Space Station Crewmembers Return to Earth, Endeavour to Run Practice Launch

Three down, one up: Some of the International Space Station crew land on Earth as the shuttle Endeavour stages a practice launch.

Expedition 26 Commander Scott Kelly and Russian flight engineers Alexander Kaleri and Oleg Skripochka safely landed their Soyuz spacecraft on the Kazakhstan Steppe this morning, wrapping up a five-month stay aboard the International Space Station, NASA reported. The trio launched aboard the Soyuz TMA-01M spacecraft from the Baikonur Cosmodrome in Kazakhstan on Oct. 8, 2010. As members of the Expedition 25 and 26 crews, they spent 159 days in space, 157 of them aboard the station.

Working in frigid temperatures, Russian recovery teams were on hand to help the crew exit the Soyuz and adjust to gravity. Kaleri and Skripochka will return to the Gagarin Cosmonaut Training Center in Star City outside of Moscow, while Kelly will fly directly home to Houston.

A new trio of Expedition 27 flight engineers-NASA astronaut Ron Garan and Russian cosmonauts Andrey Borisenko and Alexander Samokutyaev-are scheduled to launch from the Baikonur Cosmodrome no earlier than March 29, the space agency reported.

During their mission, the Expedition 25 and 26 crew members worked on more than 150 microgravity experiments in human research, biology and biotechnology, physical and materials sciences, technology development, and Earth and space sciences. A quick succession of international space vehicles arrived on the station's loading docks during Expedition 26. The Japanese Kounotori2, or "white stork," H-II Transfer Vehicle 2, the Russian cargo ship Progress 41, the European Jules Verne Automated Transfer Vehicle and space shuttle Discovery delivered more than 11 tons of supplies necessary for working and living aboard the station.

After safely reaching its launch pad at NASA's Kennedy Space Center in Florida on March 11, space shuttle Endeavour now awaits the next major milestone for its upcoming flight to the ISS-a launch dress rehearsal, known as the Terminal Countdown Demonstration Test (TCDT). The test is scheduled at Kennedy from March 29 to April 1. Six astronauts are set to begin the STS-134 mission on April 19 for Endeavour's final scheduled flight before it is retired.

The space agency said TCDT will provide Endeavour's astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On March 29, the astronauts will arrive at the Shuttle Landing Facility and make a statement and on April 1 will depart from the Operations and Checkout Building in their launch entry suits in preparation for the countdown demonstration test at the launch pad.

The 14-day mission will be the 36th flight to the space station and the 25th flight for Endeavour. The STS-134 mission will deliver the Alpha Magnetic Spectrometer, a particle physics detector designed to search for various types of unusual matter by measuring cosmic rays. The STS-134 crew also will deliver the Express Logistics Carrier-3, a platform that carries spare parts to sustain station operations once the shuttles are retired later this year.

Earlier this month, NASA celebrated the safe landing of the space shuttle Discovery after its final mission into space. After 27 years of service during which it racked up exactly one cumulative year in space and an odometer reading of more than 148 million miles, the shuttle was the orbiter fleet leader, having flown more flights than any other orbiter in the fleet, including four in 1985 alone.