might explode in the shuttle bay) and instead the payloads took interplanetary detours to be slingshot accelarated by other objects in the solar system (see Magellan http://en.wikipedia.org/wiki/Magellan_(spacecraft) and Galileo http://en.wikipedia.org/wiki/Galileo_(spacecraft)). Meanwhile the Russians already found out everything you needed to know about living in space. They'd accumulated many man-years living semi-autonomously