Engineers at The Ohio State University are developing a groundbreaking nuclear propulsion system, the Centrifugal Nuclear Thermal Rocket (CNTR), which utilizes liquid uranium to directly heat rocket propellant. This innovative approach aims to significantly enhance rocket performance and mitigate operational risks compared to conventional solid fuel elements in nuclear thermal propulsion systems.
The CNTR project is focused on boosting engine efficiency, with the potential to double the efficiency of current chemical engines. While chemical engines typically achieve a specific impulse of around 450 seconds, nuclear propulsion engines tested in the 1960s reached approximately 900 seconds. The CNTR is projected to surpass these figures, potentially enabling faster journeys and reducing fuel requirements for space exploration. Dean Wang, an associate professor involved in the project, noted the escalating interest in nuclear thermal propulsion for missions targeting the moon and cis-lunar space, highlighting the limitations of current chemical engines for such ambitious undertakings.
This advancement could drastically reduce travel times for deep-space missions. For context, the New Horizons mission to Pluto spanned nine years, underscoring the necessity for advanced propulsion to shorten travel times. PhD student Spencer Christian suggests that the CNTR could enable a six-month one-way trip to Mars, a significant reduction from current estimates. This increased speed also offers greater mission flexibility, allowing rockets to adopt new flight trajectories and potentially facilitating quicker round-trip human missions to Mars.
Historically, the United States has invested in nuclear rocket development through programs like Project Rover and the NERVA program in the mid-20th century. Despite significant progress, these programs were canceled due to budget constraints and shifting priorities, with no nuclear thermal propulsion system having flown to date as of 2025. The CNTR concept is expected to reach design readiness within five years, with a final laboratory demonstration planned to inform future nuclear thermal propulsion technologies. Wang emphasized the importance of sustained prioritization for space nuclear propulsion research to allow for technological maturation.
This research aligns with Ohio State University's commitment to aerospace innovation, including its participation in the Aerospace Propulsion Outreach Program (APOP) in April 2025, where new propulsion concepts were showcased in collaboration with the Air Force Research Laboratory. The CNTR project is currently on track for design readiness, with ongoing efforts to address engineering challenges such as ensuring stable operation, minimizing fuel loss, and preventing engine failures. The project is a collaborative effort involving faculty, students, and industry partners dedicated to advancing space travel through nuclear thermal propulsion.
The potential of CNTR technology to transform space exploration extends beyond its technical capabilities, offering a sustainable and powerful solution for future space missions. By reducing travel times and increasing payload capacities, the CNTR system could accelerate humanity's journey to understanding and exploring the solar system's most distant regions.