Launched in the summer of 1977, NASA’s Voyager 1 and Voyager 2 spacecraft were originally authorized for a brief journey to visit Jupiter and Saturn. Nearly five decades later, both probes are still operating in deep space, pushing the boundaries of human exploration.
In this installment of Cosmically Curious, host Patrick McNameeKing sits down with astronomer John Gianforte from the University of New Hampshire to discuss how a rare planetary alignment made a four-planet grand tour possible, and how nuclear technology keeps these aging probes running deep in the cosmos.
Transcript
Patrick McNameeKing: John, I recently read that the Voyager 2 satellite is set for another year of space exploration, but also that it's been going for a really long time. Can you fill me in on what the Voyager mission is?
John Gianforte: Voyager 1 and Voyager 2 were two nearly identical missions launched in the summer of 1977, and they were authorized to visit Jupiter and Saturn.
However, the engineers that designed the spacecraft said, ‘Listen, we have like a once-in-a-170-plus-year opportunity because of the position of the planets at the presumed time of launch. It will allow the spacecraft to visit the four outer planets—Jupiter, Saturn, Uranus, and Neptune—with one launch.’
So they included in the design the capability to visit all four of the outer planets. It was just an amazingly successful mission.
Patrick McNameeKing: So, I gather that when satellites are operating that far away from the sun, the solar panels don't work so well. How do the Voyager satellites power their instruments without using solar energy?
John Gianforte: They utilized a design that was actually done in the mid-to-late 1950s called a radioisotope thermoelectric generator. And it's a $50 word for a kind of nuclear power supply, a little bit bigger than a car battery. They have been powering those spacecraft ever since the summer of 1977, which is, you know, almost 50 years.
Patrick McNameeKing: Thanks, John. We'll have more next week on what the Voyager satellites are up to these days.
Have a question about the night sky? Email us at cosmic@nhpr.org.
