Some
Consequences of the Future Development of Star Wars at Fylingdales
School
of Engineering,
Leeds
Metropolitan University
Tel: 0113 2836742
Fax: 0113 2733110
Fylingdales on the
North Yorkshire Moors National Park has been the home of a US Ballistic Missile
Early Warning System (BMEWS) since the Cold War days of the 1960s. The base is
run for the US by the RAF and is one of the 3 stations in a chain linked across
the North Atlantic. The other stations are Thule in Greenland - operated by the
12th Space Warning Squadron (or SWS) and Clear in Alaska - operated by the 13th
SWS – both components of the USAF 21st Space Wing based at Peterson Air Force
Base in Colorado Springs.
The first choice for
the UK BMEWS station was in fact Prestwick in Scotland. However, according to a
1959 Report on the State Department negotiations in Aviation Week, the British were reluctant to allow it because it
was heavily populated area that would become a prime target in time of war.
They were concerned about public protest.[1]
It is clear that the
site at Fylingdales was eventually chosen because it is remote from areas of large
scale habitation and also fulfils the stated requirements of:
Under the BMEWS
agreement, signed by the then Secretary for Air in 1960, the USAF own and
supply the radar, computer and communications equipment and the UK provide the
site, power and housing and its own communications requirements and pays for
most of the maintenance and operation. Fylingdales was built in 1964 on
Ministry of Defence land in the North York Moors National Park. It cost £46
million, £35 million of which was US dollars.
RAF Fylingdales originally consisted of three white spherical radomes (or “golfballs”) 43 metres in diameter. Each radome housed and protected a large radar dish that could be mechanically steered to search for intercontinental ballistic missiles that threatened the North American Continent from the USSR. Two of the dishes tracked from side to side, one at an elevation of 2.5o and the other at 5o above the horizon. Targets found at 2.5o and then at 5o could be a rocket in its boost phase and its trajectory would be tracked by the third radar to determine the point of impact.
At this time an
uneasy balance of strategic nuclear weapons was held between the two super
powers by setting an agreed limit to each side’s ability to counter a
full-scale nuclear attack. In this way, any nuclear first strike would risk
Mutually Assured Destruction (a MAD idea in more ways than one). The
Anti-Ballistic Missile Treaty (ABMT), signed in 1972 by the US and USSR, set
limits on the anti-ballistic systems (missiles and radars) that could be
deployed by each side.
Fylingdales operates
under the US "Masterplan for tactical Warning and Attack" which lists
the aims of BMEWS as being to:
As well as its Early
Warning Function, Fylingdales also forms part of the Space Surveillance Network
(SSN), an intelligence network that tracks and maintains a database of space
objects (military and civilian satellites and space debris).
Fylingdales is
therefore a significant command, control, communications and intelligence
installation. Information gathered by the radar installation is fed directly to
the North American Aerospace Defense Command (NORAD) in Cheyenne Mountain,
Colorado. From there information is passed to the National Command authorities
and to Headquarters, Strategic Air Command (SAC). In time of war, it would
provide the US President with information on what has and has not been
attacked, monitor trajectories of both surveillance satellites and incoming
ballistic missiles and allow prioritising and accurate response and targeting
on "enemy" satellites and ballistic missiles.
Despite the
"state of the art" technology installed at Fylingdales, there have been
a number of false alarms. A flock of geese and (on 5th October,
1960) the rising moon (at Thule) have been mistaken for incoming missiles only
on last minute checks was the firing of several missiles avoided. On 24th
November, 1961 all communication links went dead between SAC HQ and the three
BMEWS sites. Was it enemy action, or the coincidental failure of all the
communication systems? All SAC bases in U.S. were alerted and B-52 nuclear
bomber crews started their engines. Eventually, radio communication was
established with a B-52 on airborne alert near Thule. It contacted the BMEWS
station by radio and could report that no attack had taken place. The reason
for the "coincidental" failure was that the redundant routes for
telephone and telegraph between NORAD and SAC HQ all ran through one relay
station in Colorado. At that relay station a motor had overheated and caused
interruption of all the lines.
In 1979 a full alert
was sounded when a ‘War Games’ simulation tape was loaded by mistake into NORAD
computers. Fylingdales warned that a salvo of missiles had been launched
against B52 bases from a Soviet submarine in the Pacific. ‘Things got very
tense’. But no radar targets appeared in the ‘threat azimuth’ (the angles of
the horizon at which a Soviet missile would normally be launched to attack
Europe or North America). Details of this error are only known because a
reporter witnessed the late stages of alert in a Virginia Air Traffic Control
Centre and asked questions.
1979 - amendment
to the 1960 agreement allowed a further $1.9 million contract to modernise the
tactical operations room to help provide (in conjunction with Defense Support
early warning satellites) a Tactical Warning/Attack Assessment directly to the
US Joint Chiefs of Staff. The contract was awarded to RCA in June 1979.
1989 - 1992 – it was announced in 1985 that the three giant golfballs were to be replaced by a Large Phased Array Radar (LPAR) in the form of a 40-meter high, truncated pyramid. Each of the 3 faces of the pyramid contains an array of 2,560 aerials, transmitting at 420-450 MHz with a total mean power output of 2.5 Megawatts. It was to cost around £200 million, of which the US would pay 70% (for the radar technology) and the UK 30% (for the operating infrastructure). This contract was awarded to Raytheon - who also upgraded Thule in 1987. Work started August 1989 and the new system became operational in October 1992.
Limited by the
conditions of the ABMT, the upgraded radar has a similar output power and the same
3000 mile range as the old one, but is able to operate over a full 360o,
rather than 120o.
In addition, CND has
always argued that this upgrade was a step towards the implementation of Ronald
Reagan’s “Star Wars” idea – and that it was in contravention of the ABM Treaty
which did not allow the construction of new radars of this type outside the
boundaries of the US and USSR.
In a letter
concerning the 1989 upgrade sent to the Chair of the Leeds City Council Peace
and Emergency Planning Committee on 10th October 1986, M. Webster of
the North York Moors National Park states:
“.. the present installation at Fylingdales and the proposed
modernization are both considered totally incompatible with the National Park,
and that Committee deeply regrets the proposal to develop the modernized BMEWS
at Fylingdales ”
The letter continues,
with “the Committee asks … [that] …the
government seeks to ensure that in the event of any future modernization being
necessary that it is then possible to relocate BMEWS outside the National Park
on environmental grounds.”
There is no evidence
that any government since then has ever given this any serious consideration.
After the LPAR
upgrade, in 1993, an ElectroMagnetic Radiation (EMR) Survey of the area
surrounding Fylingdales was commissioned by the Nuclear Free Local Authorities[2].
The survey was an
extension of an earlier report produced in the summer of 1991 and used 23
measurement sites, including moorland paths and tracks, roadside locations and
habitations. The survey found maximum field values of about 10Vm-1 with typical values
around 5Vm-1.
The report concludes:
n
“At no point in the area accessed by the survey is the field
strength due to to RAF Fylingdales’ transmission higher than that recommended
in the current UK guidelines for protection against biological hazard from
non-ionizing radiation;
n
In the northerly locations, the new phased array radar has
not significantly changed the time averaged levels of field to which walkers
and residents are exposed;
n
South of the transmitter, the levels to which walkers and
residents are exposed are now ten times that which they were before the pyramid
upgrade became operational;
The threat to vehicles using the A169 from interference to their electronic control systems has been reduced though not eliminated.”
Exposure limits for
Radio Frequency (RF) fields are developed by international bodies such as the
International Commission on Non-Ionizing Radiation Protection (ICNIRP). The
ICNIRP is a non-governmental organization formally recognised by the World
Health Organisation and has drafted guidelines to protect against RF health
effects. They state that: “Environmental
RF levels from radars, in areas normally accessible to the general public, are
normally at least 1,000 times below the limits for continuous public exposure
allowed by the ICNIRP guidelines.” [3]
At frequencies in the
range 300 MHz to several GHz, there is significant local, non-uniform
absorption by the human body – the recommended maximum field levels are shown
in Table 1 (where f is the radar
frequency).
Table 1 – Reference levels for
general public exposure to time-varying
electric and magnetic fields
(unperturbed rms values)
|
Frequency
range |
E-field
strength (V m-1) |
H-field
strength (A m-1) |
B-field (mT) |
Equivalent
power wave density (W m-2) |
|
10-400 MHz |
28 |
0.073 |
0.092 |
2 |
|
400-2000 MHz |
1.375f1/2 |
0.037f1/2 |
0.046f1/2 |
f/200 |
|
2-300 GHz |
61 |
0.16 |
0.20 |
10 |
A comparison between
the survey results and Table 1 indicates that some EMR levels recorded around
RAF Fylingdales are in fact quite close to the ICNIRP reference levels – and
certainly not “1,000 below the limits for continuous exposure”.
Also, a number of
factors significantly alter human exposure to RF generated by radar systems,
often by a factor of at least 100:
n Radar systems send electromagnetic waves in pulses and not
continuously. This makes the peak pulse power emitted much higher than the
measured average or root mean square (rms) power.
n Radars are directional and the RF energy they generate is
contained in narrow beams. RF levels away from the main beam fall off rapidly.
In most cases, these levels are thousands of times lower than in the main beam.
n
Early warning radars
are continuously changing the direction of the beam.
Some investigation
into the accepted international standards is required in order to put these
results into some kind of context. A recent report on the Physiological and
Environmental Effects of Non-ionising Electromagnetic Radiation for the
European Parliament[4] states:
“What distinguishes technologically produced electromagnetic
fields from (the majority of) those of natural origin is their much higher
degree of coherence. This means that
their frequencies are particularly well-defined, a feature that facilitates the
discernment of such fields by living organisms, including ourselves. This
greatly increases their biological potency, and ‘opens the door’ to the
possibility of frequency-specific, non-thermal influences of various kinds,
against which existing Safety Guidelines – such as those issued by the
International Commission for Non-ionising Radiation Protection (ICNIRP) -
afford no protection. For these Guidelines are based solely on consideration of
the ability of radio frequency (RF) and microwave radiation to heat tissue, and
of extremely low frequency (ELF) magnetic fields to induce circulating electric
currents in the interior of the body, both of which are known to be deleterious
to health, if excessive.”
The report points out
that the frequency-specific sensitivity of living organisms to ultra-low
intensity microwave radiation was discovered over 30 years ago in Russia and
there the exposure guidelines are approximately 100 times more stringent that
those of ICNIRP. It also notes that some symptoms have been reported in
epidemiological studies involving humans, animals and plant life connected with
a radar operating at 154-162MHz, with a pulse repetition frequency of 24.4Hz -
at a location where the intensity of the emitted radiation is comparable to that typically found at
150m from a base-station. Additional
effects include[5]:
n
Depressed nocturnal
melatonin levels in cattle[6].
n
Less developed memory
and attention span (as well as decreased endurance of their neuromuscular
apparatus) of children living within a 20 km radius of the radar, subject to a
maximum exposure of 0.00039 W m-2.
n
A six-fold increase
in chromosome damage in cows exposed to a likely maximum intensity of 0.001 W m-2.
(The
cited field intensities are estimated from information on the electric field
intensity as a function of distance from the radar installation[7]).
The Fylingdales radar operates by emitting a series of pulses and additional, perhaps more serious, problems may arise at frequencies around 17 Hz. As mentioned in the STOA report, this lies in the range of beta brain-wave activity and is close the frequency of a flashing visible light that can provoke seizures in people with photosensitive epilepsy. It is also the modulation frequency at which “there is a maximum in the expression of calcium ions from brain cells when they are irradiated with amplitude modulated, low intensity RF radiation over a wide range of carrier frequencies” and “any interference … could well undermine the integrity of the whole nervous system, although the extent to which this actually occurs is, at present uncertain, owing to a lack of the necessary research.” The pulse repetition frequency of the radar is thought to be 27 pulses per second (at least, this was the documented frequency of the previous system [8]) and it is not known whether there are any similar effects at or around this frequency that need to be examined closely.
For NMD detection and
warning are not enough. Accurate tracking and discrimination between warheads,
debris and decoys is required. A "preliminary" architecture published
in May 1999 [9]
(see Table 2) describes the NMD system as being deployed in two stages. The
first stage is to upgrade the current early warning radars – including that at
Fylingdales. The second stage includes the installation of an additional radar
system – the X-band Radar - at various sites including that of Fylingdales.
We will look at the
consequences of each of these configurations in turn.
Table 2 shows that
both NMD configurations involve the US early-warning radars in California,
Massachusetts and Alaska and at Thule and Fylingdales. Currently these systems
are not able to track targets accurately enough to guide interceptors. The
initial configuration involves an Upgraded Early Warning Radar (UEWR) program
to give them this capability. This replaces existing computers, graphic
displays, communication equipment, and the radar receiver/exciter for NMD. New
EWR software would allow the acquisition, tracking, and classification of small
objects near the horizon and this data would be passed to other NMD elements
using improved communications systems. [10]
The UEWRs would be
able to search for different types of missiles, distinguish hostile objects
such as warheads from other objects, and provide data to other NMD elements
using improved communications systems.
The US Ballistic
Missile Defense Organisation (BMDO) state that the radiated peak and average
power, radar antenna patterns, and operating bands of the UEWRs, is to remain
unchanged from current operations.
Table 2 – Preliminary NMD
Architecture
|
|
Initial
Configuration |
Final
Configuration |
|
Planned deployment date |
2005-7 |
2011 |
|
No. intercepts
deployed in Alaska |
100 |
125 |
|
No. intercepts
deployed in N. Dakota |
0 |
125 |
|
Upgraded Early
Warning Radars |
Beale (Marysville,
Calif) |
Beale |
|
X-band radars |
Shemya (Alaska)
|
Shemya |
|
Satellite based
infra-red sensors low-Earth orbit |
No |
|
The UEWRs will still be extremely limited in their ability to discriminate real warheads from decoys or to deal with other types of countermeasures [11]. The final configuration of NMD therefore includes the deployment of new high resolution phased-array X-band radars (XBRs) which use high frequencies (5.2-8.5 GHz) and advanced radar signal processing technology to improve target resolution. These systems emit a series of electromagnetic pulses over a 50o field of view in azimuth and elevation, and can be rotated to track targets from any direction.
The initial NMD
configuration includes an XBR at Shemya in the Aleutian Islands (to cover
missile launches from North Korea). The final NMD configuration would include
additional XBRs at the current BMEWS sites (including Fylingdales). When fully
operational each system will include a radar mounted on pedestal and associated
control and maintenance facility, and a power generation facility. It will need
approximately 30 to 60 personnel to operate and will encompass an area of
approximately 7 hectares (17.46 acres) for the radar alone and would need to be
surrounded by a 150 m (500-foot) controlled area (see below).[12]
XBRs have an average
power of 170 kW and an antenna area of 123 m2, which means a
power-aperture product of about 20 million, but they usually incorporate a
"thinned" array of only 1/5 of the total possible number of aerial
elements (around 81,000) decreases the gain by a factor of 5. In this case more energy goes into radar
beam side lobes but does produce a narrower beam and provides greater tracking
accuracy.
As mentioned before,
these radars are intended for tracking and discrimination. Surveillance would
be carried out by the UEWRs which will locate targets within a single XBR beam
width - allowing detection and tracking at long ranges (2,000 - 4,000 km) despite
the limited power-aperture. The detailed signature analysis for the
discrimination of decoys requires a higher signal/noise ratio than that
required for tracking and the range at which discrimination is possible would
be significantly less than the maximum detection and tracking range
Recently questions
have been raised regarding the possible danger to the health of people living
close to these installations. The BMDO insists that the microwave leakage from
these high power radars is safe – but independent investigations into possible
health hazards need to be made.
Health:
The XBR BMDO fact sheet 11 states
that “The exposure limits established by
[the US standard] ANSI/IEEE C95.1 1999 are used to ensure that public health
will not be impacted by EMR emitted from the XBR”.
Two major exposure
environments are defined: inside and outside a controlled area of radius 150m.
Security personnel would control the area to prevent any unauthorized access.
It is claimed that outside the controlled area the EMR will be no higher than
the power density levels specified in ANSI/IEEE C95.1 1999. The BMDO provide
the following table:
Table 3 – Comparison of EMR
exposures (from BMDO[13])
|
System |
Distance |
Power
Density (W m-2) |
Power
Density (mW cm-2) |