First human-made object to reach interstellar space
Launched in 1977 on a grand tour of the outer solar system, Voyager 1 flew past Jupiter (1979) and Saturn (1980) before continuing on a hyperbolic escape trajectory. In August 2012 it crossed the heliopause — the boundary between the heliosphere and interstellar space — becoming the farthest human-made object ever built. It still phones home, though one-way light-travel time exceeds 23 hours.