Voyager 2 spacecraft celebrated its 35th birthday Monday

Voyager 2

The iconic Voyager 2 spacecraft celebrated its 35^th birthday Monday (Aug. 20) in a milestone for NASA's longest-running mission ever.

Path followed by Voyager 1 & Voyager 2

Voyager 2 was launched in 1977 just 16 days before its twin, Voyager 1. The probes were tasked chiefly with studying Saturn, Jupiter and the gas giants' moons, but have continued on through the solar system and are now about to cross into interstellar space. Voyager 1 is due to cross first, becoming the first manmade object to travel beyond our solar system, and Voyager 2 is not far behind.

"Even 35 years on, our rugged Voyager spacecraft are poised to make new discoveries as we eagerly await the signs that we've entered interstellar space," Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, said in an Aug. 20 statement from NASA. "Voyager results turned Jupiter and Saturn into full, tumultuous worlds, their moons from faint dots into distinctive places, and gave us our first glimpses of Uranus and Neptune up-close. We can't wait for Voyager to turn our models of the space beyond our sun into the first observations from interstellar space."