Example image of eyePlorer eyePlorer map for 'Transit (satellite)': Global navigation satellite system Ballistic missile submarine United States Navy Applied Physics Laboratory Johns Hopkins University Thor-Ablestar Polar orbit Inertial navigation system Time transfer Distress radiobeacon Global Positioning System Doppler effect Least squares Quonset hut Gene Amdahl Lafayette class submarine TRW Magnetic core memory Parity bit Microsecond List of acronyms and initialisms: N Transit Research and Attitude Control SOLRAD I Vandenberg AFB Space Launch Complex 5 Galactic Radiation and Background Systems Nuclear Auxiliary Power Program Radioisotope thermoelectric generator Thor (rocket family) Introduction to the Global Positioning System Prime Meridian Scout (rocket family) April 21 High-altitude nuclear explosion NNSS Transit Radio navigation Bradford Parkinson September 1959 1959 Timeline of United States inventions