Alexei Krasnov, Director of Manned Space Programs Department, ROSCOSMOS, answers a reporter’s question during a Soyuz post-docking press conference at the Russian Mission Control Center in Korolev, Russia on Friday, June 18, 2010. Photo Credit: (NASA/Carla Cioffi)

NASA astronaut and Expedition 24 back-up crew member, Cady Coleman, speaks with the crew of Expedition 24 upon their arrival to the International Space Station on Friday, June 18, 2010 at Russian Mission Control Center in Korolev, Russia. Photo Credit: (NASA/Carla Cioffi)

William Gerstenmaier, second from right, NASA Associate Administrator for Space Operations, speaks to the crew of Expedition 24 shortly after their arrival to the International Space Station (ISS) aboard their Soyuz TMA-19 on Friday, June 18, 2010 at Russian Mission Control in Korolev, Russia. Photo Credit: (NASA/Carla Cioffi)

Sherry Walker, second from right, speaks to her daughter NASA Flight Engineer and astronaut Shannon Walker after she and her Expedition 24 crew mates docked to the International Space Station (ISS), Friday, June 18, 2010 in Korolev, Russia. Walker, Soyuz Commander Fyodor Yurchikhin and Flight Engineer Doug Wheelock launched aboard their Soyuz TMA-19 spacecraft on Wednesday, June 16 to start a six-month tour aboard the ISS.

ISS025-E-005117 (24 Sept. 2010) --- The Soyuz TMA-18 spacecraft departs the International Space Station on Sept. 24, 2010. Onboard are three members of Expedition 24 ? Russian cosmonaut Alexander Skvortsov, commander; along with NASA astronaut Tracy Caldwell Dyson and Russian cosmonaut Mikhail Kornienko, both flight engineers.

ISS025-E-005039 (24 Sept. 2010) --- The Soyuz TMA-18 spacecraft departs the International Space Station on Sept. 24, 2010. Onboard are three members of Expedition 24 ? Russian cosmonaut Alexander Skvortsov, commander; along with NASA astronaut Tracy Caldwell Dyson and Russian cosmonaut Mikhail Kornienko, both flight engineers.

ISS025-E-005012 (24 Sept. 2010) --- The Soyuz TMA-18 spacecraft departs the International Space Station on Sept. 24, 2010. Onboard are three members of Expedition 24 ? Russian cosmonaut Alexander Skvortsov, commander; along with NASA astronaut Tracy Caldwell Dyson and Russian cosmonaut Mikhail Kornienko, both flight engineers.

ISS025-E-005014 (24 Sept. 2010) --- The Soyuz TMA-18 spacecraft departs the International Space Station on Sept. 24, 2010. Onboard are three members of Expedition 24 ? Russian cosmonaut Alexander Skvortsov, commander; along with NASA astronaut Tracy Caldwell Dyson and Russian cosmonaut Mikhail Kornienko, both flight engineers.

Russian and American personnel work at the landing site of the Soyuz TMA-18 spacecraft near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. The Soyuz TMA-18 spacecraft landed with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko onboard. The three returned from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 NASA Flight Engineer Doug Wheelock, left, Expedition 24 Soyuz Commander Fyodor Yurchikhin and Expedition 24 Flight Engineer Shannon Walker, third from left, walk out to salute Head of the Russian Federal Space Agency Anatoly Perminov, far right, prior to their launch onboard the Soyuz TMA-19 to the International Space Station (ISS), Wednesday, June 16, 2010 in Baikonur, Kazakhstan. Photo Credit: (NASA/Victor Zelentsov)

Expedition 24 Flight Engineer Mikhail Kornienko, embraces his family after he and Expedition 24 Commander Alexander Skvortsov arrived at Chkalovskaya airport just outside Moscow on Saturday, Sept. 25, 2010. Skvortsov, Kornienko and Expedition 24 Flight Engineer Tracy Caldwell Dyson, landed in their Soyuz TMA-18 spacecraft near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Commander Alexander Skvortsov, embraces his family after he and Expedition 24 Flight Engineer Mikhail Kornienko arrived at Chkalovskaya airport just outside Moscow on Saturday, Sept. 25, 2010. Skvortsov, Kornienko and Expedition 24 Flight Engineer Tracy Caldwell Dyson, landed in their Soyuz TMA-18 spacecraft near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Mikhail Kornienko, foreground, and Expedition 24 Commander Alexander Skvortsov embrace their family and friends after their arrival at Chkalovskaya airport just outside Moscow on Saturday, Sept. 25, 2010. Skvortsov, Kornienko and Expedition 24 Flight Engineer Tracy Caldwell Dyson, landed in their Soyuz TMA-18 spacecraft near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz rocket is erected at the launch pad at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Thursday, April 24, 2003. Expedition 7 is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: (NASA/Bill Ingalls)

April 24, 2003, Baikonur Cosmodrome, Kazakhstan. The Soyuz rocket is erected at the launch pad. Expedition Seven is scheduled to launch onboard the Soyuz this Saturday April 26, 2003. Photo Credit: "NASA/Bill Ingalls"

The Soyuz rocket is erected at the launch pad at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Thursday, April 24, 2003. Expedition 7 is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: (NASA/Bill Ingalls)

S123-E-009202 (24 March 2008) --- Backdropped by Earth's horizon and the blackness of space, the International Space Station appears small from the point of view of the Space Shuttle Endeavour as the two spacecraft carry out their relative separation. Endeavour's vertical stabilizer is seen in this image photographed by a STS-123 crewmember onboard the shuttle. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

Expedition 24 Flight Engineer Tracy Caldwell Dyson, left, Expedition 24 Commander Alexander Skvortsov, center, and Expedition 24 Flight Engineer Mikhail Kornienko answer reporters questions in traditional Kazakh dress during a post flight ceremony and press conference at the Karaganda airport in Kazakhstan on Saturday, Sept. 25, 2010. The Soyuz TMA-18 spacecraft, carrying Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko, landed, near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Mikhail Kornienko, left, and Commander Alexander Skvortsov, shake hands with Russian dignitaries after their arrival at Chkalovskaya airport just outside Moscow on Saturday, Sept. 25, 2010. Skvortsov, Kornienko and Expedition 24 Flight Engineer Tracy Caldwell Dyson, landed in their Soyuz TMA-18 spacecraft near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Mikhail Kornienko answer reporters questions in traditional Kazakh dress during a post flight ceremony and press conference at the Karaganda airport in Kazakhstan on Saturday, Sept. 25, 2010. The Soyuz TMA-18 spacecraft, carrying Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Kornienko, landed, near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Commander Alexander Skvortsov, front left, and Flight Engineer Mikhail Kornienko, back left, are helped down the stairs of an airplane after their arrival at Chkalovskaya airport just outside Moscow on Saturday, Sept. 25, 2010. Skvortsov, Kornienko and Expedition 24 Flight Engineer Tracy Caldwell Dyson, landed in their Soyuz TMA-18 spacecraft near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Commander Alexander Skvortsov answer reporters questions in traditional Kazakh dress during a post flight ceremony and press conference at the Karaganda airport in Kazakhstan on Saturday, Sept. 25, 2010. The Soyuz TMA-18 spacecraft, carrying Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko, landed, near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineers Tracy Caldwell Dyson, left, Commander Alexander Skvortsov, center and Mikhail Kornienko sit in chairs outside the Soyuz Capsule just minutes after they landed near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Mikhail Kornienko is helped out of the Soyuz TMA-18 spacecraft shortly after landing with fellow crew members Commander Alexander Skvortsov and Tracy Caldwell Dyson near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Mikhail Kornienko is carried to the medical tent shortly after landing in the Soyuz TMA-18 spacecraft with fellow crew members Commander Alexander Skvortsov and Tracy Caldwell Dyson near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Russian search and rescue helicopters refuel in Arkalyk, Kazakhstan prior to the landing of the Soyuz TMA-18 spacecraft with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Tracy Caldwell Dyson exits the helicopter after her flight from the Soyuz TMA-18 spacecraft landing site near Arkalyk, Kazakhstan to Karaganda, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson returned from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Tracy Caldwell Dyson talks to her husband on a satellite phone shortly after landing in the Soyuz TMA-18 spacecraft with fellow crew members Commander Alexander Skvortsov and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft, with it's crew of three still inside, is seen just moments after landing with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Russian search and rescue personnel and engineers prepare to extract the crew from the Soyuz TMA-18 moments after it landed with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Commander Alexander Skvortsov is carried to the medical tent shortly after landing in the Soyuz TMA-18 spacecraft with fellow crew members Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Russian search and rescue teams arrive at the landing site seconds after the Soyuz TMA-18 spacecraft touched down with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Soyuz Commander and Flight Engineer Fyodor Yurchikhin performs the traditional door signing prior to his launch to the International Space Station, Tuesday, June 15, 2010 at the Cosmonaut Hotel in Baikonur, Kazakhstan. Yurchikhin was launched onboard the Soyuz rocket the following morning with Expedition 24 Flight Engineer Shannon Walker and Doug Wheelock on a mission to the ISS. Photo Credit: (NASA/Carla Cioffi)

Expedition 24 Flight Engineer Tracy Caldwell Dyson is helped out of the Soyuz TMA-18 spacecraft shortly after landing with fellow crew members Commander Alexander Skvortsov and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Russian search and rescue teams arrive at the landing site seconds after the Soyuz TMA-18 spacecraft touched down with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Russian search and rescue personnel and engineers prepare to extract the crew from the Soyuz TMA-18 moments after it landed with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Tracy Caldwell Dyson is helped out of the Soyuz TMA-18 spacecraft shortly after landing with fellow crew members Commander Alexander Skvortsov and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Tracy Caldwell Dyson signs the inside of the Russian helicopter that took her from the Soyuz TMA-18 spacecraft landing site near Arkalyk, Kazakhstan to Karaganda, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson returned from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Doug Wheelock performs the traditional door signing prior to his launch to the International Space Station, Tuesday, June 15, 2010 at the Cosmonaut Hotel in Baikonur, Kazakhstan. Wheelock was launched onboard the Soyuz rocket the following morning with Expedition 24 Flight Engineer Shannon Walker and Soyuz Commander Fyodor Yurchikhin on a mission to the ISS. Photo Credit: (NASA/Carla Cioffi)

Expedition 24 Commander Alexander Skvortsov celebrates as he is helped out of the Soyuz TMA-18 spacecraft shortly after landing with fellow crew members Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Commander Alexander Skvortsov laughs after being given fresh fruit and vegetables shortly after landing in the Soyuz TMA-18 spacecraft with fellow crew members Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

S129-E-009501 (24 Nov. 2009) --- Cosmonaut Roman Romanenko, Expedition 20/21 flight engineer, is pictured onboard the International Space Station on the eve of the undocking of the orbital outpost and the space shuttle Atlantis and the departure of the STS-129 crew. Romanenko's tenure onboard the station is winding down, also, as he is scheduled to return to Earth in less than a week onboard a Soyuz spacecraft, along with two crewmates.

The crews of Expedition 24 and Expedition 25 are seen on a video monitor at Russian Mission Control in Korolev, Russia shortly after crew members of Expedition 25 docked to and entered the International Space Station on Sunday, Oct. 10, 2010. Photo Credit: (NASA/Carla Cioffi)

The crews of Expedition 24 and Expedition 25 are seen on a video monitor at Russian Mission Control in Korolev, Russia shortly after crew members of Expedition 25 docked to and entered the International Space Station on Sunday, Oct. 10, 2010. Photo Credit: (NASA/Carla Cioffi)

S123-E-009210 (24 March 2008) --- Backdropped by Earth's horizon and the blackness of space, the International Space Station appears very small from the point of view of the Space Shuttle Endeavour as the two spacecraft carry out their relative separation. Endeavour's vertical stabilizer, orbital maneuvering system (OMS) pods and payload bay are seen in this image photographed by an STS-123 crewmember onboard the shuttle. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

April 24, 2003, Baikonur Cosmodrome, Kazakhstan. The Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad. Expedition Seven is scheduled to launch onboard the Soyuz this Saturday April 26, 2003. Photo Credit: "NASA/Scott Andrews"

ISS040-E-006303 (31 May 2014) --- An orbital sunrise is featured in this image photographed by an Expedition 40 crew member on the International Space Station. Crew members onboard the space station see, on average, sixteen sunrises and sunsets during a 24-hour orbital period.

ISS030-E-015654 (24 Dec. 2011) --- Expedition 30 Commander Dan Burbank works out on the Combined Operational Load Bearing External Resistance Treadmill (COLBERT) in Node 3 (Tranquility module) onboard the Earth orbiting International Space Station.

ISS030-E-015652 (24 Dec. 2011) --- Expedition 30 Commander Dan Burbank works out on the Combined Operational Load Bearing External Resistance Treadmill (COLBERT) in Node 3 (Tranquility module) onboard the Earth orbiting International Space Station.

ISS017-E-012545 (4 Aug. 2008) --- Tropical Storm Edouard, as photographed from the International Space Station by one of the Expedition 17 crewmembers onboard, from a vantage point of 220 statute miles above the Earth, stirs in the Gulf of Mexico roughly 24 hours prior to landfall at a point east of Galveston, Texas.

JSC2003-E-31962 (24 April 2003) --- The Soyuz rocket is erected at the launch pad at the Baikonur Cosmodrome, Kazakhstan. Expedition Seven is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: NASA/Bill Ingalls.

A Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Thursday, April 24, 2003. Expedition 7 is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: (NASA/Scott Andrews)

A Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad at the Baikonur Cosmodrome in Baikonur, Kazakhstan, Thursday, April 24, 2003. Expedition 7 is scheduled to launch onboard the Soyuz on Saturday, April 26, 2003. Photo credit: (NASA/Scott Andrews)

ISS030-E-015655 (24 Dec. 2011) --- Expedition 30 Commander Dan Burbank works out on the Combined Operational Load Bearing External Resistance Treadmill (COLBERT) in Node 3 (Tranquility module) onboard the Earth orbiting International Space Station.

ISS007-E-13392 (24 August 2003) --- This view of Webster, New York was taken by one of the Expedition 7 crewmembers onboard the International Space Station (ISS). Webster is the hometown of astronaut Edward T. Lu, NASA ISS science officer and flight engineer.

ISS017-E-012562 (4 Aug. 2008) --- Tropical Storm Edouard, as photographed from the International Space Station by one of the Expedition 17 crewmembers onboard, from a vantage point of 220 statute miles above the Earth, stirs in the Gulf of Mexico roughly 24 hours prior to landfall at a point east of Galveston, Texas.

April 24, 2003, Baikonur Cosmodrome, Kazakhstan. The Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad. Expedition Seven is scheduled to launch onboard the Soyuz this Saturday April 26, 2003. Photo Credit: "NASA/Scott Andrews"

JSC2003-E-31959 (24 April 2003) --- A Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad at the Baikonur Cosmodrome, Kazakhstan. Expedition Seven is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: NASA/Scott Andrews.

ISS040-E-008179 (7 June 2014) --- The sun, peeking through the thin line of Earth’s atmosphere, is featured in this image photographed by an Expedition 40 crew member on the International Space Station. Crew members onboard the space station see, on average, sixteen sunrises and sunsets during a 24-hour orbital period.

JSC2003-E-31961 (24 April 2003) --- The Soyuz rocket is erected at the launch pad at the Baikonur Cosmodrome, Kazakhstan. Expedition Seven is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: NASA/Bill Ingalls.

JSC2003-E-31960 (24 April 2003) --- A Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad at the Baikonur Cosmodrome, Kazakhstan. Expedition Seven is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: NASA/Scott Andrews.

ISS020-E-024201 (24 July 2009) --- This view of the Japanese Experiment Module - Exposed Facility (JEF), was photographed through a window on the port side of the JEM by one of the Expedition 20 crew members. This was an important part of the activity of flight day 10 for the STS-127 Endeavour crew and its hosts onboard the International Space Station.

JSC2003-E-31958 (24 April 2003) --- A Soyuz rocket is rolled out of the assembly building and travels via rail to the launch pad at the Baikonur Cosmodrome, Kazakhstan. Expedition Seven is scheduled to launch onboard the Soyuz on Saturday April 26, 2003. Photo credit: NASA/Bill Ingalls.

ISS017-E-012465 (4 Aug. 2008) --- Tropical Storm Edouard, as photographed from the International Space Station by one of the Expedition 17 crewmembers onboard, from a vantage point of 220 statute miles above the Earth, stirs in the Gulf of Mexico roughly 24 hours prior to landfall at a point east of Galveston, Texas

ISS040-E-008169 (7 June 2014) --- The sun, peeking through the thin line of Earth’s atmosphere, is featured in this image photographed by an Expedition 40 crew member on the International Space Station. Crew members onboard the space station see, on average, sixteen sunrises and sunsets during a 24-hour orbital period.

ISS030-E-015651 (24 Dec. 2011) --- Expedition 30 Commander Dan Burbank works out on the Combined Operational Load Bearing External Resistance Treadmill (COLBERT) in Node 3 (Tranquility module) onboard the Earth orbiting International Space Station.

ISS040-E-083603 (31 July 2013) --- The sun, peeking through the thin line of Earth's atmosphere, is featured in this image photographed by an Expedition 40 crew member on the International Space Station. Crew members onboard the space station see, on average, sixteen sunrises and sunsets during a 24-hour orbital period.

William Gerstenmaier, seated center, NASA Associate Administrator for Space Operations, speaks at a post Soyuz docking press conference at Russian Mission Control on Friday, June 18, 2010 in Korolev, Russia. Gerstenmaier is seen with NASA and ROSCOSMOS senior management members. Photo Credit: (NASA/Carla Cioffi)

S123-E-010116 (24 March 2008) --- Backdropped by a blue and white part of Earth, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009188 (24 March 2008) --- Backdropped by the blackness of space, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009354 (24 March 2008) --- Backdropped by the blackness of space, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009345 (24 March 2008) --- Backdropped by the airglow of Earth's horizon and the blackness of space, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-010177 (24 March 2008) --- Backdropped by Earth's horizon and the blackness of space, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009262 (24 March 2008) --- Backdropped by Earth's horizon and the blackness of space, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009196 (24 March 2008) --- Backdropped by a blue and white part of Earth, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009269 (24 March 2008) --- Backdropped by a blue and white part of Earth, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

S123-E-009264 (24 March 2008) --- Backdropped by a blue and white part of Earth, the International Space Station is seen from Space Shuttle Endeavour as the two spacecraft begin their relative separation. Earlier the STS-123 and Expedition 16 crews concluded 12 days of cooperative work onboard the shuttle and station. Undocking of the two spacecraft occurred at 7:25 p.m. (CDT) on March 24, 2008.

The International Space Station, with a crew of five onboard, is seen in silhouette as it transits the Sun at roughly five miles per second, Wednesday, June 24, 2020, from Fredericksburg, Va. Onboard are Expedition 63 NASA astronauts Chris Cassidy, Douglas Hurley, Robert Behnken, and Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner. Photo Credit: (NASA/Joel Kowsky)

The International Space Station, with a crew of five onboard, is seen in silhouette as it transits the Sun at roughly five miles per second, Wednesday, June 24, 2020, from Fredericksburg, Va. Onboard are Expedition 63 NASA astronauts Chris Cassidy, Douglas Hurley, Robert Behnken, and Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner. Photo Credit: (NASA/Joel Kowsky)

This composite image, made from six frames, shows the International Space Station, with a crew of five onboard, in silhouette as it transits the Sun at roughly five miles per second, Wednesday, June 24, 2020, from Fredericksburg, Va. Onboard are Expedition 63 NASA astronauts Chris Cassidy, Douglas Hurley, Robert Behnken, and Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner. Photo Credit: (NASA/Joel Kowsky)

Expedition 25 Commander Doug Wheelock signs the inside of a Russian Search and Rescue helicopter shortly after Wheelock, Expedition 25 Flight Engineers Shannon Walker and Fyodor Yurchikhin landed in the Soyuz TMA-19 spacecraft near Arkalyk, Kazakhstan on Friday, Nov. 26, 2010. Russian Cosmonaut Yurchikhin and NASA Astronauts Wheelock and Walker, are returning from nearly six months onboard the International Space Station where they served as members of the Expedition 24 and 25 crews. Photo Credit: (NASA/Bill Ingalls)

Girls in traditional Kazakhstan dress await the arrival of the Soyuz TMA-18 crew at the Karaganda airport in Kazakhstan. The Soyuz TMA-18 spacecraft, carrying Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko, landed, near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 24 Flight Engineer Tracy Caldwell Dyson shakes hands with NASA Astronaut and Chief of the Astronaut Office Peggy Whitson shortly after landing in the Soyuz TMA-18 spacecraft with fellow crew members Commander Alexander Skvortsov and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews. Photo Credit: (NASA/Bill Ingalls)

ISS011-E-05072 (24 April 2005) --- Cosmonaut Sergei K. Krikalev, Expedition 11 commander representing Russia's Federal Space Agency, closes the hatch to the Soyuz TMA-5 spacecraft docked to the International Space Station (ISS). Onboard the Soyuz are astronaut Leroy Chiao, Expedition 10 commander and NASA ISS science officer; cosmonaut Salizhan S. Sharipov, flight engineer representing Russia's Federal Space Agency; and European Space Agency (ESA) astronaut Roberto Vittori of Italy. Undocking occurred at 1:41 p.m. (CDT) on April 24.

Russian Search and Rescue and other recovery teams begin to gather around the Soyuz TMA-20 spacecraft immediately after it landed with Expedition 27 Commander Dmitry Kondratyev and Flight Engineers Paolo Nespoli and Cady Coleman onboard in a remote area southeast of the town of Zhezkazgan, Kazakhstan, on Tuesday, May 24, 2011. NASA Astronaut Coleman, Russian Cosmonaut Kondratyev and Italian Astronaut Nespoli are returning from more than five months onboard the International Space Station where they served as members of the Expedition 26 and 27 crews. Photo Credit: (NASA/Bill Ingalls)

Recovery teams move a work stand around the Soyuz TMA-20 spacecraft immediately after it landed with Expedition 27 Commander Dmitry Kondratyev and Flight Engineers Paolo Nespoli and Cady Coleman onboard in a remote area southeast of the town of Zhezkazgan, Kazakhstan, on Tuesday, May 24, 2011. NASA Astronaut Coleman, Russian Cosmonaut Kondratyev and Italian Astronaut Nespoli are returning from more than five months onboard the International Space Station where they served as members of the Expedition 26 and 27 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-19 spacecraft with Expedition 25 Commander Doug Wheelock and Flight Engineers Shannon Walker and Fyodor Yurchikhin is rolled by technicians in order to assist with getting the crew out of the capsule, near Arkalyk, Kazakhstan on Friday, Nov. 26, 2010. Russian Cosmonaut Yurchikhin and NASA Astronauts Wheelock and Walker, are returning from nearly six months onboard the International Space Station where they served as members of the Expedition 24 and 25 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 27 Flight Engineer Cady Coleman is helped out of the Spyuz TMA-20 spacecraft shortly after she and Commander Dmitry Kondratyev and Paolo Nespoli landed southeast of the town of Zhezkazgan, Kazakhstan, on Tuesday, May 24, 2011. NASA Astronaut Coleman, Russian Cosmonaut Kondratyev and Italian Astronaut Nespoli are returning from more than five months onboard the International Space Station where they served as members of the Expedition 26 and 27 crews. Photo Credit: (NASA/Bill Ingalls)

NASA, Canadian Space Agency, Roscosmos, and Russian Search and Recovery Forces arrive in Zhezkazgan, Kazakhstan in advance of the landing of Expedition 59 crew members Anne McClain of NASA, David Saint-Jacques of the Canadian Space Agency, and Oleg Kononenko of Roscosmos, Monday, June 24, 2019. McClain, Saint-Jacques, and Kononenko are returning after 204 days in space where they served as members of the Expedition 58 and 59 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

The Soyuz TMA-20 spacecraft is seen as it lands with Expedition 27 Commander Dmitry Kondratyev and Flight Engineers Paolo Nespoli and Cady Coleman in a remote area southeast of the town of Zhezkazgan, Kazakhstan, on Tuesday, May 24, 2011. NASA Astronaut Coleman, Russian Cosmonaut Kondratyev and Italian Astronaut Nespoli are returning from more than five months onboard the International Space Station where they served as members of the Expedition 26 and 27 crews. Photo Credit: (NASA/Bill Ingalls)

Expedition 27 Flight Engineer Paolo Nespoli smiles shortly after he and Commander Dmitry Kondratyev and Flight Engineer Cady Coleman landed in their Soyuz TMA-20 southeast of the town of Zhezkazgan, Kazakhstan, on Tuesday, May 24, 2011. NASA Astronaut Coleman, Russian Cosmonaut Kondratyev and Italian Astronaut Nespoli are returning from more than five months onboard the International Space Station where they served as members of the Expedition 26 and 27 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz MS-11 spacecraft is seen as it lands in a remote area near the town of Zhezkazgan, Kazakhstan with Expedition 59 crew members Anne McClain of NASA, David Saint-Jacques of the Canadian Space Agency, and Oleg Kononenko of Roscosmos, Tuesday, June 25, 2019 Kazakh time (June 24 Eastern time). McClain, Saint-Jacques, and Kononenko are returning after 204 days in space where they served as members of the Expedition 58 and 59 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

Expedition 25 Soyuz Commander Fyodor Yurchikhin is carried to a nearby medical tent near the town of Arkalyk, Kazakhstan on Friday, Nov. 26, 2010, following the landing of the TMA-19 spacecraft. Russian Cosmonaut Yurchikhin and NASA Astronauts Doucg Wheelock and Shannon Walker, returned from nearly six months onboard the International Space Station where they served as members of the Expedition 24 and 25 crews. Photo Credit: (NASA/Bill Ingalls)

The Soyuz MS-11 spacecraft is seen as it lands in a remote area near the town of Zhezkazgan, Kazakhstan with Expedition 59 crew members Anne McClain of NASA, David Saint-Jacques of the Canadian Space Agency, and Oleg Kononenko of Roscosmos, Tuesday, June 25, 2019 Kazakh time (June 24 Eastern time). McClain, Saint-Jacques, and Kononenko are returning after 204 days in space where they served as members of the Expedition 58 and 59 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)