by Brian Hagberg
50th Space Wing Public Affairs
2/20/2015 - SCHRIEVER AIR FORCE BASE, Colo. -- 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
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
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."