NASA's Voyager program began after it was discovered a 'once in a lifetime alignment' would allow a spacecraft to fly past some of the solar system's planets using their gravity.
The mission, managed by California's Jet Propulsion Laboratory, launched Voyager 2, the first of two spacecrafts, from the Kennedy Space Center in 1977. Although launched second, it was calculated that Voyager 1 would reach Jupiter and Saturn first, which it did in March 1979. Voyager 2 followed in July 1979. Their findings include the discovery of a number of new moons, with evidence of volcanic activity on Jupiter's moon Io and the storm at the center of Jupiter's red spot.
Voyager 1 passed by Saturn in November 1980, Voyager 2 in August 1981. Voyager 2 went on to become the first spacecraft to fly close to four planets, flying by Uranus in 1986 and Neptune in 1989. After this their cameras were turned off to preserve power.
In 2004 Voyager 1 crossed the termination shock, where the solar and interstellar winds meet before becoming the first human-made object to reach interstellar space in 2012. Voyager 2 followed and reached interstellar space in 2018.
- 1977-08-20 NASA launches Voyager 2 towards Jupiter, Saturn, Uranus & Neptune
- 1979-07-08 Voyager 2 takes 1st ever photo of Jupiter's satellite Adrastea (J14)
- 1979-07-09 Voyager 2 flies past Jupiter
- 1981-08-25 Voyager 2's closest approach to Saturn (63,000 miles/100,000 km)
- 1981-08-26 Voyager 2 takes photos of Saturn's moon Titan
- 1986-01-24 Voyager 2 makes 1st fly-by of Uranus (81,593 km), finds new moons
- 1989-08-02 NASA confirmed Voyager 2's discovery of 3 more moons of Neptune designated temporarily 1989 N2, 1989 N3 & 1989 N24
- 1989-08-11 Voyager 2 discovers 2 partial rings of Neptune
- 1989-08-21 Voyager 2 begins a flyby of planet Neptune
- 1989-08-25 After 12-year, 4-billion-mile journey, Voyager 2 flies over cloudtops of Neptune & its moon Triton, sending back photographs of swamps
- 2018-11-05 NASA's Voyager 2 probe leaves the solar system, becoming the second human-made object to reach interstellar space