The current NASA HD channel, that your provider may or may not carry, is going away. In its place, both the NASA TV Public Channel and Media Channel will be making the switch to HD on February 17th, while the Education Channel will remain in SD. What isn't so clear is what your premium TV provider will do once NASA flips the switch. We'd imagine they'll pass on the HD signal, but if they're short on bandwidth, there's the chance they could down convert it to SD in order to continue to provide the channels on their strained infrastructure.