The Alpha Magnetic Spectrometer is loaded into the vehicle that would take it to the space shuttle launchpad on March 15. The $2 billion cosmic ray detector will be carried to the International Space Station on Endeavour's final flight. NASA hide caption

itoggle caption NASA

Space shuttle Atlantis lifts off from Kennedy Space Center on May 14, 2010, in Cape Canaveral, Fla. Matt Stroshane/Getty Images hide caption

itoggle caption Matt Stroshane/Getty Images

Vostok: Earth's First Spaceship

The Vostok 3KA-2 was the last unmanned flight before Soviet cosmonaut Yuri Gagarin orbited the Earth on April 12, 1961. The rocket went into space carrying a dog named Zvezdochka and a mannequin in a spacesuit.

The Crab Nebula is filled with mysterious filaments that are tremendously complex. NASA, ESA, J. Hester, A. Loll (ASU) hide caption

itoggle caption NASA, ESA, J. Hester, A. Loll (ASU)