October 24, 2007	Wednesday	Shawwal 11, 1428

CAPE CANAVERAL (Florida), Oct 23: US space shuttle Discovery blasted off successfully on Tuesday on an ambitious, complex mission to the International Space Station, key to future manned flights to Mars.

The launch went ahead at 11:38am (1538 GMT) despite safety concerns voiced by a team of independent NASA engineers, and the discovery of a chunk of ice outside the craft.

The shuttle took off on schedule carrying seven astronauts, led by Commander Pam Melroy, 46, who is only the second woman to head a shuttle team since the start of the program in 1981.

Within about a minute after lift-off, with partially clouded skies over the Atlantic, the craft had accelerated to five times the speed of sound.

It reached Earth’s orbit within eight and a half minutes some 225.3 kilometres above the planet, and set course for the space station where it is due to dock on Thursday for a 10-day mission.

The mission went ahead despite some concerns over safety issues, and was watched by several invited guests including US director George Lucas, marking the 30th anniversary of the first ‘Star Wars’ movie.

On board the shuttle, the crew was carrying the lightsaber used in the movies by the character Luke Skywalker, played by Mark Hamill, a NASA spokesman said.

There had been last-minute fears the mission could be delayed after a small chunk of ice measuring about 10 centimetres long by 1.2 centimetres was found outside the craft on a liquid oxygen supply cable.

But in last-minute consultations before the countdown, officials from the National Space and Aeronautics Administration (NASA) agreed the ice posed no danger to the craft and crew.

There had also been earlier fears over the safety of the mission, when a committee of NASA engineers last week recommended replacing three of 44 thermal protection tiles on the orbiter’s wings.

The US space agency decided however the risk was not high enough to delay the launch for some two months to replace the tiles.

NASA has closely watched thermal tiles on shuttles since the 2003 Columbia catastrophe when one of them broke off on takeoff and hit a wing. The damage caused the shuttle to break up on re-entry, killing all seven crew members.

Wing bottoms have to withstand temperatures of 1,600 degrees Celsius when the shuttle makes re-entry to the Earth’s atmosphere at more than 20 times the speed of sound.

Shuttle program manager Wayne Hale told reporters last week that programme officials “decided we were in an acceptable risk posture to go fly”. The Discovery’s main mission is to deliver the Harmony module, which is key to installing the future European lab Columbus and Japan’s Kibo lab on the International Space Station.

Harmony, an Italian-made aluminum tube weighing 14.3 tons, will connect the two labs to the outpost and give it its almost final shape.

Any delay to the Discovery’s mission could have hampered NASA’s shuttle program, with plans for at least an additional 11 missions to complete the ISS by 2010, when the shuttle fleet is supposed to be taken out of service.

The ISS is a $100 billion project in which 16 countries are taking part to ready the way for future manned Mars missions.

Melroy is leading Discovery’s crew of seven, which includes five men and one other woman. The team also includes an Italian, Paulo Nespoli, with the European Space Agency.

Melroy is the second woman ever to command a space shuttle. The first was Eileen Collins, who also commanded the Discovery shuttle, in 2005.—AFP