Replica of Sputnik I, the first artificial Earth satellite launched on October 4, 1957. (NASA)

Map of Sputnik's orbit compiled by U.S. Naval Research Laboratory, released October 8, 1957.

Listening to Sputnik at the Crimean Astrophysical Observatory of the Soviet Academy of Sciences. (Author collection)

Observing Sputnik through telescopes at the astronomic post of the Novosibersk Institute of Geodasy, Aerial Photography and Cartography. (Author's collection)

Kids eagerly searching the night skies for Sputnik 1.

Examples of front-page press coverage and the excitement caused by the launch of Sputnik 1.

Dr. Robert Goddard, the father of American rocketry, with a steel combustion chamber and rocket nozzle in 1915. (NASA)

The first Cape Canaveral firing of a Bumper Project rocket on July 24, 1950. (Patrick Air Force Base, Florida)

General John B. Medaris holding a model of the Redstone rocket at a press conference at the Fairmont Hotel in San Francisco on May 17, 1957. (U.S. Army, courtesy of Medaris Collection, Florida Institute of Technology.)

During his November 7, 1957, televised address to the nation President Eisenhower displays the recovered Jupiter C nose cone, which was the first man-made object recovered from space by the United States. (U.S News and World Report Collection, the Library of Congress.)

Remains of the Vanguard TV-3 explosion, the thrust of which sent the satellite itself into the tall weeds near the launch pad on December 6, 1957. (KSC Archive)

William H. Pickering of the Jet Propulsion Laboratory, James A. Van Allen of Iowa State University, and Wernher von Braun of the U.S. Army Redstone Arsenal triumphantly holding aloft a model of Explorer I at a news conference early in the morning of February 1, 1958. (NASA)