NASA and DARPA are working on a nuclear-powered rocket that could go to Mars

With the technology currently available to NASA, it could take up to seven months to reach the Red Planet. That’s too long. Even astronauts get fussy when cooped up in a tight space for months on end. And it’s dangerous. The radiation levels on a Mars mission can expose astronauts to radiation levels more than 100 times higher than on Earth.

If NASA is going to Mars, it needs to find a way to get there much faster. That’s one of the reasons it said last week it was working with the Pentagon’s Defense Advanced Projects Research Agency to develop thermonuclear propulsion technology.

“Using this new technology, astronauts will be able to travel to and from deep space faster than ever before — an important opportunity to prepare for crewed missions to Mars,” NASA Administrator Bill Nelson said in a statement. The goal, he said, is “to develop and demonstrate advanced nuclear thermal propulsion technology as early as 2027.”

DARPA, the Department of Defense arm that seeks to develop transformative technologies, has been working on the program since 2021, when it awarded three contracts for the first phase of the program to General Atomics, Lockheed Martin and Blue Origin, the aerospace company founded by Jeff Bezos (Bezos owns The Washington Post.). A nuclear-powered rocket would use a nuclear reactor to heat propellant to extreme temperatures before firing the fuel through a nozzle to produce thrust.

Being able to move quickly “is a core tenant of modern Department of Defense operations on land, sea and air,” DARPA said in a statement at the time. “However, high-speed maneuvering in the space domain has traditionally been challenging because current electrical and chemical propulsion systems in space have disadvantages in terms of thrust and weight and propellant efficiency.” In other words, traditional systems require too much fuel that burns at relatively inefficient levels.

The program is called DRACO, for Demonstration Rocket for Agile Cislunar (or Near Moon) Operations.

Under NASA’s agreement with DARPA, the space agency will lead development of the nuclear thermal engine, while DARPA will work to develop the experimental spacecraft that will be powered by the nuclear engine. The agencies hope to be ready in 2027 to demonstrate their work with a space flight.

NASA is also working with the Department of Energy on a separate project to develop a nuclear power plant that could be used on the moon and perhaps one day on Mars.

But getting to Mars is extremely difficult, and despite NASA’s long-standing claims that it was gearing up to send astronauts there, the agency is nowhere near achieving that goal.

One of the main obstacles is distance. Earth and Mars are on the same side of the sun only every 26 months. But even at their closest points, a spacecraft would have to follow an elliptical orbit around the sun that, as Tory Bruno, the CEO of the United Launch Alliance, wrote in a recent essay, “to reach a great arc of about 300 million miles.”

The path to Mars, he wrote, would require much more efficient propulsion at speeds that could double Orion’s recent speed. that could produce nuclear energy.

“Obviously, the sooner we can complete the journey to Mars, the better,” he wrote. “This means developing a much more efficient propulsion technology that can reduce transit time by at least 50 percent, making the journey safer and leaving more mass available for experiments and research equipment.”

In an interview, Bruno said that achieving a more efficient type of propulsion is not just about reaching space, but “about transportation through space,” or traveling through space from one destination to another. With space becoming a contentious environment, developing a system that is much more efficient is something the Pentagon and the US Space Force have focused on, especially as threats to satellites have increased.

Currently, satellites usually remain in orbit over a fixed trajectory. Without the power or propellant to maneuver, they’re a bit like sitting ducks. But with a more efficient fuel such as nuclear propulsion, they could become more agile and evasive. The need for spacecraft that can maneuver away from the enemy became apparent during the war in Ukraine.

“Clearly, space travel is seen as a critical factor for both militaries,” General Chance Salzman, chief of operations for the US Space Force, said last week according to Air and Space Forces Magazine. “Both sides have attacked [satellite communication] capabilities to reduce command and control, and a concerted effort has been made to disrupt GPS to reduce its effectiveness in the region.

As those systems grow, having nuclear propulsion — a much more efficient fuel than liquid chemicals — will be key, Bruno said.

“Because space is an ever-changing environment, there is a need to move existing assets, and certainly extend their useful lives,” he said.

The Pentagon is also looking for better ways to “move larger payloads to more distant locations in cislunar space — the volume of space between the Earth and the moon,” DARPA said. But to do that, it said, “will require a leap forward in propulsion technology.”