NASA TV has announced an upcoming rejig of its HD offerings, scheduled to come into effect next month. NASA TV's Public Channel and Media Channel will finally switch to high definition, with only the Education Channel continuing to be broadcast in SD. As part of the changes, the NASA TV HD Channel, which currently serves as a high-def simulcast of the Public Channel, will cease service.
The Public Channel is carried by a wide number of satellite and cable companies, and offers live and recorded coverage of missions and events, along with documentaries and material from NASA's archives. The Media Channel is, unsurprisingly, focused on providing media organizations with audio and video material, including mission coverage and news conferences. There's currently no word from NASA on when schools can expect to benefit from a high-def version of the Education Channel. The newly announced changes will come into effect on February 17th.