Space Shuttle Solid Rocket Booster design or replacing them altogether with liquid "flyback" boosters using either Atlas V or Delta IV EELV technologies. The 5-segment SRB, which would have required little change to the current shuttle infrastructure, would have allowed the space shuttle to carry an additional of payload in an International Space Station-inclination orbit, eliminate the dangerous "Return-to-Launch Site" (RTLS) and "Trans-Oceanic Abort" (TAL) modes, and, by using a so-called "dog-leg maneuver", fly south-to-north polar orbiting flights from Kennedy Space Center. After the destruction of "Columbia", NASA shelved the five-segment SRB for the Shuttle Program, and the three surviving Orbiters, "Discovery", "Atlantis", and "Endeavour"
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