The Chinese space telescope would have a 2+meter diameter lens with a field of view 300 times that of the Hubble Space telescope, while maintaining the same level of image resolution. With such a wide field of view, the space telescope could survey 40 percent of the cosmos in ten years. Zhou Jianping, the head of China's manned space program, noted that such a wide field-of-view would create a higher fidelity image to search for dark matter, dark energy, and exoplanets. Even more notable than the capabilities, however, may be the plan for where to locate the telescope.
Zhang said that the Chinese space telescope would orbit close to a Chinese space station, likely the Tiangong 3, so that Chinese taikonauts would quickly service any problems, compared to the 3.5 year wait for NASA to correct the Hubble Telescope's mirror problems. The Tiangong 3's two 15-meter-long robotic arms would be very helpful in servicing the space telescope. Using a space station as a permanent support base for a satellite has not yet been tried before; neither Skylab, Mir, nor the ISS had any large satellites close by. To outfit the Tiangong 3 for such a mission, China would need to stockpile supplies of tools and spares to provide for prompt servicing of a space telescope, though new technology such as monitoring nanosatellites could make telescope repairs easier.
Keyhole spy satellites and the Hubble Space telescope were built of common technology and similar designs.
"Keyhole-class" (KH) reconnaissance satellites have been orbiting the Earth for more than 30 years. They are typically used to take overhead photos for military missions. A KH-12 is a $1 billion satellite that resembles the Hubble Space Telescope, except it is looking at our planet. They are supplemented by the 15-ton Lacrosse-class radar-imaging satellites. A Keyhole satellite as a gigantic orbiting digital camera with an incredibly huge lens on it. Optical image reconnaissance satellites use a charge coupled device (CCD) to gather images that make up a digital photograph for transmission back to Earth from an altitude of about 200 miles.
In 2014, the United States' spy satellite agency is giving NASA two spare space telescopes free of charge, each potentially more powerful than the Hubble Space Telescope.
The two spy satellite telescopes were originally built to fly space-based surveillance missions for the National Reconnaissance Office (NRO), but will be repurposed by NASA for astronomical research instead. Their donation to NASA was revealed in a surprise announcement.
Both NRO space telescopes have a main mirror nearly 8 feet wide (2.4 meters), rivaling the Hubble Space Telescope, and also carry a secondary mirror to enhance image sharpness, according to press reports.