On June 19, the six-wheeled explorer officially completed the longest day trip of any robot vehicle on another planet. In a ...

After its voyage past Mars, Mariner 4 maintained intermittent communication with JPL and returned data about the interplanetary environment for two more years. But by the end of 1967, the spacecraft ...

Mariner 4, built by JPL in Pasadena, took the images on July 14, 1965. One of the mission's leaders reflects on decades of studying the Red Planet.