Discovery blasted off on Tuesday for the first United States space-shuttle mission since the Columbia disaster in February 2003, which forced the US to rethink its space programme completely.
Thirteen days after a previous attempt to get the shuttle back in orbit was called off because of a fuel-gauge problem, Discovery lifted off into clear blue skies at the Kennedy Space Centre at 2.39pm GMT.
”It is time for you to return to flight. Godspeed and we will see you in a couple of weeks,” said a Nasa mission-control manager to the crew just before the engines were ignited.
It was an emotional moment for the Nasa experts and managers who watched horrified as Columbia broke up in flames as it re-entered the Earth’s atmosphere in 2003, killing all seven crew.
Discovery jettisoned its ascent motors two minutes after lift-off as planned and then headed into orbit at 7 200kph. Nasa called it a perfect launch.
The shuttle and its seven crew, including Japanese astronaut Soichi Noguchi, will spend 12 days in space to link up with the International Space Station (ISS).
The Columbia disaster forced a major rethink of the whole US space programme. The Discovery mission will test many new procedures introduced because of the disaster.
The new crew members appeared upbeat as they entered Discovery.
They smiled and waved as they boarded the shuttle, clad in their distinctive orange suits. Noguchi grinned as he held up a handwritten sign saying: ”Out to launch.”
Nasa went ahead with the launch even though there was a risk that a fuel sensor that forced the postponement of the earlier launch could play up again.
As the shuttle’s huge external tank was being filled during the night, engineers kept a close eye on the fuel sensor.
Tests had indicated the sensor was working normally, but Nasa managers said that even if it failed they would still go ahead with the launch, provided they understood the cause of the glitch.
The sensor is one of four that monitor hydrogen levels in the tank to prevent a premature shut off of the shuttle’s three engines.
During the 12-day mission, the crew will deliver supplies and equipment to the ISS.
Noguchi and other members of the crew will also carry out space walks to test some of the new measures introduced after the Columbia tragedy, which was blamed on a small piece of insulation foam that broke off after lift-off and struck the orbiter’s left wing. It caused a crack that allowed superheated gases to penetrate the structure just minutes before the planned landing.
Once Discovery reached orbit eight minutes after lift-off, Commander Eileen Collins was scheduled to tip the orbiter slightly so the crew could see the external tank as it was jettisoned, to determine whether any insulating material fell off.
Cameras on the outside of the shuttle allowed experts on the ground to monitor for debris.
Collins will also flip the orbiter over as it nears the ISS on Thursday, so the astronauts aboard the space station can inspect the shuttle’s thermal-protection system.
During one of three planned spacewalks on Discovery, Noguchi and his US counterpart Stephen Robinson will test repair techniques adopted after the Columbia disaster.
Several dignitaries, including First Lady Laura Bush and Florida Governor Jeb Bush, brother of the US president, watched the launch at the space centre near Cape Canaveral, Florida. — Sapa-AFP