The U.S. Air Force aims to develop an unmanned flying weapon by 2023 that would travel at least five times the speed of sound and might transform the nature of warfare. The Pentagon has been experimenting with unmanned hypersonic aircraft for years, launching them from bombers over the Pacific with limited success. For a vehicle to be considered hypersonic, it must travel at least at Mach 5 -- five times the speed of sound, or about 3,800 mph. That's fast enough to travel across the U.S. in around 30 minutes. What do you think hypersonic aircrafts would mean for the future of warfare? Do you think hypersonic aircraft could eventually land in the commercial passenger airliner industry?