The Navaho intercontinental cruise missile project was begun just after World War II at a time when the US Air Force considered ballistic missiles to be technically impractical. But the Navaho required a huge liquid fuel booster to get its Mach 3 ramjet up to ignition speed. And as it turned out, mastering the Mach 3 air vehicle guidance and materials problem was actually more difficult than solving those of ballistic missiles. In the end, the Atlas ICBM began flight test before the first full sized Navaho could be flown. However the Navaho program provided the technologies that allowed the US to develop ballistic missiles rapidly in order to catch up with the Russians. From the Navaho came the rocket engines for the Redstone, Thor, Jupiter, Atlas, Titan, and Saturn I rockets. Navaho also developed chem-milling fuel tank fabrication techniques, inertial and stellar navigation, and a host of other technologies used in later rockets. It put North American Aviation in a leading position that allowed it to capture the prime contracts for the Apollo and Space Shuttle projects, thereby dominating US manned spaceflight for the next fifty years. Major Events: .

• 11 January 1946 Hermes Mach 3 ramjet proposed. Launch Vehicle: Navaho G-26. More details

  Von Braun briefs Hermes; V-2 first stage, ramjet second stage, cruise at 2,100 mph at 12 miles altitude.

• 02 March 1950 Navaho XLR-43 engine test. Launch Vehicle: Navaho G-26. More details

  First full-thrust test of 75,000 pound liquid rocket engine for the Navaho (XLR43-NA-1) conducted by North American at Santa Susana, Calif.

• 19 November 1952 Navaho engine reaches 100,000 lbs thrust. Launch Vehicle: Navaho G-26. More details

  At Santa Susana, Calif., a complete liquid-rocket engine assembly (Navaho) having a thrust in excess of 100,000 pounds was fired for the first time.

• 28 August 1953 Navaho engine reaches 200,000 lbs thrust. Launch Vehicle: Navaho G-26. More details

  At Santa Susana, Calif., a complete liquid-rocket engine assembly (Navaho) having a thrust in excess of 200,000 pounds was fired for the first time.

• 14 October 1953 X-10 B-64 Navaho first flight. Launch Vehicle: Navaho G-26. More details

  Prototype of North America's B-64 Navaho, a X-10 ramjet guided missile, made its initial flight.

• 18 November 1954 Navaho inertial system tested. Launch Vehicle: Navaho G-26. More details

  Inertial guidance system for Navaho X-10 missile tested in first flight at Downey, Calif.

• 07 December 1954 Navaho first automatic recovery. Launch Vehicle: Navaho G-26. More details

  First successful recovery of a Navaho X-10 using fully automatic approach and landing system, made at Edwards AFB, Calif.

• 11 July 1957 Navaho cancelled. Launch Vehicle: Navaho G-26. More details

  Navaho ramjet intercontinental missile program canceled by Air Force.