Menwith Hill is the largest electronic monitoring station in the world. It is
run by the US National Security
Agency (NSA), which monitors the world's communication for US intelligence.
Menwith Hill employs 1,200 US civilians and servicemen to work around the clock
inside "hardened" buildings intercepting and analysing communications
mainly from Europe, Russia and the Middle East. Until a few years ago, the existence
of the NSA was a secret and its charter and any mention of its duties are still
classified. But, it does have a Web site)
in which it describes itself as being responsible for the signals intelligence
and communications security activities of the US government.
All telecommunications traffic to and from Europe and passing through Britain
is intercepted at the base, including private telephone calls, faxes, emails
and other communications. Much of the information is collected, processed and
relayed back to the United States automatically. A great deal of this information
comes from spy satellites and the base has a number of large white golfballs
or "radomes" containing satellite receiving dishes.
The importance of MHS to US intelligence activities has recently been emphasised
by the closure of other UK stations run by NSA, and by its new designation as
a Regional Sigint
Operations Centre (RSOC) which is responsible for running remote, automated
MENWITH HILL - How it Operates
The main operational activity of Menwith Hill is the collection of signals
intelligence from national and international communications systems for the
USA. Long distance national and international communications are conveyed by
cables, microwave radio links, and satellites. All forms of modern communications:
telephony, television, fax, computer links and the Internet are carried in this
way. Companies such as BT install and provide high capacity national and international
links used for these purposes and each is subject to interception. Some long
distance communications are still conveyed by traditional high frequency (HF)
radio systems. Except for domestic mobile radio systems, this traffic is predominantly
but not exclusively military.
Menwith Hill was first established to intercept traditional radio signals,
but this is now only a tiny part of its activities. Current activities are conducted
under two systems - SILKWORTH and MOONPENNY.
Its primary targets are Europe, northern Africa and western Asia. This is because
satellites which are positioned to provide communications in these regions are
visible from Menwith Hill, but would not be visible from the United States.
The SILKWORTH system, established in 1979, uses specially
designed satellites stationed over target areas to intercept long distance microwave
radio communications. Apparently operated entirely from Menwith Hill using large
satellites positioned over the Equator, SILKWORTH intercepts long distance microwave
radio relay links between cities in Eurasia and relays them back to Menwith
Operators at Menwith Hill can monitor messages and conversations passing between
companies and individuals within, say, Jordan or the Ukraine. Other international
messages and conversations being conveyed by the same route can also be intercepted.
Satellites can be directed to intercept and relay selected links and the received
communications are then sorted and processed at Menwith Hill to select those
that satisfy specific criteria. All forms of communications are intercepted
and processed. Menwith Hill controls 56 satellites and a series of radomes,
known as the RUNWAY running east and west across the south edge of Menwith,
are believed to be involved in downloading information from the geosynchronous
satellites known as VORTEX or MAGNUM and from larger, more advanced systems
such as those known as ORION. STEEPLEBUSH II, a subterranean, radiation-hardened
facility, processes information from the RUNWAY satellites.
The MOONPENNY system is the unauthorised reception of ordinary
satellite communications used by other countries. It consists of interception
terminals placed so as to intercept the signals broadcast to the earth's surface
by national or international communication satellites. These may include satellites
launched by single nations, such as Russia or Israel, or by groups of nations,
such as ARABSAT, or by the international community as a whole (INTELSAT). Because
the ordinary function of these satellites is to broadcast their signals to earth,
no special equipment needs to be placed in space to intercept them.
The NSA aims to collect, examine and process all international (and many national)
communications. The scale of the collection system was described by the former
Director of the NSA, Vice Admiral William Studeman, in 1992. At that time the
NSA's collection system generated about 2 million intercepted messages per hour.
Of these, all but about 13,000 an hour were discarded. Of these about 2,000
met forwarding criteria, of which some 20 are selected by analysts, who then
write 2 reports for further distribution. Therefore, in 1992 MHS was intercepting
17.5 billion messages a year. Of these some 17.5 million may have been studied
Prior to extensive automation, sorting of messages was carried out by reference
to a list of targets, known as a "watch list". In the last decade,
this list has evolved into a system called project ECHELON. In this system computers,
known as DICTIONARY are used to select messages which may include combinations
of specific names, dates, places, subjects etc. DICTIONARY automatically searches
through intercepted messages looking for particular subjects and people from
target lists. Those matching particular criteria are sent for further processing
by analysts. Key words for message interception are numerically coded and include
diplomatic messages as well as regional communications.
ECHELON was first revealed by Duncan Campbell in 1988 in a New Statesman article
and detailed in Secret Power by Nicky Hagar in 1996. The existence of the ECHELON
system has been officially confirmed in a report commissioned by the Civil Liberties
Committee of the European Parliament. The report, called "Assessing the
Technologies of Political Control", also calls for calls for an investigation
into the activities of the NSA at Menwith Hill. (See the European Parliament
section of the Campaign page).
... MENWITH HILL - ask no questions, get no answers ....
Euro MPs have asked the European Council of Ministers whether Menwith Hill
is undermining European jobs and businesses by selling European trade secrets
to US companies. Selected information is exchanged with the British listening
post at GCHQ, Cheltenham and a number of GCHQ staff also work at Menwith Hill.
A recent report commissioned by the European Parliament has confirmed that Menwith
Hill's role in monitoring UK communications for the NSA and pressure is being
applied by British MEPs in the European Parliament to make Menwith Hill accountable
See the page on Campaigning
The American authorities largely refuse to answer questions, give out information
or allow reporters, MPs or MEPs into the base. Answers are refused to many of
the questions that MPs ask about Menwith Hill in the House of Commons although
many MPs have asked them in the past. Among the most prolific questioners of
the status and role of Menwith Hill was Bob Cryer, who was MP for Bradford South
until his tragic death in 1994. His final speech to the House, in an adjournment
debate, was a succinct rendering of the questions at the heart of the campaign.
Questions continue to be asked in the House of Commons but satisfactory answers
are very rare. See also, page on Campaigning
MENWITH HILL - prime nuclear target ... integral part of US star wars plans
There are no missiles at Menwith Hill but the base would play a crucial role
in any nuclear strike mounted by the United States. As such, it would be a prime
nuclear target in the event of war. Menwith Hill received an award for the part
it played in "Desert Storm" during the Gulf War. Despite being an
American controlled facility, Menwith Hill was in 1996 designated a RAF base.
Menwith's ongoing expansion will also enable it to transmit and receive communications
and photographic images from space. This will help the US Space Command in its
mission to "see" and "hear" everything on the planet and
enable laser weapons to be able to reach anywhere on the earth within a target
area of about six feet.
Work has already started on the Space Based Infra Red System (SBIRS) (see "Planning
Applications" under "Menwith Hill" in CAAB News Letters 4-6).
General Howell M. Estes III (Commander in Chief, North American Aerospace Defense
Command and US Space Command and Air Force Space Command, Commander) has said
in a speech urging the US Congress to "help fulfill the promise of space"
"Our SBIRS system consolidates DoD's non-imaging infrared systems that
fulfill national security needs in areas of missile warning, missile defense,
technical intelligence and battlespace characterization. It consists of high
and low components. We need to get SBIRS High on-orbit first as a replacement
for the Defense Support Program (DSP). We're going to put four satellites up
to replace four DSPs. This will improve our location identification and tracking
capabilities by better identifying the missile launch point, impact point and
azimuth. It will also give us another level of refinement in those areas as
we work the missile defense issue. The advantage of SBIRS Low is that it can
track "cold bodies" in space. SBIRS Low is important for the ballistic
missile defense systems. With SBIRS High, you can only track infrared signatures
which means the rocket motor has to be burning. These systems will significantly
improve our ability to provide much more precise launch and impact point of
theater missiles to forces in a theater of operations. They are key to our ability
to cue systems that we'll use for active defense as part of both theater and
national missile defense."
The launch of 72 pounds of plutonium into space on Cassini in October 1997
was also connected to this space weapons program. Enormous amounts of power
have to be generated in space in order to fire the laser weapons. See also Yorkshire
CND space page.
Menwith is the largest regional signals intelligence station anywhere on earth
and is fully involved in these plans.
Updated October 1997 - Dave Lesley
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