SpaceX's cargo-carrying Dragon spacecraft docked with the International Space Station in a historic first for spaceflight.
The unmanned, cone-shaped capsule became the first privately built and operated vehicle to ever dock to the orbiting outpost at 9:02 a.m. PDT.
Shortly after docking, a smiling Elon Musk, SpaceX's 40-year-old billionaire founder and chief executive, appeared in a press briefing at the company's sprawling rocket-making facility in Hawthorne.
"This is the culmination of an incredible amount of work," he said, surrounded by a throng of cheering SpaceX workers. "There's so much that could've went wrong and it went right."
The arrival of the Dragon to the space station wasn't flawless. A problem with the spaceraft's onboard sensors pushed back the capture for about two hours later than planned.
After SpaceX engineers solved the issue, the Dragon floated in for docking. It was first grappled by the space station’s 58-foot robotic arm at 6:56 a.m. PDT, controlled by astronaut Don Pettit. Then, it was drawn in closer, inch-by-inch, to docking.
The Dragon has spent the last three days circling the Earth.
NASA officials said the crew plans to begin unloading the half ton of food, water and clothes aboard Dragon at 4:40 a.m. Saturday.
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"Today marks another critical step in the future of American spaceflight," NASA Administrator Charles Bolden said in a statement. "Now that a U.S. company has proven its ability to resupply the space station, it opens a new frontier for commercial opportunities in space -- and new job creation opportunities right here in the U.S."
SpaceX, officially known as Space Exploration Technologies Corp., is the first private company to embark on such a mission. Until now, sending a spacecraft to the space station has been a feat reserved for the world's wealthiest and most technologically advanced governments: the United States, Russia, Japan and the European Union.
The Dragon has been in orbit since it was launched in the pre-dawn hours Tuesday aboard SpaceX's Falcon 9 rocket from Cape Canaveral, Fla.
After the launch, with Dragon in Earth orbit, President Obama called Musk to congratulate him on the accomplishment.
SpaceX's mission is considered the first test of NASA's plan to outsource space missions to privately funded companies now that the fleet of space shuttles is retired. SpaceX aims to prove to NASA that its Falcon 9 rocket and Dragon capsule are ready to take on the task of hauling cargo -- and eventually astronauts -- for the space agency.
SpaceX makes the Dragon and Falcon 9 at a sprawling facility in Hawthorne that once was used to assemble fuselage sections for Boeing 747s. The hardware is put on a big rig and trucked to Cape Canaveral for launches.
The company, with about 1,800 employees, has a $1.6-billion contract to haul cargo in 12 flights to the space station for NASA. If the current test mission is successful, SpaceX will begin fulfilling the contract later this year.