Voyager 2 is a space probe launched by NASA on August 20, 1977, to study the outer planets and interstellar space beyond the Sun's heliosphere. A part of the Voyager program, it was launched 16 days before its twin, Voyager 1, on a trajectory that took longer to reach gas giants Jupiter and Saturn but enabled further encounters with ice giants Uranus and Neptune. It remains the only spacecraft to have visited a combination of either of the gas giants and both ice giant planets. Voyager 2 was the fourth of five spacecraft to achieve the Solar escape velocity, which allowed it to leave the Solar System.

Voyager 2 successfully fulfilled its primary mission of visiting the Jovian system in 1979, the Saturnian system in 1981, Uranian system in 1986, and the Neptunian system in 1989. The spacecraft is now in its extended mission of studying interstellar space. It has been operating for 44 years, 7 months and 7 days as of March 28, 2022 UTC [refresh]; as of February 9, 2022, it has reached a distance of 130.1 AU (19.463 billion km; 12.094 billion mi) from Earth.The probe entered interstellar space on November 5, 2018, at a distance of 122 AU (11.3 billion mi; 18.3 billion km) (about 16:58 light-hours) from the Sun and moving at a velocity of 15.341 km/s (34,320 mph) relative to the star. Voyager 2 has left the Sun's heliosphere and is traveling through the interstellar medium (ISM), a region of outer space beyond the influence of the Solar System, joining Voyager 1, which had reached the interstellar medium in 2012. Voyager 2 has begun to provide the first direct measurements of the density and temperature of the interstellar plasma.Voyager 2 remains in contact with Earth through the NASA Deep Space Network. In 2020, maintenance to the Deep Space Network cut outbound contact with the probe for eight months. Contact was reestablished on November 2, 2020, when a series of instructions was transmitted, subsequently executed, and relayed back with a successful communication message. On February 12, 2021, full communications with the probe were restored after a major antenna upgrade that took a year to complete. The DSS 43 communication antenna, which is solely responsible for communications with the probe, is located near Canberra, Australia.