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.
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.