SpaceX said: "Demo-2 is the final major test for SpaceX’s human spaceflight system to be certified by NASA for operational crew missions to and from the International Space Station.
The launch comes shortly after NASA and SpaceX made history, after launching humans into space from US soil for the first time since 2011.
NASA said: “Following the launch, the Crew-1 astronauts are scheduled to arrive at the space station for a six-month science mission aboard the orbiting laboratory.”
During the launch, astronauts Michael Hopkins, Victor Glover and Shannon Walker of NASA, and Soichi Noguchi of the Japan Aerospace Exploration Agency will launch into space on board a SpaceX Crew Dragon spacecraft on a Falcon 9 rocket from NASA’s Kennedy Space Centre.
"SpaceX is returning human spaceflight to the United States with one of the safest, most advanced systems ever built, and NASA’s Commercial Crew Program is a turning point for America’s future in space exploration that lays the groundwork for future missions to the Moon, Mars, and beyond."