Det 2, 21st Operations Group

Detachment 2, 21st Operations Group is a dedicated space surveillance unit on the island of Diego Garcia, in the British Indian Ocean Territories.
MISSION
The primary mission of the detachment is to detect, track, and identify all tasked space objects within its area of coverage. The unit provides data on deep space objects in the orbits from 3,000 to 22,000 miles, although it has a limited near earth detection capability. Satellite information is provided to the Joint Space Operations Center at Vandenberg Air Force Base, Calif.
TELESCOPES
The detachment is one of three worldwide Ground-based Electro-Optical Deep Space Surveillance sites. It performs its mission using three main telescopes. Each telescope has a 40-inch aperture and a two-degree field of view. All telescopes at Diego Garcia are sealed against the environment and each observatory dome has a forced air system to keep out the salt-laden air of the Indian Ocean. It is the only site south of the equator.
HISTORY
The detachment was activated on June 18, 1986 as Detachment 4, 1st Space Wing, Air Force Space Command. It was reassigned to the 18th Space Surveillance Squadron at Peterson AFB in February 1990. It was reassigned to the 73rd Space Group May 15, 1992, and reassigned again to the 21st Space Wing in May 1995. The detachment became Detachment 2 of the 18th Space Surveillance Squadron Aug. 1, 1994. On June 1, 2004, the detachment was reassigned to the 21st Operations Group, 21st Space Wing due to the deactivation of the 18th Space Control Squadron.
The site is operated and maintained by contract workers. The single Air Force officer assigned has the primary responsibility for ensuring that the mission is accomplished and the contractor's work performance is satisfactory.
LOCATION
The detachment is situated near the center of the Indian Ocean between Africa and the Indonesian Archipelago. The island is remote, with the nearest commercial port being Colombo, Sri Lanka, some 960 nautical miles away. Diego Garcia is classified as a coral atoll and is among a number of islands forming a cluster known as the Chagos Archipelago. Diego Garcia is part of the British Indian Ocean Territories and is administered by the British government.