Few events attract the eyes of the entire world like the Summer Olympics. Beginning Friday, July 27, every moment of the 2012 Summer Olympics in London will be shown live on NBC’s family of networks and its website. For those counting at home, that’s some 5,535 hours of coverage. Over 17 exciting days, familiar sports icons like LeBron James and Usain Bolt will be heard time and again. But for every Michael Phelps and Serena Williams, there are literally thousands of other athletes around the globe with amazing talents and fascinating stories to share (including Brazilian soccer sensation Marta). Here are 10 largely unknown Olympic athletes we’ll be keeping up with over the spirited weeks ahead in London, as well as a guide to the best times to see them each in action.