That's exactly correct. The alignment allowed the spacecrafts to fly by the major planets using gravity assists and minimal fuel for corrections. Both Voyagers

That's exactly correct. The alignment allowed the spacecrafts to fly by the major planets using gravity assists and minimal fuel for corrections. Both Voyagers launched in 1977. The alignment occurs every 175 years, so 130 years to go to the next one (~2152). https://en.wikipedia.org/wiki/Grand_Tour_program https://en.wikipedia.org/wiki/Grand_Tour_program