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. April 23, 1962 at 20:50 UTC · Launch Successful Atlas LV-3 Agena B — United States Air Force, to Lunar Impactor Launch Complex 12, Cape Canaveral SFS, FL, USA The world's 157th orbital launch attempt, and 15th of 1962. Data: Launch Library 2, The Space Devs. Image by NASA (NASA Image and Media Guidelines) via The Space Devs.