A team from the Department of Energy’s Oak Ridge National Laboratory, joined by university students, recently traveled to The Ohio State University Research Reactor to conduct a novel experiment on nuclear thermal rocket fuel coatings — one that could help propel NASA’s astronauts to Mars faster and more efficiently. 

“Our experiment aimed to test a fuel coating technique and evaluate if it can withstand the intense environment of a nuclear thermal rocket,” said Brandon Wilson, an R&D staff member in ORNL’s Nuclear and Extreme Environment Measurement group. “Testing materials at exceptionally high temperatures is a first and a crucial step toward helping NASA mature and qualify nuclear fuels for manned space exploration using nuclear thermal propulsion technology.” 

Nuclear thermal propulsion, or NTP, is a potentially game-changing technology for NASA’s crewed missions to Mars in the 2040 timeframe. NTP engines use a nuclear reactor to heat hydrogen to ultra-high temperatures and then expel the heated hydrogen through a nozzle, which generates thrust and moves the rocket through space more efficiently than a traditional chemical rocket. In effect, NTP engines could drastically reduce transit times to Mars while reducing overall mission costs and the effects of radiation and zero gravity on astronauts. 

However, developing and testing materials to withstand conditions unlike anything else on earth has remained a challenge. 

ORNL has pioneered a technique to coat fuel and reactor core materials in zirconium carbide, which can protect these critical components from hydrogen infiltration and corrosion without impacting the reactor's neutronics. To test this coating under the combined effects of high temperature and high radiation, researchers in the lab’s Nuclear and Extreme Environment Measurement group designed the In-Pile Steady-State Extreme Temperature Testbed, or INSET; a specialized high-temperature furnace designed to operate within a nuclear reactor.