The SpaceX Falcon 9 rocket lifted off with an unmanned Dragon capsule into dark skies above the the cape at 3:44 a.m. ET - three days after a last-second scrub kept it bolted to the launch pad even as the countdown clock ticked toward zero.
Some 11 minutes after launch, the solar arrays deployed on the Dragon, prompting cheers and high-fives among SpaceX employees in the Hawthorne, Calif., mission control center. The solar array deployment had been considered the first big post-launch test.
"Falcon flew perfectly!!" SpaceX Chief Executive Elon Musk tweeted from California. "Dragon in orbit. Feels like a giant weight just came off my back."
At a post-launch news conference, Musk described the moment as a major adrenaline rush, and "obviously an extremely intense moment."
"For us, it's like winning the Super Bowl," he said.
Tuesday's liftoff was the second attempt to launch SpaceX's demonstration mission for NASA. If all goes well in a series of maneuvers and tests SpaceX will put the Dragon through, the cargo vehicle could arrive at the space station Friday. It is carrying 1,200 pounds of supplies, such as food and clothing, for the six-person station crew.
"Every launch into space is a thrilling event, but this one is especially exciting because it represents the potential of a new era in American spaceflight," said John Holdren, assistant to President Obama for science and technology.
SpaceX officials and NASA cautioned that much work lies ahead.
But Musk said, "Everything is looking really good." He added: "I would really count today a success no matter what happens with the rest of the mission."
If SpaceX successfully docks, it could prove the company's readiness to start delivering cargo under a $1.6 billion contract. The other company with a NASA cargo contract is Orbital Sciences Corp., which is set to test launch its rocket this summer.
"Today marks the beginning of a new era of exploration," said NASA chief Charles Bolden, speaking at Kennedy Space Center. "The significance of this day cannot be overstated. A private company has launched a spacecraft to the International Space Station that will attempt to dock there for the first time. And while there is a lot of work ahead to successfully complete this mission, we're certainly off to a good start and I hope you all would agree on that."
SpaceX initially had planned to launch the Falcon 9 early Saturday but trouble with one of the rocket's nine engines forced a last-second abort. A valve on the engine was replaced, and the rocket was cleared to go. NASA officials said they were impressed with the professionalism of the SpaceX team in getting to this point.
"There is something special about a rocket launch. Everybody smiles. Everybody high-fives each other. That's universal," said Bill Gerstenmaier, associate administrator for human exploration and operations for NASA.
The spacecraft is to return to Earth on May 31.
The Associated Press