Washington: US space firm SpaceX successfully sent a European commercial communications satellite into space but failed to land it on a drone ship, media reports said on Saturday.
The space firm failed in an attempt to softland the spent first stage of its Falcon 9 rocket on a drone ship in the Atlantic Ocean on Friday, Xinhua news agency reported.
SpaceX achieved one successful soft landing in December last year on a land-based pad at Cape Canaveral, but its three previous attempts to land the first stage on an ocean drone ship - in January 2015, April 2015, and January 2016 - all failed.
About one hour after launch, SpaceX CEO Elon Musk tweeted: "Rocket landed hard on the droneship. Didn't expect this one to work ... but next flight has a good chance."
The failure was not a surprise as SpaceX itself had little hope for the rocket recovery test, part of the company's efforts to produce a fully reusable rocket.
SpaceX said a reusable rocket would dramatically reduce the cost of space transport.
Traditionally, rockets are designed for a single use only, burning up or crashing into the ocean after liftoff.
The Falcon 9 rocket shot into the sky from Cape Canaveral Air Force Station in the US state of Florida, carrying a commercial communications satellite called SES-9, which would deliver television and high-speed broadband services to the Asia-Pacific region.
The rocket's first stage separated about 2.5 minutes after launch and then performed a series of engine burns for an experimental landing on the "Of Course I Still Love You" drone ship, which was stationed in the Atlantic Ocean off the Florida coast.
This time, the SES-9 was headed for the Geostationary Transfer Orbit, about 36,000 kilometres above the Earth, which required the rocket to fly faster than usual.
This made it more difficult for a landing after stage separation. SpaceX said in a pre-launch statement that "a successful landing is not expected".