There is much more to the Voyager probes than the exploration of the solar system. With a launch date in 1977, the mission objectives were to observe the solar system's gas planets. Nevertheless, they have now moved into interstellar space after crossing the heliopause - the point of termination of the sun's influence. Valuable insights have been provided by Voyager 1 and Voyager 2 about the heliosphere, magnetic fields and interstellar medium density. Moreover, they have reported a low frequency humming sound which seems to be somewhere in our interstellar space. Its role and function is currently being investigated. Voyager probes were intended to be able to reach the unexplored regions of the universe and analyze the interstellar matter and its possible sources.