Voyager 2 Launches: Journey to the Outer Planets

A Titan IIIE rocket lifted Voyager 2 off the launch pad at Cape Canaveral on August 20, 1977, beginning a journey that has now lasted nearly five decades and carried a 1,592-pound spacecraft more than 12 billion miles from Earth. Voyager 2 remains the only human-made object to have visited all four outer planets: Jupiter, Saturn, Uranus, and Neptune. As of 2026, it is still transmitting data from interstellar space, its radio signal taking more than 18 hours to reach Earth. The mission exploited a rare alignment of the outer planets that occurs once every 175 years, allowing a spacecraft to use each planet's gravity to slingshot to the next. NASA engineers called the trajectory the "Grand Tour." Voyager 2 was actually launched before its twin, Voyager 1, but on a slower path that would allow it to visit Uranus and Neptune. Voyager 1, launched 16 days later on a faster trajectory, reached Jupiter and Saturn first but was directed past Saturn's moon Titan, sending it on a course that bypassed the two outermost planets. The discoveries were revelatory. At Jupiter in 1979, Voyager 2 photographed active volcanoes on the moon Io, the first seen anywhere beyond Earth. At Saturn in 1981, it revealed the astonishing complexity of the ring system. At Uranus in 1986, it found 10 new moons and discovered that the planet's magnetic field was tilted at a bizarre 59-degree angle to its axis. At Neptune in 1989, it photographed the Great Dark Spot and measured winds of 1,200 miles per hour, the fastest in the solar system. Both Voyager spacecraft carry a Golden Record, a 12-inch gold-plated copper disc containing sounds and images selected to represent the diversity of life on Earth. The record includes greetings in 55 languages, music from Bach to Chuck Berry, natural sounds from whale songs to thunder, and 116 photographs of humans, animals, and landscapes. Voyager 2 crossed the heliopause into interstellar space in November 2018, becoming only the second human-made object to leave the sun's sphere of influence. Its nuclear power source is expected to sustain basic instruments until approximately 2030.