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
Space Shuttle Independence Space Center outside Houston, Texas. The replica shuttle was stripped of the name "Explorer" as part of the dismantling process. Upon arriving in the Houston area by barge on June 1, 2012, the shuttle was taken to the Johnson Space Center dock on Clear Lake, and preparations were made to move the shuttle to Space Center Houston during the early morning hours. As with Florida, several light poles along NASA Parkway were taken down and trees trimmed back to allow passage. The shuttle was moved by another 144-wheel trailer down the closed highway to the visitor center. Johnson Space Center