Photos: A century of helicopters

In the years ahead, drones will do a lot of the flying for us. These unmanned aerial vehicles, or UAVs, are one of the hot areas of development across the aerospace sector. (Unmanned ground vehicles are all the rage as well--witness DARPA's upcoming Urban Challenge.)

This, for instance, is the Northrop Grumman MQ-8B Fire Scout, which made its first flight in December 2006. Being designed in versions for both the Army and the Navy, it can fly at more than 125 knots, reach a ceiling of 20,000 feet, and lift 600 pounds. Flight time for the 9.5-foot-tall helicopter with a minimal payload is greater than eight hours, the company says. It's designed for missions including surveillance, reconnaissance and targeting.