Can humans live in space? If so, for how long? What effect will zero gravity have on the body? These are just a few of the questions that were sparked by man’s first ventures into space atop repurposed nuclear ballistic missiles in the early 1960s. To answer these questions, a series of space stations were built throughout the latter half of the 20th century with names like Skylab and Mir.
As one would imagine, real estate in earth orbit is pretty expensive what with having to transport all the building materials with rockets and all. To save money and to prove that people from different countries really can work together well (even when those countries include Russia and the United States), several nations signed onto a treaty to build the International Space Station.