Nasa

NASA TV (originally NASA Select) is the television service of the National Aeronautics and Space Administration (NASA). It is broadcast by satellite with a simulcast over the Internet. Local cable television providers across the United States and amateur television repeaters may carry NASA TV at their own discretion, as NASA-created content is considered a work of the U.S. government and is within the public domain. NASA TV is also available via various cable, satellite, and over-the-top media services around the world. The network was formally created in the early 1980s to provide NASA managers and engineers with real-time video of missions.[3][4] NASA has operated a television service since the beginning of the space program for archival purposes, and in order to provide media outlets with video footage.[5] The network airs a large amount of educational programming, and provides live coverage of an array of manned missions (including the International Space Station), robotic missions, and domestic and international launches. The network completed its conversion from analog to digital transmission in late 2005 following the launch of STS-114, ending a period of dual analog and digital broadcasting, although some cable television systems may still have transmitted in analog prior to the U.S. digital television transition. The satellite link uses the DVB-S system for transmission.