Smithsonian curators found themselves chasing the proverbial moving target when they put together a new permanent exhibition opening Friday that explains how people get from A to B.

The front end of "Time and Navigation: The Untold Story of Getting from Here to There" was simple enough, as it links the history of modern navigation to the development of ever-more-precise timepieces since the 14th century.

But keeping pace with modern-day advances in global positioning satellite (GPS) technology in smartphones and other personal electronic devices was quite another matter for a project that's been in works for more than five years.

"We knew things were shrinking (in size) but the iPhone was kind of a surprise to everybody" involved in the exhibition at the Smithsonian's National Air and Space Museum, co-curator Andrew Johnston told AFP.

A disassembled black smartphone with a GPS receiver, magnetic compass, gyroscope and accelerometer all packed into a wafer-thin, finger-length circuit board is so small, it's easy to miss in its exhibition case.

On the other hand, it's hard to skip over the bulky inertial navigation system once fitted within a US nuclear submarine, a pre-GPS Transit satellite or primitive boxy radio equipment from World War II bombers.

"We were very much aware of GPS, but we also realize that most people don't understand how important navigation and timing are to our daily lives," said space historian Paul Ceruzzi, another of the show's four curators.

"GPS satellites are invisible, they're thousands of miles away .. but they are every bit as important as electric power to our daily lives, and we wanted to tell that story," he told AFP during a press preview Wednesday.

Other exhibits include the first made-in-America marine chronometer, assembled from a French model during the War of 1812; the single-engine airplane Winnie Mae in which aviator Wiley Post circumnavigated the world in the 1930s; and a robot SUV called Stanley that can find its way on its own.

"Some of these objects hopefully we'll be able to change out," said Johnston, pointing to a model of an indoor GPS system for firefighters that is still in the development stage.