Space policy and the size of the space shuttle fleet

During the space shuttle era, policy makers have repeatedly wrestled with the issue of fleet size. The number of shuttles had both practical and symbolic significance, reflecting the robustness of the space transportation system and US preeminence in space. In debating how many shuttles were needed, NASA and other government entities weighed various arguments to determine the optimum number of vehicles for human spaceflight. Deliberations and decisions about shuttle fleet size reflected changing policy priorities and attitudes about the role of the shuttle. That history frames issues that may arise again in planning for new space transportation vehicles beyond the shuttle.