The North American SM-64 Navaho was a supersonic intercontinental cruise missile project built by North American Aviation (NAA). The final design was capable of delivering a nuclear weapon to the USSR from bases in the US, while cruising at Mach 3 (3,675 km/h; 2,284 mph) at 60,000 feet (18,000 m) altitude. The missile is named after the Navajo Nation.
The original 1946 project called for a relatively short-range system, a boost-glide weapon based on a winged V-2 rocket design. Over time the requirements were repeatedly extended, both due to the US Air Force's desire for longer ranged systems, as well as competition from similar weapons that successfully filled the shorter-range niche. This led to a new design based on a ramjet powered cruise missile, which also developed into a series of ever-larger versions, along with the booster rockets to launch them up to speed.
Through this period the US Air Force was developing the SM-65 Atlas, based on rocket technology developed for Navaho. Atlas filled the same performance goals but could do so with total flight times measured in minutes rather than hours, and flying at speeds and altitudes which made them immune to interception, as opposed to merely very difficult to intercept as in the case of Navaho. With the launch of Sputnik 1 in 1957 and the ensuing fears of a missile gap, Atlas received the highest development authority. Navaho continued as a backup, before being canceled in 1958 when Atlas successfully matured.
Although Navaho did not enter service, its development provided useful research in a number of fields. A version of the Navaho airframe powered by a single turbojet became the AGM-28 Hound Dog, which was carried towards its targets on the Boeing B-52 Stratofortress and then flew the rest of the way at about Mach 2. The guidance system was used to guide the first Polaris submarines. The booster engine design, spun off to NAA's new Rocketdyne subsidiary, was used in various versions of the Atlas, PGM-11 Redstone, PGM-17 Thor, PGM-19 Jupiter, Mercury-Redstone, and the Juno series; it is therefore the direct ancestor of the engines used to launch the Saturn I and Saturn V moon rockets.
The Germans had introduced a number of new "wonder weapons" during the war that were of great interest to all the allied forces. Jet engines were already widely used after their introduction in the UK, but the V-1 flying bomb and V-2 rocket represented technologies that had not been developed elsewhere. In German use these weapons had relatively little strategic effect and had to be fired in the thousands to cause any real damage. But if armed with a nuclear weapon, even a single such weapon would cause damage equivalent to thousands of conventionally armed versions, and this line of research was quickly taken up by the US Army Air Force (USAAF) in late 1944.
Vannevar Bush of the USAAF's Scientific Advisory Board was convinced that manned or automated aircraft like the V-1 were the only possible solution for long range roles. A ballistic missile capable of carrying even the smallest warhead was "at least ten years away", and when asked directly about the topic, noted:
In my opinion, such a thing is impossible. I don't think anybody in the world knows how to do such a thing and I feel confident it will not be done for a very long time to come.
Army planners began planning for a wide variety of post-war missile systems that varied from short-range ballistic missiles to long range flying bombs. After considerable internal debate among Army branches, in August 1945 these were codified in a classified document outlining many such systems, among them a variety of nuclear-armed cruise missiles, essentially V-1s with extended range and the greater payload needed to carry a nuclear warhead. There were three broad outlines depending on range, one for a missile flying 175 to 500 miles (282–805 km), another 500 to 1,500 miles (800–2,410 km), and finally one for 1,500 to 5,000 miles (2,400–8,000 km). Both subsonic and supersonic designs would be considered.
The various proposals were sent to seventeen aviation firms on 31 October 1945. Of the many proposals received, six companies were granted development contracts. Submissions for the longer-range requirements were all based on cruise missile designs, while the shorter-range examples were a mixture of designs. These were assigned designations in keeping with the USAAF's Experimental Engineering Section's "MX" series.
NAA chief designer, Dutch Kindelberger, was convinced missiles were the future, and hired William Bollay from the US Navy's Bureau of Aeronautics to run their newly formed research laboratory. Bollay had previously run the Navy's turbojet development. Bollay arrived to find the Army proposals, and decided to submit a short-range design based on a winged ballistic missile based on the German A-4b design (sometimes known as the A-9), a development of the basic V-2. On 24 March 1946, NAA received letter contract W33-038-ac-1491 for this missile, designated MX-770. The initial design called for a range of 500 miles (800 km) with a 2,000-pound (910 kg) payload, but on 26 July this was increased to 3,000 pounds (1,400 kg).
A number of other designs were also accepted, but these were all cruise missile designs to fill the longer range requirements. These were Martin's MX-771-A for a subsonic missile and -B for a supersonic version, MX-772-A and -B from Curtiss-Wright, MX-773-A and -B from Republic Aircraft, and MX-775-A and -B from Northrop. It was intended that one subsonic and one supersonic design would be put into production, and these were granted the designations SSM-A-1 and SSM-A-2, respectively. The only ballistic missile in the group, MX-774, went to Consolidated-Vultee.
When President Harry S. Truman ordered a massive cut in military spending for FY1947, as part of the Truman Doctrine, the USAAF was forced to make major cuts to their missile development program. Missile funding was cut from $29 million to $13 million (from $325 million to $146 million in today's dollars). In what became known as "the black Christmas of 1946", many of the original projects were cancelled, with the remaining companies working on a single design instead of two. Only Martin continued development of a subsonic design, their MX-771-A, delivering the first SSM-A-1 Matador in 1949. The rest of the companies were told to work only on supersonic designs.
NAA began experimenting with rocket engines in 1946, firing the rockets in the company parking lot and protecting the cars by parking a bulldozer in front of the engines. They first used a 1,100-pound-force (4,900 N) design from Aerojet, and then designed their own model of 300 pounds-force (1,300 N). But by the spring of 1946, captured German data was being disseminated around the industry, and in June 1946 the team decided to abandon their own designs and build a new engine based on the V-2's Model 39.
In late 1946 two Model 39 engines were sent to NAA for study, where they were referred to as the XLR-41 Mark I. The "XLR" referred to "eXperimental Liquid Rocket", a new designation system being used by the Army Air Force. They used these as the basis for a conversion from metric to SAE measurements and US construction techniques, which they called the Mark II.
During this period, the company received a number of late-war reports on developments of a Model 39a engine for the V-2, which replaced the original model's eighteen separate fuel injectors with a single "shower head" plate inside a single larger combustion chamber. This not only simplified the design, it made it lighter and improved performance. The Germans were never able to get this working due to combustion instability and continued using the earlier design in spite of lower performance.
The team that had designed the engine was now in the United States after being captured as part of Operation Paperclip. Many of them were setting up a new Army-funded research effort under the direction of Wernher von Braun. The company hired Dieter Huzel to act as a coordinator between NAA and the Army missile team. In September 1947, the company began design of an engine incorporating the showerhead design, which they called the Mark III. Initially the goal was to match the 56,000 pounds-force (250,000 N) thrust of the Model 39, but be 15% lighter.
Work on the Mark II continued and the detailed design was completed in June 1947. In March, the company rented a large tract of land in the western San Fernando Valley north of Los Angeles, in the Santa Susana Mountains, for use in testing of large engines. A rocket test center was built here, using $1 million (equivalent to $11 million today) of corporate funds and $1.5 million ($16.8 million today) from the USAAF. The first parts began to arrive in September. Development of the Mark III proceeded in parallel using a scaled-down version developing 3,300 pounds-force (15,000 N) that could be fired in the parking lot. The team made a string of changes to this and eventually cured the combustion problems.
Another set of German research papers received by NAA concerned work on supersonic ramjets, which appeared to make a highly supersonic cruise missile design possible. Bollay began a series of parallel design projects; Phase 1 was the original boost-glide design, Phase 2 was a design that used ramjets, and Phase 3 was a study for what sort of booster rocket would be needed to get the Phase 2 vehicle up to speed from a vertical launch system.
Meanwhile, aerodynamicists in the company discovered that the A-4b's swept wing design was inherently unstable at transonic speeds. They redesigned the missile with a delta wing at the extreme rear, and canards at the nose. Engineers working on the inertial navigation system (INS) invented an entirely new design known as the Kinetic Double-Integrating Accelerometer (KDIA) that measured not only velocity as in the V-2's version, but then integrated that to provide the location as well. This meant that the autopilot simply had to compare the target location with the current location from the INS to develop a correction, if any, that needed to bring the missile back on target.
So, by June 1947, the original A-4b design had been changed at every point; the engine, airframe and navigation systems were now all new.
In September 1947 the US Air Force was split off from the US Army. As part of the split, the forces agreed to divide ongoing development projects based on range, with the Army taking all the projects with a range of 1,000 miles (1,600 km) or less, and the Air Force everything above that. MX-770 was well below that limit, but instead of handing it over to the Army's Ordnance Department who were working with von Braun on ballistic missiles, in February 1948 the Air Force instead requested that NAA double the range of the MX-770 to put it into the Air Force's domain.
Examining the work to date, NAA abandoned the boost-glide concept and moved to the ramjet powered cruise missile as the primary design. Even with the more efficient propulsion offered by the ramjets, the missile would have to be 33% larger to reach the required range. This, in turn, demanded a more powerful booster engine to power the launcher, so the requirement for the XLR-41 Mark III was raised to 75,000 pounds-force (330,000 N). However, the N-1 INS system drifted at a rate of 1 mile per hour, so at its maximum range it would not be able to meet the Air Force's 2,500-foot (760 m) CEP. The company began development of the N-2 to fill this need and provide considerable headroom if greater range was requested. It was essentially the mechanism of the N-1 paired to a star tracker which would provide midcourse updates to correct for any accumulated drift.
The Air Force assigned the missile the XSSM-A-2 designation, and then outlined a three-stage development plan. For Phase 1, the existing design would be used for technology development and as a testbed for various launch concepts, including the original booster concept, as well as rocket-track launches and air dropped versions. Phase 2 would extend the range of the missile to 2,000 to 3,000 miles (3,200–4,800 km), and Phase 3 would further increase that to an intercontinental 5,000 miles (8,000 km) while carrying a heavier 10,000 pounds (4,500 kg) warhead. The design evolution finally ended in July 1950 with the Air Force of Weapon System 104A specifications. Under this new requirement the purpose of the program was the development of a 5,500-mile (8,900 km) range nuclear missile.
Under WS-104A, the Navaho program was broken up into three guided missile efforts. The first of these missiles was the North American X-10, a flying subrange vehicle to prove the general aerodynamics, guidance, and control technologies for vehicles two and three. The X-10 was essentially an unmanned high performance jet, powered by two afterburning Westinghouse J40 turbojets and equipped with retractable landing gear for take off and landing. It was capable of speeds up to Mach 2 and could fly almost 500 miles (800 km). Its success at Edwards AFB and then at Cape Canaveral set the stage for the development of the second vehicle: XSSM-A-4, Navaho II, or G-26.
Step two, the G-26, was a nearly full-size Navaho nuclear vehicle. Launched vertically by a liquid-fuel rocket booster, the G-26 would rocket upward until it had reached a speed of approximately Mach 3 and an altitude of 50,000 ft (15,000 m). At this point the booster would be expended and the vehicle's ramjets ignited to power the vehicle to its target. The G-26 made a total of 10 launches from Launch Complex 9 (LC-9) at Cape Canaveral Air Force Station (CCAFS) between 1956 and 1957. Launch Complex 10 (LC-10) was also assigned to the Navaho program, but no G-26s were ever launched from it (it was only used for ground tests of the planned portable launcher).
The final operational version, the G-38 or XSM-64A, was the same basic design as the G-26 only larger. It incorporated numerous new technologies, Titanium components, gimballed rocket engines, a Kerosene/LOX propellant combination, and full solid-state electronic controls. None were ever flown, the program being cancelled before the first example was completed. The advanced rocket booster technology went on to be used in other missiles including the Atlas intercontinental ballistic missile and the inertial guidance system was later used as the guidance system on the first U.S. nuclear-powered submarines.
Development of the first-stage rocket engine for the Navaho began with two refurbished V-2 engines in 1947. That same year, the phase II engine was designed, the XLR-41-NA-1, a simplified version of the V-2 engine made from American parts. The phase III engine, XLR-43-NA-1 (also called 75K), adopted a cylindrical combustion chamber with the experimental German impinging-stream injector plate. Engineers at North American were able to solve the combustion stability problem, which had prevented it being used in the V-2, and the engine was successfully tested at full power in 1951. The Phase IV engine, XLR-43-NA-3 (120K), replaced the poorly cooled heavy German engine wall with a brazed tubular ("spaghetti") construction, which was becoming the new standard method for regenerative cooling in American engines. A dual-engine version of this, XLR-71-NA-1 (240K), was used in the G-26 Navaho. With improved cooling, a more powerful kerosene-burning version was developed for the triple-engine XLR-83-NA-1 (405K), used in the G-38 Navaho. With all the elements of a modern engine (except a bell-shaped nozzle), this led to designs for the Atlas, Thor and Titan engines.
The first launch attempt, on 6 November 1956, failed after 26 seconds of flight. Ten failed launches followed, before another got off successfully, on 22 March 1957, for 4 minutes, 39 seconds of flight. A 25 April attempt exploded seconds after liftoff, while a 26 June flight lasted only 4 minutes, 29 seconds.
Officially, the program was canceled on 13 July 1957, after the first four launches ended in failure. In reality the program was obsolete by mid-1957 as the first Atlas ICBM began flight tests in June and the Jupiter and Thor IRBMs were showing great promise. These ballistic missiles however would not have been possible without the liquid fuel rocket engine developments accomplished in the Navaho program. The launch of the Soviet Satellite Sputnik in October 1957 only finished Navaho as the Air Force shifted its research money into ICBMs. But the technologies developed for the Navaho were reused in 1957 for the development of the AGM-28 Hound Dog, a nuclear cruise missile which entered in production in 1959.
The Soviet Union had been working on parallel projects, The Myasishchev RSS-40 "Buran" and Lavochkin "Burya" and a little later, the Tupolev Tu-123. The first two types were also large rocket-boosted ramjets, while the third was a turbojet-powered machine. With the cancellation of the Navaho and the promise of ICBMs in the strategic missile role, the first two were canceled as well, though the Lavochkin project, which had some successful test flights, was carried on for research and development purposes, and the Tupolev was reworked as a big, fast reconnaissance drone.
One Navaho missile in existence is currently displayed outside the south entrance gate of Cape Canaveral Air Force Station, Florida. The remaining X-10 is on display at the United States Air Force Museum Annex at Wright-Patterson AFB, OH. A Navaho booster rocket, though not marked as such, was displayed in front of a VFW post in Fort McCoy, Florida.
Aircraft of comparable role, configuration and era
The Burya ("Storm" in Russian; Russian: Буря) was a supersonic, intercontinental cruise missile, developed by the Lavochkin design bureau (chief designer Naum Semyonovich Chernyakov) under designation La-350 from 1954 until the program cancellation in February 1960. The request for proposal issued by the Soviet government in 1954, called for a cruise missile capable of delivering a nuclear payload to the United States. Analogous developments in the United States were the SM-62 Snark and SM-64 Navaho cruise missiles, particularly the latter, which used parallel technology and had similar performance goals.Cape Canaveral Air Force Station Launch Complex 10
Launch Complex 10 (LC-10) at Cape Canaveral Air Force Station, Florida was a launch pad used by SM-64 Navaho missiles, and later Jason sounding rockets and the Alpha Draco research missile. It was located north of Launch Complex 17, where Launch Complexes 31 and 32 are now located. The pad consisted of a small concrete launch structure with an elevated launch pedestal and built-in flame trench, centered on a small oval-shaped concrete pad.
A single Navaho missile was test-launched from LC-10, on 12 August 1957, and was one of only three Navahos to complete a successful flight. Following the cancellation of the Navaho, LC-10 was reused for launches of Jason and Draco sounding rockets during 1958 and 1959. The last launch to use the site was of a Draco on 27 April 1959.
LC-10 was subsequently demolished during the construction of Launch Complexes 31 and 32, which were built on the same site.Cape Canaveral Air Force Station Launch Complex 9
Launch Complex 9 (LC-9) at Cape Canaveral Air Force Station is a launch pad on Cape Canaveral in Florida. It is north of Launch Complex 17. It is a small concrete structure consisting of an elevated launch pedestal and flame trench, centered on a small oval-shaped concrete pad.
It was used for ten test launches of SM-64 Navaho missiles. The Navaho was a supersonic nuclear-armed cruise missile. In addition to LC-9, Navaho tests were also conducted at LC-10 and Edwards Air Force Base. The Navaho was cancelled after poor performance in testing, eight of the eleven test launches of the final prototype failed. All of the failed launches were conducted from LC-9.
As of 2011, the concrete launch structure is still standing, but is not maintained; and the launch support equipment has been removed. The site is not accessible to the general public.Cruise missile
A cruise missile is a guided missile used against terrestrial targets, that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhead over long distances with high precision. Modern cruise missiles are capable of travelling at supersonic or high subsonic speeds, are self-navigating, and are able to fly on a non-ballistic, extremely low-altitude trajectory.Hey Sandy
"Hey Sandy" is a song by the American indie rock band Polaris which serves as the theme song for the Nickelodeon television show The Adventures of Pete & Pete. It's well-known by fans of the show and the band alike that its lyrics, which are not only nearly indecipherable in the first place, but also have generated considerable debate as to their meaning.Launch Complex 10
Launch Complex 10 may refer to:
Cape Canaveral Air Force Station Launch Complex 10, a launch pad used by SM-64 Navaho missiles and Jason and Draco sounding rockets
Vandenberg AFB Space Launch Complex 10, a space launching facilityList of canard aircraft
This is a list of canard aircraft, having a foreplane in front of the main wing instead of a conventional tailplane.List of nuclear weapons
This is a list of nuclear weapons listed according to country of origin, & then by type within the states.Navajo (disambiguation)
The Navajo are a Native American people of the Southwestern United States.
Navajo or Navaho may also refer to:
Navajo Nation, the governmental entity of the Navajo people
Navajo language, spoken in the Southwestern United StatesNorth American X-10
The North American X-10 (model RTV-A-5) was an unmanned technology demonstrator, developed by North American Aviation. It was a subscale reusable design that included many of the design features of the SM-64 Navaho missile. The X-10 was similar to the development of Bell's X-9 Shrike project, which was based on features of the GAM-63 RASCAL.RSS-40 Buran
The Buran cruise missile, designation RSS-40, was a Soviet intercontinental cruise missile by Myasishchev capable of carrying a 3,500 kg hydrogen bomb payload. The project was canceled before flight tests began. It is unrelated to the later Buran reusable orbiter.RTV-A-3 NATIV
The RTV-A-3 NATIV was an experimental missile program, developed by North American Aviation for the United States Air Force in the late 1940s to test and evaluate guided missile technologies.
Originally given the project number MX-770, NATIV - the North American Test Instrument Vehicle - was influenced by the design of the Wasserfall surface-to-air missile developed in Germany during World War II. Used as a test vehicle for missile technology on behalf of the SM-64 Navaho project, information on the results of the NATIV project are inconsistent, with some sources claiming six successes of 20 launch attempts, while others suggest only one of six launch attempts was a partial success.SM-62 Snark
The Northrop SM-62 Snark was an early-model intercontinental range ground-launched cruise missile that could carry a W39 thermonuclear warhead. The Snark was deployed by the United States Air Force's Strategic Air Command from 1958 through 1961. It represented an important step in weapons technology during the Cold War. The Snark took its name from the author Lewis Carroll's character the "snark".The Snark missile was developed to present a nuclear deterrent to the Soviet Union and other potential enemies at a time when Intercontinental ballistic missiles (ICBMs) were still in development. The Snark was the only surface-to-surface cruise missile with such a long range that was ever deployed by the U.S. Air Force. Following the deployment of ICBMs, the Snark was rendered obsolete, and it was removed from deployment in 1961.W21
The W21 was an hydrogen bomb design for the US military. It would have used the physics package of the TX-21 bomb. The TX-21 was a weaponized version of the "Shrimp" device tested in the Bravo shot of Operation Castle. A TX-21C was tested as the Navajo shot, Operation Redwing. The TX-21, was a scaled-down version of the Runt device (M-17 hydrogen bomb). Smaller in size and weight to the Mk-17, the Mk-21 was considered as a potential missile warhead. Far more powerful than the TX-13, which was a high-yield atomic bomb developed from the Mk-6 bomb, the XW21 was to replace the XW13 in the weapons pod of the B-58 bomber and for the SM-64 Navaho missile.
At the same time the Mk-21 bomb was being developed, the Mk-15 was also being developed. A missile warhead version was developed for the Navajo, Matador and Regulus missiles (a XW29 version was designed for Snark and Redstone). The XW15 design developed into the XW39 which was eventually deployed on Redstone and Snark missiles.
The XW21 was cancelled in favor of the much smaller and lighter XW-39 in 1957. Though several hundred Mk-21 hydrogen bombs were briefly stockpiled, no W21 warheads were ever constructed.
The W21 is an example of how the rapid development of hydrogen bombs in the mid-1950s created many dead-end designs which were quickly overtaken by smaller, lighter, and more efficient weapons.W41
W41 was the designation of an American nuclear warhead, which was investigated during the late 1950s. Intended for use in the SM-64 Navaho cruise missile, the program was cancelled in 1957. The program was brief, considered at the same time as the TX-29, WX-15-X1 and XW-21 warheads. All were eventually replaced as the proposed Navaho warhead by the W39. The W41 was an adaptation of the B41 thermonuclear bomb which was produced in large numbers and served in stockpile for 15 years.Weapon system
Weapon System was a United States Armed Forces military designation scheme for experimental weapons (e.g., WS-220) before they received an official name — e.g., under a military aircraft designation system. The new designator reflected the increasing complexity of weapons that required separate development of auxiliary systems or components.
In November 1949, the Air Force decided to build the Convair F-102 Delta Dagger around a fire-control system. This was "the real beginning of the weapon system approach [and the] aircraft would be integrated into the weapon system "as a whole from the beginning, so the characteristics of each component were compatible with the others".Around February 1950, an Air Research and Development Command "study prepared by Maj Gen Gordon P. Saville...recommended that a 'systems approach' to new weapons be adopted [whereby] development of a weapon "system" required development of support equipment as well as the actual hardware itself."The earliest WS designation was the 1954 WS-117L.US weapon programs were often begun as numbered government specifications such as an Advanced Development Objective (e.g., ADO-40) or a General Operational Requirement (e.g., GOR.80), although some programs were initially identified by contractor numbers (e.g., CL-282).1Other weapons-programs designators included MX, for military experimental. The first Skunk Works program, dubbed MX-813, produced the Convair XF-92 in 1946),Wright XRJ47
The Wright XRJ47 was an American ramjet engine developed in the 1950s to help propel the rocket-launched SM-64 Navaho supersonic intercontinental cruise missile. Although the design flight Mach Number was 2.75, a peak flight speed of Mach 3.0, at altitudes up to about 77000 ft, was envisaged. This very large ramjet had a number of design problems, including some difficulty in light-up. Development of the Navaho missile was cancelled along with the ramjet engine in 1957.XSM-73 Goose
The Fairchild SM-73 (originally Bull Goose) was a sub-sonic, jet-powered, ground-launched decoy cruise missile.XSM-74
The Convair XSM-74 was a sub-sonic, jet-powered, ground-launched decoy cruise missile.
1955–1962 United States Air Force rocket and missile designations
United States Air Force rocket and missile designations 1947–1951