Inaugurating the era of space exploration [ http://www.hq.nasa.…] for the US, the First Explorer [ http://antwrp.gsfc.…] was launched [ http://newproducts.…] into Earth orbit forty years ago [ http://www.jpl.nasa…] (February 1, 1958) by the Army Ballistic Missle Agency [ http://www.redstone…]. The Explorer I satellite [ http://history.msfc…] weighed about 30 pounds, was 6 feet long, 6 inches in diameter and consisted of batteries, transmitters, and scientific instrumentation [ http://www-spof.gsf…] built into the fourth stage of a Jupiter-C rocket. Foreshadowing NASA and the adventurous [ http://www.osf.hq.n…] and successful Explorer Program [ http://msl.jpl.nasa…], Explorer I bolstered national prestige in the wake of Sputnik [ http://antwrp.gsfc.…]. The satellite also contributed to a spectacular scientific bonanza - the discovery of Earth-girdling belts of magnetically trapped charged particles now known as the Van Allen Radiation Belts [ http://www-spof.gsf…].
Explanation
Inaugurating the era of space exploration [ http://www.hq.nasa.…] for the US, the First Explorer [ http://antwrp.gsfc.…] was launched [ http://newproducts.…] into Earth orbit forty years ago [ http://www.jpl.nasa…] (February 1, 1958) by the Army Ballistic Missle Agency [ http://www.redstone…]. The Explorer I satellite [ http://history.msfc…] weighed about 30 pounds, was 6 feet long, 6 inches in diameter and consisted of batteries, transmitters, and scientific instrumentation [ http://www-spof.gsf…] built into the fourth stage of a Jupiter-C rocket. Foreshadowing NASA and the adventurous [ http://www.osf.hq.n…] and successful Explorer Program [ http://msl.jpl.nasa…], Explorer I bolstered national prestige in the wake of Sputnik [ http://antwrp.gsfc.…]. The satellite also contributed to a spectacular scientific bonanza - the discovery of Earth-girdling belts of magnetically trapped charged particles now known as the Van Allen Radiation Belts [ http://www-spof.gsf…].
