The  1st  Voyager  was  launched on August 20th, and  the second  on  September  1st,  1977.  They  arrived  at  Jupiter  in 1979,  Saturn  in 1980,  and  Uranus  in  1986.  Voyager 2 reached Neptune in 1989.  The  two spacecraft  were  considered  to  have  left  the  solar  system when  they  crossed  the  orbit  of  Pluto  in  1989.