The shuttle crew traveled two days to reach the space station, where, during a weeklong stay, they will continue construction on the orbiting lab and replace one station crew member with another.

The sensor recorded a level of impact not considered worrisome, Shannon said, but managers decided to take a closer look to be safe and perhaps eliminate the need to do a time-consuming focused inspection later in this jam-packed mission. NASA officials have not determined the significance of the blip, though they don’t expect it to affect the mission.

"It looks like something happened," said John Shannon, chairman of the mission management team, noting that the wing looked fine during a focused inspection performed Sunday.

The shuttle delivered a 2-ton, $11 million cube-shaped addition to the space station, using the shuttle and the station’s robotic arms. The addition will be attached to the station during a spacewalk Tuesday.

To link up with the station, Discovery commander Mark Polansky moved the shuttle a tenth of a foot per second before latches connected it shortly before a sunrise.

"Space shuttle Discovery arriving," space station resident Michael Lopez-Alegria told Mission Control in Houston at 6:54 p.m. EST as the hatch between the two spacecraft opened to the traditional ringing of a bell.

Televised images from the orbiting space lab showed Bob Curbeam, due to perform three spacewalks, bouncing over two hugging astronauts to shake the hand of space station resident Thomas Reiter, who will return to Earth with the shuttle crew. Christer Fuglesang, now the first Swede in space, spoke into a videocamera, then let it float away.

Eventually the two crews gathered for a group shot, all smiles and with some ponytails floating, as they flew 220 miles above Australia.

"You guys all look great," Mission Control radioed up. "We’re waving back."

Six of Discovery’s seven astronauts planned to spend a week at the space station. The seventh astronaut, Sunita "Suni" Williams, will live there for six months, replacing German astronaut Reiter of the European Space Agency.

The two will swap places before the end of the day, making Williams only the third woman in history to reside long-term at the space station.