GPS, or the Global Positioning System, is a relatively young technology we already take for granted. Paper maps are practically obsolete now that we use GPS to get just about everywhere. But consider this the next time you need directions to your friend's house: It took a tragedy to bring GPS to your fingertips.
On September 1, 1983, during a particularly tense period of the Cold War, Korean Air Lines Flight 007 strayed into USSR airspace on its way to Seoul, and was shot down by a Soviet fighter jet. Conspiracy theories abound, but most believe that the deviation from the standard flight course was due to pilot navigational error. In response, President Reagan issued a directive: Once completed, the satellite navigation project then under development would be freely available for civilian use.
This burgeoning system, then known as Navstar-GPS, was a combination of several initiatives developed independently by various branches of the U.S. military. In the 1960s, the constant fear of Soviet aggression made funds for military projects readily available, even for something as staggeringly expensive as space programs. The Army sent up a surveying satellite known as SECOR, the Navy launched the rudimentary TRANSIT satellite navigation system to guide missile-carrying subs, and the Air Force invested in a similar navigational system called Project 621B for their fighter jets and bombers. In 1973, the best parts of each system were incorporated into Navstar, and GPS as we know it was born.
Since its inception, the basic principles behind GPS haven’t changed. The Air Force operates a constellation of satellites (currently 27, plus a few backups), orbiting at about 20,000 kilometers from the Earth’s surface. The orbits are designed so that pretty much any place on the planet has line-of-sight to a minimum of six satellites at any given time. On board each satellite are an ultra-precise atomic clock and a transmitter, sending out a constant stream of data including the current time and the satellite’s position.
Because radio waves travel at the speed of light, knowing the satellite’s position and the time it transmitted the message (plus a little math) can determine the distance from the receiver to the satellite. By combining the input from three or more different satellites — a process called triangulation — a GPS receiver can fix its position precisely.
The addition of this one piece of data — the exact location on the planet where something is — has radically altered enormous aspects of our lives. You already know you can now get into a car to go to the grocery store by punching the address into a navigation system, which might even help us outsmart traffic along the way by using crowdsourced GPS data from fellow users’ phones. You may not, however, realize that vegetables in the produce aisle may have been saved from a pest infestation by GPS-enabled pinpoint spraying, or that the steaks in the meat department could have come from cows whose GPS collars kept them from wandering too far from home. Meanwhile, everything was delivered to the store by GPS-tracked fleets of trucks. And if you have to call 911 for an accident outside the store, the EMTs have your location on lock.
By having GPS access at a personal level, we can find new restaurants, events, or potential dates nearby. Businesses can entice us with coupon alerts as we pass by, and invite us to show loyalty to our favorites by tagging ourselves when we visit. We can track our workouts, our commutes, and our driving habits, quantifying our behavior and helping us make informed decisions. We can even keep an eye on things that might go missing — children, pets, and our phones themselves.
The applications are broader still — from keeping ships on course to dispatching disaster relief, from guiding unmanned surveillance aircraft to tracking elephant migrations.
The Air Force continues to bolster their satellite constellation to keep up with demand, and they’re looking for your ideas about determining the best place in space to put the next one.
The Air Force Collaboratory, a collaborative platform built from the ground up to solve real-world challenges faced by the Air Force, was created as a forum for those ideas. It allows everyday citizens to work with Airmen to do research into GPS, and help apply those findings out in the world. This is an unprecedented chance to help send the newest GPS satellite into orbit, and your work will directly influence positioning technology's next major evolution.
Want to find out how your ideas could help launch the next iteration of GPS technology? Click here to join The Air Force Collaboratory to start submitting your ideas.