50 Years Ago: Ranger IX Crashes into the Moon

Last of the Ranger probes, Ranger IX.

Quickly following the successful flight of Gemini 3 the day before, NASA scientists were busy crashing a probe into the lunar surface - on purpose. Ranger IX was the last in the Ranger series of Lunar Exploration probes designed to give scientists close up video and pictures of potential landing sites. On March 24, a final use of thrusters precisely tilted the spacecraft for maximum camera use and the craft plunged to its impact site in the crater Alphonsus. The speed of the crash was at about 8,800 feet per second.

Ranger image of the floor of the crater Alphonsus before impact.

50 Years Ago: Ranger Probes Explore the Moon

Ranger 8 launch from Cape Canaveral.

Fifty years ago on February 17, 1965, NASA launched the latest in its series of Ranger-class lunar probes. Ranger 8 blasted off from Cape Canaveral's LC-12 pad on an Atlas-Agena rocket, reaching Earth orbit at 185 kilometers altitude. The Agena second stage ignited and sent the Ranger 8 space probe on its way to the Moon on a course to reach the Lunar surface on February 20. The ranger series was designed to take as many pictures of the lunar surface as it could manage, and transmit them to the Earth before crashing into the surface.

Diagram of the Ranger block III spacecraft.

The Ranger probe was powered by twin solar panels throughout its journey. It made a mid-course correction using hydrazine thrusters. SIx cameras were carried on board, each with their own control system and transmitter for rapid transfer to Earth. Before it crashed, the cameras sent back 7,137 pictures before impact on the surface. The pictures were used by NASA to help plan future lunar landings for the Apollo program, including the first close-up pictures of the Apollo 11 landing site.

Picture of lunar surface from Ranger 8.

One more Ranger was planned in the program, for a launch a few weeks later in March.

50 YA - Ranger 3 Misses the Moon

Artist idea of Ranger probe traveling through space. This replica of Ranger was used at the Parade of Progress Show in Cleveland Ohio in 1964. I would love to find out where this is today. Perhaps the Smithsonian?

Fifty years ago on January 26, 1962, NASA launched an Atlas-Agena B rocket from Cape Canaveral. Lifted beyond Earth orbit, Ranger 3 was set on course to begin our epic reconnaissance of the Moon. On board were not only experiments to test the functionality of the Ranger series of probes, but also a Seismometer capsule which would roughly land and begin studying moonquakes. The craft itself was intended to crash into the surface of the Moon, as engineers had not yet devised a way to softly land a spacecraft on the lunar surface. A camera would send images of the lunar surface back to Earth before the expected crash, and instruments would make radar reflections of the surface, measure the altitude from the surface, and study gamma rays while in space.

Side view or Ranger 3.

Power for the craft was provided by two solar panel wings providing energy to a 1000-watt capacity battery. A large communications antenna was attached to the base. In a way, Ranger 3 appeared much as most of our satellites of the period would look.

Atlas-Agena B lifts off from Cape Canaveral.

The Ranger 3 mission did not go as planned (surprise!). The booster guidance system suffered a malfunction which caused the spacecraft to speed up beyond the planned acceleration. The mid course correction failed, and the spacecraft was unable to relay data and information clearly. Ranger 3 missed the moon by about 22,000 miles. Eventually, some data was received that helped engineers fine-tune the design for the next mission. Ranger 3 itself kept on flying- it eventually began to orbit the Sun, and remains out there to this day.

Science fiction fans may remember that the TV series "Buck Rogers" used a space-shuttle derived design as Buck's spaceship, which was named "Ranger-3."