Discovery and seven astronauts blasted off Tuesday on America's first manned space shot since the 2003 Columbia disaster, ending a painful, 2 1/2-year shutdown devoted to making the shuttle less risky and NASA more safety-conscious.
At stake were not only the lives of the astronauts, but also America's pride in its technological prowess , the fate of the U.S. space program and the future of space exploration itself.
"Our long wait may be over. So on behalf of the many millions of people who believe so deeply in what we do, good luck, Godspeed and have a little fun up there," launch director Mike Leinbach told the astronauts right before liftoff.
Space program employees and relatives of both the Discovery and Columbia crews watched nervously as the shuttle rose from its pad at 10:39 a.m., climbed into a hazy midsummer sky, pierced two decks of clouds, and headed out over the ocean in the most scrutinized launch in NASA history. Two chase planes and more than 100 cameras documented the ascent from every possible angle to capture any sign of flying debris of the sort that doomed the last flight.
The multitude of images will not be fully analyzed and NASA will not give a final verdict on whether Discovery is safe to return to Earth until halfway through the 12-day flight.
The fuel-gauge problem that thwarted a launch attempt two weeks ago did not resurface before liftoff, to NASA's great relief, and the countdown was remarkably smooth. The space agency had been prepared to bend its safety rules to get the shuttle flying.
During the mission, commander Eileen Collins and her crew will deliver supplies to the international space station and test new techniques for inspecting and patching the shuttle in orbit.
The 114th shuttle liftoff came after painful self-examination on NASA's part, extensive safety modifications to the spacecraft and many months of hurdles and setbacks. A launch attempt July 13 was scrapped after one of four critical hydrogen-fuel gauges in Discovery's giant orange external tank failed just two hours before liftoff.
Hundreds of engineers chased the problem, which had cropped up three months earlier in a fueling test. In the end, they could not fully explain the trouble but fixed some bad electrical grounding inside the shuttle in hopes that might solve it.
The space agency said it was prepared to relax a rule, instituted after the 1986 Challenger explosion, that required that all four gauges be working for launch.
NASA Administrator Michael Griffin said the shuttle was as safe as NASA could make it, but was still a risky venture.
"Some things simply are inherent to the design of the bird and cannot be made better without going and getting a new generation of spacecraft. That's as true for the space shuttle as it is for your toaster oven," he told The Associated Press on the eve of launch.
at stake : at risk; dependent on what happens（利害攸关；濒于险境）
prowess: a superior skill that you can learn by study and practice and observation（威力）
godspeed : good luck, esp. in a journey or activity（祝幸运，祝万事如意）
countdown: counting backward from an arbitrary number to indicate the time remaining before some event (such as launching a space vehicle)（倒数记秒）