New Nuclear Rocket Concept Could Slash Mars Travel Time in Half

Engineers from Ohio State University are developing a new way to power rocket engines, using liquid uranium for a faster, more efficient form of nuclear propulsion that could deliver round trips to Mars within a single year.

NASA and its private partners have their eyes set on the Moon and Mars, aiming to establish a regular human presence on distant celestial bodies. The future of space travel depends on building rocket engines that can propel vehicles farther into space and do it faster. Nuclear thermal propulsion is currently at the forefront of new engine technologies aiming to significantly reduce travel time while allowing for heavier payloads.

Traveling faster than before

Nuclear propulsion uses a nuclear reactor to heat a liquid propellant to extremely high temperatures, turning it into a gas that’s expelled through a nozzle and used to generate thrust. The newly developed engine concept, called the centrifugal nuclear thermal rocket (CNTR), uses liquid uranium to heat rocket propellant directly. In doing so, the engine promises more efficiency than traditional chemical rockets, as well as other nuclear propulsion engines, according to new research published in Acta Astronautica.

If it proves successful, CNTR could allow future vehicles to travel farther using less fuel. Traditional chemical engines produce about 450 seconds of thrust from a given amount of propellant, a measure known as specific impulse. Nuclear propulsion engines can reach around 900 seconds, with the CNTR possibly pushing that number even higher.

“You could have a safe one-way trip to Mars in six months, for example, as opposed to doing the same mission in a year,†Spencer Christian, a PhD student at Ohio State and leader of CNTR’s prototype construction, said in a statement. “Depending on how well it works, the prototype CNTR engine is pushing us towards the future.â€

CNTR promises faster routes, but it could also use different types of propellant, like ammonia, methane, hydrazine, or propane, that can be found in asteroids or other objects in space.

The concept is still in its infancy, and a few engineering challenges remain before CNTR can fly missions to Mars. Engineers are working to ensure that startup, shutdown, and operation of the engine don’t cause instabilities, while also finding ways to minimize the loss of liquid uranium.

“We have a very good understanding of the physics of our design, but there are still technical challenges that we need to overcome,†Dean Wang, associate professor of mechanical and aerospace engineering at Ohio State and senior member of the CNTR project, said in a statement. “We need to keep space nuclear propulsion as a consistent priority in the future, so that technology can have time to mature.â€