CAPE CANAVERAL, Fla. -- The space shuttle Endeavour launched Monday on its final mission, carrying a $2 billion astrophysics device and a little bit of the hearts of thousands of space shuttle workers.
Perhaps a half-million people crowded the coastline to watch the next-to-last scheduled launch in the 30-year history of the shuttle program.
Among those with top vantage points at Kennedy Space Center was U.S. Rep. Gabrielle Giffords, D-Ariz., whose husband, Navy Capt. Mark Kelly, commanded the Endeavour in his fourth flight into space. Giffords is recovering from a gunshot wound to the head.
President Barack Obama, who brought his family to the previous launch attempt on April 29, did not return for Monday's launch. They and 750,000 other people who turned out that day were disappointed when NASA scrubbed the launch because of an electrical problem.
This time Endeavour's countdown was flawless, except for a broken tile that technicians quickly repaired Monday morning. The orbiter punched through a canopy of light clouds at 8:56 a.m., roaring toward a 16-day mission to deliver equipment, supplies and the Alpha Magnetic Spectrometer to the International Space Station.
In the moments before blastoff, Kelly called Endeavour "this incredible ship," thanked the thousands of space workers who kept it flying and addressed the country.
"As Americans, we endeavor to build a better life than the generation before and endeavor to be a united nation. In those efforts, we are often tested. This mission represents the power of teamwork, commitment and exploration. It is in the DNA of our country to reach for the stars and explore. We must not stop."
The AMS, under development since 1993, was supposed to go into space in the middle of the last decade. But it lost its ride after the shuttle program shut down for nearly two years after the loss of Columbia in 2003 and all flights' manifests were rebooked to hasten the orbiters' retirement.
NASA scheduled this Endeavour mission only after Congress, and Obama's 2010 federal budget, authorized an additional flight to deliver and install the AMS.
The latest delay came three hours before the April 29 scheduled liftoff, when an electrical switch box caused fuel-line heaters to malfunction.
Now the scientists behind the AMS hope to prove it will be worth all the delays. The device will sit outside the space station, seeking to collect high-energy cosmic rays and space particles that may have originated with the "big bang," which astrophysicists theorize created the universe. The findings could help them understand the makeup and origins of the universe.
Some scientists have expressed strong skepticism that the AMS would work, but others think it might become the greatest astrophysics tool since the Hubble Space Telescope. Even if it does not detect its primary goals -- big-bang antimatter and so-called "dark" matter -- the AMS's potential to analyze cosmic rays and particles is unparalleled and its findings likely will be invaluable, said its principal investigator, Nobel Prize laureate Samuel Ting.
More than 600 scientists from 16 countries are involved with it.
All of Endeavour's crew members are space veterans. Kelly, 47, is on his fourth shuttle mission. Pilot Greg Johnson, 49, also piloted Endeavour in 2008. The mission specialists are Mike Fincke, 44, who has been to the space station twice on Russian spacecraft; Roberto Vittori, 46, an Italian astronaut who has been to the station twice on Russian craft; Drew Feustel, 45, who is on his second shuttle flight; and Greg Chamitoff, 48, who has flown to and from the space station on different shuttles.