In Photos: The International Space Station Turns 20

Mission Specialists Robert L. Curbeam, Jr (left) and Christer Fuglesang participate in the first of the mission’s three planned sessions of extravehicular activity as construction resumes on the International Space Station in 2008

Photograph: NASA

The space shuttle Endeavour is silhouetted against the backdrop of Earth’s horizon prior to docking with the International Space Station in this picture taken by an Expedition 22 crew member in 2010.

Photograph: Nasa Nasa/Reuters