Key Dates:
- 04.23.62: Launch (20:50 UT)
- 04.26.62: Lunar Impact (12:49:53 UT)
- Status: Crashed on the Moon
Scientific Intruments:
- imaging system
- gamma-ray spectrometer
- single-axis seismometer
- surface-scanning pulse radio experiment
Ranger 4 Information:
Each Ranger spacecraft was designed to make a "kazikaze" dive straight into the Moon and send close-range images back to Earth right up until they crashed into the surface. The cameras onboard each spacecraft were designed to provide different exposure times, fields of view, lenses, and scan rates, and they were arranged in two separate self-contained chains, each with its own power supply, timer, and transmitter.
Ranger 4 was a successful failure. While a power failure in its central computer made it incapable of carrying out its mission objectives, it was the first American spacecraft to reach another celestial body. Ranger 4 crashed into the far side of the Moon on April 26, 1962. The coordinates are 15°31' south latitude and 130°42' west longitude. Although Ranger 4 did not complete it mission, this was also the time the first Atlas-Agena booster rocket performed flawlessly.