During the 1960s, while public attention was focused on NASA's manned and unmanned spacecraft, aircraft technology took several bold steps forward. Although in the shadow of the space program, U.S. subsonic jet transports captured the world commercial market and became indispensable to intercontinental travel. Along came the variable sweep wing and the supercritical airfoil-developments not nearly as spectacular as the Apollo 11 lunar landing in July 1969, but nevertheless invaluable to more efficient flight in the atmosphere. And of course atmospheric flight is infinitely more frequent than space flight. The helicopter, too, grew to technological maturity during this period. Supersonic transports were also on the drawing boards. Far from being eclipsed by space feats, aeronautics prospered as never before. It was the Jet Age, with its jet set and jet lag and all the excitement of thousands of sleek, powerful craft crisscrossing the world at nearly the speed of sound.
The preceding chapter records NASA's response to its space flight assignments in the area of wind tunnels. Emphasis was on hypersonic and hypervelocity wind tunnels, arc jets and shock tubes, and tunnels for testing the effect of aerodynamic heating on spacecraft structures. These facilities had to be built quickly to win the space race, as it was called during the decade after Sputnik. On the aeronautics side, NASA had inherited an impressive inventory of facilities from NACA consisting of several dozen wind tunnels at the Ames, Langley, and Lewis laboratories. Many of these were modern and already laboring at the forefront of technology. There were only a few obvious gaps in the spectrum, and NASA quickly rectified these shortcomings with three new tunnels, all possessing unique or modestly revolutionary features.