— CAPE CANAVERAL, Fla. - Six astronauts rode the space shuttle Endeavour into space for the last time on Monday as a wounded congresswoman and hundreds of thousands of others watched.
Endeavour rose on a pillar of flame and quickly disappeared into Florida's cloudy morning skies. Two weeks earlier, an electronics glitch spoiled the previous launch attempt, but Monday's countdown was mostly trouble-free.
"Looks like a good day to launch Endeavour for a final time," launch director Mike Leinbach told the crew's commander, Mark Kelly, just before liftoff.
In response, Kelly thanked Leinbach and the rest of the launch team, and suggested that NASA's role in exploration should continue after the shuttle program's end. "It is in the DNA of our great country to reach for the stars and explore," he said. "We must not stop."
The shuttle is due to link up with the International Space Station on Wednesday. "Godspeed, Endeavour. We're ready for you," NASA astronaut Ron Garan said in a Twitter update from the International Space Station.
Endeavour's 16-day mission to the space station, known as STS-134, is notable for several reasons — including its status as the second-to-last scheduled flight for the 30-year-long space shuttle program as well as its planned delivery of a $2 billion particle-physics experiment.
But there's a big personal angle as well: Kelly's wife is U.S. Rep. Gabrielle Giffords, the Arizona Democrat who suffered a life-threatening head wound during a mass shooting in Tucson in January. The prospect of attending this launch served as a therapeutic goal for Giffords, who has spent much of the past four months at a Houston rehabilitation center.
Godspeed from Giffords
Giffords attended Endeavour's first launch attempt on April 29, and came back to the Cape for Monday's launch. Her staff reported that she said goodbye to her husband during a beach-house gathering on Sunday afternoon.
Giffords' chief of staff, Pia Carusone, told NBC's TODAY show that the congresswoman was "really excited" to see Kelly blast off and was "obviously happy she was able to make it."
"It's a good day for everyone here," Carusone said.
Giffords and Kelly traded their wedding rings for the mission, and all six of Endeavour's astronauts are carrying "Peace-Love-Gabby" bracelets in Giffords' honor.
The congresswoman did not appear in public or meet the press during her visit, due to her medical condition as well as the more general privacy concerns for the Endeavour crew's families. However, her staff did report her reaction to the launch.
"Good stuff, good stuff," Carusone quoted Giffords as saying.
Huge turnout ... with some no-shows
NASA expected up to 500,000 people to turn out for Monday's liftoff — which is more than the usual crowd for a shuttle launch, but less than the 750,000 that was projected two weeks ago for the initial attempt. Vehicles lined the roads surrounding the space center; however, traffic reports indicated that the Monday morning tie-up was not as bad as some had feared. Titusville Assistant Police Chief John Lau gave The Associated Press an estimate of 350,000 to 400,000 spectators.
One would-be spectator who didn't return is President Barack Obama. He and his family took a quick tour of Kennedy Space Center on April 29 but missed out on the big event. First Lady Michelle Obama said witnessing a launch in person was "a priority" — which means she has just one chance left.
Monday's smooth countdown came in contrast to last month's launch attempt, which was scrubbed due to a glitch that affected the heaters in one of the orbiter's auxiliary power units. The shuttle's three APUs provide hydraulic power for the aerodynamic flight control system, and all of them have to be in working order to proceed to launch.
Over the past two weeks, launch-pad workers traced the problem to a blown circuit in a switch box, replaced the entire box, and double-checked the electronics in the box as well as the wiring attached to the box. The problem did not reappear during Monday's countdown.
After the crew took their seats in the orbiter, the close-out crew reported minor damage to a tile area around the shuttle's crew hatch, but the ding was quickly patched.
During Endeavour's ascent to orbit, several pieces of foam were seen coming off the external fuel tank, which had been extensively repaired after Hurricane Katrina in 2005. Bill Gerstenmaier, NASA's associate administrator for spaceflight operations, told reporters that the flying foam did not appear to damage the orbiter. Nevertheless, Endeavour's protective skin will undergo a detailed examination on Tuesday.
Milestone mission for science and shuttle program
Endeavour's final spaceflight looms as one of the most important science missions of the 30-year space shuttle program.
The shuttle is loaded up with nearly 15 tons of supplies and equipment, highlighted by the 7.5-ton Alpha Magnetic Spectrometer, which will be attached to the space station's exterior during a robotic arm operation. Once it's installed, the $2 billion particle detector will almost immediately start sending down data about cosmic rays.
Physicists from 16 nations have worked for 17 years to build the AMS, and for a while it looked as if all that effort would be wasted. Fortunately, Congress and NASA worked together to get the van-sized device on this mission. Over the next decade or longer, physicists hope that findings from the AMS will shed light on the mysteries surrounding the nature of dark matter, and the balance of matter and antimatter in the universe.
Endeavour's payload also includes a platform loaded with spare parts for the station, as well as communication equipment and a wide range of scientific experiments.
Shuttle program's last spacewalks
Four spacewalks are to be conducted during the shuttle's visit, marking the last scheduled outings by shuttle astronauts at the space station. The spacewalkers are to install equipment, do electrical work and conduct maintenance on the station's cooling system and robotic arm.
In addition to Kelly, the all-male, all-veteran crew includes pilot Greg Johnson, spacewalkers Mike Fincke, Drew Feustel and Greg Chamitoff, and Italian astronaut Roberto Vittori.
This mission will feature the first-ever departure of a Russian Soyuz spacecraft while a shuttle is docked to the International Space Station. NASA's Cady Coleman, Russia's Dmitri Kondratyev and Italy's Paolo Nespoli are due to leave the station and head back down to Earth on May 23.
Mission planners shuffled the schedules of the station and shuttle astronauts to accommodate the trio's departure. As a result, the two crews will be working separate shifts.
After Endeavour's return to Earth, the shuttle will be prepared as a museum piece for the California Science Center in Los Angeles. NASA has scheduled only one more shuttle flight to the station, to be taken on by Atlantis no earlier than mid-July.
When the shuttles retire, NASA will have to depend on Russian, European and Japanese transports to get supplies to the space station — at least until next year, when U.S. commercial cargo flights are due to begin. NASA hopes that commercial crew transports will become available starting in the middle of this decade.