Imagine travelling alone in a car and getting lost on a deserted road. As you approach a crossroad, you have no idea where to go. What will you do in such a situation? Well, today, the answer is pretty simple: Global Positioning System (GPS). But a few decades back, things were not that easy. So come, let's delve into the history behind this invention that revolutionised travel on this planet.
From the fundamental determination of location, tracking, mapping and timing to agriculture, marine, military and self-driving cars, GPS has become an indispensable part of our daily lives. It has found its way into our vehicles, cameras, laptops, and smartphones. But the real purpose behind the invention of GPS was altogether something else.
According to Britannica, GPS, or the Global Positioning System, developed by the Department of Defense (DoD) of the United States, was initially designed to assist soldiers, military vehicles, planes, and ships in accurately determining their locations. The early concept of GPS dates back to the Sputnik era when the Soviet Union launched the Sputnik-I satellite, which set fire the space war and intensified the Cold War.
NASA's official website states that "GPS has its origins in the Sputnik era when scientists were able to track the satellite with shifts in its radio signal known as the "Doppler Effect." Identifying Sputnik's Doppler Effect allowed scientists to use radio signals to track the satellite's movement from the ground. Scientists further expanded this idea; if a satellite's location could be determined from the ground via the frequency shift of its radio signal, in that case, a receiver's location on the ground could also be determined by its distance from a satellite.
In the mid-1960s, the United States Navy conducted satellite navigation experiments to track U.S. submarines carrying nuclear missiles. According to NASA, they were able to observe the satellite changes in Doppler and pinpoint the submarine's location, with six satellites orbiting the poles. The U.S. Department of Defense further expanded this to create today's precise location tracking GPS.
During the Gulf War of 1990-91, the U.S. military relied heavily on GPS for the Operations Desert Shield and Desert Storm.
The DoD officially commenced the GPS project in the year 1973. An experimental prototype, the Block-I GPS satellite of the Navigation System with Timing and Ranging (NAVSTAR), was launched from Vandenberg Air Force Base in 1978.
After the Korean Air Lines Flight 007 crash of 1983, the U.S. made GPS available for civilian use to increase safety for air traffic and to improve navigation. In 1985, the U.S. government opened contracts with private companies to create portable GPS receivers. From 1989 to 1993, more capable Block-II models were sent into orbit.
During the Gulf War of 1990-91, the U.S. military relied heavily on GPS for the Operations Desert Shield and Desert Storm. According to Britannica, the DoD decreased the accuracy of GPS readings for non-military use during 1990, following the Gulf War, fearing adversaries achieving military benefits. It was known as Selective Availability (SA).
According to Britannica, "The launch of the 24th Block II satellite in 1994 completed the GPS constellation, which now consists of two dozen Block II satellites (plus three spares orbiting in reserve) marching in single file in six circular orbits around Earth."
The removal of Selective Availability (SA) in 2000 is identified as one of the significant milestones in the history of GPS. It allowed civilians access to a more precise location which led to greater commercial use and opened the door to new technological innovations.
The orbits of the satellites are positioned so that at least five satellites are in sight from most points on Earth. The Block-III satellites joined the constellation in 2018. Block-III satellites continue to join the constellation, with the final launch scheduled for 2023.
The GPS technology improved over the years and is now capable of pinpointing locations with an accuracy of feet or even inches.
GPS technology got introduced commercially in the late 1980s. Electronic navigation company Magellan developed the first portable GPS receiver for consumers. The inaugural device, the NAV 1000, cost $3,000 and weighed over 1.5 pounds.
The former head of Naval Research Laboratory's space applications branch, Roger L. Easton, founding president of The Aerospace Corporation, Dr Ivan Getting, NAVSTAR GPS Joint Program Manager and known as the 'Father of GPS', Brad Parkinson, and recently the most hailed person behind the invention of GPS, Dr Gladys West are some of the names most commonly associated to the creation of the Global Positioning System. However, there have been controversies regarding the inventors. Dr West's contributions were unknown until the recent past. Forbes even published an article titled "GPS Only Exists Because Of Two People: Albert Einstein And Gladys West".
Today the U.S. Air Force manages GPS. It consists of three essential parts; satellites, ground stations and receivers (the actual GPS unit). The GPS technology improved over the years and is now capable of pinpointing locations with an accuracy of feet or even inches. The Global Positioning System comprises 32 active satellites in 6 orbits that circle Earth every 12 hours. Among the 32, 24 serve as core satellites, and the rest serve as emergency replacements.
Russia has its version of a navigation system called GLONASS (Global Orbiting Navigation Satellite System). In addition, China (Beidou Navigation Satellite System), India (Indian Regional Navigation Satellite System), Japan (Quasi-Zenith Satellite System) and the European Union (Galileo) have created navigation systems of their own. Like self-driving cars, in the coming future, we can expect the GPS and other navigation systems to create absolute wonders.
Now put on your thinking hats and think about the following questions for a couple of minutes.
How would you describe the term “global positioning system” to your students?
Can you think of the importance of GPS in today’s world?
Write down your thoughts and discuss them with your students, children and your colleagues. Listen to their views and compare them with your own. As you listen to others, note how similar or different your views are to others’.
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Happy Teaching!
The Invention That Helps “Navigate" the World