Today marks the 35th anniversary of Voyager 1's launch on the Grand Tour of the outer solar system. It will likely still be going long after humans become extinct. The craft is currently more than 11 billion miles from the sun, or 121.764 AU as I write this article. See where the Voyager spaceraft are now.
The mission objective of the Voyager Interstellar Mission (VIM) is to extend the NASA exploration of the solar system beyond the neighborhood of the outer planets to the outer limits of the Sun's sphere of influence, and possibly beyond. This extended mission is continuing to characterize the outer solar system environment and search for the heliopause boundary, the outer limits of the Sun's magnetic field and outward flow of the solar wind. Penetration of the heliopause boundary between the solar wind and the interstellar medium will allow measurements to be made of the interstellar fields, particles and waves unaffected by the solar wind.
Read more about the Interstellar Mission of the Voyager spacecraft at the NASA webpage.
Here is a Martin-Marietta video of the original mission of the Voyager space probes: The Grand Tour.