After 166 days, six hours, and 27 minutes in flight, and some 2,580 orbits of Earth, the Expedition 38 mission has concluded safely with the touchdown in Kazakhstan of Soyuz TMA-10M and its crew of Russian cosmonauts Oleg Kotov and Sergei Ryazansky and NASA astronaut Mike Hopkins. The trio landed at 11:24 p.m. EDT Monday (9:24 a.m. local time Tuesday), after a dramatic mission which included dozens of scientific experiments, three Visiting Vehicles—including the first dedicated flight of Orbital Sciences Corp.’s Cygnus cargo ship—and multiple EVAs.
Launched last 25 September, Kotov, Ryazansky, and Hopkins were aware from the outset that their six-month mission would be distinct in its own way from its predecessors. For the first time since 2009, they remained part of a six-person increment for the entirety of their stay aboard the International Space Station (ISS). Under normal conditions, ISS crews followed an “indirect rotation” protocol, whereby a given three-member subset departs, reducing the expedition strength to three members, before another three-person team launches about two weeks later, restoring it back up to six. When Kotov, Ryazansky, and Hopkins arrived, they were greeted by Soyuz TMA-09M’s Fyodor Yurchikhin, Karen Nyberg, and Luca Parmitano. However, due to Russia’s desire to stage a special EVA to display the Olympic Torch outside the space station—part of a publicity campaign ahead of the Winter Olympics in Sochi—a “direct handover” was adopted. This allowed the torch to be carried into orbit by Soyuz TMA-11M on 7 November, taken outside the ISS on a spacewalk by Kotov and Ryazansky on 9 November, then returned to Earth with Yurchikhin, Nyberg, and Parmitano aboard Soyuz TMA-09M on 11 November.
This “ballet” of crewed vehicles got underway on 7 November, when Soyuz TMA-11M was launched, and after its arrival at the ISS its crew of Russian cosmonaut Mikhail Tyurin, NASA astronaut Rick Mastracchio, and Japan’s Koichi Wakata temporarily expanded the station’s population to nine members. Two days later, Kotov and Ryazansky ventured outside on their historic EVA, whose primary focus in the eyes of most of the world was to display the Olympic Torch. Two days later, Soyuz TMA-09M returned to Earth and Expedition 38 got underway, with Kotov in command.
For the next four months, the six men worked together on a multitude of scientific experiments and welcomed three Visiting Vehicles: Progress M-21M, launched on 25 November, Orbital Sciences Corp.’s ORB-1 Cygnus, launched on 9 January, and Progress M-22M, launched on 5 February. They also supported no fewer than four EVAs, two of which came about following the shutdown of one of the space station’s external coolant loops on 11 December. Over Christmas week, Mastracchio and Hopkins removed and replaced a failed pump module, and on 27 December Kotov and Ryazansky ventured outside in an attempt to install Canadian-built Earth-observation cameras onto the exterior of the Zvezda service module. Although the first attempt was unsuccessful, due to telemetry problems, the cosmonauts established a new record for Russia’s longest EVA, at eight hours and seven minutes. A month later, on 27 January, they embarked on the fourth spacewalk of Expedition 38 and successfully installed the cameras.
With Expedition 38 entering its homestretch, Kotov ceremonially transferred command of the ISS to Wakata last Sunday (9 March), and Expedition 39 officially got underway. In the meantime, the three outgoing crewmen packed the remainder of their equipment aboard Soyuz TMA-10M and checked out their craft in readiness for undocking. At 8:02 p.m. EDT Monday, they undocked from the station’s space-facing (or “zenith”) Poisk module to commence the three-hour process of returning to Earth. The orbital and instrument modules of the Soyuz were detached, leaving the three men alone in their beehive-shaped descent module to endure the perilous descent back through the atmosphere toward a touchdown in Kazakhstan. Landing safely, not far from the city of Jezkazgan, the crew was soon reported safe, well, and cheerful after almost six months in orbit.
In the aftermath of landing, Kotov and Ryazansky were to be flown back to the cosmonauts’ training center at Star City, on the forested outskirts of Moscow, whilst Hopkins boarded a NASA Gulfstream III aircraft to return to Ellington Field in Houston, Texas, with refueling stops planned in Glasgow, Scotland, and Goose Bay, Canada. All three men have ratcheted up the list of accomplishments during Expedition 38. As first-time spacefarers, both Ryazansky and Hopkins can now boast 166 days of experience, whilst Kotov—who previously flew aboard Expedition 15 in April-October 2007 and Expeditions 22-23 in December 2009-June 2010—has accrued more than 526 days. Across his three missions, he has amassed more than 36 hours of spacewalking time in six EVAs. Ryazansky now has three EVAs and more than 20 hours outside the ISS, whilst Hopkins has two EVAs and almost 13 hours of time spent in open space.
With the safe return of Kotov, Ryazansky, and Hopkins, the Expedition 39 crew will remain at three-man strength—with Wakata, Tyurin, and Mastracchio—for the next two weeks. During that time, it is expected that they will welcome SpaceX’s third dedicated Dragon cargo ship (SpX-3), and on 25 March Soyuz TMA-12M will launch from Baikonur, carrying Russian cosmonauts Aleksandr Skvortsov and Oleg Artemyev and U.S. astronaut Steve Swanson. This will restore the ISS crew back to its full six-man strength for the remaining few weeks of Expedition 39. Wakata will then relinquish command to Swanson in mid-May, ahead of his crew returning to Earth.