據報導：

美國空軍關閉VHF太空柵欄
太空柵欄 Spece Fence 是一組VHF 雷達系統，可以偵測太空中三萬公里內，任何大於十公分的物體。
每年要花掉一千四百萬美金操作費, 所以於 2013-09-01 關閉停用，

美國空軍希望向美國國會爭取新的 S-band 太空柵欄
http://www.thespacereview.com/article/2357/1
---------------------------------------------------------------------


US Space Fence Shut Down

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
http://www.af.mil/News/ArticleDisplay/tabid/223/Article/466832/air-
force-space-command-to-discontinue-space-surveillance-system.aspx

Space News, August 6, 2013
http://www.spacenews.com/article/military-space/36655shelton-orders-
shutdown-of-space-fence

SatWatch http://www.satwatch.org/

High Frequency Active Auroral Research Program (HAARP) shuts down
http://www.southgatearc.org/news/july2013/haarp_facility_shuts_down.h
tm

[ANS thanks AMSAT-UK for the above information]


---------------------------------------------------------------------