This claim is often made, but it seems rather dubious. http://www.guardian.co.uk/science/2011/jul/21/space-shuttle-programme http://www.guardian.co.uk/science/

This claim is often made, but it seems rather dubious. http://www.guardian.co.uk/science/2011/jul/21/space-shuttle-programme http://www.guardian.co.uk/science/2011/jul/21/space-shuttle-...