The crew of the International Space Station Expedition 25 landed safely in Kazakhstan just before midnight on Thursday (Friday morning Kazakhstan time). The trio-Doug Wheelock, Shannon Walker and Soyuz Commander Fyodor Yurchikhin-undocked in the Soyuz TMA-19 at 8:23 p.m., ending their five and a half month stay at the ISS, NASA reported. Wheelock has spent 178 days in space on his two missions (15 days on STS-120).
Walker spent 163 days in space on this, her first mission. Each spent 161 days aboard the station as members of Expedition 24/25. Yurchikhin has 371 total days in space (163 during Expedition 24/25). He was also a flight engineer during Expedition 15 (197 days) and a mission specialist for STS-112 (11 days). Staying behind on the orbiting laboratory are Expedition 26 Commander Scott Kelly and flight engineers Alexander Kaleri and Oleg Skripochka.
Their increment officially began when the Soyuz TMA-19 undocked. The departing Expedition 25 crew spent its final days packing gear for the return home as well as reviewing and training for its landing procedures. They also participated in the usual station science and maintenance activities. The space agency reported the crew members remaining behind had been preparing for their handover activities all week. They reviewed emergency procedures as the outgoing station residents transitioned into their new roles and also continued station science activities such as collecting and storing blood samples for the Human Research Facility, according to reports from NASA officials.
The Expedition 25 and 26 crews, comprising nine residents over a span of eight months, conducted microgravity experiments in human research, biology and biotechnology, physical and materials sciences, technology development, and Earth and space sciences. They also accepted delivery of the newest external instrument, the Alpha Magnetic Spectrometer, designed to plumb fundamental issues related to the origin and structure of our universe. The crews are working with some 115 experiments involving approximately 380 researchers across a variety of fields, including human life sciences, physical sciences and Earth observation, and conduct technology demonstrations ranging from recycling to robotics.
Seventy-two of these experiments will be sponsored by U.S. investigators, including 18 under the auspices of the U.S. National Laboratory program, and 43 sponsored by international partner investigators. More than 680 hours of research are planned. As with prior expeditions, many experiments are designed to gather information about the effects of long-duration spaceflight on the human body, which NASA said would help scientists understand complicated processes such as immune systems while planning for future exploration missions.
In addition, the arrival of the Permanent Multipurpose Facility, an Italian-built converted pressurized cargo carrier named Leonardo, will add 2,700 cubic feet of pressurized volume to the orbiting laboratory, increasing the total habitable volume of the station to 13,846 cubic feet. Robonaut 2 will be installed in the U.S. Destiny Laboratory, providing scientists and engineers on the ground and crews on the station with an opportunity to test how humans and humanlike robots can work shoulder to shoulder in microgravity. NASA mission documents noted once this has been demonstrated inside the station, software upgrades and lower bodies can be added, potentially allowing Robonaut 2 to move around inside the station and eventually work outside in the vacuum of space.
The first station expedition crew-Commander Bill Shepherd and flight engineers Sergei Krikalev and Yuri Gidzenko-took up residence on the station on Nov. 2, 2000, following an Oct. 31 launch from the Baikonur Cosmodrome in Kazakhstan. Since then, more than 200 explorers have visited the orbiting complex; 15 countries have contributed support, modules and in-orbit hardware; and more than 600 experiments have been conducted.