The dreamers who first launched man into space were not much concerned about what he would do when he got there. When the question was put, many of them simply referred to Columbus's discovery of the New World, as if the analogy were exact and the implications self-evident. Others dusted off the apocryphal story about Ben Franklin at the first balloon flight in Paris in 1783. "But what good is it?," someone asked the American minister. "What good is a newborn baby?," Franklin rep...