SpaceX Falcon 9 rocket landing fails after booster leg breaks

This is the third time SpaceX has attempted to land a rocket booster on an unmanned drone ship

A SpaceX Falcon 9 rocket takes off from Cape Canaveral in Florida in June 2015 (BRUCE WEAVER/AFP/Getty Images)

SpaceX has failed in their third attempt to vertically land a rocket booster on an unmanned ship, after their Falcon 9 spacecraft broke one of its legs in a hard landing.

SpaceX said the rocket, which had just delivered a satellite into orbit, was not upright after it reached the 90-by-50-metre landing pad in the Pacific Ocean, off the coast of San Diego. No further details were available.

The private space transport company, owned by tech billionaire Elon Musk, managed a successful landing in December, when another Falcon 9 rocket made a safe vertical landing at Cape Canaveral in Florida after delivering a payload into space.

However, it's never been able to make a landing at sea. One previous attempt failed due to the rocket coming in too fast, while the other abruptly ended when the booster tipped over due to too much horizontal movement at the time of landing.

SpaceX livestreamed the landing attempt on their website, but the video feed cut out just before the rocket touched down - however, the company confirmed on Twitter that the Falcon 9 experienced a "hard landing".

This article will be updated.