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"
Space Shuttle retirement to 2028 or beyond. Until another U.S. crew vehicle is ready, crews will access the ISS exclusively aboard the Russian Soyuz spacecraft. The Soyuz was chosen as the ISS lifeboat during the development of the International Space Station, and has been one of the space taxis used by the international participants to this program. A Soyuz took Expedition 1, which included one U.S. astronaut in the year 2000. Previously the United States and Russia had collaborated on extended the Mir space station with the Shuttle-Mir program in the 1990s. Although the Orion spacecraft is oriented towards deep-space missions such as