Meeting The Challenge

Prior to the 1930s flying in aircraft was costly and potentially dangerous. There were fewer passengers and less cargo than required for profitability without government subsidy. The Douglas Aircraft Company design team took the train to New York City to meet with TWA officials rather than fly the airliners of the day, as there just had been a series of accidents including the one that Knute Rockne, the Notre Dame football coach, had perished on. Gene Raymond, the Chief Engineer for Douglas used the newly dedicated GALCIT wind tunnel at California Institute of Technology (CalTech) to experimentally verify the aerodynamics of the new aircraft. Raymond used the latest aluminum stressed skin structure developed by Jack Northrop for the Lockheed's aircraft fuselages. The engines were the new Wright Cyclones radial air-cooled engines that developed 900 horsepower. So Gene Raymond integrated the three principal elements for a successful aircraft from the newly demonstrated "industrial capability". In 1932, the Douglas Aircraft Company introduced the DC-2, and in 1934 the DC-3. The result was a commercial airliner that offered speed, distance and safety to the passenger and profitability to the airlines without subsidy. The aircraft was a sustained-use vehicle that flew hundreds of times per year and therefore at an affordable price. By 1939 the DC-3 was flying tens of thousands of passengers for the airlines worldwide.

Like the DC-3, there were other aircraft built from the available state of the art. One such aircraft was the operational Mach 3-plus SR-71 developed by Clarence (Kelly) Johnson's "Skunk Works"1 team at the Lockheed Burbank plant. The other aircraft was the North American X-15 research aircraft developed to investigate speeds up to Mach 6. The extensive wind tunnel testing established the aerodynamic characteristics of both. The structure was high-temperature nickel-chrome alloys for the X-15 and beta-titanium for the SR-71 in a structure analogous to a "hot" DC-3. The rocket engine for the X-15 was developed from earlier rockets and developed to a level not yet installed on an aircraft. The turbo-ramjet propulsion for the SR-71 has yet to be duplicated 50 years later. For the X-15 the challenging goal was the flight control system that had to transition from aerodynamic control to reaction jet control at the edge of space. For the SR-71 the challenge was to design an integrated control system for both the engine inlets and the aircraft, and from high supersonic speeds to low landing speeds. This had not been done before, and it was accomplished before the era of integrated circuits and digital control. The goal for the X-15 was an approach to fly to space as frequently as could be expected of an aircraft-launched experimental vehicle. By 1958 the X-15 was approaching 300 successful flights. The X-15 was achieving flight speeds at almost Mach 6, and could briefly zoom to the edges of near-Earth space. Rockets of the day were single use and costly, with numerous launch failures. These aircraft were developed by engineers that did not ask, "What is the technology availability date?" but rather, "Where can we find a solution from what we already know or can discover?'' And in both the X-15 and the SR-71, solutions that were not previously known were discovered and used to solve the problems in a timely manner. That spirit enabled the Apollo team to fabricate a Saturn V rocket of a size that was previously inconceivable, and succeed.

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