International Space Station program out of 28 flights have not been to the ISS, and only the planned Hubble Space Telescope servicing mission in 2009 will not be ISS-related out of 13 planned missions until the end of the Space Shuttle program in 2010). The Space Shuttle was retired from service upon the conclusion of Atlantis' final flight on July 21, 2011. NASA was reliant even at the time on some of the resupply contracts being fielded out to Soyuz and Progress and the other unmanned tugs, but it had launched a few years earlier into a program of aggressive development of commercial US
Space Shuttle program from the two destroyed orbiters. The Space Shuttle program was extended several times beyond its originally envisioned 15-year life span because of the delays in building the United States space station in low Earth orbit—a project which eventually evolved into the International Space Station. It was formally scheduled for mandatory retirement in 2010 in accord with the directives President George W. Bush issued on January 14, 2004 in his Vision for Space Exploration. A$2.5 billion spending provision allowing NASA to fly the Space Shuttle beyond its then-scheduled retirement in 2010 passed the Congress in April 2009, although neither NASA nor