Four years from now, if all goes well, a nuclear-powered rocket engine will launch into space for the first time. The rocket itself will be conventional, but the payload boosted into orbit will be a different matter.

NASA announced Wednesday that it is partnering with the US Department of Defense to launch a nuclear-powered rocket engine into space as early as 2027. The US space agency will invest about $300 million in the project to develop a next-generation propulsion system for in-space transportation.

“NASA is looking to go to Mars with this system,” said Anthony Calomino, an engineer at NASA who is leading the agency’s space nuclear propulsion technology program. “And in this test is really going to give us that foundation.”