Space Shuttle Columbia facility beginning in January 1984, undergoing modifications that removed the Orbiter Flight Test hardware and bringing it up to similar specifications as those of its sister orbiters. At that time the shuttle fleet was expanded to include "Discovery" and "Atlantis". "Columbia" returned to space on January 12, 1986, with the launch of STS-61-C. The mission's crew included Dr. Franklin Chang-Diaz, as well as the first sitting member of the House of Representatives to venture into space, Bill Nelson. The next shuttle mission, STS-51-L, was undertaken by "Challenger". It was launched on January 28, 1986, ten days after STS-61-C had landed,
Space Shuttle retirement and then be replaced by a new vehicle. When the concept of the U.S. space station evolved into that of the International Space Station, which suffered from long delays and design changes before it could be completed, the service life of the Space Shuttle was extended several times until 2011 when it was finally retired. In 2010 the Shuttle was formally scheduled for retirement with "Atlantis" being taken out of service first after STS-132 in May of that year, but the program was once again extended when the two final planned missions were delayed until 2011. Later, one additional mission