Launched in 1977 , Voyager 1 was part of a twin - spacecraft mission on a multi - planet tour . `` Voyager took advantage of alignment of the outer planets , which are Jupiter , Saturn , Uranus and Neptune , to be able to go by all four of those planets in a 12-year period . A rare planetary alignment let the spacecraft travel past Jupiter , Saturn , Uranus , Neptune . The two spacecraft have provided unparalleled insight into our solar system . NASA announced Voyager 1 had left orbit last year , but some dispute that .
Launched in 1977 , Voyager 1 was part of a twin - spacecraft mission on a multi - planet tour . A rare planetary alignment let the spacecraft travel past Jupiter , Saturn , Uranus , Neptune . The two spacecraft have provided unparalleled insight into our solar system . NASA announced Voyager 1 had left orbit last year , but some dispute that .