Space shuttle Discovery's seven astronauts arrived at the Kennedy Space Center Sunday for a final stretch of training and preparations before they are launched on a 12-day mission to rewire the international space station.
Liftoff was set for Thursday at 9:35 p.m. EST. It will be the first night launch in four years.
"We're going to go ahead and hopefully have one heck of a night show to give everybody this Thursday night," Mark Polansky, Discovery's commander, said after he and his crew arrived from Houston aboard five training jets.
Polansky and pilot William Oefelein will spend the next several days practicing landings in a shuttle-training aircraft, and other crew members will study up on their mission tasks. The countdown clock was set to begin ticking Monday night.
Discovery's astronauts will rewire the space station, bring up an $11 million addition and drop off astronaut Sunita Williams for a six-month stay at the space lab.
"I just can't wait to get to my new home," Williams said Sunday.
NASA has required daylight liftoffs ever since the 2003 Columbia accident to make sure the agency could get good daytime photos of the external fuel tank in case debris fell from it during launch.
Foam breaking off the tank and striking Columbia's wing at liftoff caused the damage which led to the disaster that killed seven astronauts.
Comforted by the acceptable levels of foam loss during the last two liftoffs, NASA officials now believe radar is sufficient to spot pieces falling from Discovery's tank, and that the illumination from the solid rocket boosters will provide enough light to take images during the first two minutes of liftoff. There will also be inspections in orbit to spot any unseen damage.
The crew includes mission specialists Joan Higginbotham and Nicholas Patrick; lead spacewalker Bob Curbeam; and the European Space Agency's Christer Fuglesang, who will become the first Swede in space.
"I'm not going to wipe this grin off my face until December 19th, when we land," said Higginbotham, referring to the landing date if everything goes on schedule. "And then, I'm sure I'll still have a hard time wiping it off my face."