Voyager spacecraft fly-by. Computer artwork depicting a Voyager spacecraft passing by an alien planet. The planet has blue seas, landforms, and an atmosphere containing clouds. The spacecraft has a main dish-antenna (circular), a boom pointing toward bottom left which supports imaging equipment, and a boom pointing upwards which carries a small magnetometer probe. Two Voyager spacecraft were launched in 1977 with a mission to survey the outer planets of our Solar System. This mission continued for 12 years, the final planetary encounter being Voyager 2's fly- by of Neptune in August 1989. Both spacecraft are still being tracked out of our Solar System.