On April 2, 1963, the Soviet Union launched the Luna 4 spacecraft to attempt the first-ever soft landing on the moon.

The launch was a success, but Luna 4 never actually made it to the moon. One day after Luna 4 launched, it was supposed to fire its rocket engines to help steer it toward the moon. But it wasn't able to complete this midcourse correction, because the spacecraft's navigation system was malfunctioning. Mission control wasn't able to orient the spacecraft so that the engine burn would send it in the right direction. This error caused Luna 4 to miss the moon by more than 5,000 miles. It ended up in a solar orbit somewhere between the Earth and Mars.