Voyager 1 is a space probe that was launched by NASA on September 5, 1977. Part of the Voyager program to study the outer Solar System, Voyager 1 was launched 16 days after its twin, Voyager 2. Having operated for 43 years, 6 months and 22 days as of March 27, 2021 UTC [refresh], the spacecraft still communicates with the Deep Space Network to receive routine commands and to transmit data to Earth. Real-time distance and velocity data is provided[3] by NASA and JPL. At a distance of 152.2 AU (22.8 billion km; 14.1 billion mi) from Earth as of January 12, 2020,[4] it is the most distant human-made object from Earth.[5]

The probe's objectives included flybys of Jupiter, Saturn, and Saturn's largest moon, Titan. Although the spacecraft's course could have been altered to include a Pluto encounter by forgoing the Titan flyby, exploration of the moon took priority because it was known to have a substantial atmosphere.[6][7][8] Voyager 1 studied the weather, magnetic fields, and rings of the two planets, and was the first probe to provide detailed images of their moons.

As part of the Voyager program, like its sister craft Voyager 2, the spacecraft is in an extended mission to locate and study the regions and boundaries of the outer heliosphere, and to begin exploring the interstellar medium. Voyager 1 crossed the heliopause and entered interstellar space on August 25, 2012, making it the first spacecraft to do so.[9][10] Two years later, Voyager 1 began experiencing a third "tsunami wave" of coronal mass ejections from the Sun, that has continued to at least December 15, 2014, further confirming that the probe is indeed in interstellar space.[11]

In a further testament to the robustness of Voyager 1, the Voyager team tested the spacecraft's trajectory correction maneuver (TCM) thrusters in late 2017 (the first time these thrusters had been fired since 1980), a project enabling the mission to be extended by two to three years.[12] Voyager 1's extended mission is expected to continue until about 2025, when its radioisotope thermoelectric generators (RTGs) will no longer supply enough electric power to operate its scientific instruments. (Wikipedia)