PBS
Pbs Learning Media: Pilotless Flight: Timeline of Unmanned Aerial Vehicles
Explore this NOVA: "Spies That Fly" interactive timeline and discover the many technological innovations in the history of unmanned flight, from hot-air balloons to miniature flying robots.
PBS
Pbs Learning Media: Airplanes: Designing for Stealth
Explore this NOVA: "Battle of the X-Planes" interactive activity to see how engineers have modified a military plane's sound, shape, and heat emissions to minimize detection.