SpaceX blasts off unmanned Dragon cargo ship to space station, but stage-one rocket crashes into the sea

Capsule due to arrive at the space station on Saturday, despite first-stage rocket failure following launch

SpaceX has launched its unmanned Dragon cargo capsule, propelling its payload to the International Space Station (ISS) despite a post-launch failure affecting the first-stage rocket.

The Falcon 9 rocket lifted off successfully at 1:16 pm Eastern Standard Time from Florida's Cape Canaveral Air Force Station, carrying 2,500 kilos of supplies, including science experiments and food for six astronauts currently on board the ISS.

While the Dragon capsule is currently on its way to the ISS, the rocket's spent first stage rocket failed to land properly at its designated "Landing Zone 1" pad along the Cape Canaveral coast.

The first stage rocket had separated normally several minutes after the lift-off, but as it approached the landing site, it started spinning rapidly. Finally, it splashed down in the ocean.

"Grid fin hydraulic pump stalled, so Falcon landed just out to sea," SpaceX CEO Elon Musk said in a tweet after the missed landing.

"Appears to be undamaged & is transmitting data. Recovery ship dispatched."

According to Musk, the rocket could still be re-used as its engines stabilised the spin just in time to ensure an intact landing in water.

The Falcon rocket used for Wednesday's launch was not used in any prior mission.

SpaceX spokesperson John Insprucker said that the team will use the telemetry from the first-stage booster to find out the reason behind the failed landing.

John Insprucker also revealed that rocket's second stage was precise.

"Dragon, you saw separate, and now the solar arrays coming out. All told, another great day for SpaceX and NASA," he added.

The Dragon space capsule that SpaceX used for the current mission was earlier used in February 20017 as part of the CCRS-10 supply mission.

The capsule is due to arrive at the space station on Saturday morning.

Wednesday's mission (CRS-16) was initially scheduled to blast off on Tuesday, but was postponed for a day after the mission team found that the mouse food in one of the science experiments had gone mouldy. The mice and their habitat were loaded into spacecraft shortly before launch, but the spoiled food had to be replaced ahead of launch.

NASA has also sent a science experiment to the ISS, which will make use of 36,000 tiny worms to study muscle degeneration in a microgravity environment. By the time the mission ends, these worms should have increased their population to between two to three million, according to scientists.