NASA recounts the 1977 launch of Voyager 1 and 2

NASA has described the 1977 launch of Voyager 1 and Voyager 2, which took place during a planetary alignment that recurs only about once every 175 years. The alignment brought Jupiter, Saturn, Uranus and Neptune into a favourable arrangement for the mission. The probes were built to make use of six gravity assists as they travelled to the outer planets. The mission, known as the Grand Tour, was designed to study those planets and their satellites, and it returned close-up views of the gas and ice giants and their moons.