For anyone wanting to sink their teeth into the previous grand challenge, autonomous cars, there is a Nova special called "The Great Robot Race" [1]. It's available to watch on Netflix streaming [2]. I couldn't find a link to watch the full special online via other means.

[1] http://www.pbs.org/wgbh/nova/darpa/

[2] https://signup.netflix.com/movie/The-Great-Robot-Race-Nova/7...