NASA engineers reveal how they pushed technology to new limits when they created the Shuttle. Historian Roland White suggests the original intention for the Shuttle was to use it to carry out spying missions. And NASA's Wayne Hale remembers the Challenger disaster.

Following the Challenger disaster, the Shuttle was saved by the fall of the Soviet Union, as America worried that Russian scientists would defect to rogue states and advance their own space projects. President Clinton was then persuaded to use the Shuttles to supply Russia's Mir space station. This cooperation eventually led to the creation of the International Space Station.