Updated

A Russian Soyuz spacecraft is poised to blast off from Central Asia today, carrying three new crewmembers to the International Space Station.

NASA astronaut Catherine Coleman, Russian cosmonaut Dmitry Kondratyev and European astronaut Paolo Nespoli are set to launch today (Dec. 15) at 2:09 p.m. EST (1909 GMT) from Kazakhstan's Baikonur Cosmodrome. The trio will fly to the station aboard a Russian Soyuz TMA-20 spacecraft.

Coleman, Kondratyev and Nespoli will round out the space station's existing Expedition 26 crew — station commander Scott Kelly of NASA and flight engineers Alexander Kaleri and Oleg Skripochka of Russia. The three new crewmembers will dock at the orbiting outpost on Friday (Dec. 17) at 3:12 p.m. EST (2012 GMT). [Graphic: Inside and Out: The International Space Station]

During their long-duration mission, Coleman, Kondratyev and Nespoli will participate in a range of scientific research and experiments, including fluid physics, radiation, biology, technology demonstrations and education outreach. Cosmonauts Kondratyev and Skripochka are also scheduled to perform at least one spacewalk to perform maintenance activities on the station's exterior.

The crewmembers will also be on hand for two space shuttle visits — the STS-133 flight of Discovery in February 2011, and the subsequent STS-134 flight of Endeavour, which is now targeted to fly in April. Discovery's liftoff was originally planned for November, but technical issues with the shuttle's external fuel tank have grounded the orbiter until at least early February.

Meet the crew

Catherine "Cady" Coleman was commissioned as a second lieutenant in the U.S. Air Force in 1983, and was selected by NASA as an astronaut candidate in March 1992. She is a veteran of two space missions, and has logged more than 500 hours in space.

Coleman served as a mission specialist on the STS-73 flight of the shuttle Columbia, which launched on Oct. 20, 1995, and was the second United States Microgravity Laboratory mission. Then she was the lead mission specialist on Columbia's STS-93 mission, which launched on July 22, 1999, and deployed NASA's Chandra X-ray Observatory.

"I've always wanted to go and live on the space station for as long as I can remember," Coleman told SPACE.com in a preflight interview. "I had a 16-day experiment flight, and I didn't want to come home. To understand living in a different kind of environment — I think that is pretty cool to be a part of."

Coleman recently celebrated her 50th birthday on Dec. 14 — just one day before her journey to the space station.

First time in space

Cosmonaut Dmitry Kondratyev, 41, was born in Irkutsk, Russia, and rose to the ranks of colonel in the Russian air force. He was selected as a test cosmonaut candidate in December 1997 and qualified in 2000.

From May 2006 through April 2007, Kondratyev served as director of operations for the Russian Space Agency while stationed at the Johnson Space Center in Houston. Today's spaceflight will be Kondratyev's first, and he will act as commander of the Soyuz TMA-20. Once onboard the space station, Kondratyev will perform duties as a flight engineer, but will take over as the space station commander for Expedition 27.

"It will be one of the most exciting moments in my life because spaceflight is something extraordinary and many people dream of it," Kondratyev said in a preflight interview. "I will be very glad and proud."

Throughout the mission, Kondratyev will also be occupied with various science experiments.

"There are lots of experiments onboard the Russian segment of the station — environmental experiments, medical experiments, technological experiments," he said. "I will be a subject for some of them. It will help scientific institutions to develop things that are new and unique."

Return to the space station

European Space Agency astronaut Paolo Nespoli, 53, was born in Milan, Italy. He joined ESA's European Astronaut Center in Cologne, Germany, in 1991, and was selected as an astronaut by the Italian space agency in July 1998.

In June 2006, Nespoli was assigned to the crew of Discovery's STS-120 flight, which was a mission to help assemble the space station. STS-120 launched on Oct. 23, 2007, and delivered the Italian-built Harmony (Node 2) module to the station.

For this upcoming flight, Nespoli will serve as a flight engineer for Expeditions 26 and 27.

"Our main goal there is to be available for carrying out experiments and use this laboratory that is up there and can let us do things that we cannot do on Earth," Nespoli said in a preflight interview. "Most of our time will be spent in either being an operator or a subject for experiments."

The six-person Expedition 26 crew will spend about three months together before Kelly hands over command of the station to Kondratyev. Kelly, Kaleri and Skripochka are set to return to Earth in mid-March, while Coleman, Kondratyev and Nespoli will remain on the station until May.

*   Graphic: Inside and Out: The International Space Station
  *   Gallery: Space Windows on the World
  *   Earth at Night: Astronaut Shares Dazzling Photos From Space Station

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