Mariner 4

One of the great successes of the early American space program, the Mariner 4 mission journeyed to Mars -- making its closest approach on July 15, 1965 -- and took the first photos of another planet from space.

In addition to providing key information about how to safely deliver future missions to the Martian surface, the spacecraft far outlasted its planned eight-month mission. It lasted about three years in solar orbit, continuing long-term studies of the solar wind and making coordinated measurements with the Mariner 5 spacecraft.