A redesigned fuel tank for NASA's first post-Columbia launch emerged from a darkened barge into the morning sunlight Thursday, inspiring dozens of space shuttle workers who gathered to watch.
"We're no longer recovering from the accident. We're really heading toward a launch. Big change in momentum and morale," launch director Mike Leinbach said.
"This is huge," said shuttle program manager Bill Parsons. "We're getting ready to stack this thing and launch, in the May-June timeframe."
The arrival of the external fuel tank from a manufacturing plant in Louisiana moved the space program closer to its goal of a late spring liftoff for Discovery.
Engineers blamed the crumbling foam insulation of the Columbia's fuel tank for the 2003 accident which killed seven astronauts, reports CBS News Correspondent Peter King.
Some workers photographed the 154-foot-long, 30-feet-wide orange-yellow tank as it was hauled atop a wheeled flatbed into the Vehicle Assembly Building, and others walked alongside, pointing out new features.
Clearly missing were the pair of foam ramps that caused the deadly shedding during Columbia's final flight. In their place were eight new heaters, designed to prevent ice buildup when super-cold fuel is loaded right before launch.
"It's the safest tank we've ever flown. There's no doubt about it," Parsons said.
Parsons, who was celebrating his 48th birthday, called the tank's arrival the perfect gift.
"It's back to business," said Parsons. "It's getting where we are really feeling like we're going to pull this off, and I think that this is just an indication, one of those big symbols that comes in and says, 'You're there. You're getting there.'"
Within half an hour, the tank was inside the assembly building, where it will undergo a month of final prepping.
The tank will be attached to the two solid rocket boosters in February, and all that will be mounted to Discovery in March.
There was good news in orbit, too, on Thursday: The two men aboard the international space station got their primary oxygen generator working after a five-day breakdown.
Discovery will carry much-needed spare parts and supplies to the space station. It will be essentially a test flight, not only for the redesigned shuttle tank but also for the inspection and repair methods for astronauts in orbit.
NASA's three remaining space shuttles have been grounded ever since Columbia ruptured on Feb. 1, 2003, killing all seven astronauts aboard.