OAK RIDGE, Tenn. - How do you control a nuclear space propulsion system? Very carefully. To help with this, the Oak Ridge National Laboratory (ORNL) has built a simulated nuclear reactor test bed to develop the engines that could send astronauts to Mars and beyond, David Szondy writes for New Atlas. Continue reading original article.
The Military & Aerospace Electronics take:
12 September 2025 - New Atlas' Szondy writes that NASA’s earlier nuclear engine tests, such as the NERVA program in the 1960s, relied on rigid, preprogrammed control sequences, which worked for ground experiments but lacked flexibility for real missions. A functional space reactor must be far more responsive and adaptive.
To address this, Oak Ridge National Laboratory has built a non-nuclear test bed that uses six movable control drums fitted with sensors like resolvers, optical encoders, and torque meters to measure their operation. Instead of liquid hydrogen, a two-phase flow of water and air simulates propellant behavior through pumps, valves, and channels, with flow, pressure, and temperature carefully monitored.
The entire system is run by a NVIDIA Jetson single-board computer, which employs an MQTT broker to manage communications between the simulated hardware and control software. Using this safe, adjustable setup allows engineers to refine autonomous reactor controls and identify issues on Earth before such systems are trusted on long-duration crewed missions far from home.
Related: Nuclear engine with NASA support could send humans to Mars in 45 days
Jamie Whitney, Senior Editor
Military + Aerospace Electronics
