Shuttle lifts off with space railroad

Atlantis departs Kennedy Space Center

(CNN) -- The space shuttle Atlantis roared in orbit Monday afternoon, bound for the international space station with seven astronauts and the building blocks of the first railroad in space.

The 11-day mission to the space station was delayed from Thursday when a fuel line ruptured and spewed flammable hydrogen hours before launch.

NASA technicians repaired the line over the weekend. And while strong winds threatened to postpone the launch again Monday, the conditions remained calm enough for the shuttle to blast off from the Kennedy Space Center off shortly after 4:30 p.m. EDT.

Atlantis should dock with the space station Wednesday, after which shuttle astronauts will conduct four spacewalks to install a variety of expensive pieces of hardware.

CNN NewsPass VIDEO Watch the launch of space shuttle Atlantis as it begins its mission to deliver a key construction part to Space Station Alpha (April 8) Play video   EXTRA INFORMATION Space: The railroad's final frontier     •  Shuttle mission guide  •  CNN Presents: what makes the shuttle fly Movies:  •  Atlantis returns to earth  •  Atlantis leaves space station  •  CNN's Miles O'Brien talks with shuttle crew  •  CNN's John Zarrella previews the mission  •  Watch the launch from Kennedy Space Center  •   NASA animation of completed space station railroad More resources:  •  Cult 3-D model of the space shuttle  •  Milestones in space shuttle history  •  Space: The final frontier for railroads

The main one is a squat, three-dimensional, metal trapezoid replete with electrical wires, cables and computers. The $600 million truss will enable future research and construction projects on the expanding station.

The 44-foot (13-meter) long, 13.5-ton structure will have railroad tracks attached to it. In the future, a railcar will shuttle the station's robotic arm, allowing it to grasp and move massive pieces of equipment around the modular outpost.

Atlantis is bringing the first railroad segment along with the $190 million railcar. The track is slated to eventually stretch more than 360 feet (110 meters).

Designing the first railroad for the harsh conditions of space has been no easy task, said NASA engineers.

"These rails will run in temperatures far hotter than any desert and far colder than any mountain," said Tom Farell of NASA's Johnson Space Center in a statement.

Moreover, "we've done a lot of work to make certain it can't jump the tracks ... during all the station's activities, like re-boosting its orbit or having visiting vehicles dock."

The shuttle will also carry along scientific experiments. One known as the Photosynthetic Experiment and System Testing and Operation, or PESTO, could lead to better space food.

The wheat growth project, which will remain on the station at least two months, could help scientists determine how to grow grains in space, raising the prospect of astronauts baking their own bread.

The research "will provide important knowledge necessary for future interplanetary travel," said NASA project manager David Cox.

The shuttle mission is the 13th to visit the international space station.

For the three space station residents, the arrival of Atlantis will mean a cuisine improvement. The shuttle astronauts, the first visitors to the space station since the current space station inhabitants arrived in December, are bringing fresh food and supplies to the orbiting outpost.

Hours before launch, a private aircraft flew into restricted airspace around the Florida launch site. Two Air Force F-15 fighters patrolling the region escorted the Cessna craft to an area airport.

The local sheriff's department was questioning the pilot but military authorities described the incident as an "innocent intrusion." Since September 11, the U.S. government has tightened security for shuttle launches to prevent terrorist attacks.