KH-12
From Wikipedia, the free encyclopedia
The KH-12, also known by the codenames Ikon and Improved Crystal, is a successor to the KH-11 reconnaissance satellite and also used digital imaging. It is believed that the KH-12 improved upon the previous design by including signals intelligence capabilities, sensitivity in broader light spectrums (probably into infrared), and possibly including the ability to view "live" images. Data is transmitted through a relay network of communications satellites. The satellite, with a mass of 19,600 kilograms, has been manufactured by Lockheed. Ground resolution is probably 0.15 meters (6 inches) or better. Like the KH-11 (Crystal), the KH-12 is believed to use a large mirror to capture light, and probably resembles the Hubble Space Telescope (HST) in size and shape.
As the "Improved Crystal" nickname implies, many believe that the KH-12 is largely an incremental improvement upon the KH-11, and a number of observers classify the spacecraft as a KH-11. Similarly, a successor KH-13 program may or may not currently exist (some have called that a "KH-12B").
The spacecraft's mirror is believed to be as large as or larger than that of the KH-11, believed to have a 2.3 meter diameter. It may be as large as 4 meters. As a point of comparison, the HST's mirror is 2.4 m in size. Jane's Defence Weekly indicates that the secondary mirror in the Cassegrain reflecting telescope system can be moved significantly, allowing images to be taken from angles unusual for a satellite. Also, there are indications that the satellite can take images every five seconds. Sources vary on how the KH-12 communicates with ground stations. Several different clusters of relay satellites are available, so the birds may use the Satellite Data System (SDS), MILSTAR, or Tracking and Data Relay Satellite System (TDRSS) networks.
At least three were launched between February 1990 and December 1996, and others have probably been launched since. It is believed that one was released by the Space Shuttle Atlantis on STS-36, though others were launched on Titan 4 rockets.
KH-12 satellites are believed to have been the source of some imagery of Russia and China made public in 1997, as well as images of Sudan and Afghanistan made public in 1998 that were related to the response to the 1998 U.S. embassy bombings.
[edit] References
- Mark Wade (August 9, 2003). KH-12. Encyclopedia Astronautica. Accessed April 23, 2004.
- John Pike (September 9, 2000). KH-12 Improved Crystal. Federation of American Scientists. Accessed April 23, 2004.
- John Pike (August 22, 1998). KH-12 product. Federation of American Scientists. Accessed April 23, 2004.
- (October 17, 2001). US space-based reconnaissance reinforced. Jane's. Accessed May 3, 2004.
- KH-12 Improved Crystal. GlobalSecurity.org.
