Timing is everything.
- By J.R. Dailey
- Air & Space magazine, January 2013
"Viewport," by National Air and Space Museum director J.R. Dailey, opens each issue of Air & Space magazine. The column highlights the Museum's ongoing efforts to preserve the history of aviation and spaceflight. This article appeared in the February/March 2013 issue.
As a Marine aviator who began flying after the Korean War, I benefited from electronic navigation equipment that pilots and navigators a decade or two earlier could have only dreamed about. Today almost all of us benefit from a more advanced navigation system—the Global Positioning System—sometimes even when we don’t know we’re using it.
How GPS works is part of a new, long-term exhibition on navigation opening March 29 at the National Air and Space Museum. Called “Time and Navigation: The Untold Story of Getting from Here to There,” the gallery spans 300 years of innovations and focuses on a key requirement for how we navigate: If you want to know where you are, you need an accurate clock. Measuring time has been essential as humans have moved from the sailing vessels of the 19th century to the transoceanic flying boats of the 1930s to the space probes of today. In the exhibit, displays explain how the unique challenges of navigating on the sea, in air, and in space, combined with advances in timekeeping, have shaped our world.
The emergence of accurate and reliable sea-going chronometers, along with improved sextants, gave sailors in the late 18th century the ability to determine longitude, a skill that helped keep ships from being stranded on shoals. Most aviators today forget that celestial navigation using a clock and sextant was essential to the rise of overseas airline service as well as the long-range transport, bombing, and reconnaissance flights of World War II and the cold war era. Even today, on aircraft with global reach, like the B-2, crews rely on celestial navigation as a backup for GPS. Radio navigation systems, including satellite navigation, also depend on accurate timekeeping to determine position, with each GPS satellite carrying four atomic clocks (for redundancy) to provide the time signals that the chip in your smartphone uses to calculate position.
The gallery will feature artifacts like the Winnie Mae, Wiley Post’s famed Lockheed Vega, which in the early 1930s twice shattered previous around-the-world records; Stanley, a robotic car that is the technological predecessor of the self-driving Google cars that have recently been in the news; and the Navy’s Transit satellite, a precursor to GPS (see In the Museum, page 16). In a museum dedicated to reaching higher and further, the exhibit shows how our lives are being shaped by spaced-based navigation, aided by systems like inertial navigation that evolved from aerospace programs.
Perhaps the greatest surprise for the visitor will be just how much our celebrated heroes of exploration have depended on complex navigation systems. As seen on page 28, Charles Lindbergh came to realize that when crossing oceans, superb airmanship was only half the battle. To get where he wanted to go, he had to find someone with a better clock.