GPS – where is it taking you?
Brief history, pre-space to satelites
As early as 1903, the Russian scientist Konstantin Tsiolkovskiy had proven mathematically the
feasibility of using the reactive force that lifts a rocket to eject a vehicle into space above the pull
of the earth's gravity. Twenty years later, Romanian-born Hermann Oberth had independently
worked out similar formulas. Neither man built a usable rocket to demonstrate the validity of his
theories, nor had they so much as mentioned an unmanned artificial satellite. However the
groundwork had been laid for just such work. (Green, Constance McLaughlin, and Milton
Lomask, 1970)
An American by the name of Robert Goddard had a similar vision, and while engaging in
postgraduate work at Princeton University before World War I, Goddard demonstrated in the
laboratory that rocketry propulsion would function in a vacuum. By 1918 Goddard had
successfully developed a solid-fuel ballistic rocket, and by 1926 had successfully launched a
rocket propelled by gasoline and liquid oxygen. In 1937 he launched a rocket that reached an
altitude of 9,000 feet. Goddard was making great progress, but his work was not followed except
by a small community of rocket enthusiasts. (Green, Constance McLaughlin, and Milton
Lomask, 1970)
In 1943, the Nazi "buzz" bombs and the supersonic "Vengeance" missile – the "V-2s" that
rained on London during 1944 and early 1945 – awakened the entire world to the use of rockets
as weapons. Soon a good many physicists and military men began to study the work of Robert
Goddard with attention. (Green, Constance McLaughlin, and Milton Lomask, 1970)
With the practical use of rockets now established, the post-war nations of the United States and
the Soviet Union soon turned their attention to two fronts in rocketry: the development of
intercontinental ballistic missiles and the development of a rocket capable of launching a satellite
into space.
The Space Age
The Soviet Union launched the first man-made space vehicle, Sputnik (meaning “space
companion”), in 1957, and thereby launched us all into the space age along with it. On January
31, 1958, the United States followed suit with the launch of Vanguard 1. (Green, Constance
McLaughlin, and Milton Lomask, 1970)
Prior to the launch of the Russian satellite, scientists had experimented with bouncing radio
waves off of the moon. Therefore, they were eager to study and experiment with a manmade
satellite and test their theories concerning tracking via radio waves. By studying the orbit of
Sputnik, scientists discovered that it could indeed be tracked by its radio signal. This led to the
concept that man could also determine his position on the earth by reading the signal from a
satellite or space vehicle given that the precise orbit of the satellite was known. Several programs
then began to be discussed in serious terms.
The U. S. Navy’s NRL Naval Center for Space Technology (NCST) conceived of the
TIMATION (TIMe/navigATION) program in 1964. This program was designed to provide the
basis for a navigation system with three-dimensional coverage (longitude, latitude, and altitude)
throughout the world. (U.S. Navy, Naval Research Laboratory, 2001)
In 1973 the TIMATION program was merged with the Air Force's 621B program to form the
Navigation Signal Timing and Ranging Global Positioning System or NAVSTAR GPS program
(originally named the Navigation Technology program). The NAVSTAR GPS program is funded
and controlled by the U.S. Department of Defense (DOD), and its primary function is to support
military operations throughout the world. The (NAVSTAR) GPS program was officially
declared fully operational July 17, 1995. (U.S. Navy, Naval Research Laboratory, 2001)
