This was the first time NASA delivered a Russian compartment to the 12-year-old space station and required two astronauts working a big robot arm.
Normally, Russian space station modules dock automatically. That's how a similar compartment got to the space station last November.
Astronaut Garrett Reisman operated the space station's robot arm, driving in the module with such precision that the first capture sensor didn't even go off.
"He went right down the middle and got a hole in one," Mission Control said. Reisman was assisted by Piers Sellers, who called out all the milestones.
The six space station residents - especially the three Russians - were thrilled with the addition. Commander Oleg Kotov thanked NASA for delivering the compartment, named Rassvet, or Dawn in Russian.
"The International Space Station has grown by one more module," he called down in Russian.
Rassvet - nearly 8 feet in diameter - is stuffed with more than 3,000 pounds of space station supplies, all provided by NASA under a barter agreement with the Russians. There's even equipment attached to the outside of the compartment for use on the full-scale science lab that Russia plans to launch in 2012.
The addition - which provides an extra docking port - now puts the space station at 98 percent complete in terms of habitable volume and 93 percent complete in terms of structure. Its mass exceeds 816,000 pounds.
NASA's share of the construction work is almost over. Only two shuttle missions remain; they're currently scheduled for fall. This is the last planned flight for Atlantis after 32 flights over 25 years.
President Barack Obama wants NASA out of the shuttle business as soon as possible so it can focus on trips to asteroids and Mars. American astronauts will hitch rides to the space station on Russian rockets until U.S. companies develop their own launch vehicle.
Next up for the Atlantis astronauts: two more spacewalks. Two of the crew will venture out on another spacewalk Wednesday to replace three space station batteries. Another three batteries will be replaced Friday.
With so few shuttle flights left, NASA wants to leave behind as many new parts as possible so the space station can keep running until 2020.
The spacewalking astronauts also may be asked to untangle a cable on the shuttle's inspection boom that's prevented a proper safety survey of Atlantis.
