The Voyager two space probe was the second human-made object to reach interstellar space. But what did it see during its historic 42 year trip out of the solar the system?
Voyager 2 is a space probe launched by NASA on August 20, 1977, to study the outer planets. A part of the Voyager program, it was launched 16 days before its twin, Voyager 1, on a trajectory that took longer to reach Jupiter and Saturn but enabled further encounters with Uranus and Neptune.
It is the only spacecraft to have visited either of these two ice giant planets. Voyager 2 is the fourth of five spacecraft to achieve the Solar escape velocity, which will allow it to leave the Solar System.
Its primary mission ended with the exploration of the Neptunian system on October 2, 1989, after having visited the Jovian system in 1979, the Saturnian system in 1981, and the Uranian system in 1986.
Voyager 2 is now in its extended mission to study Interstellar Space and has been operating for 43 years, 6 months and 19 days as of March 12, 2021. It remains in contact through the NASA Deep Space Network.
Maintenance to the Deep Space Network created the longest period of silence in outbound communications to the probe for a period of 8 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.
As of February 12, 2021, full communications with the probe was restored after a major antenna upgrade, that ended up taking a year, of the DSS 43 communications link, solely responsible for communications with the probe, in Canberra, Australia.
On November 5, 2018, at a distance of 122 AU (1.83×1010 km, about 16:58 light-hours) from the Sun, moving at a velocity of 15.341 km/s (55,230 km/h) relative to the Sun, Voyager 2 left the heliosphere, and entered 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.