A space capsule successfully docked with the International Space Station (ISS) 250 miles above the Earth Monday during the first manned orbiting mission since the disintegration of the space shuttle Columbia.

After launching from the Baikonur cosmodrome in Kazakhstan on Saturday, the Soyuz TMA-2 capsule carrying a U.S.-Russian duo locked onto the floating space lab.

The mission will end when the astronauts currently living on the space station return to Earth Saturday, marking the first time U.S. astronauts will come home on a Russian spacecraft.

Expedition Seven's mission

The Soyuz carried two astronauts, Edward Lu, an American research physicist and Yuri Malenchenko, a Russian pilot and engineer. Known as Expedition Seven, the duo will replace U.S. astronauts Kenneth Bowersox and Donald Pettit and Russian cosmonaut Nikolai Budarin, who were stuck on the station following the Feb. 1 Columbia disaster.

Lu told reporters on Friday that he would wear the same arm patch as the Columbia crew to honor them.

"We are doing what I think they would have wanted and what their families wished for us to do, which is to continue the process of flying in space," the astronaut said. "We'll be thinking about them during the liftoff and during the flight."

Fredrick Gregory, deputy administrator of NASA, called Monday's maneuver a "beautiful docking."

"The International Space Station partnership has been tested by a great challenge. The partnership has risen to the challenge and demonstrated that we are able to overcome any obstacle on this road to the future," Gregory said.

The new crew's mission is to keep the ISS in working order until U.S. shuttles are back in service, which will take at least a year, according to NASA officials. In addition the astronauts will continue scientific experiments during their six month stint in space.

A historic return for U.S. astronauts

During a short hand-over period the outgoing crew must share a lot of information with the incoming astronauts. The outgoing crew must give the new residents a tour and explain safety procedures; the new crew will provide a refresher course on how to operate the Soyuz capsule.

The returning crew will travel to Earth on May 3 using an older Soyuz capsule that is already docked to the station. The Soyuz that carried Lu and Malenchenko will remain at the space station as an "emergency lifeboat" in case they need to leave quickly.

The Russian Soyuz is now the only ship capable of carrying crews to and from the space station following the grounding of all U.S. space shuttles.

Problems with the use of Russian spacecrafts

The use of the Russian spacecrafts creates several problems for the International Space Station. The Soyuz crafts can only ferry small crews and limited cargo. With the grounding of U.S. shuttles only the most basic of repairs and maintenance can be completed.

Construction on the station began in 1998 and is only half-finished. The completion date has been pushed back from 2004 to 2008.

Sixteen nations are helping build the International Space Station. By the time it’s finished, the orbiting laboratory will weigh 418 tons and be 7 stories high. As they conduct research in medicine, industry, technology and the environment, astronauts on the space station can watch 16 sunrises each day.

-- By Annie Schleicher, NewsHour Extra