NASA is getting ready to launch its massive, fully expendable rocket for the first crewed flight to the Moon since Apollo. The agency’s new era of spaceflight comes with a few parts from its past, ...

I’ve grown up with rockets that burn chemical fuel, but NASA’s next big leap in propulsion could make those engines look as dated as steam trains. By turning to nuclear power in space, the agency is ...

NASA’s first crewed moon mission in decades was delayed as its engineers grapple with an all-too-familiar rocket problem: hydrogen leaks. Fixing the issue is even trickier than it may seem.