Voyager 1 became the first human-made object to enter interstellar space.
NASA launched Voyager 1 on September 5, 1977, to study Jupiter and Saturn. It crossed the heliopause, the boundary where the solar wind gives way to interstellar space, in August 2012 at a distance of about 121 astronomical units from the Sun.
Voyager 1 returned landmark images of Jupiter, Saturn, and their moons, including evidence of active volcanism on Io. Its cameras were switched off in 1990 after it made the famous “Pale Blue Dot” image of Earth.
Interstellar space does not mean Voyager 1 left the Solar System’s entire gravitational influence. The probe remains far inside the distant Oort Cloud, but it is traveling through the region beyond the Sun’s plasma environment.