In 1977, two probes launched less than a month apart on a mission to the great beyond. The twin Voyager spacecraft were to travel where no other mission had gone before, exploring what lies outside the vast bubble that surrounds our solar system, beyond the influence of our host star. Voyager 1 reached the beginning of interstellar space in 2012, while Voyager 2 reached the boundary in 2018, traveling beyond the protective bubble surrounding the solar system known as the heliosphere. The Voyager...