Billionaire Elon Musk’s SpaceX launched an unmanned Falcon 9 on a resupply mission to the International Space Station but narrowly missed a second attempt to recover the rocket’s first stage.

The rocket, carrying its Dragon cargo spacecraft and 4,300 pounds (1,950 kilograms) of supplies and payloads, rumbled aloft at 4:10 p.m. New York time Tuesday from Cape Canaveral, Florida.

“Rocket landed on droneship, but too hard for survival,” Musk said in Twitter posts shortly after the launch. “Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post landing.”

Space Exploration Technologies Corp. wants to cut the cost of spaceflight by creating reusable rockets. The closely held Hawthorne, California-based company attempted to guide the booster to a vertical touchdown on Just Read the Instructions, a vessel floating hundreds of miles out in the Atlantic Ocean.

SpaceX posted a photograph of Falcon 9’s first stage approaching the ship on Twitter; Musk tweeted that video will be available when the ship returns to port in a few days.

“This was a historic attempt to recover the booster by landing on this drone ship in the Atlantic today,” Steve Jurvetson, a SpaceX director, said in a statement. “Imagine you threw the jet away after each flight. Flying would be expensive and impractical for most common applications. Same with rockets. To lower cost another 100x, they need to be fully reusable.”

January Attempt

SpaceX in January first tested the ability of the Falcon 9 to touch down its landing legs on a barge. In that attempt, the 14-story-tall rocket ran out of hydraulic fluid shortly before it hit the ship and broke into pieces.

“Rocket made it to drone spaceport ship, but landed hard,” said Musk on Twitter Jan. 10. “Close, but no cigar this time. Bodes well for the future tho.”

In February, another test was called off because of rough seas.

SpaceX has a $1.6 billion contract with NASA to resupply the International Space Station, and Tuesday’s launch marked SpaceX’s sixth official Commercial Resupply Services mission to the orbiting lab. SpaceX also has a second contract, valued at as much as $2.6 billion, to transport crews.

The company’s investors include Musk, Founders Fund, Draper Fisher Jurvetson, Valor Equity Partners, Google Inc. and Fidelity Investments.