1957-1978: GPS conceptualization and first satellite launch
During the height of the Cold War, the Soviet Union dealt a major blow to U.S. morale with the launch of Sputnik in 1957. While Sputnik was a victory for the Soviets during the space race, it actually helped lead to the development of GPS. Scientists discovered the Doppler Effect, the thing that makes the timbre of a car horn change as the car passes by, could be applied to the radio signals being emitted from Sputnik. Essentially, they realized that satellites could be tracked from the ground by measuring the frequency of signals they emitted as they passed a fixed receiver location, and vice versa.
In 1960, the first navigation satellite, TRANSIT IB, was put in orbit with the primary function of providing navigational and tracking aids for seagoing vessels, primarily submarines. The U.S. Navy’s launch of TIMATION satellites in 1967 and 1969 proved that a three-dimensional navigation system, using latitude, longitude and altitude, and highly accurate clocks, was possible. The TIMATION program was merged with the Air Force’s 621B program in 1973 in order to form the NAVSTAR GPS program, according to Encyclopedia Astronautica. On Feb. 22, 1978, the first of 11 NAVSTAR satellites was launched, paving the way for the current GPS constellation.
September 1983: Korean Air Flight 007 shot down, President Reagan calls for civilian access to GPS
On Sept. 1, Korean Air Flight 007 accidentally strayed into Soviet restricted airspace on its way from Alaska to South Korea. The Soviets shot down the passenger plane, killing all 269 people on board. On Sept. 16, President Ronald Reagan issued a statement condemning the act and calling for civilian access, free of charge, to GPS technology in order to prevent a similar event from occurring. The U.S. policy of offering GPS technology to civilians at no charge has remained in place.
1990-1991: Operations Desert Shield and Desert Storm give GPS first combat test
On Aug. 2, 1990, Iraqi forces began occupying Kuwait. Five days later, President George H.W. Bush ordered U.S. forces to Saudi Arabia and so began Operation Desert Shield. Desert Shield, and later Desert Storm, would mark the first time military forces used GPS technology in a combat situation. Allied troops relied heavily on GPS to navigate the Arabian Desert.
April 1995: GPS achieves full operational capability
GPS passed all its tests and on July 17, the Air Force issued a statement announcing that GPS had met the requirements for full operational capability. “FOC marks the successful completion of Department of Defense testing of the 24 Block II satellites now in orbit and confirmation of their operational capabilities,” the statement said.
1998: GPS inducted into the Space Foundation’s Space Technology Hall of Fame
According to spacefoundation.org, the Space Technology Hall of Fame exists to honor individuals, organizations and technologies using space technologies to improve the quality of life for all humanity. The foundation included eight individuals and 10 corporations as a part of the technology’s induction into its Hall of Fame.
May 1, 2000: Presidential directive calls for the immediate discontinuance of Selective Availability
A statement from President Bill Clinton said, “The decision to discontinue SA is the latest measure in an on-going effort to make GPS more responsive to civil and commercial users worldwide.”
Once deactivated, civilian signal accuracy improved by 10 times, paving the way for increased civilian use. Industries from shipping to fishing to transportation all began using GPS technology, and private companies begin to manufacture and market personal GPS products.
Source:: Air Force Space Command