With Constellation canceled and the shuttle winding down, NASA was in a bind. The Commercial Crew program was born, calling for private companies to build vehicles and operate flights to the ISS under NASA charter. However, the program was still in its infancy, and the first commercial crew flights were at least four years away. NASA decided to extend the Space Shuttle Program with one final mission to carry supplies, equipment, spare parts, and the Alpha Magnetic Spectrometer to the ISS.
