They are the space probes that will not quit. Many of us are looking to retire after more than 30 years of work.  Not NASA's two Voyager spacecraft, racing through interstellar space.   VOA's Paul Sisco has more.

An artist's conception of one of the Voyager probes traveling through our solar system

They were built to last five years and make close-up observations of the planets Jupiter and Saturn and their larger moons.  With "mission accomplished" and energy to spare, in 1982 they flew to Uranus and Neptune, the two outermost giants in the solar System.

Project scientist Ed Stone remembers. "As a scientist it was just an incredible period of discovery, and even today, as we head to interstellar space, we're still discovering things we had not thought about before.  But as we flew by Jupiter and then Saturn and then Uranus and Neptune we discovered world after world which had just been points of light and each was distinct and different."

Ed Stone

As the probes passed each body, they were flung deeper into space.

With images and data of Uranus's moon, Miranda, NASA scientists created a three dimensional animation of its rugged surface and bizarre canyons more that 25 kilometers deep.

Voyagers taught us that Neptune has the fastest winds of any planet, up to 2,000 kilometers per hour.

Roger Launius

The crafts are running out of power quickly, but will still send bits of information back to Earth for at least a few more years.  The Voyagers also carry two gold-plated discs [phonograph records, the audio technology of the time], should there ever be a chance encounter from a distant world. The greeting says, "Hello from the children of planet Earth ..."

A Voyager model on display at the Air and Space Museum

The messages are intended to let those who find them know that we exist.