Since the opening of the space age nearly 50 years ago, the U.S. government has spent close to 1 trillion dollars on space related activities. Although by no means the largest public expenditure over that period- it is easily dwarfed by national defense, social security, and countless other federal programs- it is still, by any measure, an enormous amount of money. It therefore seems perfectly reasonable to ask: what has the American taxpayer gotten in return for this rather large investment