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 flight participant same level of training as career NASA astronauts and were not employed by NASA, so they were essentially private astronauts. In the early days of the Shuttle program, NASA was also eager to prove its capability to Congressional sponsors, and Senator Jake Garn and (then-Representative, now Senator) Bill Nelson were both given opportunities to fly on a Shuttle mission. As the Shuttle program expanded, NASA developed the Space Flight Participant Program, where civilians, with an emphasis on creative people, would be sent into space to increase public awareness of NASA's mission. The initial goal was that two or three shuttle