Voyager 40th anniversary: Tracing an epic journey of discovery

On August 20, 1977, Voyager 2 was

launched, beginning humanity's most epic astronomical adventure. Two weeks later its sister spacecraft, Voyager 1, was launched, and the two explorers set out to shed light on the mysteries of our solar system by getting up close and personal with our distant neighbors for the first time ever. Forty years later, both pioneers are still operating, sending back data, and heading on their way out of our solar system to explore further than any spacecraft ever launched.