National Museum of the US Air Force
Chrysler SM-78/PGM-19A JUPITER
The Jupiter Intermediate Range Ballistic Missile (IRBM), in service from 1960 to 1963, was an important link between early, short-range rockets and later weapons that could reach any point on Earth. Jupiter was a close relative of the Army's Redstone missile, and its development began in 1956 as a joint US Army and US Navy project. Rocket pioneer Wernher von Braun conceived the Jupiter after the Redstone proved successful, and rockets with a range of up to 1,500 miles seemed possible. Soviet development of similar missiles around the same time underscored the need for Jupiter. President Dwight Eisenhower gave the IRBM high priority in weapons development, second only to the Intercontinental Ballistic Missile (ICBM).
Originally designed for shipboard use, Jupiter was a compromise between Army and Navy designs. In 1956, the Department of Defense gave the USAF responsibility for building and operating all missiles with more than a 200-mile range, but the Army continued developing Jupiter in case the Air Force's Thor IRBM program failed. The first successful Jupiter launch took place in May 1957.
In October 1957, the USSR launched Sputnik, the first satellite-an event that caused the US to greatly speed up missile development to counter the Soviet threat. As Jupiter was quickly made ready, the US explored basing options. The single-stage missile's range of 1,500 miles required bases on the periphery of the USSR. Negotiations with France proved unsuccessful, and finally Italy and Turkey accepted IRBM bases. Italian and Turkish crews trained to operate the missiles, but Americans controlled the nuclear warheads. Two squadrons with a total of 30 missiles were operational at Gioia del Colle, Italy, by 1961; a single squadron of 15 Jupiters became operational at Cigli Air Base, Turkey, in 1962. Due in part to the Cuban Missile Crisis of 1962, the US removed its Jupiter missiles from Italy and Turkey by July 1963.
TECHNICAL NOTES
Warhead: Single W-49 in the megaton range
Engine: One Rocketdyne LR-79 of 150,000 lbs thrust
Guidance: All-inertial
Range: 1,500 miles
Length: 60 ft
Diameter: 8 ft 9 in
Weight: 108,804 lbs (fully fueled)
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Martin Marietta SM-68A/HGM-25A TITAN I Intercontinental Ballistic Missile
Entering operational service in 1962, Titan I was the United States' first multi-stage ICBM (Intercontinental Ballistic Missile). Incorporating the latest design technology, Titan provided an additional nuclear deterrent to complement the US Air Force's Atlas missile. Though the SM-68A was operational for only three years, it was an important step in building the Air Force's strategic nuclear forces.
The first American ICBM based in underground silos, Titan I gave USAF managers, contractors, and missile crews valuable experience building and working in vast bunkers containing every thing the missiles and crews needed for operation and survival. These early silos, however, had certain drawbacks. First, the missiles took about fifteen minutes to fuel, and then had to be lifted to the surface on huge elevators for launching, which slowed their reaction time. Rapid launching was crucial to avoid possible destruction by incoming missiles, even though Titan shelters were designed to withstand nuclear blasts. Second, the missiles' placement close together in groups of three-necessary because they shared a single ground-based radio guidance system-made them vulnerable to nuclear attack. All-inertial guidance, which does not depend on ground computers, was not yet perfected
In its brief career, Titan I equipped six squadrons of nine missiles each, in Colorado, Idaho, California, Washington state, and South Dakota. Although Titan I's two stages gave it true intercontinental range and foreshadowed future multistage rockets, its propellants were dangerous and hard to handle. Super-chilled liquid oxygen oxidizer had to be pumped aboard the missile just before launch, and complex equipment was required to store and move this liquid. Kerosene fuel also was pumped aboard just before launch.
Titan I allowed USAF missileers to perfect techniques for efficiently operating strategic missile facilities spread across several states and requiring great coordination and skill. Still, the SM-68A was a transitional missile. Even as the USAF deployed 54 Titan Is on operational alert from 1963-65, it prepared to deploy more advanced Titan Ils in their place. Later missiles, like Titan II, used safer fuels and more advanced guidance, but followed the SM-68A example of underground basing and multiple stages.
TECHNICAL NOTES
Warhead: Single W-38 in the megaton range.
Re-entry vehicle: Avco Mark 4, ablative
Engines:
(1st stage) Aerojet LR87-AJ-1 of 300,000 lbs thrust,
(2nd stage) Aerojet LR91-AJ-1 of 80,000 lbs thrust
Propellants: RP-1 kerosene fuel and liquid oxygen oxidizer
Range: 6,300 miles
Length: 98 ft
Diameter: 10 ft
Weight: 220,000 lbs fueled
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Martin Marietta SM-68B/LGM-25C TITAN II Intercontinental Ballistic Missile
Titan II was the longest-serving ICBM (Intercontinental Ballistic Missile) in the US Air Force strategic arsenal. The SM-68B, developed from the Titan I ICBM, was on operational alert from 1963 to 1987. For most of its nearly 25 years of operation, Titan Il was the largest and most powerful American nuclear- armed missile. The Titan design also enjoyed a long career as a space launch vehicle, sending satellites and manned spacecraft into earth orbit.
While the SM-68A Titan I system was becoming operational, the USAF recognized that it could be simplified and improved. Using the same manufacturing and test facilities, the SM-68B took shape as a major step forward in ICBM technology. Perhaps Titan Il's most important feature was its quick-launch capability. It could be launched in about 60 seconds from inside its underground silo (Titan I took 15 minutes and had to be elevated above ground first). This speed was crucial in responding to a preemptive nuclear attack before incoming missiles arrived.
New "hypergolic" liquid fuels made Titan Il's quick launches possible. Hypergolic fuels ignite on contact with one another, eliminating the need for an ignition system, and they can be stored at room temperature inside the missile. Partly as a result of using these new propellants, the SM-68B had fewer parts and a simpler design than the SM-68A. Also, a new silo design vented the tremendous blast of Titan Il's improved engines away from the missile, allowing in-silo launching and eliminating the need to elevate the SM-68B to ground level before launch.
Titan Il's advanced "all-inertial" guidance system made the missile less vulnerable to enemy attack. Each SM-68B carried its own self-contained guidance equipment and did not rely on ground computers. This improvement made widely dispersed bases possible, and Titan II sites were typically several miles apart, enhancing survivability during a potential nuclear strike.
At the height of SM-68B operations, the USAF deployed 54 Titan lls at three bases in Arizona, Kansas, and Arkansas. Each base had two squadrons of nine missiles each. The combat crew for a single missile included two officers and two enlisted personnel, but many support troops were required to maintain the missiles, train crews, and provide security.
In 1981, the USAF undertook a missile modernization program, and Titan II ICBM operations ceased in 1987. Spare SM-68BS were converted to space boosters and used to launch satellites. This role was not new for Titan II, since this powerful and reliable rocket had been used for many years in civil and military space programs. Titan lls launched manned Gemini missions for NASA in the mid-1960s, and later Titans evolved into more powerful space boosters with the addition of "strap-on" solid rockets, launching some of the most important US military satellites.
TECHNICAL NOTES
Warhead: Single W-53 in the megaton range
Re-entry vehicle: General Electric Mark 6, ablative
Engines:
(1st stage) Aerojet LR87-AJ-5 of 430,000 lbs thrust each
(2nd stage) Aerojet LR91-AJ-5 of 100,000 lbs thrust
Propellants: Aerozine 50 fuel and nitrogen tetroxide oxidizer
Range: 9,000 miles
Length: 108 ft
Diameter: 10 ft
Weight: 330,000 lbs fueled
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DOUGLAS SM-75/PGM-17A THOR Intermediate Range Ballistic Missile
The SM-75/PGM-17A Thor intermediate range ballistic missile (IRBM) was the product of the early Cold War race to deploy nuclear armed missiles before the Soviets. Thor was designed to be an interim nuclear deterrent while the US Air Force developed long-range intercontinental ballistic missiles (ICBMs) as a top national priority. The IRBM concept called for a missile with a range of about 1,500 miles that would be based in Europe. Great Britain agreed to host four IRBM bases, and Thors were operational in England from June 1959 to August 1963. Royal Air Force crews operated the missiles, but USAF personnel controlled their nuclear warheads.
The USAF developed the SM-75 quickly, in just over three years beginning in 1956. Interservice competition to control the emerging strategic missile mission meant that the US Army developed its Jupiter missile, which was ultimately assigned to the Air Force, at the same time. Thor's rapid design and deployment resulted from having much in common with the Atlas ICBM, which was then still in the planning stages. Thor's engine, guidance, and warhead came from the Atlas program, and only its airframe was new. After three failed test flights, Thor's first fully successful flight took place in September 1957. The following month, the USSR launched its Sputnik satellite-proving Soviet rocket capability and generating much anxiety in the US-and President Dwight Eisenhower rushed Thor into production as a result.
The SM-75 was a one-stage liquid fueled rocket. Powered by liquid oxygen and kerosene, the vehicle could reach an altitude of about 280 miles before releasing its war- head on a ballistic (unpowered) trajectory toward its target. The missile required about 15 minutes to prepare for launch from its above-ground shelter, and could reach its target after about 18 minutes of flight.
Following its withdrawal as an IRBM when the Atlas ICBM became available, the Air Force used Thor as a nuclear atmospheric test vehicle and an antisatellite weapon. The USAF and NASA also adapted the Thor design to a very successful variety of space launch roles.
TECHNICAL NOTES
Warhead: Single W-49 in the kiloton range
Engines: One Rocketdyne LR79-NA-9 of 150,000 lbs thrust; two Rocketdyne LR101-NA vernier engines (for small thrust and direction adjustments) of 1,000 lbs thrust each
Guidance: All-inertial
Range: 1,500 miles
Length: 65 ft
Diameter: 8 ft
Weight: 110,000 lbs (fully fueled)
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BOEING LGM-118A PEACEKEEPER
The Peacekeeper was the US Air Force's most powerful, accurate, and technologically advanced intercontinental ballistic missile (ICBM) when it served as a deterrent from 1986 to 2005. The USAF began planning for a missile to replace Minuteman ICBMS in 1972, and named the projected weapon "missile X," or MX. It would use the latest targeting technology to deliver many independently targeted nuclear warheads by each missile. The ability to deliver several warheads on one missile is known as MIRV, or Multiple Independently targeted Re-entry Vehicles. MX eventually was named Peacekeeper and designated LGM-118A.
Full-scale development of the Peacekeeper began in 1979, and the first test flight took place in 1983 at Vandenberg AFB, California. It became operational in 1986, when ten missiles were deployed at F.E. Warren AFB, Wyoming. By 1988, 50 missiles were in service there.
Basing-whether in stationary hardened silos or on mobile railways that would keep the Soviets guessing at the missiles' true location-was a major issue during Peacekeeper's development. Funding problems and competing ideas about the wisdom of each basing solution delayed Peacekeeper production and deployment. Eventually, it was decided to base all LGM-118As in hardened, underground silos.
TECHNICAL NOTES
Payload: 10 Avco MK-21 re-entry vehicles
Stages:
(1st) solid fuel, Thiokol
(2nd) solid fuel, Aerojet
(3rd) solid fuel, Hercules
(4th) storable liquid fuel, Rocketdyne
Maximum speed: Approximately 15,000 mph
Range: Greater than 6,000 miles
Guidance: Inertial
Height: 71 ft
Weight: 195,000 lbs
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LGM-30G MINUTEMAN III INTERCONTINENTAL BALLISTIC MISSILE
The Minuteman III Intercontinental Ballistic Missile, or ICBM, is currently the United States' only operational land-based strategic nuclear missile. It is one leg of the nuclear deterrent "triad" that also includes USAF bombers and US Navy submarine-launched missiles. US nuclear forces are on alert at all times, ensuring a swift response in the event of a nuclear attack.
Minuteman III became operational in 1970, and is the most modem missile in the Minuteman family. The Minuteman series was the first in the US ICBM arsenal to use solid fuel. This important feature allows the missile to be stored for long periods in its silo, requiring much less maintenance and fewer technicians than older liquid-fueled missiles like Titan and Atlas. It can also be launched almost instantly. Minuteman III was the world's first missile to carry more than one warhead, using a "Multiple Independently-targetable Re-entry Vehicle" (MIRV) system. Though Minuteman III can carry three warheads, each missile has been limited to one by international treaty since 2005.
The Minuteman system was designed in the 1950s. Minuteman I, the first of the family, became operational in 1962 during the Cuban Missile Crisis. Later, the retirement of the US Air Force's Minuteman II missiles in 1995 and Peacekeeper missiles in 2005 left Minuteman Ill as the only American land-based ICBM. Today, Minuteman III missiles are located in widely-separated, hardened underground silos at three bases-F.E. Warren AFB, Wyoming, Malmstrom AFB, Montana, and Minot AFB, North Dakota
