On Sept. 4, 1962, NASA's Mariner 2 spacecraft performed the first-ever rocket maneuver in deep space as it did a quick mid-course correction on its way to Venus.

It had launched just eight days earlier and needed to burn its engines to ensure that its trajectory would take it to Venus. The midcourse maneuver was necessary because the Atlas-Agena rocket that launched Mariner 2 didn't launch with enough accuracy to get the trajectory right in one shot.
When it was about 1.5 million miles (2.4 million km) from Earth, it fired its engines for 34 minutes to help steer it in the right direction. The entire maneuver required five separate commands sent from mission control, telling the spacecraft to roll, pitch, turn and burn its motor.
One hundred days later, Mariner 2 flew by Venus and became the first spacecraft to successfully fly by another planet.