Updated Monday am
A rocket that propelled an ocean-monitoring satellite into space has toppled over while landing on a floating barge after one of its support legs failed to lock.
California company SpaceX said that data now showed that the Falcon 9 rocket's first stage landed softly within 1.3 metres of the centre of the 300 by 170ft landing pad.
SpaceX founder Elon Musk tweeted that the rocket's speed at touchdown was good, "but a leg lockout didn't latch, so it tipped over after landing".
The rocket successfully delivered the Jason-3 satellite into orbit after launching from Vandenberg Air Force Base, north west of Los Angeles.
SpaceX hopes to reduce launch costs by reusing rockets rather than having them fall into the ocean.
Nasa said the US-European Jason-3 satellite was in orbit and "ready for science operations".
Jason-3's mission is to continue an unbroken record of more than two decades of sea level measurements from orbit.