This is the first privately-funded spaceflight to the International Space Station; it launched Tuesday after a scrubbed mission over the weekend.
Opening a new, entrepreneurial era in spaceflight, a ship built by a billionaire businessman sped toward the International Space Station with a load of groceries and other supplies Tuesday after a spectacular middle-of-the-night blastoff.
The launch of the Falcon 9 rocket and its unmanned Dragon capsule marked the first time a commercial spacecraft has been sent to the orbiting outpost.
Tracing a fiery arc across the night sky, the rocket lifted off just before 4 a.m. and smoothly boosted the capsule into orbit. The capsule is expected to rendezvous with the space station within days, delivering a half-ton of provisions for its six crew members.
It is considered just a test flight — in fact, the capsule was packed with only nonessential items, in case something went disastrously wrong — but if all goes well with this mission and others like it, commercial spaceships could be carrying astronauts to and from the space station in three to five years.
Musk later told reporters: "For us, it's like winning the Super Bowl."
Up to now, flights to the space station were something only major governments had done.
The White House offered congratulations.
"Every launch into space is a thrilling event, but this one is especially exciting," said John Holdren, President Barack Obama's chief science adviser. "This expanded role for the private sector will free up more of NASA's resources to do what NASA does best — tackle the most demanding technological challenges in space, including those of human spaceflight beyond low-Earth orbit."
NASA is looking to the private sector to take over flights to the space station now that the space shuttle has been retired. Several U.S. companies are vying for the opportunity.
"The significance of this day cannot be overstated," said a beaming NASA Administrator Charles Bolden. "It's a great day for America. It's actually a great day for the world because there are people who thought that we had gone away, and today says, 'No, we're not going away at all.'"
Flight controllers applauded when the Dragon reached orbit nine minutes into the flight. Then they embraced once the solar panels on the craft popped open. Many of the SpaceX controllers wore untucked T-shirts, jeans or shorts, a stark contrast to NASA's suit-and-tie shuttle crowd.
A previous launch attempt, on Saturday, was aborted with a half-second left in the countdown because of a bad valve in one of Falcon's nine engines.
Another important test comes Thursday when the Dragon draws close to the space station. It will undergo practice maneuvers from more than a mile out. If all goes well, docking will occur on Friday. Musk will preside from the company's Mission Control in Hawthorne, Calif.
Since the shuttle's retirement last summer, American astronauts have been hitching rides to the space station aboard Russian rockets, and Russian, Japanese and European ships have been delivering supplies.
SpaceX has spent more than $1 billion on the project.
Musk, the 40-year-old entrepreneur who helped create PayPal and runs the electric car company Tesla Motors, has poured in millions of his own fortune, and NASA has contributed $381 million in seed money in a venture that has been likened to the public-private collaboration that built the Internet and won the West.
Even Musk's rivals were rooting for a successful flight.
"The shuttle may be retired, but the American dream of space exploration is alive and well," said Mark Sirangelo, chairman of Sierra Nevada Corp.'s space systems, which is developing a mini-shuttle to carry space station crews in a few years.
The Dragon capsule will stay at the space station for a week and then splash down in the Pacific, bringing back experiments and equipment. None of the other cargo ships now in use are designed to return safely; they burn up on the way down.
Two more Dragon supply missions are planned this year, regardless of what happens this week.
The rocket also blasted into orbit around the Earth the ashes of more than 300 people, including Mercury astronaut Gordon Cooper and actor James Doohan, who played Scotty on "Star Trek." The ashes were in a section of the rocket that was jettisoned during the climb into space.