LIM-49 Spartan

Last updated
LIM-49 Spartan
Spartan missile.jpg
Type Anti-ballistic missile
Place of originUnited States
Service history
In service1975-1976
Production history
Manufacturer Western Electric & McDonnell Douglas
Specifications
Mass29,000 lb (13,100 kg)
Length55 ft 2 in (16.8 m)
Diameter3 ft 7 in (1.08 m)
Wingspan9 ft 9.6 in (2.98 m)
Warhead W71 nuclear; 5 megatonnes of TNT (21 PJ)

Engine1st Stage: Thiokol TX-500 (2200 kN);
2nd Stage: Thiokol TX-454;
3rd Stage: Thiokol TX-239
PropellantSolid fuel
Operational
range
460 mi (740 km)
Flight altitude350 mi (560 km)
Maximum speed >Mach 3-4
Guidance
system
Radio command
Launch
platform
Silo

The LIM-49 Spartan was a United States Army anti-ballistic missile, designed to intercept attacking nuclear warheads from intercontinental ballistic missiles at long range and while still outside the atmosphere. For actual deployment, a five-megaton thermonuclear warhead was planned to destroy the incoming ICBM warheads. [1] It was part of the Safeguard Program.

Contents

The Spartan was the latest and, as it turned out, final development in a long series of missile designs from the team of Bell Laboratories and Douglas Aircraft Company that started in the 1940s with the Nike. Spartan was developed directly from the preceding LIM-49 Nike Zeus, retaining the same tri-service identifier, but growing larger and longer ranged, from the Zeus' 250 nautical miles (460 km; 290 mi) to approximately 450 nautical miles (830 km; 520 mi).

The Spartan was superseded by the Nike-X project, later becoming the Sentinel Program. This was eventually cancelled and replaced with the much smaller Safeguard Program. Spartans were deployed as part of the Safeguard system from October 1975 to early 1976.

History

Zeus

The US Army started their first serious efforts in the anti-ballistic missile arena when they asked the Bell Labs missile team to prepare a report on the topic in February 1955. The Nike team had already designed the Nike Ajax system that was in widespread use around the US, as well as the Nike Hercules that was in the late stages of development as the Ajax's replacement. They returned an initial study on Nike II in January 1956, concluding that the basic concept was workable using a slightly upgraded version of the Hercules missile, but requiring dramatically upgraded radars and computers to handle interceptions that took place at thousands of miles an hour.

Work began on the resulting LIM-49 Nike Zeus system in January 1957, initially at a low priority. However, several developments that year, including the development of the first Soviet ICBMs and the launch of Sputnik I, caused the schedule to be pushed up several times. In January 1958 Zeus was given "S-Priority", the highest national priority, with aims to deploy the first operational sites in 1963.

To test the system fully, the Army took control of Kwajalein Island from the US Navy, and began building an entire Zeus site on the island. By 1962 the system was ready for testing, and after some initial problems, demonstrated its ability to intercept warheads launched from California. Eventually fourteen "all up" tests were carried out over the next two years, with ten of them bringing the missile within the lethal radius of its warhead, sometimes within a few hundred meters.

Cancellation

In spite of Zeus' successful testing program and interceptions, it was becoming increasingly clear that the fully integrated system would not be effective in an actual operational scenario. This was due primarily to two problems; decoys shielding the warhead from detection until it was too late for interception, and the rapid increase in the number of deployed ICBMs which threatened to overwhelm the system.[ citation needed ]

The former problem was becoming increasingly apparent beginning in approximately 1957. Missiles designed to carry a specific warhead began having increasing levels of excess throw-weight as warhead design improved, resulting in smaller and lighter warheads. Missile design improved as well, further increasing excess capacity. Even a small amount of excess capacity could be used to carry radar decoys or chaff, which is very light weight, and would create additional radar returns that would act indistinguishably from those of the real warhead, in the airless, exo-atmospheric vacuum of sub-orbital space where the missile intercept was planned.

In that environment it would be difficult to pick out the warhead. As long as the decoys spread out or the chaff blocked an area larger than the lethal radius of the 5 Megaton (Mt) interceptor (much smaller in space than in the atmosphere), several interceptors would have to be launched to guarantee the warhead would be hit. Adding more decoys was extremely inexpensive, requiring very expensive ABMs to be added in response.

At the same time, both the US and USSR were in the midst of introducing their first truly mass-produced ICBMs, and their numbers were clearly going to grow dramatically during the early 1960s. Zeus, like Hercules and Ajax before it, used mechanically directed radar dishes that could track only one target and one interceptor at a time. It was planned that Zeus bases would actually consist of several launcher sites connected to a central control, but even in this case, the site might be able to guide four to six missiles simultaneously. As the ICBM fleet numbered hundreds even before Zeus could become operational, it would be simple to overcome the defense by directing sufficient warheads over it to overwhelm its ability to guide interceptions rapidly enough.[ citation needed ]

Nike X

The solution to both of these problems was to improve speed of both the defending missiles, and the defensive system as a whole.

Decoys are less dense than warheads, though with the same aerodynamics. Therefore, they are subject to more deceleration when they begin their reentry of the upper atmosphere. The warhead, which is dense and streamlined, experiences less deceleration from air resistance, eventually passing by the decoys. The rate at which this happens depends on the types of decoys used, but the warhead will have passed even advanced types of decoy by the time it is 250,000–100,000 feet (76,000–30,000 m). At this point the warhead is vulnerable to attack, but is only 5 to 10 seconds from its planned detonation (air burst or ground burst). To address these issues, a very high speed missile was required. Zeus was simply not fast enough to perform such an attack; it was designed for interceptions lasting about two minutes.

Likewise, the solution to dealing with massive numbers of warheads was to use faster computers and automated radars, allowing many interceptors to be in flight simultaneously. Zeus was being developed just as digital computers were experiencing a massive improvement in performance. Radar systems were likewise introducing the first phased array radar (Passive electronically scanned array) systems. Combining the two would allow hundreds of warheads and interceptors to be tracked and controlled at once. As long as the interceptor missile was not significantly more expensive than the ICBM, which was likely given their relative sizes, overwhelming such a system would not be feasible in a weapons system.[ citation needed ]

Taking these factors into consideration, ARPA outlined four potential approaches to a new ABM system. The first was Nike Zeus in its current form. The second was Zeus combined with a new radar system. The third included new radars and computers. Finally, the fourth, or X, plan called for all of these changes, as well as a new short-range missile. As the shorter range missile would overlap with Zeus, X also called for Zeus to be modified for even greater range as "Zeus EX". After considerable debate, the decision was made to cancel the existing Zeus deployment and move ahead with the X plan.

Testing

The first test-launch of the Spartan, as the X plan came to be called, occurred at Kwajalein Missile Range on 30 March 1968. [2]

Survivors

See also

Related lists

Related Research Articles

<span class="mw-page-title-main">Anti-ballistic missile</span> Surface-to-air missile designed to counter ballistic missiles

An anti-ballistic missile (ABM) is a surface-to-air missile designed to counter ballistic missiles. Ballistic missiles are used to deliver nuclear, chemical, biological, or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" is a generic term conveying a system designed to intercept and destroy any type of ballistic threat; however, it is commonly used for systems specifically designed to counter intercontinental ballistic missiles (ICBMs).

<span class="mw-page-title-main">Project Nike</span> Missile program of the United States Army

Project Nike was a U.S. Army project, proposed in May 1945 by Bell Laboratories, to develop a line-of-sight anti-aircraft missile system. The project delivered the United States' first operational anti-aircraft missile system, the Nike Ajax, in 1953. A great number of the technologies and rocket systems used for developing the Nike Ajax were re-used for a number of functions, many of which were given the "Nike" name . The missile's first-stage solid rocket booster became the basis for many types of rocket including the Nike Hercules missile and NASA's Nike Smoke rocket, used for upper-atmosphere research.

<span class="mw-page-title-main">United States national missile defense</span> Nationwide missile defense program of the United States

National missile defense (NMD) refers to the nationwide antimissile program the United States has had in development since the 1990s. After the renaming in 2002, the term now refers to the entire program, not just the ground-based interceptors and associated facilities.

<span class="mw-page-title-main">Nike Hercules</span> Type of surface-to-air missile

The Nike Hercules, initially designated SAM-A-25 and later MIM-14, was a surface-to-air missile (SAM) used by U.S. and NATO armed forces for medium- and high-altitude long-range air defense. It was normally armed with the W31 nuclear warhead, but could also be fitted with a conventional warhead for export use. Its warhead also allowed it to be used in a secondary surface-to-surface role, and the system also demonstrated its ability to hit other short-range missiles in flight.

<span class="mw-page-title-main">Missile defense</span> System that destroys attacking missiles

Missile defense is a system, weapon, or technology involved in the detection, tracking, interception, and also the destruction of attacking missiles. Conceived as a defense against nuclear-armed intercontinental ballistic missiles (ICBMs), its application has broadened to include shorter-ranged non-nuclear tactical and theater missiles.

<span class="mw-page-title-main">Safeguard Program</span> System designed to protect U.S. missile silos

The Safeguard Program was a U.S. Army anti-ballistic missile (ABM) system designed to protect the U.S. Air Force's Minuteman ICBM silos from attack, thus preserving the US's nuclear deterrent fleet. It was intended primarily to protect against the very small Chinese ICBM fleet, limited Soviet attacks and various other limited-launch scenarios. A full-scale attack by the Soviets would easily overwhelm it. It was designed to allow gradual upgrades to provide similar lightweight coverage over the entire United States over time.

<span class="mw-page-title-main">Sprint (missile)</span> Anti-ballistic missile

The Sprint was a two-stage, solid-fuel anti-ballistic missile (ABM), armed with a W66 enhanced-radiation thermonuclear warhead used by the United States Army during 1975–76. It was designed to intercept incoming reentry vehicles (RV) after they had descended below an altitude of about 60 kilometres (37 mi), where the thickening air stripped away any decoys or radar reflectors and exposed the RV to observation by radar. As the RV would be traveling at about 5 miles per second, Sprint needed to have phenomenal performance to achieve an interception in the few seconds before the RV reached its target.

<span class="mw-page-title-main">W71</span> American thermonuclear weapon

The W71 nuclear warhead was a US thermonuclear warhead developed at Lawrence Livermore National Laboratory in California and deployed on the LIM-49A Spartan missile, a component of the Safeguard Program, an anti-ballistic missile (ABM) defense system briefly deployed by the US in the 1970s.

<span class="mw-page-title-main">Western Electric System 1393 Radar Course Directing Central</span>

The Western Electric System 1393 Radar Course Directing Central (RCDC) was a Cold War complex of radar/computer systems within the overall Improved Nike Hercules Air Defense Guided Missile System. The RCDC was installed at the "battery control areas" of ~5 hectares each which was for commanding a nearby missile Launching Area (LA), firing a missile from the LA, and guiding a launched missile to a burst point near an enemy aircraft.

<span class="mw-page-title-main">Nike Zeus</span> Type of anti-ballistic missile

Nike Zeus was an anti-ballistic missile (ABM) system developed by the United States Army during the late 1950s and early 1960s that was designed to destroy incoming Soviet intercontinental ballistic missile warheads before they could hit their targets. It was designed by Bell Labs' Nike team, and was initially based on the earlier Nike Hercules anti-aircraft missile. The original, Zeus A, was designed to intercept warheads in the upper atmosphere, mounting a 25 kiloton W31 nuclear warhead. During development, the concept changed to protect a much larger area and intercept the warheads at higher altitudes. This required the missile to be greatly enlarged into the totally new design, Zeus B, given the tri-service identifier XLIM-49, mounting a 400 kiloton W50 warhead. In several successful tests, the B model proved itself able to intercept warheads, and even satellites.

<span class="mw-page-title-main">MIM-3 Nike Ajax</span> First operational guided surface-to-air missile

The Nike Ajax was an American guided surface-to-air missile (SAM) developed by Bell Labs for the United States Army. The world's first operational guided surface-to-air missile, the Nike Ajax was designed to attack conventional bomber aircraft flying at high subsonic speeds and altitudes above 50,000 feet (15 km). Nike entered service in 1954 and was initially deployed within the United States to defend against potential Soviet bomber attacks, though it was later deployed overseas to protect US military bases, and was also sold to various allied militaries. Some examples remained in use until the 1970s.

<span class="mw-page-title-main">Project Wizard</span> US anti-ballistic missile system

Project Wizard was a Cold War-era anti-ballistic missile system to defend against short and medium-range threats of the V-2 rocket type. It was contracted by the US Army Air Force in March 1946 with the University of Michigan's Aeronautical Research Center (MARC). A similar effort, Project Thumper, started at General Electric.

<span class="mw-page-title-main">AN/FPQ-16 PARCS</span> United States Space Force phased-array radar system located in North Dakota

The AN/FPQ-16 Perimeter Acquisition Radar Attack Characterization System is a powerful United States Space Force phased-array radar system located in North Dakota. It is the second most powerful phased array radar system in the US Space Force's fleet of missile warning and space surveillance systems, behind the more modern PAVE PAWS phased array radar.

<span class="mw-page-title-main">White Sands Launch Complex 38</span>

Launch Complex 38 was the White Sands Missile Range facility for testing the Nike Zeus anti-ballistic missile. The site is located east of the WSMR Post Area.

<span class="mw-page-title-main">Nike-X</span> Anti-ballistic missile system

Nike-X was an anti-ballistic missile (ABM) system designed in the 1960s by the United States Army to protect major cities in the United States from attacks by the Soviet Union's intercontinental ballistic missile (ICBM) fleet during the Cold War. The X in the name referred to its experimental basis and was supposed to be replaced by a more appropriate name when the system was put into production. This never came to pass; in 1967 the Nike-X program was canceled and replaced by a much lighter defense system known as Sentinel.

<span class="mw-page-title-main">Sentinel program</span> Proposed US Army anti-ballistic missile system

Sentinel was a proposed US Army anti-ballistic missile (ABM) system designed to provide a light layer of protection over the entire United States, able to defend against small ICBM strikes like those expected from China, or accidental launches from the USSR or other states. The system would have seventeen bases, each centered on its Missile Site Radar (MSR) and a computerized command center buried below it. The system was supported by a string of five long-range Perimeter Acquisition Radars (PAR) spread across the US/Canada border area and another in Alaska. The primary weapon was the long-range Spartan missile, with short range Sprint missiles providing additional protection near US ICBM fields and PAR sites. The system would initially have a total of 480 Spartan and 192 Sprint missiles.

<span class="mw-page-title-main">Sentry program</span> Proposed United States anti-ballistic missile program

Sentry, known for most of its lifetime as LoADS for Low Altitude Defense System, was a short-range anti-ballistic missile (ABM) design made by the US Army during the 1970s. It was proposed as a defensive weapon that would be used in concert with the MX missile, a US Air Force ICBM that was under development.

Prim–Read theory, or Prim–Read defense, was an important development in game theory that led to radical changes in the United States' views on the value of anti-ballistic missile (ABM) systems. The theory assigns a certain cost to deploying defensive missiles and suggests a way to maximize their value in terms of the amount of damage they could reduce. By comparing the cost of various deployments, one can determine the relative amount of money needed to provide a defense against a certain number of ICBMs.

Project BAMBI was a project as part of the United States national missile defense.

<span class="mw-page-title-main">Hardpoint (missile defense)</span> Proposed anti-ballistic missile system

Hardpoint was a proposed short-range anti-ballistic missile (ABM) system conceived by ARPA and developed by the US Army under ARPA's Project Defender program. Hardpoint was designed to exploit the relatively low accuracy that Soviet ICBMs had, which would make destroying missile silos difficult. The idea was to only shoot at warheads which would be expected to impact within lethal distance of silos, ignoring the rest and allowing them to hit the ground. This acted as a force multiplier, allowing a small number of interceptors to offset a large number of Soviet missiles.

References

  1. "List of All U.S. Nuclear Weapons".
  2. James Walker; Lewis Bernstein; Sharon Lang (2005). Seize the High Ground: The U.S. Army in Space and Missile Defense . Government Printing Office. ISBN   0160723086. The SPARTAN test program began on 30 March 1968
  3. "Sprint Gallery 1".
  4. ADA park (Fort Sill), photo journal of Daniel DeCristo