... Taken from the NASA/JPL information summary "Our Solar System at a Glance". The National Aeronautics and Space Administration's (NASA's) automated spacecraft for solar system exploration come in many shapes and sizes. ... Electrical power is required to operate the spacecraft instruments and systems. ... Between 1959 and 1971, NASA spacecraft were dispatched to study the Moon and the solar environment; they also scanned the inner planets other than Earth -- Mercury , Venus and Mars . ...