MGM-134A Midgetman / Small ICBM
In order to maintain a credible deterrent to nuclear attack, it is necessary that retaliatory forces survive a nuclear "first strike" with the capability of responding. A major problem is protecting intercontinental ballistic missile (ICBM's) and their associated control equipment against such a first strike. Fully hardened silos and the like for land-based ICBM's are generally effective, but only at great cost. Also, the degree of hardening, may become insufficient with improvements in accuracy and power of the "first-strike" weapons.
In order to limit the ability to accurately target retaliatory missiles, various mobile missile concepts had been proposed. Generally, the missile is moved among a number of fixed, hardened protection enclosures. Unfortunately, the number of enclosures is limited by their high cost, and it became possible to simultaneously attack a large number of such enclosures using multiple independent reentry vehicles (MIRV).
ICBM modernization continued to be a topic of controversy after several years of debate.
In 1983 it appeared that the acceptance of the recommendations of the President’s Commission on Strategic Forces [the Scowcroft Commission], calling for deployment of 100 Peacekeeper missiles in Minuteman silos and development of a single warhead Small ICBM, had calmed the debate. The President’s Commission recommended the development of a new, lightweight missile carrying only one reentry vehicle. The missile configuration that has been of prunary mterest is a single warhead missile weighing about 30,000 pounds. This missile had been recommended because of its survivability potential. Also, since it has a single warhead, it would be a relatively low value target. As such, the Commission considered it to be stabilizing and to enhance the arms control process.
This apparent consensus was, however, short-lived. The number of Peacekeeper missiles to be deployed in Minuteman silos was reduced from 100 to 50. The search for survivable basing for Peacekeeper missiles has been renewed. The high cost of deploying and maintaining a force of 500 Small ICBMS led to discussions of its affordability. To reduce costs, consideration was given to deploying Small ICBMS at Minuteman sites or some combination of this and random movement at government installations. Based on a need for increased range and payload flexibility, design studies of a single warhead Small ICBM weighing about 37,000 pounds were begun in January 1986. Also, studies of larger mobile missiles to accommodate two or three warheads as alternatives to the Small ICBM were initiated. Missile quantities, basing characteristics, and other factors that influence program costs for the Small ICBM were under study. Preliminary life cycle cost estimates, in 1985 dollars, for deploying a force of 500 Small ICBMS range from $44.8 billion to $52.1 billion.
The level of survivability for the Small ICBM has not been specified, and the level achievable is uncertain. DOD believes that it is not possible to determine a fixed level of survivability for the missile, but plans to build a system that would make a Soviet attack prohibitively costly However, without defining the survivability requirement, it may be difficult to determine if the system(s) being proposed meets, exceeds, or fails to meet mission needs. To be survivable, Small ICBMS deployed on hard mobile launchers must generate a barrage area large enough to make the number of attacking weapons so great that the Soviets would be unwilling to pay the price of an attack. The Air Force believes that the required barrage areas can be generated. However, estimates were subject to change based on the selection of deployment locations and more knowledge about terrain features, road conditions, and bridge characteristics.
To ensure adequate survivability, a launcher must have adequate mobility and be able to withstand nuclear effects. Preliminary moblllty test results, using vehicles designed to carry a 30,OOOpound missile, are promising. The technology which protects a launcher against the high winds generated by a nuclear explosion has been demonstrated. How- ever, hardening the vehicle’s electronics agamst radiation remained a program challenge. The hard mobile launcher’s weight is also important to ensure successful mobile basing, and DOD wants to keep it below 200,000 pounds. The launcher’s weight, together with the 30,000-pound missile, was approaching 200,000 pounds. A 37,000-pound missile and its launcher could exceed 200,000 pounds.
Armored missile-carrying vehicles had been proposed which are either road mobile or helicopter carried. However, these have proved to be very large, heavy and cumbersome. Also, they tend to be easily overturned or blown away by the blast winds resulting from otherwise-survivable nuclear detonations in the vicinity.
The commonly proposed solution for the blast wind problem is to tie the vehicle down or to extend struts or outriggers. These are impractical because there is generally insufficient time to stop the vehicle and engage tie-downs or extend struts, the tie-down anchors must be already in place with the capability to withstand loads in the 100,000 pound range, and struts would be prohibitively long and heavy. Attempts have been made to seal structures to the ground and/or fasten them between spaced walls to help resist nearby nuclear blasts. These structures, while increasing blast resistance somewhat, have not been entirely satisfactorily mobile, could not reach the protected status quickly and resist blast waves only to a limited degree.
a nuclear blast hardened mobile vehicle capable of carrying an ICBM, a control center, etc., which includes a blast resistant protective shell over the contents and fastened to a chasis which is movable on a plurality of driven motive members such as wheels, tracks, or the like. Sensors on the shell detect the light flash of a nearby nuclear detonation and start an automatic sequence of braking, motive member retraction, vent closure and seal activation (if used). A skirt around the shell rides a uniform selected distance above the ground when the vehicle is in motion. When the motive members are retracted, the skirt drops into engagement with the earth to prevent blast over-pressure winds from leaking under the vehicle. The protective skirt also absorbs the thermal radiation, preventing destruction of the driven motive members, which may include rubber tires or the like. Once the blast over-pressure has passed the vehicle, an ICBM carried thereby can be erected and launched, any other facility carried by the vehicle can continue in operation, or the motive members can be extended and the vehicle can again move under its own power.
Sealing of the skirt against the earth's surface can be enhanced in any of several ways, if desired. The bottom edge of the skirt can be designed to maximize friction for a range of ground surfaces. Seals or short struts designed to accommodate an irregular ground surface may be used. The chamber bounded by the bottom of the vehicle, the ground surface under the vehicle and the skirts may be reduced to less than atmospheric pressure by actively pumping air from that chamber to increase the downward force and the resulting horizontal friction force resisting blow-away.
Chamber volume overpressure relief valves may be provided to relieve the pressure in the volume under the vehicle if it exceeds the lowest pressure outside the vehicle. This excess pressure may be due to chamber skirt seal leakage and/or outside pressure below normal due to blast rarefaction wave. The relief valves will be mounted so that the chamber is automatically vented to the lowest pressure face of the vehicle. If desired, the protective sequence may be initiated manually upon receipt of an attack warning instead of automatically by the sensors.
Active pumping of air from the chamber either into the interior of the vehicle above the chamber or to the outside atmosphere can increase blast hardness by increasing the pressure differential between the chamber and the outside air which increases the downward force and the resulting horizontal friction force resisting blow-away. Also, such pumping reduces the level of seal excellence required by allowing a higher level of seal leakage for a given pressure differential. Any conventional gas pumping techniques can be used to move air from the chamber to either the upper interior of the vehicle or to the outside atmosphere. Such methods include ducting of the vehicle engine intakes to the chamber, use of engine exhaust driven turbo-blowers (superchargers) to pump the chamber, use of solid propellant cartridge gas generator driven blowers (similar to turbojet engine starters) to pump air from the chamber, or pumping the chamber with solid propellant rocket/ejectors or blowers mechanically driven by the vehicle engines.
The development program produced an engineering model, or Engineering Test Unit (ETU), of a mobile, radiation-hardened, truck launcher designed to carry and launch the MGM-134A Small Intercontinental Ballistic Missile (unofficially known as the "Midgetman"). It can travel up to 55 mph on the highway, but it can also travel off the road. The vehicle is capable of using the trailer-mounted plow to dig the launcher into the earth for additional protection from a nuclear blast. The ETU tractor-launcher combination weighs 239,000 lbs. and has a draw bar pull capability of more than 80,000 lbs. It is powered by a 1,200 hp. Rolls-Royce Perkins diesel engine that drives all eight tractor wheels through an electro-hydraulic transmission. The ETU was designed and built by Boeing Aerospace and Electronics, and by Loral Defense Systems Division. It was delivered to the Air Force in December 1988 and tested until 1991 at Malmstrom AFB, Montana.
Anti-nuclear activists were hard at work laying the foundation for waging a campaign against deployment of small ICBMs. Efforts were underway to gather and utilize infonnation about potential small missile sites, with emphasis on technical, cost and environmental impact data, as well as budget requirements. Senator from Tennessee Albert Gore was a leading Congressional proponent of the Midgetman program. And Gore had made a series of speeches which made the case crystal clear that America can have star wars or arms control, but cannot have both. Some of the most prominent Democrats in the country hade endorsed the small ICBM program as their rebuttal to charges that Democrats are "soft on defense". Consequently, the anti-nuclear movement faced a serious dilemna and potential conflicts with allies in dectdfng how hard to push on the small missle, particularly among "moderate" Democrats who had helped them on key votes in the past.
President Reagan authorized full-scale development of the Small ICBM (SICBM) in December 1986. SICBMs would be housed in mobile launchers based at widespread locations. When hostilities threatened, the launchers would drive out onto the roadways and scatter across the country. The program narrowly escaped termination in 1988 because of reduced funding. It achieved its first totally successful flight test on 18 April 1991, when a SICBM that had been cold-launched from a canister at Vandenberg AFB reached its target in the Kwajalein Test Range. Nevertheless, President Bush canceled the SICBM program in January 1992 because strategic tensions seemed to have decreased after the end of the Cold War.
Frank C. Carlucci, who had served as Caspar Weinberger's deputy secretary between 1981 and 1983, succeeded him as secretary of defense on 23 November 1987. A long-standing issue related to the 50 MX intercontinental ballistic missiles placed in hardened underground silos in the mid-1980s. Carlucci considered these missiles vulnerable to Soviet attack and advocated putting all of them, including a second 50 MXs, on moving railroad cars. Congressional opposition prevented him from proceeding with the rail basing plan. Complicating this issue was congressional and other support for the proposed Midgetman missile, a 15-ton single-warhead mobile missile first proposed in 1983. Carlucci felt that the Midgetman would not be cost-effective and would compete for funds with the MX in a tight Pentagon budget, but he proposed a modest allocation in the FY 1988 budget to keep the Midgetman alive. Neither the MX rail-based mode nor the Midget-man proposal ever went forward; the end of the Cold War in the years immediately following Carlucci's term made these proposals less urgent.
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