Ranger 4 was a spacecraft designed to softly impact the lunar surface. Its solar panels were never extended and its sun and earth acquisition system was not initiated due to a failure of a timer in its central computer. It impacted the far side of the Moon on April 26 after 64 hours of flight.

Mission type: Lunar Exploration · Orbit: Lunar Impactor

Rocket: Atlas Agena B · Provider: United States Air Force