Voyager 1; Voyager 2

The Voyager mission was designed to take advantage of a rare geometric arrangement of layout of Jupiter, Saturn, Uranus, and Neptune, which occurs about every 175 years. This allowed for a four-planet tour for a minimum of propellant and trip time. The flyby of each planet bends the spacecraft’s flight path and increases its velocity enough to deliver it to the next destination. Using this “gravity assist” technique, the flight time to Neptune was reduced from 30 to 12 years.

Both spacecrafts were launched from Cape Canaveral. Voyager 2 was launched first, on August 20, 1977; Voyager 1 was launched on a faster, shorter trajectory on September 5, 1977.

The prime mission to Jupiter and Saturn brought Voyager 1 to Jupiter on March 5, 1979, and Saturn on November 12, 1980, followed by Voyager 2 to Jupiter on July 9, 1979, and Saturn on August 25, 1981. Voyager 1’s trajectory, designed to send the spacecraft close to Titan and behind...