Part III: Finding Our Location Today!As technology improved into the mid-twentieth century, new possibilities emerged for determining precise locations. In October of 1940 the National Defense Research Council in Washington D.C. suggested a new navigation system that used radio signals. Technology had made it possible to measure the time it would take for a radio signal to travel from one point to another, and then, knowing the speed of the signal, determine the distance. Whenever a receiver could pick up at least two different signals, and determine its distance from each source, the precise location would be where the distances intersected. So, a system called LORAN was developed based on this principle, using land-based radio transmitting stations. The first stations were set up along the North Atlantic, and were used during World War II to guide Allied convoys.But for LORAN to always be effective, a ship had to be within a certain distance from the stations to receive the radio signals. This meant that a lot of radio transmitters would have to be set up all over the world. Even now, LORAN radio stations have not been set up everywhere. Another navigation system was also set up, called Omega. It uses a lower frequency signal, which has a longer range. This made it possible to cover more of the world with fewer transmitters, but it also was less accurate. Meanwhile, the exploration of space began in 1957 when the Soviet Union launched Sputnik-I, the first artificial satellite. The Americans followed a few months later with their own satellite, Explorer I. The Space Age had begun!
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