The 6555th, Chapter II, Section 4

MATADOR and the Era of Winged Missiles

The NAVAHO Program

No review of the winged missile era would be complete without some mention of the NAVAHO program. The NAVAHO was a very ambitious effort, but it was even less successful than the SNARK. Only two of three planned versions (e.g., the X-10 and the XSM-64) were ever launched at the Cape, and the program was cancelled by Air Force Headquarters in July 1957. Left-overs from the program were launched as part of the "Fly Five" project and Project RISE (i.e., Research in the Supersonic Environment), but neither effort was successful. Even if the NAVAHO had been successful as a weapon system, it would have been eclipsed by the ATLAS, TITAN and MINUTEMAN ballistic missiles in the early 1960s. Those criticisms aside, the NAVAHO proved that good things can come out of bad programs: the missile's inertial guidance system found its way successfully into nuclear-powered submarines, Navy attack aircraft, and the HOUND DOG and MINUTEMAN missiles. Though the 6555th had no involvement in the program, the NAVAHO's impact on AFMTC and Cape Canaveral must be mentioned to put other missile activities -- including ballistic missile programs -- in perspective.41

[Photo]NAVAHO X-10 ON SKID STRIP - Cape Canaveral, 1956



The goal of the NAVAHO program was to produce a surface-to-surface guided missile capable of carrying an atomic warhead 5,500 nautical miles at a speed of at least Mach 2.75 with sufficient accuracy to insure that at least 50 percent of all missiles struck within 1,500 feet of the target. The North American Aviation Company was the prime contractor for the missile, but the Wright Aeronautical Company had a contract to develop the ramjet engines that would be used on the XSM-64 (Phase Two) test vehicle and, presumably, the production (Phase Three) missile. During Phase One of the program, Westinghouse provided North American with the 10,900-pound thrust J-40-1 turbojet engines that were used in pairs on single-staged, recoverable X-10 test vehicles. North American also procured pairs of 120,000-pound thrust rocket engines from its Rocketdyne division to power the booster stage of its two-staged XSM-64 test vehicle during Phase Two. A series of fifteen X-10 flights were conducted at Edwards Air Force Base, California as part of Phase One in 1953 and 1954. North American also began operating a small field office at Patrick Air Force Base in 1953 to coordinate support efforts for the program, including the construction of two missile assembly buildings, a vertical launch facility for the XSM-64 and a 200 x 10,000-foot landing strip on Cape Canaveral for the X-10 vehicle.42


Cape Canaveral, 1957

The X-10's first flight was scheduled to be launched from the Cape in the summer of 1955, so North American tripled its field office staff from 22 to 77 people in 1954. It also began installing equipment in the guidance laboratory, the blockhouse and the NAVAHO'S flight control building even before construction of those facilities was completed. The first X-10 was launched from the Cape on 19 August 1955, and the NAVAHO quickly replaced the MATADOR as the Range's principal user (though only for the short term). Support facilities were completed in the last half of 1955, and seven more X-10s were launched from the Cape over the next twelve months. By the middle of 1956, North American had 605 people working on the NAVAHO program at Cape Canaveral and Patrick.43

Five more X-10 flights were completed in the last half of 1956, but problems with an auxiliary power unit held up the XSM-64's first launch until 6 November 1956. After six months of delays, the XSM-64's debut on November 6th was not encouraging: the pitch gyro failed 10 seconds after lift-off, and the missile and its booster broke up and exploded 26 seconds into the flight. Three more XSM-64s were launched over the next seven months with depressing, if not equally dismal, results. On 22 March 1957, the first of those missiles impacted 25 nautical miles downrange after the booster's engine shut down prematurely. The next missile fell back on the launch pad on April 25th after rising only four feet. (The subsequent explosion and fire did considerable damage to the pad.) The last of the three was launched on 26 June 1957. It performed well until the ramjets failed to operate after booster separation, and the missile impacted about 42 miles downrange.44

[Photo]NAVAHO WRECKAGE NEAR PAD - 25 April 1957

In addition to those failures, the first in a series of 1,500-mile-long auto-navigator test flights was attempted 10 times in the first three months of 1957 without a single launch. The only bright spots in the program seemed to be some static tests of the NAVAHO's booster rockets and North American's isolation of problem areas revealed in the first four XSM-64 flights. Unfortunately for North American, NAVAHO was already doomed. In a message dated 12 July 1957, Air Force Headquarters terminated the NAVAHO's development. Because the auto-navigator showed promise, the Air Force authorized five auto-navigator flights and one radio command flight with no landing capability. The first of those flights was conducted on August 12th, and it suggested that the auto-navigator functioned properly -- at least until the left ramjet blew out about seven and a half minutes into the flight. The second flight, on September 18th, was even more successful, but the missile had to be destroyed after it entered a slow right turn about 450 miles downrange. Two other flights were less successful, but one NAVAHO managed to autonavigate as far as the Range's station on Mayaguez (about 1075 miles downrange) before its ramjets failed.45


Cape Canaveral, 1957

[Photo]NAVAHO XSM-64 LAUNCH - 26 June 1957

The seven remaining XSM-64s were designated for supersonic research to support the B-70 bomber and long-range interceptor programs, but only two were ever launched from the Cape. The first of them reached Mach 3.1 at an altitude 63,000 feet on 11 September 1958, but its ramjets failed to ignite and the missile crashed 82 miles downrange. The other XSM-64 achieved Mach 3.0 at 77,000 feet before breaking up 60 seconds into its flight on 18 November 1958. The B-70 Weapons System Project Office urged termination of the RISE program as soon as possible, and no more XSM-64s were launched.46

As North American closed out the NAVAHO program, three X-10s were selected as support drones for BOMARC missile tests in late 1958 and early 1959. Two X-10 drones supported BOMARC launches successfully on 24 September and 13 November 1958, but both X-10s burned after running off the end of the Skid Strip at the end of their missions. The last X-10 was launched on 26 January 1959 with no apparent problems, but it self-destructed and crashed approximately 57 miles downrange after experiencing a power failure. It was the NAVAHO's final flight from Cape Canaveral.47

[Photo]X-10 DRONE FLIGHT FROM SKID STRIP - 24 September 1958

Like the SNARK, the NAVAHO had been an overly ambitious attempt to find the practical limits of the winged missile as a weapon system. Some good things came out of the program, but critics maintain (with some justification) that too much effort was expended on the SNARK and NAVAHO, and that the money spent on aerodynamic missile programs would have been better spent elsewhere. The SNARK certainly lingered far too long, but what might have happened to the NAVAHO if ballistic missiles had proved impractical? The ATLAS and TITAN were not assured success when their requirements were laid down in the 1950s. Who could say -- in 1953 -- whether the ATLAS or the NAVAHO would be the better missile? (Admittedly, future prospects looked better for the ATLAS and worse for the NAVAHO after 1956.) In the spirit of the times, aerodynamic and ballistic missile programs were pursued to provide a margin of safety against the failure of either type of missile. Air Force planners in the early 1950s did not have the luxury of our hindsight to guide their future and our past. The apparent anachronism of winged and ballistic missiles being launched within days of each other at Cape Canaveral can only be explained in that context. It is also true that there is normally some overlap between old and new technologies whenever a culture is about to make a great leap forward. The era of winged missiles helped shape the overlapping age of modern weapon systems, as evidenced by the transfer of guidance systems and other components to intercontinental ballistic missiles, cruise missiles, and tactical air-to-air missiles in the 1960s. In that respect, very little of the effort invested in the MATADOR, MACE, BOMARC, SNARK and NAVAHO was completely wasted.

The 6555th: Missile and Space Launches Through 1970
by Mark C. Cleary, Chief Historian
45 Space Wing Office of History
1201 Minuteman Ave, Patrick AFB, FL 32925