The Jet Propulsion Laboratory, builder of the famous Voyager 1 and 2 spacecrafts and the Curiosity and Opportunity Mars Rovers,
has launched an application (called NASA's Eyes) to track their spacecrafts in real-time. If you are interested in that, you can follow the link below.
It requires a small download (<100 MB):
You can start here: Download NASA's Eyes
Enjoy!