The concept of a Space Elevator started over a century ago but started to move from science fiction to reality in the 1990s with the promising advent of a super strong material, carbon nanotubes, that theoretically had the strength to build a ribbon into space. NASA started investigating the concept in the 1990s. When it happens, it will replace rockets as the easier and cheaper way to leave Earth, opening up space travel the way airplanes opened up world travel.