CAPE CANAVERAL, Fla. -- Endeavour blasted off on NASA's next-to-last shuttle flight, thundering through clouds into orbit Monday morning as the mission commander's wounded wife, Gabrielle Giffords, watched along with an exhilarated crowd well into the thousands.
NASA is winding down its 30-year-old shuttle program before embarking on something new. The event generated the kind of excitement seldom seen on Florida's Space Coast on such a grand scale - despite a delay of more than two weeks from the original launch date because of an electrical problem.
The shuttle quickly disappeared into the clouds, within seconds of liftoff.
Just before launching, commander Mark Kelly made some patriotic remarks: "It's in the DNA of our great country to reach for the stars and explore. We must not stop. To all the millions watching today, including our spouses, children, family and friends, we thank you for your support."
Remarkably, Giffords made a return visit to see Kelly off. She is still undergoing rehabilitation in a Houston hospital to recover from a gunshot wound to the head in an assassination attempt little more than four months ago.
The Arizona congresswoman was shielded from the cameras on launch day, as were the families of the other five astronauts. All watched the liftoff in private.
Giffords has kept out of the public eye since the Jan. 8 shooting that wounded her and killed six others in Tucson, Ariz.
She and Kelly said their goodbyes, face to face on Sunday.
"Who's ready for the best show on Earth?" her staff asked in a Twitter update before liftoff.
With Kelly at the helm, Endeavour and its experienced crew of five Americans and an Italian are headed for the International Space Station. They will arrive at the orbiting outpost Wednesday, delivering a $2 billion magnetic instrument that will seek out antimatter and dark energy in the universe.
Up to 45,000 guests jammed into NASA's launch site, and thousands packed area roads and towns to see Endeavour soar one last time. Only one shuttle flight remains.
Advance estimates had put Monday's crowd at 500,000, more than the number that saw Discovery's final hurrah in February. Across the Indian River in Titusville, though, the number of spectators appeared to be down compared with Endeavour's previous launch attempt.
Electrical trouble grounded the shuttle on April 29, disappointing the hordes of visitors, including President Barack Obama and his family. Repairs over the past two weeks took care of the problem.
"God Speed Endeavour We're ready for you!" space station resident Ronald Garan Jr. said in a Twitter update. At launch, the space station was 220 miles high, just southeast of Halifax, Nova Scotia.
Kelly almost didn't make the flight.
The 47-year-old Navy captain took a leave from training to be by his wife's side after she was wounded. He was gone a month, and it seemed unlikely he would make the space flight he was training for. But Giffords improved and was moved from the hospital in her hometown of Tucson to Houston where Kelly lives and does astronaut training. Her days were filled with rehab work, and he yearned to see the shuttle mission through. A month after the shooting, he announced he would fly.
"Everybody felt that this was the right thing for me to do," he said at the time. He added that his wife "is a big supporter of my career, a big supporter of NASA."
He rejoined his crew in February, still managing to see his wife across town every morning and evening.
Giffords' visit to Kennedy Space Center - the third time she's seen her husband soar into space - ratcheted up the excitement level for what already was a big event, said launch officials.
Kelly's identical twin, Scott, who's also an astronaut, witnessed the launch with his two teenage nieces, Mark's daughters from a previous marriage.
This is the 25th and final flight of Endeavour, the baby of NASA's shuttle fleet. It was built to replace Challenger, destroyed during liftoff 25 years ago this past January, and made its maiden journey six years later to capture and repair a stranded satellite. That first flight ended 19 years ago Monday.
Endeavour carried the first Hubble Space Telescope repair team, which famously restored the observatory's vision in 1993, and the first American piece of the space station in 1998.
It will end its days at the California Science Center in Los Angeles.
As of Monday, Endeavour had logged more than 116 million miles, circled Earth some 4,500 times, spent 283 days in space and carried 170 people, including the last two people to fly a space shuttle for the first time. American Mike Fincke and Italian Roberto Vittori are making their first flight on a shuttle although they've been to the space station twice, ferried their by Russian Soyuz rockets.
Fincke will team up with Andrew Feustel and Gregory Chamitoff for four spacewalks during the 16-day mission. It will be the last spacewalks conducted by a shuttle crew.
NASA's last shuttle flight, by Atlantis, is targeted for July. After that, Atlantis will remain at Kennedy, where it will go on display at the visitor complex. Discovery will head to the Smithsonian Institution's hangar outside Washington.
American astronauts, meanwhile, will continue to hitch rides to the space station on Russian Soyuz rockets. Private companies hope to pick up the slack, but that's still years away.
Once Atlantis flies, it will be three years - at best - before Americans are launched again from U.S. soil. Some NASA observers fear it could be a full decade.
The White House wants NASA focusing on eventual expeditions to asteroids and Mars, unfeasible as long as the shuttles are flying given budget constraints.
It was the first shuttle launch for spectator Frewen Wilson of Raleigh, N.C. He and an old college buddy set up lawn chairs on the back of a pickup truck in Titusville to watch.
"There are not many chances left to see this," Wilson said.