NASA TV used to be available from most cable providers, until NASA switched to digital-only satellite broadcast, when many dropped it due to waning interest. They also made the switch during the post-Columbia down-time, when no one was watching, anyway. My cable channel carries it occasionally during missions (for briefings, launches, other significant events) on an HD channel, but I don’t have an HDTV, so’s I’m stuck with teh Internetz.