Outer space

NASA Is Bringing Back Nuclear-Powered Rockets to Get to Mars

In the race to land humans on Mars, NASA is blowing the cobwebs off a technology it shelved in the 1970s — nuclear-powered rockets.

Last year, NASA partnered with BWXT Nuclear Energy Inc. for an $18.8 million contract to design a reactor and develop fuel for use in a nuclear-thermal propulsion engine for deep-space travel. While that small start is a long way from the the heady days of the Space Race of the Cold War, it marks the U.S. return to an idea that is also being pursued by Russia and China.

Unlike conventional rockets that burn fuel to create thrust, the atomic system uses the reactor to heat a propellant like liquid hydrogen, which then expands through a nozzle to power the craft.

That doubles the efficiency at which the rocket uses fuel, allowing for a “drastically smaller” craft and shorter transit time, said Stephen Heister, a professor at Purdue University’s School of Aeronautics and Astronautics. “This factor is absolutely huge, especially for very difficult missions that necessitate a lot of propellant such as a Mars flight.”