The International Space Station has had multiple crews dock with the orbiting laboratory. Three crew members of Expedition 31 returned to Earth today after three men spent more than six months in space. Expedition 32 astronauts will continue mankind's presence in Earth orbit as both crews overlap their missions. Expedition 31 officially concludes today.
Dec. 21: Part of Expedition 31's crew launched
Oleg Kononenko, Andre Kuipers and Don Pettit launched from Kazakhstan to become part of Expedition 31's crew. NPR reports the crew returned to earth more than six months later.
March 7: Robotic Refueling Mission began
The Canadian-made robotic arm on the International Space Station began its first Robotic Refueling Mission on March 7. Designers and engineers tested equipment for future missions in which satellites are refueled by autonomous missions. Satellites rely on more than just solar panels for power. Gases are used for propulsion and maneuvering. Having robots refuel key satellites is an innovation that saves time and money -- there are no extra human crews involved whatsoever. Eventually, NASA hopes to expand refueling missions into robotic retrieval, repositioning and repair of satellites without the use of humans. The two-armed Dextre robot is also used in refueling test missions.
March 14: Robonaut 2 first utilized
Robonaut 2, delivered when the Space Shuttle Discovery last visited the station, accomplished its first task in mid-March. Burbank put a gauge in the robot's hands to allow the device to measure air flow in the Destiny laboratory. Robonaut 2 is designed to accomplish tasks too mundane or too dangerous for humans. In this case, the airflow test can be contaminated by a human bobbing up and down in microgravity and by the astronaut's own breath. Robonaut 2 did its first "real" work by taking two accurate measurements of air flow in the Destiny lab.
April 25: Expedition 31 officially began
Three astronauts undocked from the station and the Expedition 31 crew was complete. NASA missions overlap each other when crews arrive and depart the station. Joe Acaba, Gennady Padalka and Sergei Revin arrived in mid-May to complete Expedition 31's manifest of six. The original three astronauts of the expedition arrived in late December while some of Expedition 30's astronauts were still on board.
May 25: Dragon capsule docking
History was made in late May. After a delay pushed back the launch, Space X's Dragon capsule docked with the International Space Station. It was the first privately owned company in history to rendezvous with the space station. The automated module delivered supplies to the station and splashed down in the Pacific Ocean May 31, according to ABC News. Dragon's flight mission lasted nine days.
July 1: Disembark
According to Space.com, the three aforementioned astronauts disembarked the International Space Station for a return to Kazakhstan in the early morning hours of July 1. Expedition 32 began as soon as the three men departed. Padalka is the current mission commander taking over for Kononenko.
William Browning is a research librarian.