Satellite, Pioneer IV

This object is a flight spare of the Pioneer IV spacecraft, which was launched March 3, 1959, on a Juno II launch vehicle. The principal objectives of Pioneer IV were to measure radiation in space, test a photo-electric sensor in the vicinity of the Moon, sample the Moon's radiation, and test long-range tracking. On March 4, 1959, it came within 37,300 miles of the Moon, which was somewhat short of the original goal of 20,000 miles. It was tracked for 82 hours to a distance of 407,000 miles. Currently, Pioneer IV is in solar orbit.The Jet Propulsion Laboratory donated this object to the Museum in 1961.