On April 18th, 2014, a new experiment called the High Definition Earth Viewing (HDEV) was installed in the International Space Station, after being delivered by the SpaceX Dragon spacecraft. HDEV consists of four commercial HD video cameras that provide uninterrupted streaming footage of planet Earth viewed from stationary orbit. This real-time eye in the sky is accessible to anyone with a computer and an internet connection.
According to NASA, the overt mission of HDEV is to test how long video cameras can operate in outer space. When the ISS is in orbital night, the screen appears black. During a camera switch or communications interruption, the screen is gray.