The seven astronauts aboard space shuttle Discovery have docked with the International Space Station.
The shuttle finished its approach with a "textbook" alignment, NASA said Sunday evening.
Tying up with the station was expected to be more difficult than normal because the shuttle has experienced thruster problems. The crew was told to shut down two minor thrusters after liftoff because one of them was found to be leaking.
Rick Sturckow, Discovery's commander, used the primary thrusters to dock, which are more powerful. He has trained for this but the method has never been used to dock with the ISS.
Otherwise, officials believe Discovery fared well as it left the Earth's atmosphere. There were no sightings of large foam insulation pieces coming loose from the fuel tank -- a major problem in previous missions.
But more analysis about the ship's condition is needed, said LeRoy Cain, the head of NASA's mission management team. The shuttle will be photographed from the space station right before it docks, to get a better idea of whether it's been damaged.
"We used the robotic arm to do our routine inspection of the Shuttle's thermal protection system," Jose Hernandez, a first-time astronaut on board discovery, wrote in a Twitter update from orbit this morning.
Hernandez grew up in a migrant worker family and applied for 12 years in a row to become an astronaut. He was finally selected in 2004.
"Micro G is great," he wrote earlier. "Finished setting up the computers and ready for bed! Don't need pillow!"
The shuttle lifted off on Friday night and is carrying a variety of gear to the space station. There are more than 7,500 kilograms of equipment and science experiments on board. Among other things, Discovery is flying six mice to the station, which will remain in space for three months as part of a bone-loss study.
Discovery is also delivering a new treadmill to the space station that will add to its exercise room. The treadmill has been named after Comedy Central TV show host Stephen Colbert. That was decided after Colbert won an online vote earlier this year.
On Saturday, a headline on the website of Colbert's TV show quipped, "The universe just got a little bit slimmer."
Discovery's astronauts will carry out three spacewalks while at the station to replace an ammonia tank and complete other maintenance tasks.
The shuttle's docking will mark the second time 13 people are together in space. The last time that happened was last month, when space shuttle Endeavour arrived at the station.
NASA's website said that Discovery's crewmembers woke up early on Sunday afternoon to the song "Made to Love" by Toby Mac. They began maneuvering to dock with the space station at 3:29 p.m.
The station is expected to photograph the shuttle heat shield at approximately 8 p.m. from 600 feet away.
Space shuttle Columbia exploded in midair six years ago due to a hole in the wing. NASA has been watchful about signs of launch damage since then.
With files from The Associated Press
