China has launched an Earth observation/remote sensing satellite able to “stare” at regions of the Earth continuously from its Geostationary orbit some 36,000km away from the Earth’s surface. The 4,600kg spacecraft, called Gaofen-4, was built by CAST (China Academy of Space Technology) and was launched aboard a Long March 3B/G2 launch vehicle from the Xichang launch site in China at 1605 GMT on 28 December 2015. The Gaofen-4 spacecraft is equipped with a staring camera to deliver 50m resolution continuous realtime imagery (imaging area of 7000 by 7000 Km consisting of 400 by 400km frames).
Comment by David Todd: While high resolution Earth observation/spy satellites are often portrayed in fictional films and literature as having the ability to “stare”, the actual “sun-synchronous” low Earth orbits with altitudes of 600-1200km used by such satellites, have periods of rotation which are normally too fast to allow this to happen. Thus snap shots or short bursts of imagery is usually the best that can be achieved. This new satellite in a much higher orbit does now have the ability to “stare” at the Earth given its 24 hour period, albeit that it has a much lower resolution. Thus such a satellite is more relevant to scientific and environmental monitoring rather than spying. Of course, nowadays, military reconnaissance agencies worked out how to get high resolution staring imagery without having to use satellites directly. Their “staring assets” are now more likely to be “stealthy” unmanned reconnaissance aircraft and drones whose imagery can be relayed by communications relay satellites back to base.
