HOUSTON -- The space shuttle Atlantis, with a preliminary clean bill of health, is about to make a 17.5-ton delivery.
This morning, astronauts are scheduled to use the shuttle's robotic arm to remove a giant truss with two attached solar wings from the shuttle's cargo bay and hand it over to the international space station.
With that delivery, Atlantis, just two days off the launch pad, will have accomplished a big chunk of its main mission.
The goal of the Atlantis crew is to resume construction on the international space station after a three-year hiatus after the loss of the space shuttle Columbia. More parts will be added in 14 other flights.
The more than 300-foot-long truss will provide power, data, and temperature control to the station's electronics.
There's a lot of work to be done after the truss is delivered. Astronauts have to hook up the plumbing and electricity. This is no easy task 213 miles above Earth, so it will take four astronauts three spacewalks over the next week to get the truss hooked up and to unfurl the solar wings.
But before any of that is to happen, Atlantis has to dock with the space station in a maneuver that has become routine, yet remains delicate and could be dangerous with a wrong move.
Early this morning, commander Brent Jett is expected to guide Atlantis slowly toward the space station until they are separated by 600 feet. Then Atlantis would then make a backflip and connect with the orbital outpost.
NASA has reported no serious problems with the Atlantis heat shield. Astronauts spent much of yesterday using the shuttle's robotic arm to take pictures of the wings. The underbelly will be checked during the backflip.
Early indications show no problems from debris created upon takeoff, NASA said.