Mission Summary
The second attempt of America’s early lunar landing program, this spacecraft lifted off from Cape Canaveral on April 23, 1962. The probe carried an ambitious set of goals: it was supposed to snap close-up pictures of the lunar surface during its final minutes and drop a rugged, balsa-wood-cushioned capsule containing a sensor onto the ground to listen for moonquakes.
The launch started out smoothly. The massive rocket performed its job exactly as planned, giving the spacecraft a precise push on a direct path toward the Moon. But just as the flight got underway, a silent disaster struck inside the probe itself. A central internal timer failed completely. Without this master clock to issue commands, the spacecraft never opened its solar panels for power or turned on its steering systems.
Left blind and completely unresponsive to commands from ground control, Ranger 4 was effectively brain-dead just hours into its flight. Its small backup batteries drained entirely after 10 hours, silencing its radio completely. Guided only by the momentum of its initial push, the ghost ship swept across the void and slammed into the far side of the Moon on April 26, 1962, traveling at nearly 6,000 miles per hour. Though it failed to send back a single picture, the accidental crash earned the silent craft an unexpected spot in history as the very first American machine to reach another celestial body.
Sources and notes can be found on the Sources page.
