General Dynamics is providing the Network Communications Element (NCE), including the UHF Crosslink and Tracking, Telemetry and Command subsystems for the GPS III Satellites. (Photo Credit: Lockheed Martin)
GPS has come a long way during the last 40-plus years. From its initial conception in the early 1960s, to the latest modernization efforts, GPS has achieved milestones and garnered recognition for its contributions to the betterment of humanity. Here are a few of the most notable GPS achievements and milestones.
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.
December 8, 2004: National Executive Committee for Space-Based Positioning, Navigation and Timing is formed
A presidential policy directive, forming the National Executive Committee for Space-Based Positioning, Navigation and Timing, ensures GPS remains equally influenced by military and civilian interests. The committee is co-chaired by the Secretaries of Defense and Transportation and is responsible for managing GPS.
September 2007: Architecture Evolution Plan implemented; GPS III purchase announcement
On Sept. 14, the $800 million Architecture Evolution Plan, the first upgrade to GPS’s ground control segment in 22 years, was implemented in real time without data service interruption to users. The upgrade was the first step in a modernization plan to make current and future GPS features available to users on the ground. The immediate benefit from AEP was the ability to tie the control system into the Air Force Satellite Control Network.
Four days later, President George W. Bush issued a statement announcing the end to procurement of GPS satellites with SA capability. “This decision reflects the United States strong commitment to users of GPS that this free global utility can be counted on to support peaceful civil activities around the world,” the statement said.
October 2011: GPS receives the IAF 60th Anniversary Award
GPS was presented with the International Astronautical Federation’s 60th Anniversary Award on Oct. 4 as the space program that has been of biggest benefit to humanity. The IAF set up the award to “recognize an organization or key individual for a singular and successful project in the field of Space Applications, Space Science and Exploration, which could demonstrate through its implementation, that measurable benefit to humanity has been achieved,” according to iafastro.org. GPS was chosen as the winner because it is the “space program that touches and aids more humans every minute of every day in every corner of the globe.”