History changed on October 4, me hearties, 1957, when t' Soviet Union successfully launched Sputnik I. Avast! T' world's first artificial satellite was about t' size o' a beach ball (58 cm.or 22.8 inches in diameter), ya bilge rat, weighed only 83.6 kg. or 183.9 pounds, and took about 98 minutes t' orbit t' Earth on its elliptical path. Blimey! That launch ushered in new political, arrr, military, technological, and scientific developments. While t' Sputnik launch was a single event, it marked t' start o' t' space age and t' US-USSR space race. Avast, me proud beauty! On January 31, shiver me timbers, 1958, me bucko, t' United States successfully launched Explorer I. This satellite carried a small scientific payload that eventually discovered t' magnetic radiation belts around t' Earth, named after principal investigator James Van Allen. T' Explorer program continued as a successful ongoin' series o' lightweight, scientifically useful spacecraft.