It looks like a hollow metal canister the size of a single-decker bus. But to the European Space Agency, the precious cargo that blasted off from Cape Canaveral today aboard the shuttle Atlantis represents an historic turning point in more than 50 years of space dominance by Russia and the US.

Almost five years after it was first scheduled to fly, the agency’s 4.5-meter diameter Columbus module is finally en route to the international space station 220 miles above Earth, where it will be attached and wired in to provide astronauts with an additional 75 cubic meters of laboratory room.

Yet its significance for the European space program extends beyond the provision of an upgraded facility to conduct scientific experiments aboard the orbiting outpost. Paired with the launch of a new space station supply ship, the Automatic Transfer Vehicle, nicknamed Jules Verne, from French Guiana later this spring, it gives the 17-nation ESA an unprecedented capability to manage its own affairs in space rather than an almost total reliance on partner nations.

"For the first time we’ll have control of our own spacecraft and our own astronauts from our own ground control center in Europe," said Alan Thirkettle, ESA’s space station manager.

"We’ve been part of a European ground agency for too long, as far as the space station is concerned. This more than gives us a voice at the table."

He said he was relieved to finally see Columbus off the ground following years of delays caused by developmental problems and the 2003 Columbia shuttle disaster.

Atlantis blasted off at 2.43pm ET (7.43pm GMT), two months after its original launch was shelved because of problems with engine fuel sensors. Nasa fixed those, found a solution to a kinked coolant hose by stuffing it back into its protective box and beat a weather forecast earlier in the day predicting a 70% chance of thunderstorms that would have forced a further postponement.

"It’s lift-off for the space shuttle Atlantis, as Columbus sets sail on a voyage of science for the space station," said Nasa’s launch commentator George Diller as the shuttle climbed into the sky atop a blazing fireball.

Two ESA astronauts were among the crew of seven accompanying the €5bn (£3.75bn) Columbus to the space station, which has been continually manned since 2000 by Russians and Americans, with only short-term stays for Europeans and a handful of fare-paying space tourists.

Leopold Eyrharts of France will remain in space for two months once Atlantis has departed for Earth at the end of its 11-day journey, and Hans Schlegel of Germany will join fellow space walker and Nasa astronaut Rex Walheim in a tricky manoeuvre four days in to the mission to remove the module from the shuttle’s payload bay and bolt it to the space station.

Next year, after Columbus is fully operational, the permanent space station crew will double to six and European astronauts will spend six months aboard every two years, with negotiations under way for more.

Mr Thirkettle said that Columbus, which weighs 10,300kg and has space for 10 experiment racks the size of telephone boxes, will open a door previously difficult for European scientists to pass through.

"We want to use this station to improve the lives our citizens," Mr Thirkettle said. "We will, in fact, be getting science back from the Columbus laboratory data within a week or 10 days of launch. That’s something we’re very excited and very pleased about."

The first experiments will take place while Atlantis is still docked, including the fixing of a solar observatory to the exterior of Columbus during the mission’s third and final spacewalk.

The laboratory, which has an estimated operating life of 10 years, will then host experiments including the examination of human reaction to micro gravity and the effects of space on various fluids and objects.

"The payback is over a long time, it’s not a road to Damascus," Mr Thirkettle said. "We’ll see it in the improvement of life on Earth, in the developments of water treatments, in the materials that improve aircraft engines."

With Nasa’s 28-year-old space shuttle program set to end in 2010, and the replacement Ares rockets not scheduled to fly until at least late 2014, ESA managers expect to share a bigger role in the maintenance and supply of the space station with Russia.

France, Germany and Italy are ESA’s three biggest contributors, with Britain – as a junior partner – not contributing to its astronaut program.

For Nasa, meanwhile, the launch of Atlantis marks the start of one of the busiest periods in the space agency’s 50-year history. Two further shuttle missions are scheduled to follow in the next 14 weeks, part of a testing schedule of 12 more construction flights to the space station, plus one to fix the ailing Hubble space telescope, before the aging fleet of orbiters – Atlantis, Discovery and Endeavor – is retired in two years’ time.