NASA scientists at JPL, elsewhere reflect on Voyager’s journey

Voyager 1 was built at the Jet Propulsion Laboratory. Today it is in interstellar space, 11.6 billion miles from Earth.
<i>This post has been corrected, as indicated below.</i>

Now that Voyager 1 has safely reached interstellar space, scientists who have spent decades working on the mission at NASA’s Jet Propulsion Laboratory can finally breathe a sigh of relief.

“We’ve had 30 years of fear that something could go wrong,” said Torrence Johnson, a senior research scientist at JPL who worked on Voyager camera equipment. “There were white-knuckle moments.”

Those fears are gone now.

The Voyager 1 probe, first conceived in 1972 and launched in 1977, has exited the sun’s heliosphere, considered by many to be the informal boundary of the solar system. It’s the first man-made object to do it.


“We got there,” said Ed Stone, a Voyager project scientist at Caltech and former JPL chief. “This is something we hoped for when we started this 40 years ago.”

Scientists declared that Voyager had crossed the boundary after tracking the density of plasma surrounding the spacecraft. They got readings that were only possible once Voyager had left the heliosphere, the bubble-shaped region of space dominated by the sun’s gusting solar winds.

“We’re in a truly alien environment,” Stone said.

Listen to the sounds of interstellar space

Even as they cheered the accomplishment, the NASA scientists were quick to turn their focus toward the future.

“There is a sense that this is only the beginning,” said Gary Zank, director of the Center for Space Plasma and Aeronomic Research at the University of Alabama in Huntsville. Though “we’re out of our solar environment,” he said, “we’ve stepped into the galaxy.”

Johnson, 68, was just a twentysomething doing postdoctoral research at MIT when he moved to California in 1968 to work for JPL.

The Caltech grad and Altadena resident said scientists assigned to the mission in its early days were ambitious about what Voyager could accomplish. However, they weren’t always completely upfront about their grand designs when they sold the project to the lawmakers in Washington who controlled NASA’s purse strings.


Voyager would go to Jupiter and maybe Saturn, they said at the time. A mission to those planets was cheaper than one bound for Neptune and beyond. But hey, if the planets happened to align at the right time (they would) and Washington approved additional funds after the mission was underway (they did), Voyager could provide mounds more data about the solar system as the planets’ gravity flung it deeper into space.

Though it has crossed a historic threshold, Voyager’s mission is far from over. Its camera was turned off in 1990 and another important tool failed a decade earlier, but there’s plenty “the little space craft that could” can still accomplish, said Voyager project manager Suzanne Dodd.

Voyager 1 will continue to operate as-is until 2020. Then, over the next five years, scientists will shut down its instruments one at a time until it’s almost completely dead.

Voyager can continue sending basic engineering data to Earth until 2035, Dodd said.


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[For the Record, 2:50 p.m. PDT Sept. 13: An earlier version of this story said Voyager’s camera died in 1990. It didn’t die; NASA engineers shut it off to save power.]