Elon Musk-owned SpaceX's Crew Dragon is set to launch its first unmanned test flight to the International Space Station (ISS) on March 2, the first test mission of a commercially-built and operated American spacecraft and rocket designed for humans, NASA said on Friday.

The debut test flight, called Demonstration Mission-1 or DM-1, will be launched on the company's Falcon 9 rocket at 2.49 a.m. ET on March 2 from NASA's Kennedy Space Centre in Florida, the US space agency tweeted. 

"... Crew Dragon spacecraft (is) built to carry astronauts into orbit. We're preparing to once again launch American astronauts from American soil on American rockets," said NASA chief Jim Bridenstine.

The spacecraft will carry about 400 pounds of crew supplies and equipment to the space station where it will remain docked for about two weeks and return some critical research samples to Earth. 

According to weather forecasters, there is an 80 per cent chance of favourable weather for launch on Saturday morning, with the possibility of thick clouds or cumulus clouds posing the main concern.

The Demo-1 uncrewed flight test will demonstrate the company's ability to safely launch crew to the space station and return them home.

"Demo-1 is a demonstration of the Falcon 9 rocket, Crew Dragon spacecraft, ground systems and overall operations - basically just about everything that needs to be operating and operating well before we want to put our astronauts on-board," said Mike Lee, NASA mission manager for SpaceX's Demo-1 flight test. 

NASA and SpaceX will use data from Demo-1 to further prepare for Demo-2, the crewed flight test that will carry NASA astronauts Bob Behnken and Doug Hurley to the ISS. It is currently targeted for July.