NASA Administrator Jim Bridenstine tweeted that billionaire entrepreneur Elon Musk's space company, SpaceX, will send two NASA astronauts to the International Space Station from the US state of Florida — marking the company's first mission carrying humans.

"On May 27, NASA will once again launch American astronauts on American rockets from American soil!" Mr Bridenstine tweeted.

stronauts Doug Hurley and Bob Behnken will blast off atop a SpaceX Falcon 9 rocket, departing from the same Kennedy Space Centre launch pad used by shuttle Atlantis in July 2011, as well as the Apollo moonshots a half-century ago.

As with most high-profile missions, the new date could slip.

Astronauts haven't launched into orbit from the US since NASA's last space shuttle flight in 2011 and the agency has relied on Russia's space program to ferry astronauts to the space station.

Only three countries have launched people into orbit since 1961: Russia, the US and China, in that order. SpaceX would be the first private company to do so.

Boeing also is working to launch astronauts under NASA's commercial crew program, but the company's effort suffered a serious setback following last December's botched test flight.

Launching without anyone on board, Boeing's Starliner capsule failed to reach the space station after ending up in the wrong orbit and came close to destruction twice because of software errors.

The coronavirus pandemic, meanwhile, is likely to delay NASA's plans for another moon landing.

President Donald Trump had set the goal of landing on the moon by 2024 for the first time in half a century.

NASA said it had halted production and testing of its Space Launch System and Orion crew capsule due to the crisis.