Ground-Based Electro-Optical Deep Space Surveillance
Published September 15, 2010
The Ground-Based Electro-Optical Deep Space Surveillance System, or GEODSS, plays a vital role in tracking deep space objects. More than 2,500 objects, including geostationary communication satellites, are in deep space orbits varying in altitude from 10,000 to 45,000 kilometers from Earth.
Approximately 20,000 known man-made objects in orbit around the Earth. These objects range from active payloads, such as weather satellites or Global Positioning System satellites to "space junk" such as rocket bodies or debris from past satellite breakups.
U. S. Strategic Command's Joint Space Operations Center Space Situational Awareness Operations Cell, located at Vandenberg Air Force Base, Calif., is responsible for tracking all man-made objects in orbit. The center receives on-orbit positional data, known as element sets, from the Space Surveillance Network which comprises optical and radar sensors throughout the world. This enables the center to maintain accurate data on every man-made object currently in orbit.
There are three operational GEODSS sites that report directly to Air Force Space Command's 21st Operations Group, 21st Space Wing at Peterson AFB, Colo. They are: Detachment 1, Socorro, N.M.; Detachment 2, Diego Garcia, British Indian Ocean Territory; and Detachment 3, Maui, Hawaii.
GEODSS performs its mission using a one-meter telescope that is equipped with a highly sensitive digital camera technology, known as Deep STARE. The operational GEODSS sites have three telescopes that are used in conjunction with each other or separately. These telescopes are able to "see" objects 10,000 times dimmer than the human eye can detect. As with any optical system, cloud cover and local weather conditions directly influence its effectiveness and can only operate at night.
The Deep STARE system is able to track multiple satellites in the field of view. As the satellites cross the sky, the telescopes take rapid electronic snapshots, showing up on the operator's console as tiny streaks. Computers then measure these streaks and use the data to figure the current position of a satellite in its orbit. Star images, which remain fixed, are used as a reference or calibration points for each of the three telescopes. This data, known as observations, is then sent instantaneously to the Joint Space Operations Center Space Situational Awareness Operations Cell.
The GEODSS system has been an important piece of U.S. Strategic Command's space situational awareness mission since the early 1980s. In 2004, each site began using telescopes that were equipped with Deep STARE. This upgrade provided the site with some of the most accurate and sensitive optical telescopes in the world. The GEODSS system can track objects as small as a basketball more than 20,000 miles away and is a vital part of the AFSPC's space surveillance network.