Mrbm SM-75/PGM-17A Thor



    Surface PU

    management system:

    management software








    2,400 km.

    year development:


    mrbm sm-75/pgm-17a thor In 1951, the Air Force Center for the development of the flying technique (" Air Force's Wright Air Development Center "), placed on the AFB Wright- Patterson (Ohio), came to the conclusion that tactical cruise missile TM-61 "Matador", was the Air Force, has a poor performance from the perspectives of the development of air defense missile-USSR. Had recommended the Air Force to develop and adopt a tactical ballistic missile range, which intercept at that time was not possible technically. Tactical Air Command ("Tactical Air Command") launched by the Air Force approved the concept, and soon put the Air Force General Staff Command of the Air Force Research and Development ("Air Research and Development Command") order on the development of a detailed plan for a new rocket to 1 June 1955 year. By 1960, scheduled to begin flight tests of a new missile.

    In the initial period of the development of a new missile program was not considered in the Air Force program of special importance - the military paid more attention to improve the strategic bomber fleet and the development of technologies for creating ICBMs. The situation with the development of promising tactical missiles for the needs of the Air Force has changed dramatically in 1955 after the so-called treatment. Killian Committee to President Eisenhower. The report of the committee stated that, along with the development of ICBMs, the U.S. should immediately begin to develop MRBM with a range of about 2,400 km. New class of missiles was to be deployed on land (at U.S. bases in Europe) and the sea (the variants of the new missiles based on submarines, as well as special courts). The need to develop a new class of missiles was proved by reference to the intelligence indicates that the USSR has already started to develop their own MRBM. By the end of 1955 Army, Air Force and the U.S. Navy announced the principled readiness to proceed with the development BRSD. However, the beginning of concrete actions hampered by uncertainty about what kind of exactly the agency should be responsible for developing new missiles. In November 1955, Secretary of Defense Charles Wilson announced that the Air Force will be responsible for the development of land-based MRBM, a joint team of Army / navy - for the development of sea-based MRBM. In December 1955, President Dwight D. Eisenhower development program has ranked among the programs BRSD highest priority.

    land-based missiles, produced by the Air Force, was designated SM-75 "Thor" (rocket development was conducted as part of a weapon system WS-315A). In May 1955, the scientific and technical program management from the Air Force Center for the development of the flying equipment was transferred to West Branch of the promising developments ("Western Development Division"), California. In November of the same year started WDD to the final choice of the main contractor to build the rocket. Originally there were three candidates - the company "Douglas Aircraft", "Lockheed Aircraft", "North American Aviation". After considering all proposals by the end of December 1955 was named the main contractor - the company "Douglas Aircraft" (rocket design designations received DM-18). When creating a new MRBM as widely as possible (especially when creating a power plant, control systems, assembly BS / BSc) used unification already asking missile programs, especially "Atlas". The main contractor to build the power plant was chosen branch "Rocketdyne Division" Company "North American Aviation". Office is developing an inertial separation "AC Spark Plug" corporation "General Motors", and duplicate / complementary radioinertsialnuyu control system that allows the missile to control ground station (especially when testing) provides a firm "Bell Telephone Laboratories". Combat unit created corporation "General Electric", a traditionally designed warhead Atomic Energy Commission ("Atomic Energy Commission").

    Given the extreme haste caused by the desire to beat the Air Force not only the Soviet Union, but also with its own army BRSD "Jupiter", WDD drifted a new program to the number of programs "maximum risk." This prediction proved to be true - the first, second and third test-firing, held, respectively, in January, April and May 1957, the Eastern test range (Eastern Missile Range), Patrick AFB, Florida, were unsuccessful. However, work on troubleshooting with the participation of all involved in the program of scientific and technical personnel in the "three shifts, seven days a week" to bear fruit - in August of the first flight, recognized as "partially successful." September 20, 1957, the first fully successful launch BRSD "Thor". Despite these advances, the Air Force had reasons to worry - the program "Thor" had a strong opponent MRBM program "Jupiter", which was similar to the "Thor" characteristics. However, fears have not come true - in the wake of unjustified panic (carefully buoyed interested representatives of the U.S. military industry), caused by the launch of a Soviet Sputnik, President Dwight D. Eisenhower in October 1957 gave the order to start serial production of both American BRSD.

    In December 1957, U.S. President decided in principle on the deployment BRSD "Thor" on the European continent (and previously considered exotic options such as placing BRSD "Thor" in Alaska near Fairbanks). In February 1958 was signed a joint US-British agreement "of understanding" to deploy four squadrons BRSD "Thor" (60 MRBM). British made for themselves the right to exercise self-service missiles, which were to bear the insignia of the Royal Air Force. However, combat troops were to remain at the disposal of the Strategic Air Command and the U.S. Air Force dock at BRSD only with permission of the American side (it was later agreed right of each party to use weapons in the normal gear without consent of a partner in the case of "extraordinary circumstances" - the so-called . "Project E"). Transport and financial services missiles had the maximum extent provided by the American side. The final agreement was signed in June 1958. Agreement on technical cooperation between the U.S. Air Force and the Royal Air Force as part of the deployment and further maintenance BRSD "Thor" was signed in July. Program in the UK to deploy new MRBM was named "Project Emily". To monitor and support the deployment of new weapons systems SAC USAF in February 1958 activated the 705 th Strategic Missile Wing at the air base Leykenhit, UK. Equipment and systems to be deployed, began to move to the UK in August 1958. First BRSD was assigned to the Royal Air Force in September of the same year.

    mrbm sm-75/pgm-17a thor

    In June 1958, Patrick airbase was made the first successful launch of a prototype BRSD "Thor" with a prototype native launcher. The first successful launch of the system in the standard equipment was completed in November 1958, ibid. Since December 1958 launch was carried out and the West test site ("Western Missile Range"), Vandenberg Air Force Base, California. First run BRSD "Thor" was produced by British personnel with Vandenberg Air Force Base in April 1959 (Operation "Lion's Roar"). In June of the same year fit for further objection to combat duty was recognized first base BRSD "Thor" in the British Isles - Feltuell airbase, which housed the 77th Strategic Missile Squadron RAF. In September 1959, fit for combat duty was recognized as second base BRSD "Thor" in the British Isles - Hemsuell airbase, which housed the 97th Strategic Missile Squadron RAF. In October, Vandenberg Air Force Base British staff successfully completed the first launch BRSD "Thor" on the program of combat training (up to June 1962 was carried out such launches 12). In November commissioned third base BRSD "Thor" in the UK - Driffield, which houses the 98th Strategic Missile Squadron RAF. In December 1959 the United States and Great Britain signed a joint protocol, which certifies that deployed by the time on British soil BRSD "satisfactorily demonstrated operational readiness." In April 1960 deployment BRSD "Thor" in the UK was completed with the commissioning of the fourth missile base - North Laffenhem where based 144th Strategic Missile Squadron RAF. First thermonuclear warhead native was docked to BRSD to carry duty in June 1960 at the airbase Feltuell. In 1962, after the change of notation in the U.S. Air Force missile "Thor" was designated PGM-17A.

    By the spring of 1962, SAC Air Force has successfully completed the deployment of the first generation of ICBMs ("Atlas" and "Titan I"), has begun deployment of second-generation ("Minuteman I" and "Titan II"), the Navy conducted a successful deployment of nuclear missile submarines with SLBMs "Polaris" on board. Considering these factors, it became clear that ground BRSD too vulnerable, especially the "Thor", whose PU were stationary. Therefore, in May 1962, U.S. Secretary of Defense Robert McNamara informed his British counterpart P. Thorneycroft that after October 31, 1964 the United States stopped transportation services deployed in the UK BRSD. In this regard, after analyzing the situation in August of the same year P. Thorneycroft informed the British Parliament about the upcoming deactivation BRSD "Thor" by 31 December 1963. However, despite the deactivation data BRSD as planned, the presence of a significant number of U.S. missiles in its class in Italy and Turkey, together with the clear dominance of U.S. strategic bombers and ICBMs forced the Soviet leadership to adopt similar measures. By October 1962 in Cuba were placed Soviet MRBM, who took a substantial part of the continental U.S. in the sights. T. n. "Caribbean crisis" that erupted in October 1962, allowed the Soviet Union to raise the issue of deactivation American BRSD in Europe in exchange for the withdrawal of Soviet missiles from Cuba. Agreement between the parties was reached. First BRSD "Thor" has been removed from combat duty in late November 1962. Last BRSD in the UK has been removed from duty in August 1963, and in late September sent a plane to the United States. Finally deactivation BRSD "Thor" as a weapon system was completed in December 1963.

    Assessing program "Thor", it should be noted that in a relatively short period of time, the Americans managed to create a sufficiently reliable BRSD, provides assurance by the standards of the early 60-ies defeat major military and political objectives in the Soviet Union and the Warsaw Pact. Unlike its rivals - BRSD "Jupiter" - a rocket "Thor" very actively used as a booster with a variety of additional steps to become the progenitor of the family in the future RN "Delta". Rocket "Thor" (modification of "Thor" DSV-2J) formed the basis for one of the first American space defense systems "Program 637", which has stood on combat duty in August 1964 on Johnston Island (Pacific Ocean). System was on duty until 1975, although its expected efficiency was low.

    were built 224 missiles "Thor" various modifications.


    mrbm sm-75/pgm-17a thor Launch" Thor "was designed by the scheme to the supporting structure of tanks and structurally divided into several parts (see diagram). In the power plant compartment, which bore the designation MB-1, was marching liquid rocket engine LR-79-NA-9 and controls. To the rear compartment bulkhead fastened two auxiliary (vernier) liquid rocket engine LR-101-NA-7, guided missiles in the boost phase via heel, and is also used to adjust the velocity of the rocket after main engine cutoff. Missile control pitch and yaw channels ensures deflection of the main engine gimbaled to an angle of 5 °. All engines used turbopump fuel feed system without afterburning gas generator gas. At the bottom of the engine compartment 4 fastened to the body of the stabilizer. Engine compartment was attached to the tank oxidizer (liquid oxygen), which, in turn, joined to the central portion of the rocket (intertank segment), which housed accessories, including a self destruct system. This was followed by the fuel tank (rocket kerosene RP-1) and a compartment with guidance and control system.

    warheads Mk2, containing a thermonuclear warhead W-49, joined the compartment guidance and control system. The missile body was made from high-strength aluminum alloy. Section compartments fuel tanks were collected from panels with power set wafer obtained by stamping, followed by chemical milling. Warhead missiles was a truncated cone with a pointed nose part. At the base of the control equipment was BB and BB stabilization after separation from the sustainer stage. BB separated from the rocket body after work vernier engines. Disposed sustainer stage of BB carried out using solid motors of low power, placed on the inter-tank section compartment. A thermal barrier coating was carried out under the scheme BB absorption heat fluxes (hereinafter an option for equipping new BRSD BB Mk3 with ablative thermal barrier coating).

    BRSD "Thor" were placed at the starting position (see diagram), made of reinforced concrete with a high percentage of reinforcement dimensions 76.2 * 15.2 m in a horizontal position on a special device with hydraulic lifts. Device with untucked propellants BRSD camouflaged rolled back by guiding light roof length of 30.5 meters. After receiving the order to launch the start payment rolled back the roof and brought the rocket using lifts to a vertical position. After installing the missiles began the process of filling speed rocket propellants, which at the end and check all systems considered rocket ready for launch. The whole procedure of preparing a rocket for launch took less than 15 minutes. After receiving the signal of the complete system ready the officer initiated the start. First involves boosters. Vernier engines included after 2.5 seconds. Time of flight engine - 157 seconds. After cutoff propulsion engine thrust vernier engines make accurate correction rocket speed for 9 seconds. Then followed them off, triggered explosive bolts, linking MS with the body of the sustainer stage. Finally, the signal control system triggered solid motors pull. Flight time at maximum range - about 18 minutes.

    Each strategic missile squadron, which had armed CRS "Thor", was on duty 15 missiles distributed to 5 and starting positions (3 MRBM at each position). Each missile launcher housed at a distance of 180-280 meters from the adjacent CP. Tanks with fuel components were placed in special concrete pits. Various support mechanisms (diesel generators, etc.) were covered with concrete facing. Methodology organize BRSD "Thor" provided a very limited resistance to PFYAV.


    firing range, km


    apogee trajectory km


    CWE km


    Power warhead, Mt


    length assembly, m


    Diameter maximum, m


    diameter by stabilizers, m


    curb weight, t


    weight warheads, t


    Sustainer engine:
    - Thrust at sea level, kN
    - Thrust in vacuum, kN
    - Specific impulse at sea level, with
    - Specific impulse in a vacuum, with


    vernier motor (2 pcs):
    - Thrust each at sea level, kN



Site is a private collection of materials and is an amateur informational and educational resource. All information is obtained from public sources. The administration does not apply for authorship of the materials used. All rights belong to their owners