It is reported on SatWatch that the 216 MHz US Space Fence, used to detect orbital objects, was turned off on September 1, 2013 at 0000 UT.
The Air Force Space Surveillance System (AFSSS), known as the Space Fence, is a U.S. government multistatic radar system built to detect orbital objects passing over the United States. There are three transmitter sites operating on 216.983, 216.97 and 216.99 MHz and six receiving stations.
According to Wiki the system is understood to be capable of detecting a 10 cm object at an altitude of 30,000 km and makes 5 million satellite observations each month.
Early in August Space News reported that: Gen. William Shelton, commander of Air Force Space Command, “has directed that the Air Force Space Surveillance System be closed and all sites vacated” effective Oct. 1, the memo said.
It seems appear the closure may have occurred earlier than initially reported.
The reason for the shutdown has been reported as being because Federal Government expenditure is exceeding budget resulting in automatic budget cuts known as sequestration, however, a Space Review article suggests another reason http://www.thespacereview.com/article/2357/1
Air Force Space Command (AFSPC) officials say they have devised modified operating modes for the Perimeter Acquisition Radar Characterization System at Cavalier Air Force Station, N.D., and for the space surveillance radar at Eglin Air Force Base, Fla., which allows the discontinuation of AFSSS operations while still maintaining solid space situational awareness.
Air Force Space Surveillance System http://en.wikipedia.org/wiki/Air_Force_Space_Surveillance_System
Air Force Space Command to discontinue space surveillance system
Space News, August 6, 2013
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