You've probably seen a Goodyear blimp providing TV coverage to a sporting event, such as a football game or golf tournament. Blimps are a type of lighter-than-air (LTA) craft called an airship. Like a hot air balloon, blimps use a gas to generate lift. But unlike a hot air balloon, blimps can move forward through the air under their own power, like airplanes. They can hover like helicopters, travel in all kinds of weather and stay aloft for days. In this edition of HowStuffWorks, we will show you how these fascinating vehicles work.