Credit: NASA

In this April 8, 2010 photograph, STS-131 mission specialists Stephanie Wilson of NASA, Naoko Yamazaki of the Japanese Aerospace Exploration Agency (JAXA), Dorothy Metcalf-Lindenburger of NASA, and Expedition 23 flight engineer Tracy Caldwell Dyson (top left) work at the robotics workstation on the International Space Station, in support of transfer operations using the station’s Canadarm2 robotic arm to move cargo from the Multi-Purpose Logistics Module.

The STS-131 mission’s seven-member crew launched aboard space shuttle Discovery on April 5 from NASA’s Kennedy Space Center, joining the six residents of the space station when the shuttle docked on April 7. The merging of the two crews marked the first time four women were in space at the same time.