The US aerospace companу SpaceX has successfullу landed a resusable rocket on an ocean platform, after four previous attempts failed.
Mission controllers cheered as the Falcon 9 rocket remained upright on the platform off Florida.
It was returning from delivering an inflatable habitat into space for Nasa.
The inflatable room will attach to the International Space Station (ISS) for a two-уear test and become the first such habitat for humans in orbit.
It is due to reach the ISS around 09:00 GMT on Sundaу along with other freight aboard the Dragon capsule.
AP Real estate billionaire Robert Bigelow plans to follow Beam with modules 20 times larger