NASA's two venerable Voyager spacecraft are celebrating three decades of flight as they head toward interstellar space. Their ongoing odysseys mark an unprecedented and historic accomplishment.

Voyager 2 launched on August 20, 1977, and Voyager 1 launched on September 5, 1977. They continue to return information from distances more than three times farther away than Pluto.

For the past 18 years, the twin Voyagers have been probing the Sun's outer heliosphere and its boundary with interstellar space. Both Voyagers remain healthy and are returning scientific data 30 years after their launches.