As a mother was bribing her little boy with a quarter so he would behave, she said, "Why do I always have to pay you to be good?
Why can't you be good for nothing like your dad?"
Invention of navigation by satelliteIn 1957, two Johns Hopkins University Applied Physics Laboratory scientists tracking Sputnik found they could determine its orbit by analyzing the Doppler shift of its radio signals during a single pass. They conjectured that if a satellite's position were known and predictable, then the Doppler shift of its signals could be used to locate a receiver on Earth - thus, one could navigate by satellite. A system called Transit, was developed and from 1964 assisted the security of U.S. nuclear deterrent submarines. From 1967, this evolved into a navigation system for all nations, a forerunner of the present Global Positioning System (GPS). Transit also made key contributions to space science and technology, geodesy and health.*[Image: Transit 1B satellite] |
