By Irene Klotz
CAPE CANAVERAL, Florida (Reuters) - NASA astronauts attached a Russian docking and research module onto the International Space Station on Tuesday, bringing the $100 billion complex to near completion.
The compartment, known as Rassvet -- Russian for "dawn" -- was delivered aboard shuttle Atlantis, which is making the third-to-last flight of the shuttle program.
Russia plans to launch its prime research laboratory in 2012, which will complete the $100 billion orbital outpost, a project of 16 nations that has been under construction 220 miles above Earth since 1998.
NASA has two shuttle missions remaining. Discovery is due to fly in September with a final load of spare parts and a storage pod that will be left at the station.
Endeavour, on NASA's 134th shuttle flight, will mark the program's finale with the delivery of the $2 billion Alpha Magnetic Spectrometer particle detector. The physics experiment will be mounted outside the station.
With Rassvet, the station now has 13 rooms, including two core Russian modules, Zarya and Zvezda, three major laboratories -- the U.S.'s Destiny, Europe's Columbus and Japan's Kibo complex -- two airlocks, two combination docking
compartments/mini research labs, three connecting hubs, and an observatory, known as the Cupola. There also is an outside porch for science experiments and a storage room on the Kibo lab.
Atlantis and six astronauts arrived at the station on Sunday for an eight-day stay.
During the first of three spacewalks on Monday, astronauts Garrett Reisman and Steve Bowen installed a spare communications antenna and outfitted the station's Canadian robotic crane with a work platform.
Spacewalks on Wednesday and Friday are devoted to replacing six huge batteries for the station's solar power system.
The shuttle, which blasted off on Friday, is due back at the Kennedy Space Center in Florida on May 26.
(Editing by Tom Brown and Eric Walsh)