NASA has announced that they are going to switch to HD with their public broadcasts in USA.
The US space agency said in a notification:
Beginning Feb. 17, 2012, NASA Television’s Public and Media channels will transmit their respective content in high definition.
NASA Television’s Public Channel (101), the channel most often carried by cable and satellite service providers, provides digital coverage of NASA missions and events, as well as documentaries, archival and other special programming.
NASA TV’s Media Channel (103) provides mission coverage, news conferences and relevant video and audio materials to local, national and international news-gathering organizations.
NASA TV’s Education Channel (102) will continue in standard definition. The current NASA TV HD Channel (105) will cease service.