50 YA: Discoverer I & Pioneer IV

This entry covers two satellite launches from Fifty Years Ago. On February 28, 1959, the Air Force launched Discoverer I into a polar orbit on a Thor-Agena A booster from the Pacific Missile Range. Evidently there was trouble tracking the 1,450 pound satellite. Well, it was the early days, after all.

Then on March 1, 1959, Pioneer IV was launched on a Juno II rocket into a solar orbit. A NASA directed project, this satellite had an interesting path to orbit- they launched it on a trajectory so that it actually passed within 37,000 miles of the moon before reaching orbit around the sun. They managed to keep in radio contact out to some 406,000 miles away. It was the first US Satellite to orbit the sun. This satellite was the fourth in the series of projects for the International Geophysical Year series. The picture above is shows how Pioneer 3 and 4 looked.