Mission Type: Impact
Launch Vehicle: Atlas-Agena B (no. 4 / Atlas D no. 133 / Agena B no. 6004)
Launch Site: Cape Canaveral, United States, launch complex 12
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: 331.12 kg
Spacecraft Instruments: 1) imaging system; 2) gamma-ray spectrometer; 3) single-axis seismometer and 4) surface-scanning pulse radio experiment
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
National Space Science Data Center, http://nssdc.gsfc.nasa.gov/
This spacecraft, similar in design to Ranger 3, was the first U.S. spacecraft to reach another celestial body. A power failure in the central computer and sequencer stopped the spacecraft's master clock and prevented the vehicle from performing any of its preplanned operations, such as opening its solar panels.
Drifting aimlessly and without any midcourse corrections, Ranger 4 impacted the Moon on its far side at 12:49:53 UT on 26 April 1962. Impact coordinates were 15 degrees 30' south latitude and 130 degrees 42' west longitude.
Although the spacecraft did not achieve its primary objective, the Atlas-Agena-Ranger combination performed without fault for the first time.