It was to be an American probe to venture to the Red Planet. But, it failed to properly get underway on its mission.
Mariner 3 was to follow-up Mariner 2's voyage to Venus with an unmanned fly-by of the fourth planet in the solar system, Mars.
The unmanned probe was to take pictures and record scientific data of Mars.
It was launched aboard an Atlas-Agena rocket on November 5th, 1964. However, the covering on the rocket that carried into orbit failed to open properly. This kept solar power from reaching the spacecraft and it soon lost power.
Later, its sister craft, Mariner 4 successfully flew by Mars and returned the first close-up pictures of the planet.