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NASA's Voyager Spacecraft Still Sending Data Back to Earth After 40 Years

NASA's Voyager 1 and 2 spacecrafts are setting space exploration milestones

This undated photo provided by NASA's Jet Propulsion Lab showing the Voyager spacecraft in Passadena, Calif.
This undated photo provided by NASA's Jet Propulsion Lab showing the Voyager spacecraft in Passadena, Calif. JPL/NASA via AP

Forty years ago, Man, or rather NASA, shot off spacecraft into outer space, and they are still going strong. The Voyager 1 and 2 hit that 40-year mark in August and September - and are still sending data back to Earth despite their vast distance. 

In honor of the anniversary, William Shatner helped send a special message to the distant spacecraft, selected by popular vote. Space.com reported that Shatner, Star Trek's Captain Kirk, opened the envelope to read the message: "We offer friendship across the stars. You are not alone."

Voyager 1 and Voyager 2 spacecraft were launched in 1977 to take advantage of an alignment of Jupiter, Saturn, Uranus and Neptune that made it possible to use gravitational assists to explore the planets in a much shorter time. This alignment, discovered by Gary Flandro, who was a doctoral student at Caltech in 1965, appears once every 175 years.

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Voyager 2 was launched on August 20, 1977. It was the only spacecraft that conducted flybys of Jupiter, Saturn, Uranus and Neptune. Voyager 1 was launched on September 5, 1977. It took a shorter but faster trajectory that used a gravity assist at Saturn to take it out of the solar system.

Each spacecraft carries a gold-plated record of Earth sounds, pictures and messages for any intelligent extraterrestrial life that might find them.

"None of us knew, when we launched 40 years ago, that anything would still be working, and continuing on this pioneering journey," Ed Stone, Voyager project scientist based at Caltech in Pasadena, California said in a press release. "The most exciting thing they find in the next five years is likely to be something that we didn't know was out there to be discovered."

In 2012, Voyager 1 became the first spacecraft to leave the Solar System entirely, and cross into interstellar space. It is still transmitting data at a staggering distance of 13 billion miles away from Earth.

Leaving the Solar System means that the sun nolong

Voyager 2 is in the space known as heliosheath, almost 11 million miles from Earth. It is expected to enter interstellar space in the next few years.