(By Saras Sarasvathy, the sidore Horween Research Professor,  at the Darden Graduate School of Business, University of Virginia) In a dramatic scene in the film Gravity, a space shuttle on a research mission is bombarded by high-speed space debris. The resulting damage kills an astronaut and hurls another into deep space. The movie then gets busy with making life worse for its main characters. The message that space exploration is perilous is only half the message, of course. The other half of the message is usually the point of the story, namely, that some things are worth doing, even if...