31 ianuarie 1958 - Explorer 1 dupa Sputnik 1

First Soviet's Sputnik (1957) - On Oct. 4, 1957, Sputnik 1 successfully launched and entered Earth's orbit.

Explorer 1 - First U.S. Satellite (1958) - On Jan. 31, 1958, the JPL-designed and -built Explorer 1 soared into space. The spacecraft, a quick response to the Soviet's Sputnik, l ofted the United States into the Space Age.
(www.jpl.nasa.gov/explorer/captions/launch.php)


"Today – January 31 – is an important date in the history of space exploration. In 1958, Explorer 1 was the first American satellite to be launched into orbit; though of course it was not the first satellite ever, as the Soviets had launched Sputnik 1 on October 4, 1957." (universitydiary.wordpress.com)

Exploration and conquest of space.
"History changed on October 4, 1957, when the Soviet Union successfully launched Sputnik I. The world's first artificial satellite was about the size of a beach ball (58 cm. or 22.8 inches in diameter), weighed only 83.6 kg. or 183.9 pounds, and took about 98 minutes to orbit the Earth on its elliptical path. That launch ushered in new political, military, technological, and scientific developments. While the Sputnik launch was a single event, it marked the start of the space age and the U.S.-U.S.S.R space race."
Sursa: http://history.nasa.gov/sputnik/