Shuttle, space station link amid Nasa woes

The shuttle Discovery astronauts boarded the International Space Station high above the Earth yesterday, the first crew to visit since the Columbia disaster and, because of new concerns over safety, possibly the last for some time.

The two space behemoths, each weighing more than 100 tonnes, linked up with barely a bump as commander Eileen Collins slowly guided the shuttle in.

"This was so much easier than the sims," she radioed to Mission Control, referring to preflight docking simulations.

Following US Navy tradition, astronaut John Phillips on the space station rang a ship's bell to welcome the shuttle crew aboard.

"Discovery arriving," Mr Phillips called out, as Commander Collins, pilot Jim Kelly, flight engineer Steve Robinson, Japan's Soichi Noguchi and astronauts Andy Thomas, Charles Camarda and Wendy Lawrence floated into the station's Destiny laboratory module.

This flight was supposed to have been a triumphant return of the shuttle to the space station for the first time since November 2002, but Nasa's surprise decision on Wednesday to ground the rest of the aging orbiter fleet took the glow off.

The US space agency said flying debris captured on video at Discovery's launch on Tuesday was too similar to what brought down shuttle Columbia on February 1, 2003, and showed that the debris problem was not fixed after two-and-a-half years of work and more than $1 billion in safety improvements.

Nasa officials believe Discovery is unharmed and will be able to come home on August 7, but they do not know when shuttles will fly again. Atlantis was scheduled to launch in September. Images showed chunks of foam missing from at least three places on Discovery's external fuel tank, including one almost as big as the piece that struck Columbia. There are also nicks in the protective tiles on Discovery's belly.

A 0.75-kilogramme piece of insulating foam from Columbia's external fuel tank broke loose at launch on January 16, 2003, and struck the left wing, causing a hole in the heat shield that doomed the shuttle during re-entry 16 days later.

As Columbia glided towards Florida, superheated gases from the earth's atmosphere entered the breach and broke the ship apart over Texas, killing its seven astronauts.

The stray foam on Tuesday's launch, the first since the three-shuttle fleet was grounded after Columbia, meant it was back to the drawing boards, shuttle programme manager Bill Parsons said in a briefing.

"Until we're ready, we won't fly again," he said. "I don't know when that might be."

Nasa administrator Michael Griffin told CNN the shuttle programme would continue until its scheduled end in 2010.

"Right now, we are planning on flying the shuttle until 2010 and using it to assemble the international space station. And then moving on with a return of US astronauts to the moon," he said. The shuttle transports the modules used to piece together the still-unfinished $95 billion space station. In space, the seven astronauts on Discovery, which flew its first mission in 1984, went about their business.

In a manoeuvre planned before launch, Commander Collins steered Discovery into a slow back flip 182 metres below the space station while station crew members Sergei Krikalev and Phillips snapped pictures of Discovery's damaged tiles.