There are more than 3,000 satellites orbiting earth. While we go about our daily lives, these contraptions are hard at work in our stratosphere, beaming the latest episodes of American Idol, snapping photos of black holes, and enabling governments to spy on obscure regions of Afghanistan. Leroy Chiao, the 311th astronaut in space, takes us on a tour of some satellites past and present. 

Whimsical, clear, thoroughly delightful and informative.