Over the years, scientists and astronomers alike have made many significant advances in space exploration. In the middle 20th century, scientists and astronomers compiled data, which in turn led to numerous questions concerning the make-up of our solar system. The questions would remain unanswered until technology increased to a level which would help them explore their curiosities. In the mid 1950's, The Pioneer Space Program began revealing many answers to scientists. Over time this consisted of thirteen satellite's which all possessed objectives in which some were related, and others entirely different. The Pioneer Space Program progressed through four stages: Pioneer's 1-5, Pioneers 6-9, Pioneers 10 and 11, and the most recent 12 and 13.
Between 1958 and 1960, Pioneer's 1-5 were launched. Among the accomplishments of these satellites were; discovery of the first and second radiation belts around earth (Pioneer's 1 and 3); the first craft to escape Earth's gravitational pull while passing within 36,650 miles of the moon (Pioneer 4); established a record of 106 days of functionality at a record distance of 22 ½ million miles from earth while reporting a map of the interplanetary magnetic field (Pioneer 5). Pioneer's 6-9, which were launched between 1965 and 1968, are known for recording the first detailed measurements of solar wind, solar magnetic field and cosmic rays (4). Pioneer 10 and 11, launched in 1972 and 1973 respectively are noted for their exploration of Jupiter and Saturn. Pioneers 12 and 13, launched in 1978, were named the Venus Orbiter and Venus Multiprobe. The primary purpose of these spacecraft were to accomplish the global mapping of Venus including clouds, atmosphere and ionosphere, and solar wind-ionosphere interaction; and mapping of the planet's surface by radar (1). Of the thirteen Pioneer Space Program satellites, Pioneer 10 and 11 are the most visibly noted in the program for their accomplishments.