CAPE CANAVERAL, Fla. -- Discovery thundered into orbit for the final time Thursday, heading toward the International Space Station on a journey that marks the beginning of the end of the shuttle era.
The six astronauts on board were thrilled to be on their way after a delay of nearly four months for fuel tank repairs. But it puts Discovery on the cusp of retirement when it returns in 11 days and eventually heads to a museum, possibly the Smithsonian Institution.
"Discovery now making one last reach for the stars," the Mission Control commentator said once the shuttle cleared the launch tower.
Discovery is the oldest of NASA's three surviving space shuttles and the first to be decommissioned this year. Two missions remain, first by Atlantis and then Endeavour, to end the 30-year program.
It was Discovery's 39th launch and the 133rd shuttle mission overall.
As the final minutes ticked away, commander Steven Lindsey thanked everyone for the work in getting Discovery ready.
"And for those watching," he called out, "get ready to witness the majesty and the power of Discovery as she lifts off one final time."
"Look forward to having company here on ISS in a couple days," station commander Scott Kelly said in a Twitter message. Discovery should reach the space station on Saturday.
The orbiting lab was soaring over the South Pacific when Discovery took off.
On-board TV cameras showed pieces of foam insulation breaking off the external fuel tank four minutes into the flight, but it shouldn't pose any safety concerns because it was late enough after liftoff, officials said.
An estimated 40,000 guests gathered at Kennedy Space Center to witness history in the making, including a small delegation from Congress and Florida's new Gov. Rick Scott.
Discovery frenzy took over not only the launch site, but neighboring towns. Roads leading to the launching site were jammed with cars parked two and three deep; RVs snagged prime viewing spots well before dawn. Businesses and governments joined in, their signs offering words of encouragement. Groceries stocked up on extra red, white and blue cakes with shuttle pictures. Stores ran out of camera batteries.
The launch team also got into the act. A competition was held to craft the departing salutation from Launch Control: "The final liftoff of Discovery, a tribute to the dedication, hard work and pride of America's space shuttle team."
Kennedy's public affairs office normally comes up with the parting line. Souvenir photos of Discovery were set aside for controllers in the firing room. Many posed for group shots.
Unlike the first try back in November, no hydrogen gas leaked during Thursday's fueling. NASA also was confident no cracks would develop in the external fuel tank; nothing serious was spotted during the final checks at the pad. Both problems cropped up during the initial countdown in early November, and the repairs took almost four months. The cracks in the midsection of the tank, which holds instruments but no fuel, could have been dangerous.
Packed aboard Discovery is Robonaut 2, or R2, set to become the first humanoid robot in space. The experimental machine -- looking human from the waist up -- will remain boxed until after Discovery departs. Its twin was at the launch site, perched atop a rover, waving goodbye.
"I'm in space! HELLO UNIVERSE!!!" R2 announced in a tweet sent by a NASA spokeswoman.
Discovery already has 143 million miles to its credit, beginning with its first flight in 1984. By the time this mission ends, the shuttle will have tacked on another 4.5 million miles. And it will have spent 363 days in space and circled Earth 5,800 times when it returns March 7.
No other spacecraft has been launched so many times.
Discovery's list of achievements include delivering the Hubble Space Telescope to orbit, carrying the first Russian cosmonaut to launch on a U.S. spaceship, performing the first rendezvous with the Russian space station Mir with the first female shuttle pilot in the cockpit, returning Mercury astronaut John Glenn to orbit, and bringing shuttle flights back to life after the Challenger and Columbia accidents.