Cape Canaveral, FL- Shuttle Endeavor is poised to blast into history Monday morning, embarking on is final flight.
Just two weeks after the first attempt was scrubbed, wounded Congresswomen Gabrielle Giffords flew in again, to see her astronaut husband off.
The countdown is on for one last mission before Space Shuttle Endeavor soars to its final frontier: retirement.
Half a million Americans lined the roads to watch Endeavor's 25th and final flight ... joining wounded Congresswoman Gabrielle Giffords to watch husband Mark Kelly command.
Mark Kelly says, "She has been working really hard to make sure her doctors would permit her to come."
From as far away as California, where Endeavor will retire in Los Angeles.
"I want to watch Endeavor launch and land then I'm going to follow her back home to California."
"It'll kind of like shake the ground a little."
"It's a once in a lifetime experience."
NASA engineers scrubbed a launch attempt two weeks ago over an electrical problem ... now resolved, NASA officials say. Mike Moses,Chairman of NASA's Mission management team says, "Everything is in really great shape, really no issues at all."
This is the second time Giffords has made the journey from Houston, where she's recovering after being shot in the head in January.
Pia Carusone is Giffords' chief of staff. She says the Congresswoman is going well. "It seems she understand everything. I mean if not everything then almost everything. So she is really there, she follows directions, she laughs at jokes, recognizes friends," Carusone said.
On its 16-day mission, Endeavor will deliver a cosmic ray detector to the space station, which scientists hope will give them a glimpse into the very first moments of the universe, just after the big bang. On board, the astronauts are all wearing the blue bracelets celebrating Giffords life.
The liftoff of Endeavor marks the beginning of the end of an era for the shuttle program. It's the next to last launch. Atlantis lifts off in June, bringing the 30-year shuttle program to an end.