Ranger 5 was a spacecraft of the Ranger program designed to transmit pictures of the lunar surface to Earth stations during a period of 10 minutes of flight prior to impact on the Moon, to rough-land a seismometer capsule on the Moon, to collect gamma-ray data in flight, to study radar reflectivity of the lunar surface, and to continue testing of the Ranger program for the development of lunar and interplanetary spacecraft. Due to an unknown malfunction, the spacecraft ran out of power and ceased operation. It passed within 725 km of the Moon.