"Im hoping that people will look at this mission as the beginning of a great dawn for space research," Atlantis mission specialist Robert Curbeam told SPACE.com before the flight.

"Well finally have the heart and soul of the station [in orbit], and people will look back and say, `Gosh, that was the linchpin right there. And once that lab got up, we started doing what we planned to do with the station, and we never looked back.'"

Coming after a three-week delay to inspect suspect solid-fuel rocket booster cabling, the shuttles earthshaking climb into orbit began as the 13-story station was flying over the North Atlantic Ocean due east of St. Johns, Newfoundland.

Led by veteran skipper Ken Cockrell, the astronauts set out on a two-day chase that is expected to culminate in a docking at the station about noon EST (17:00 GMT) Friday.

Anxiously awaiting their arrival: U.S. astronaut Bill Shepherd and two Russian cosmonauts -- Yuri Gidzenko and Sergei Krikalev -- who have been aboard the outpost for 97 days.

"Im sure theyll be happy to see us because well have some fresh food and some gifts," Cockrell said. "And then well get straight to work."

During a weeklong flurry of work both inside and outside the station, the visiting shuttle astronauts aim to mount and activate the Destiny lab, which will serve as the scientific heart -- and the new central command center -- for the station.

"This is the nerve center for the space station," Atlantis mission specialist Tom Jones said. "It contains not only laboratory space for the experiments that will be coming up in the next year or two, but its also got the brains of the station -- a whole array of computers to control the station."

A can-shaped aluminum module made up of 415,000 parts, the massive lab weighs 32,000 pounds (14,400 kilograms), stretches 28 feet (8.5 meters) from end to end and sports 26 miles (41.6 kilometers) or wiring.

Said Jones: "Its about the size of a school bus [and] looks like a big soda can."

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Inside the lab: Room for 24 refrigerator-sized "racks" that will house either life- and lab-support systems or experiment apparatus that will enable scientists to conduct research in a variety of disciplines, including fundamental physics, biology, chemistry, Earth science and space science.

Considered the most expensive and important U.S. station segment, the Destiny lab will enable NASA to assume command and control of the entire outpost -- a responsibility now carried out at Russias Mission Control Center outside Moscow.

The Destiny lab also will provide electrical power, cooling, carbon dioxide removal and oxygen generation for European and Japanese research facilities still to be added to the outpost. Those other labs, consequently, all will depend upon Destiny.

Whats more, the U.S. lab must be put in place before NASA and its international partners can continue further construction of the outpost, which eventually will include five additional science labs and an American-made dormitory module.

"Its our crown jewel," said Mark Stephenson, a senior station manager with The Boeing Co., NASAs prime contractor on the project. "Thats our cornerstone contribution to the project."

Putting the cornerstone in place will be no easy task.

With a Canadian-built robot arm serving as a construction crane, Atlantis mission specialist Marsha Ivins will attempt to move a shuttle docking port to a temporary stowage location on an outpost truss about 8:30 a.m. EST (13:30 GMT) Saturday.

Astronauts Curbeam and Jones then will float outside Atlantis to give Ivins a spacewalking assist as she hoists the hefty lab from the shuttles cargo bay and then attempts to flip it 180 degrees so it properly positioned atop the station.

Cockrell calls it "a very non-trivial event" -- and the shuttle crew is keenly aware of its importance to the space station construction project.

"We certainly dont want to mess it up," the shuttle commander said.

Jones and Curbeam also will route electrical and cooling lines between the lab and the rest of the station during the spacewalk, which is the first of three planned for the mission.

The pair will venture outside again about 10:30 a.m. EST (15:30 GMT) Tuesday to move the shuttle docking port to the forward end of the lab, where it will serve as a parking place for U.S. orbiters flying future station assembly missions.

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The final spacewalk -- which will begin about 10 a.m. EST (15:00 GMT) Wednesday, Feb. 14 -- primarily involves stowing a spare communications antenna outside the outpost. Jones and Curbeam also will perform that spacewalk.

In between and after the spacewalks the joined shuttle and station crews will be busy inside the station activating and outfitting the lab, the presence of which will double the amount of pressurized working space aboard the outpost.

With three other pressurized wings already in place, the lab will make the station larger in terms of habitable space than NASAs 1970s Skylab complex or the Russian Mir outpost, which will be sent on a destructive dive into the Pacific Ocean in early March.

A final farewell and hatch closing ceremony now is scheduled for 7:18 a.m. EST (12:18 GMT) Friday, Feb. 16. Atlantis and its crew will depart the station a little less than two hours later, flying a giant loop around the outpost before heading toward a 1 p.m. EST (18:00 GMT) Sunday, Feb. 18, landing here at NASAs Florida spaceport.

Coming six years after the agency set out to build the Destiny lab, the upcoming delivery of the stations first science facility is expected to clear the way for the start of orbital research by the end of March.

"Its been a long time in coming," said NASA station project manager Tommy Holloway.

"With the addition of the U.S. lab, the station can finally begin to realize `raison d'être -- which is fundamental scientific research," added NASA mission manager Jon Cowart. "I cannot even begin to imagine the discoveries that will be made on this spaceship of research and inquiry."

Cradled just inside a Destiny hatch, meanwhile, is a small sign meant to depict NASAs commitment to orbital research and the promise that the lab holds for scientific breakthroughs.

"Its a cloth sheet with the signatures of most of the NASA team members who have poured their lives into preparing this spaceship for flight," Cowart said.

"Equally important also is the message which weve inscribed. In bold letters, it says: "Dreams are like stars. You choose them as your guides, and following them, you reach your destiny."

Exactly where that orbital road leads is anybodys guess.

"You cannot possibly predict where todays discoveries will lead us tomorrow," Cowart said. "But it is a journey you cannot make if you dont set sail -- and I think Destiny is our vessel."