The Jet Propulsion Laboratory is the lead U.S. center for robotic exploration of the solar system. JPL spacecraft have visited all known planets except Pluto (a Pluto mission is currently under study for the early part of the next decade). Also included is the 2 NASA Live streams and the Hidden Universe series.
Soooooooooo awesome! My oldest son is a NASA Nut (and admittedly, so is his father). We have been without the NASA/JPL channel for so long as users of Verizon FiOS. Goodbye forever Verizon (well, your crappy TV programming anyway).