Mar 3 1959
From The Space Library
PIONEER IV, fourth U.S.-IGY space probe, a joint ABMA-JPL project under direction of NASA, was launched by a Juno II rocket from AMR and achieved earth-moon trajectory, passing within 37,000 miles of the moon before going into permanent solar orbit. Radio contact was maintained to a record distance of 406,620 miles. It was the first U.S. sun-orbiter.