Space Shuttle program to the International Space Station (ISS), as the station could be used as a safe haven for the crew awaiting rescue in the event that damage to the orbiter on ascent made it unsafe for re-entry. The board recommended that for the remaining flights, the shuttle always orbit with the station. Prior to STS-114, NASA Administrator Sean O'Keefe declared that all future flights of the shuttle would go to the ISS, precluding the possibility of executing the final Hubble Space Telescope servicing mission which had been scheduled before the "Columbia" accident, despite the fact that millions of dollars worth of
Space Shuttle program from the back of a specially modified Boeing 747, only for initial atmospheric landing tests (ALT). "Enterprise"'s first test flight was on February 18, 1977, only five years after the Shuttle program was formally initiated; leading to the launch of the first space-worthy shuttle "Columbia" on April 12, 1981 on STS-1. The Space Shuttle program finished with its last mission, STS-135 flown by "Atlantis", in July 2011, retiring the final Shuttle in the fleet. The Space Shuttle program formally ended on August 31, 2011. Before the Apollo 11 moon landing in 1969, NASA began early studies of space shuttle designs.