NASA, DARPA enlist Lockheed to build nuclear-powered spacecraft

NASA's ambitions to speed up space travel are about to go nuclear, as its joint project with military boffinry unit DARPA has found a builder for an experimental nuclear thermal rocket vehicle, or X-NTRV: Lockheed Martin.

If all goes according to plan, NASA's Demonstration Rocket for Agile Cislunar Operations program (DRACO) will have its first test craft in orbit and ready to fire by no later than 2027, according to Lockheed, which NASA and DARPA enlisted to begin fabrication and design of the X-NTRV.

Nuclear thermal rockets (NTRs) have significant advantages over traditional chemical rockets, but that doesn't mean they eliminate the need for propellant entirely. Using an onboard nuclear reactor fueled with high-assay low-enriched uranium (HALEU), nuclear thermal propulsion systems heat hydrogen propellant and funnel released gasses through a nozzle. 

"​An NTR achieves high thrust similar to in-space chemical propulsion but is two-to-three-times more efficient," said DRACO program manager Tabitha Dodson, meaning far less propellant would be needed to do things like transport supplies to the Moon - or further to Mars.  

Reduced propellant load, and the longer burn time with its associated ability to continually accelerate the craft, means getting to whatever destination NASA chooses with more scientific payload and less travel time for astronauts - both things the space agency is sure to be keen on. 

"With a successful demonstration, we could significantly advance humanity's means for going faster and farther in space and pave the way for the future deployment for all fission-based nuclear space technologies," Dodson added.

DRACO is the latest project to attempt a nuclear thermal rocket, but it's not new. NASA and DARPA joined forces on the effort in January of this year, with NASA committing to tackling development of the engine itself and DARPA overseeing the rest of the program. 

Lockheed Martin, which will build the craft itself, is partnering with BWX Technologies for development of the X-NTRV nuclear reactor and HALEU production.

Nuclear rockets: As American as apple pie

The idea of flying a nuclear missile through space is anything but new - it goes back nearly 70 years to the halcyon days of the post-WWII era nuclear age. 

In the 1950s and 60s, NASA, DARPA's predecessor, ARPA, and the US Air Force joined forces to experiment with a different type of nuclear propulsion: Explosions. The Orion project proposed a nuclear pulse rocket that would use a series of small directional nuclear explosions and a shock-absorbing steel pusher plate to propel a craft through space. The Partial Test Ban Treaty of 1963, which banned experiments with nuclear weapons in space, effectively ended the program.

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DARPA itself has been working on experimental NTR spacecraft since 2021, and has leaned on other early experiments into nuclear propulsion, the Rover program and its successor, the Nuclear Engine for Rocket Vehicle Applications (NERVA) program, the pair of which ran from the 1950s until the '70s. Both were considered successful, but never resulted in space flights, making DRACO's X-NTRV potentially the first craft of its kind to reach space - if someone else doesn't beat NASA and DARPA to it. 

To avoid the risk of blowing up a nuclear reactor in the Earth's atmosphere or low orbit, the X-NTRV will be launched by a traditional rocket commanded by the US Space Force when it launches in 2027. The reactor will be off for the whole of its launch, only turning on once it reaches a designated orbit. 

Once it proves its mettle running cislunar missions, NASA plans to use DRACO to get to Mars, which it said an NTR could do far faster, protecting astronauts from space radiation exposure and other risks. 

"This demonstration will be a crucial step in meeting our Moon to Mars objectives for crew transportation into deep space," said NASA Deputy Administrator Pam Melroy. ®