How far can humans really travel into space? The Moon marks the furthest point ever reached by a human being. Beyond that limit, the human body simply cannot survive long-term exposure to radiation, isolation, and deep-space conditions. Voyager 1 tells a different story. Launched in 1977, Voyager became the farthest object humanity has ever sent into the universe. It has passed the Moon, the planets, the edge of the Solar System — and is now traveling through interstellar space, more than twenty