Cruise missiles were not a new weapon in the 1980s but had actually been in service since the early 1940s. Nazi Germany used V1 missiles in attacks against Britain in World War Two. These were very different from the weapons carried by armed forces in the Cold War. The Soviets themselves deployed various types of cruise missiles, mainly types that would be launched from aircraft or ships, and the US also deployed small numbers of strategic range cruise missiles in the late 1950s. These types however lacked the sophistication and accuracy that was to come from the revolution in microcomputers, satellite technology, and artificial intelligence.
Essentially, a cruise missile is a projectile that flies within the altitude of a normal aircraft unlike a ballistic missile that follows a ballistic arc to reach its target (which may mean flying outside the atmosphere). One of the founding fathers of later US Cruise missiles was artificial intelligence genius, Marvin Minski. Minski's work allowed a computer to follow a landscape intelligently in a way that could keep at a predetermined height and avoid obstacles on the landscape. In other words, it could navigate by its own onboard computer and with great accuracy. Such a missile got its information on a given landscape from computer mapping provided by satellites.
Work started on the later American cruise missile in 1972 when the US Navy was looking for a compact missile that could be launched from submarines with a medium range. The results were so impressive that worked continued in the 1970s on an air-launched version using the B-52 bomber as a launch platform. This could then extend the life of the B-52 as the missiles meant it could mount stand-off attacks without actually having to penetrate too deeply into hostile airspace. Such attacks were later used to great effect on Iraq.
The missile test proved that system was reliable, accurate and relatively inexpensive to developing and deploying Strategic range nuclear forces. When NATO decided on force modernization in the late 1970s, it was looking to deploy a weapon that would in fact provide a visible force. Given the pace and qualitative improvements in the Warsaw Pact through the 1970s, such a visible deterrent would act to reassure the public that its government took our security seriously. It was then decided that a mobile ground launched variant of the General Dynamics BGM-109 would be the ideal weapon to modernise US nuclear forces within Western Europe without disturbing the strategic balance created by the SALT accords of 1972 and 1979. In addition, the Soviet deployments of it mobile intermediate range SS-20s put US air bases such as Upper Heyford and Lakenheath at serious risk. Flights of ground launch cruise missiles could release the F1-11s at those bases for other roles and the new weapons had the in built survivability of being mobile.
Deployments of GLCMs were also vital to restoring NATO's key doctrine from 1967 of Flexible Response. This emerged as a result of information that suggested a Soviet attack on NATO might not go nuclear immediately but might commence with a period of sustained conventional strikes. Flexible Response meant that NATO had to be capable of responding at four levels of war: conventional, battlefield nuclear, theatre nuclear, and strategic warfare. The idea was to contain the Soviet onslaught at the lowest possible levels for as long as possible. Yet with the deployment of the SS-20s, Backfire and Fencer bombers as well as the sheer force of numbers, NATO needed a more convincing solution to respond to its deteriorating and unstable position.
The deployment of GLCMs was agreed by NATO in Dec 1979 but it was also agreed to withdraw 1,000 theatre nuclear warheads from Western Europe. The deployment of GLCMs and of Pershing 2 represented a significant improvement in NATO's ability to actually strike within the territory of the Warsaw Pact and with far greater accuracy than ever before.
The eventual deployment of the new missiles can also be seen as part of a change in US strategy. on September 25th 1980, President Jimmy Carter discussed Presidential Directive 59. The directive allowed a greater range of nuclear targeting options reinforcing a nuclear doctrine of Counterforce. This was not actually a new concept but was a more credible alternative to the fear of Mutually Assured Destruction that had dominated East-West nuclear strategy since President Kennedy. Counterforce meant that the US and NATO would attempt to target the enemy's nuclear weapons themselves rather than deterring the enemy from thinking his cities and populations would be struck. The accuracy of the new weapons (especially the Pershing IIs and development of Stealth bombers) meant that this doctrine was an emerging possibility.
These developments meant that the theory of deploying Ground Launched Cruise Missiles as a weapon had to be tested in practice, in the field. In the late 1970s, a unit was assembled that would test out the practicalities of deploying such a system under combat conditions. It needed to find out how units could conceal themselves, how many security personnel would be required, an appreciation of the difficulties of basic operating conditions in the field, what kind of vehicles would be needed, what technical difficulties might be encountered.
At the same , shelters had to be designed to protect the GLCMs from possible nuclear and or conventional attacks.
From Commemorative Intelligence Agency, Washington:
A QRA (Quick Reaction Alert) GLCM shelter where missiles could be held on alert.
These shelters included accommodation for crews on the alerts.
So what would happen if tensions mounted and war looked likely? During such a crisis, the GLCMs and control vehicles along with heavy security would be taken from Greenham or other bases to certain pre-surveyed secret launch sites in remote areas.The areas need to be pre-surveyed in order to provide accurate data to feed into the missiles targeting computer. The convoys would travel along roads that will have been closed to traffic so as to prevent them being followed by Soviet saboteurs. Security forces will also be provided by the host nation. If possible, convoys will travel after dark to maintain a low profile.
Once at the secret site, two officers within each Launch Control Centre begin a 20 minute process of entering launch codes received via satellite. A telex machine punches out a code which is entered. Once authorisation is accepted, the two officers simultaneously agree "ready to execute" and both press the execute button. The missiles are launched. The missiles burst out of the launch vehicle climbing slowly at first but eventually reaches mach 0.7. Onboard, the missiles computer calculates distances, times and its coordinates. The missile then climbs to a high altitude over friendly and neutral airspace in order to conserve its fuel. It is possible it may have to overfly neutral Sweden and might be attacked if detected there. This is unlikely. The small size of the missile, its flight characteristics and tiny radar signature of a 15th of that of a B-1b Lancer bomber mean it is a stealthy weapon. Its onboard computers mean it emits no give away radio signals.
After at least an hour, the missile needs to update its onboard systems to remain on target. This is when it revolutionary DPW-23 systems come into use. Also know as TERCOM (for TERain CONtour Matching) the DPW-23 allows the missile to make calculation on its position based on an exact profile of the Earth's surface and the route it must now take to reach its target. Once approaching hostile territory and to maintain concealment from enemy radars, the missiles swoops down to an altitude of around 50 feet. It will then avoid and skim the terrain. When approaching the final target, the GLCM switches on its highly accurate Terminal Correlator Unit. This gives the missile details of how the target will appear to the approaching missile including Infra Red wavelengths. The missile warhead then arms itself in readiness. The computer searches exactly for its target based on the picture in its computer. It will then climb high to avoid any physical barriers or defences that may have been assembled around the target area before flying down on the target still updating it position until it detonates. The missile is exceptionally accurate, to within 60 feet of its target after a flight of up to 1,550 miles lasting up to three hours.
Possible (and speculative) GLCM targets (if launched from Western Europe 1983-1991). Targets would include airfields, strategic rail nodes, ammunition depots, enemy HQs and command posts:
1. Kronstadt Naval base nr. Leningrad, Soviet Union
2. Kaliningrad, Baltic, Soviet Naval base, Soviet Union
3. Severomorsk, HQ Soviet Northern Fleet, Soviet Union
4. Polyarnyy, Soviet submarine base, Soviet Union
5. Gadziehvo, Soviet submarine base, Soviet Union
6. Legnica, HQ Northern Group Forces, Poland
7. Zossen-Wunsdorf, HQ Soviet Forces Germany, GDR
The launch officers themselves however had no idea of what the actual targets would be.
At Greenham Common, the flight schedules rotated every two months or so like this:
A & B flights: deployment training from Greenham to Salisbury Plain.
C & D flights: base security (GAMA & flightline) and deployment preparation.
E & F flights: base security (GAMA & flightline).
This meant that once or twice a month, convoys of GLCM flights would leave the base, normally at night, to conduct realistic field exercises. Curiously, outsiders always seemed to know the exact times of departure. A GLCM convoy was not easy to conceal. A complete flight of GLCMs consisted of 22 vehicles. It had armoured cars for 44 armed guards, a supply truck and breakdown vehicle. Its Launch Control Vehicles and Launchers were armoured to protect themselves from small arms of up to 7.62 calibre. The convoys could travel at up to 45mph and six of the 22 vehicles were over 56 feet long! The vehicles could cope with rough terrain and deep water. The purpose of the exercises was to practice possible deployment procedures in the event of a real conflict and to familiarise personnel with according procedures. Live warheads never left the base. Special inert training canisters were used on such exercises to simulate the presence of the real weapons.
From Commemorative Intelligence Agency, Washington
GLCM crews at Greenham had to undergo a special training course at Davis Monthan AFB in Arizona prior to coming to Britain. Some of those operating GLCMs had a background operating ICBMs such as Titan II or the Minuteman or would go on to carry out such duties in future. Each member of the crew had to undergo psychological monitoring to be ready to carry out such a responsibility.