total parabolic flights across the experiment campaign, culminating in a successful final round this spring. The results will help identify the coating that offers the best insulation performance in microgravity.
“Boil-off behavior in space is completely different from on Earth because there’s no buoyancy in microgravity,” Chung explained. “The microgravity environment provided by the parabolic flight was indispensable in developing and validating our technology.”
The technology developed at UF could play a pivotal role in extending human exploration beyond low Earth orbit. For missions to the moon, Mars, or even further destinations, every drop of fuel matters. Space agencies are particularly interested in improving long-term in-orbit fuel storage, where the absence of gravity makes traditional thermal management techniques less effective.
“The extension of human space exploration — from low Earth orbit to the moon, Mars, and beyond — is one of NASA’s greatest challenges,” said Chung. “A sufficient, reliable supply of cryogenic propellant is essential, and our work contributes to making that feasible.”
As a member of the Astraeus Space Institute, Chung’s team represents UF’s growing role in national space innovation. Astraeus connects researchers from across disciplines to tackle the toughest questions in human spaceflight and aerospace systems.
“We’ve completed four flights so far and are still analyzing data,” Chung said. “Our preliminary results show promising trends, and we plan to apply for two additional flights to test even more coating candidates. We hope this research will soon offer meaningful new options for NASA and the space industry to manage boil-off more effectively.”
With NASA looking ahead to the Artemis missions and eventual crewed travel to Mars, UF researchers are helping ensure that tomorrow’s spacecraft are not only launch-ready, but deep-space ready.
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