Houston, we have Hubble on our arm

Scott Altman Columbia commander

The four-storey observatory will now be serviced and upgraded over five days of space walks.

Mission control gave the go-ahead for the grab on Saturday after deciding that a problem with a radiator line would not after all interfere with the shuttle's work.

It broke the good news to the crew to the music from the spy film Mission Impossible.

Currie: Long experience with robotic arm

"Your mission, if you choose to accept it, is to rendezvous and grapple the Hubble Space Telescope and then spend five days massively re-outfitting and upgrading the telescope," controllers said in the tongue-in-cheek message, adding that the tape would "self-destruct in five seconds".

It fell to Nancy Currie, a US Army helicopter pilot, to wield the robotic arm as both the shuttle and telescope moved at a speed of eight kilometres a second about 580 kilometres above the Pacific Ocean southwest of Mexico.

The astronaut previously notched up two triumphs with the robotic arm when she joined the first two modules of the International Space Station.

"Houston, we have Hubble on our arm," the shuttle commander, Scott Altman, announced to mission control.

Blockage fears

Columbia blasted off on its 11-day mission on Friday but ground controllers soon detected a blockage in a radiator line used to cool the shuttle's electronics system.

It is believed the blockage may be debris from a welding job carried out during the shuttle's recent overhaul.

Hubble history

1977 - Project begins 1985 - Hubble built 1990, 24 April - Hubble launched 1990, 18 May - First light 1993, December - Flawed mirror corrected 1997, February - Second servicing mission 1999, December - Emergency service to repair gyroscopes 2002, March - Repairs not done in 1999 2010 - End of Hubble mission

Problems may arise, however, when the shuttle re-enters the Earth's atmosphere on its return.

Even before the positive decision, Commander Altman said he and his crew were "charging ahead full speed with our eyes on the goal".

"We're letting the smart folks on the ground really worry for us," said fellow astronaut John Grunsfeld.

The 12-year-old orbiting Hubble observatory has taken some astonishing pictures of deep space and is expected to do even better after its upgrade.

The shuttle is on an 11-day mission

The Columbia crew must fit Hubble with a new camera, solar wings, a power-control unit, a steering mechanism and a refrigerator system that should allow scientists to use an infrared camera.

The most daunting part of the mission - currently set for 5 March - will be to fit the new power unit.

Astronauts will have to switch the telescope off and Nasa cannot guarantee that it will be able to switch it back on again.