Last year the U.S. Air Force decided to extend the life of its U-2 fleet and cut back on the use of large UAVs for strategic reconnaissance. One of the many upgrades U-2s will now receive will be better cockpit pressurization. Currently, pilots operate in a cockpit pressurized to conditions found at 9,600 meters (30,000 feet). This puts more strain on the pilot's body. That, and the fact that they breathe pure oxygen while up there, means they tend to be completely exhausted after returning from a long mission. So pressuring the cockpit to the level of a lower altitude...