Endeavour is due to dock at the space station just after midnight Wednesday morning to deliver the station's newest room, called Tranquility, and a seven-window dome designed to give astronauts stunning views of the Earth from space.
"It's a beautiful day up here on Endeavour," shuttle commander George Zamka told Mission Control after his crew awoke at 5:14 p.m. EST. Mission Control played the song "Katmandu" by Bob Seger for Zamka at the request of his family.
Zamka and his crew are due to dock at the space station at 12:06 a.m. EST. They are on an overnight shift that requires them to work at night and sleep in the day.
"So far, things are looking very favorable for an on-time docking," shuttle flight director Kwatsi Alibaruho said earlier today.
The astronauts did spot a piece of a so-called "flipper door" seal sticking up from the top of Endeavour's left wing and sent photos of it to Mission Control for analysis.
The seal is used to control venting air from an avionics cavity inside the shuttle's wing during launches and landing, said LeRoy Cain, NASA's deputy shuttle program manager. It is one of many along each of the shuttle's wings. The protruding piece is near the aft of the wing and not a safety concern to the orbiter or its crew, Cain said.
The top of a shuttle's wing does not see the hot, scorching temperatures experienced by its underbelly during re-entry, Cain said. The seal is also about 3 feet long, with only a small 4-inch strip peeled up at its leading edge, he added.
"From a mechanical and structural perspective, it's really not going to pose a problem for us," Cain said.
Next stop: Space Station
Endeavour blasted off from NASA's Kennedy Space Center in Florida before dawn on Monday in what is expected to be NASA's last night launch of a shuttle ever. The shuttle's STS-130 mission is the first of five final shuttle missions before NASA retires its three-orbiter fleet later this year.
Yeah! Endeavour is on our way!" space station astronaut Soichi Noguchi, representing Japan's space agency, wrote on his Twitter page after watching Endeavour launch via a video link on Monday.
Endeavour's 13-day mission will deliver the can-shaped Tranquility module and the bay window-like Cupola dome. Both additions were built for NASA by the European Space Agency. Together, they cost nearly $409 million and require three spacewalks by astronauts to install.
The new station additions represent NASA's last big add-ons for the $100 billion space station, which has been under construction since 1998 by five different space agencies representing 16 countries. The space station will be 98 percent complete once they're installed.
But first, Zamka and his crew have to dock at the space station at 12:06 a.m. EST.
Before the astronauts arrive, Zamka will park Endeavour about 600 feet below the space station and then guide the 100-ton spacecraft through an orbital backflip.
During the maneuver, astronauts inside the space station will snap high-resolution photographs of Endeavour's tile-covered belly. The images will be beamed to Earth later so experts can use them to check the health of Endeavour's heat shield.
Shuttle health has been a vital concern for NASA since 2003, when heat shield damage to the left wing of the shuttle Columbia led to the loss of that orbiter and its seven-astronaut crew.
So far, video images of Endeavour's heat shield recorded during launch have revealed no obvious damage, though cameras did spot several pieces of foam debris fly off the tank during liftoff.
Cain said none of those pieces appear to have struck the shuttle, and some of them appear to have separated from the back side of the tank.
On Tuesday, Endeavour astronauts completed the first of two planned inspections of their shuttle's nose cap and wing edges using a 100-foot (50-meter) inspection pole tipped with laser sensors. That data will be analyzed along with images from today's docking, Alibaruho said.
All of Endeavour's astronauts have said they are eagerly looking forward to seeing the space station outside their shuttle's windows. But the view will be extra special for two of them.
Endeavour pilot Terry Virts is making his first spaceflight on the mission and is the crew's only rookie. Before launch, he said the views out the window were likely going to be among his favorite.
U.S. Navy Reserve Capt. Kathryn "Kay" Hire is the only veteran spaceflyer on Endeavour's crew who has yet to visit the space station. She is making her second spaceflight. Her first one, STS-90 in 1998, was a 16-day science flight that used a Spacelab module in the payload bay of Columbia.
The space station, she said, is much, much larger. It has about the same living space inside as a Boeing 747 jumbo jet and an exterior structure that is as long as a football field. The station can be easily seen by the naked eye from Earth on clear nights.
"It's just a tremendously exciting thing to be able to see that, to be a part of that and know that we have that available for science to the international community," Hire said.