NASA and DARPA aim to test a nuclear rocket in space by 2027

Nuclear rockets will quickly and efficiently transport “material to the Moon and eventually, people to Mars.”

Chris Young
NASA and DARPA aim to test a nuclear rocket in space by 2027
An artist's impression of the experimental nuclear rocket.

DARPA 

NASA is partnering with DARPA in a bid to develop a working nuclear thermal rocket by 2027.

NASA Administrator Bill Nelson introduced the new project on Tuesday, January 24, during a presentation at this year’s American Institute of Aeronautics and Astronautics (AIAA) SciTech Forum and Exposition in National Harbor, Maryland.

The NASA chief said the space and defense agencies will partner to “develop and demonstrate advanced nuclear thermal propulsion, a revolutionary technology that will allow the United States to expand the possibilities for future human spaceflight missions.”

NASA and DARPA will develop and demonstrate nuclear rocket propulsion

The new partnership will see NASA join DARPA’s Demonstration Rocket for Agile Cislunar Operations, or DRACO, program, which began in 2021. That program was tasked with developing a nuclear thermal engine for use in an experimental spacecraft called the experimental NTR vehicle (X-NTRV), also designed by DARPA.

Together, NASA and DARPA aim to conduct an in-space demonstration of the resulting nuclear rocket as early as 2027.

Dr. Stefanie Tompkins, director of DARPA, highlighted the two agencies’ historic collaboration on spacecraft such as Saturn V for the Apollo missions. “The ability to accomplish leap-ahead advances in space technology through the DRACO nuclear thermal rocket program will be essential for more efficiently and quickly transporting material to the Moon and, eventually, people to Mars,” she explained.

NASA and DARPA have published an interagency agreement that sets out the key role each agency will play in developing the new spaceflight technology. The agreement grants NASA final authority over the nuclear thermal rocket engine’s development. However, DARPA will have final authority on the X-NTRV and will also be responsible for operating the experimental spacecraft and disposing of it in orbit.

NASA has a long history of nuclear rocket experimentation

NASA has been considering nuclear propulsion for rockets for decades. The space agency successfully carried out initial tests but then defunded Nuclear Engine for Rocket Vehicle Application (NERVA) concept around the same time the Apollo Era came to a close in 1973. More recently, NASA also tested nuclear propulsion concept technologies with Project Prometheus in the early 2000s.

Earlier this month, the U.S. space agency also selected a nuclear propulsion concept for Phase I development as part of its Innovative Advanced Concepts (NIAC) program for 2023. That new concept would use a new class of bimodal nuclear propulsion system with a “wave rotor topping cycle” to reach Mars in only 45 days.

In its statement, DARPA said it is leveraging the lessons learned in NASA’s past experiments. Crucially, though, “instead of using highly-enriched uranium, DRACO is using high-assay low-enriched uranium (HALEU) fuel to have fewer logistical hurdles on its ambitious timeline.” The defense agency also stated that, as a safety precaution, it would design its system so that the fission reaction only turns on once the spacecraft is in space.

NASA is, of course, set on eventually sending humans to Mars. The agency’s Artemis program, which will establish a permanent presence on the moon, is seen as a stepping stone toward the eventual colonization of Mars. SpaceX, meanwhile, is on the verge of launching its next-generation Starship rocket, which will form an integral part of NASA’s Artemis missions — it will function as the first lunar lander for the program — and is also expected to send humans to the red planet eventually.