The Pioneer P-1, -3, -30 and -31 series was intended to be a lunar orbiter probe, but the mission failed shortly after launch. The objectives were to place a highly instrumented probe in lunar orbit, to investigate the environment between the Earth and Moon, and to develop technology for controlling and maneuvering spacecraft from Earth.

Mission type: Lunar Exploration · Orbit: Lunar Orbit

Rocket: Atlas-Able · Provider: United States Air Force