Shuttle crew prepares for early morning landing

CAPE CANAVERAL: The shuttle Endeavour crew closed the payload bay doors in preparation for a scheduled landing early on Wednesday, as sister ship Atlantis neared the launch pad for the shuttle program's final flight.

Endeavour was scheduled to wrap up a 16-day servicing call at the International Space Station with a 2:35 a.m. (0635 GMT) touchdown at the Kennedy Space Center in Florida.

With good weather expected for landing, the astronauts late on Tuesday closed Endeavour's cargo bay doors for the first time since the shuttle reached orbit on May 16.

The primary goal of the mission, the 134th and next to last in the US space shuttle program, was to deliver the $2 billion Alpha Magnetic Spectrometer particle detector and a pallet of spare parts to the station.

The crew also made four spacewalks to complete assembly of the US side of the $100 billion outpost, a project of 16 nations that has been under construction since 1998.

As the Endeavour crew prepared for its homecoming, shuttle Atlantis began the six-hour trek to the launch pad.

Thousands of NASA workers and their families jammed the spaceport on Tuesday night to watch NASA's final shuttle roll-out, including the four astronauts who will be aboard Atlantis when it blasts off on a supply run to the station. Launch is targeted for July 8.

"Look at this vehicle, look how majestic it looks rolling out to the launch pad," Atlantis astronaut Sandy Magnus told reporters. "Look at that and see what we can do when we put our minds to it."

The United States is retiring its three-ship fleet due to high operating costs and to free up funds to develop new spacecraft that can travel beyond the space station's 220-mile- (346-km) high orbit where the shuttles cannot go.

"The space shuttle has been the workhorse of the US space program for better than 30 years now, so it'll be sad to see it retired," Endeavour commander Mark Kelly said during an in-flight interview late on Monday.

"But we are looking forward to new spacecraft and new destinations and we're all excited about the future," he added.

The US decision to retire the shuttles without having a replacement ship ready has drawn criticism, including a public rebuke from Apollo 11 commander Neil Armstrong, the first person to walk on the moon.

It will be at least four years before NASA astronauts can fly out of the United States again. Until new ships are ready, Russia will transport crews to the station, at a cost of more than $50 million a person.

Endeavour returns with a new record-holder aboard: Mike Fincke, who previously served two long-duration missions on the space station, will have spent 381 days in space more than any other US astronaut.

Russia, which flew a series of space stations before partnering with NASA in the international endeavor, dominates the space endurance record books. Topping the list is cosmonaut Sergei Krikalev, who flew six missions on the Soviet-era Mir space station, two shuttle missions and two stints on the International Space Station, for a total of 803 days in space.

Copyright Reuters, 2011