SpaceX rocket hoists cargo to space station ahead of unexpected splashdown

Three days and 3,000 miles apart, SpaceX accomplished its second successful rocket launch of the week Wednesday, sending cargo to the International Space Station. But this launch came with a little added drama: An unexpected splashdown by the returning rocket just offshore.

By now, it's routine for the Falcon 9 rocket first stages to make dramatic upright landings a few miles from their launch pads or out at sea on barges. It's part of the company's push for reusability to drive down launch costs.

When a Falcon 9 hoisted 64 small satellites in a single launch from California on Monday, it was the third flight for that particular booster.

Today, an uncrewed Dragon cargo capsule - itself on its second mission - blasted off from its Florida pad atop a brand new Falcon 9 rocket. But after the second stage separated and continued toward space, the returning first stage twisted and danced in the sky as it plunged towards its landing pad.

In the final seconds, the booster seemed to right itself, but by then it was too late. Sensing trouble, the rocket automatically remained out to sea. The booster hovered just over the water, then toppled out of view -- the first failure over land in the last 12 tries, though that's not quite how one of SpaceX's top engineers painted it.

"The vehicle kept well away from anything where it could pose even the slightest risk to population or property. Public safety was well-protected here," Hans Koenigsmann offered after the launch. "As much as we are disappointed...it shows the system overall knows how to recover from certain malfunctions."

SpaceX founder and lead designer Elon Musk quickly explained that a hydraulic failure on the steering fins prevented a safe landing. The booster splashed down just offshore intact, he said, and it was even transmitting data.

Meanwhile, the Dragon cargo capsule was safely on its way to a docking with the station later this week. It's carrying an in-space refueling experiment, a new forest-monitoring sensor for the station, and supplies for the six astronauts aboard the orbiting lab, three of whom just arrived after launching aboard a Russian rocket Monday.

SpaceX hopes to take on that job soon, too. The crew-carrying version of Dragon is scheduled to fly a test mission next month, and if all goes well, will carry astronauts to the station later in the year in what would be the first crewed flight from U.S. soil since the space shuttles retired in 2011.