The last attempt at a strategy was George Mueller’s shuttle, the concept for which originated with Noordung in WWII, but which Mueller started talking about in 1968; virtually all of the great 60s leaders in manned space flight, by 1968 or 69, were in agreement that a flyback vehicle which could be reused in order to save on manufacturing costs was a necessity. It was a necesity because they needed something to replace Saturn and Apollo, which were unaffordable,