Thinking big can lead to breakthroughs or spectacular failures, and the Pentagon agency DARPA has had its share of both. DARPA is the acronym for The Defense Advanced Research Projects Agency. It started off as ARPA, before the “D” for defense was added. Its mission is to create innovative defense technologies and its projects have ranged from space based missile shields to cyborg insects. The innovations have had practical applications in the civilian world ranging from the internet to robot vacuum cleaners. Sharon Weinberger is the author of the new book The Imagineers of War. Her research includes recently declassified documents as well as interviews she conducted with people who have worked on DARPA projects.