Watch the launch of space shuttle Discovery

The six-man crew was given the go-ahead for the rendezvous with Mir after cosmonauts on board the Russian space station fixed its automatic steering system.

Discovery blasted off on Tuesday night from Cape Canaveral in Florida, on Nasa's ninth and final shuttle hookup with the space station.

Discovery took off despite fears of delays

"Everything is fine on Mir as we hear. A decision was taken to launch the shuttle on Tuesday as initially planned, " said Kathleen Maliga, of the Russian Mission Control at Korolyov outside Moscow.

The shuttle will bring home Andrew Thomas, the last of seven American astronauts to live on the ageing space station.

Mr Thomas, who has been aboard Mir since January, had his bags packed and made a special request for his first meal upon his return to Earth.

"He said he would like lasagna and Oreo ice cream," said Ms Maliga.

There had been fears the mission would be delayed after Mir suffered a computer failure at the weekend.

But the cosmonauts worked around the clock to resolve the problem.

The computer broke down on Saturday, leaving the station adrift in orbit but in no immediate danger. It was replaced by the three-man crew on Sunday, but the new computer also shut down because of an electronic fault.

The computer controls Mir's automatic steering system, needed to keep the space station steady when the shuttle docks with it.

Watch how three years of collaboration between Russia and the US will conclude with this shuttle mission

It is expected that Discovery will link up with Mir on Thursday and have Mr Thomas back on Earth on June 12.

The American mission will be the last before the space station is taken out of service later this month and marks more than three years of collaboration between Russia and the US onboard Mir.

Nasa officials say the assembly of a new space station to replace Mir will be delayed to the end of the year.

Cosmonauts worked round the clock to fix a computer fault

The first part of the International Space Station was to have been launched this month - but that has now been put back to November because Russia has fallen behind in building the space station's first module.

Financial constraints on the Russian space programme have been blamed for the delay.

Nasa says it expects the new station to be completed by January 2004, a month behind schedule.

The shuttle is using a new fuel tank built with a new light-weight aluminum lithium alloy for the first time on the mission.

While identical in appearance to the previous tanks, the lighter design will allow the shuttle to haul heavy parts of the planned International Space Station into orbit.

The shuttle's crew expressed no concerns about flying with the slimmed-down tank.

"We feel extremely confident in that tank's ability to do its job," Discovery's pilot Dom Gorie said.