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,
Criticism of the Space Shuttle program costs through amortization. Development costs were expected to be recouped through frequent access to space. These claims were made in an effort to obtain budgetary funding from the United States Congress. Beginning in 1981, the space shuttle began to be used for space travel. However, by the mid-1980s the concept of flying that many shuttle missions proved unrealistic and scheduled launch expectations were reduced 50%. Following the "Challenger" accident in 1986, missions were halted pending safety review. This hiatus became lengthy and ultimately lasted almost three years as arguments over funding and the safety of the program continued. Eventually the