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In a Breathtaking First, NASA Craft Exits the Solar System In a Breathtaking First, NASA Craft Exits the Solar System
(about 3 hours later)
PASADENA, Calif. — The spacecraft’s technology is laughable by today’s standards: it carried an 8-track tape recorder and computers with 1/240,000th the memory of a low-end iPhone. When it left Earth 36 years ago, it was designed as a four-year mission to Saturn, and everything after that was gravy. PASADENA, Calif. — By today’s standards, the spacecraft’s technology is laughable: it carries an 8-track tape recorder and computers with one-240,000th the memory of a low-end iPhone. When it left Earth 36 years ago, it was designed as a four-year mission to Saturn, and everything after that was gravy.
But Voyager I has become — unexpectedly — the Little Spacecraft That Could. On Thursday, scientists declared that it had become the first man-made object to exit the solar system, a breathtaking achievement that NASA could only fantasize about back when it was launched in 1977, the same year that “Star Wars” was released. But Voyager 1 has become — thrillingly — the Little Spacecraft That Could. On Thursday, scientists declared that it had become the first manufactured object to exit the solar system, a breathtaking achievement that NASA could only fantasize about back when Voyager was launched in 1977, the same year “Star Wars” was released.
“I don’t know if it’s in the same league as landing on the moon, but it’s right up there — ‘Star Trek’ stuff, for sure,” said Donald A. Gurnett, a professor of physics at the University of Iowa and the co-author of a paper published Thursday in the journal Science about Voyager’s feat. “I mean, consider the distance. It’s hard even for scientists to comprehend.”“I don’t know if it’s in the same league as landing on the moon, but it’s right up there — ‘Star Trek’ stuff, for sure,” said Donald A. Gurnett, a professor of physics at the University of Iowa and the co-author of a paper published Thursday in the journal Science about Voyager’s feat. “I mean, consider the distance. It’s hard even for scientists to comprehend.”
Even among planetary scientists, who tend to dream large, the idea that something they built could travel so far for so long and pierce the Sun’s reach is an impressive one. Plenty of telescopes gaze at the far parts of the Milky Way, but Voyager 1 can now touch and feel this unexplored region and send back detailed dispatches. Given the distance, it takes about 17 hours for Voyager’s signals to reach NASA’s Jet Propulsion Laboratory here. Even among planetary scientists, who tend to dream large, the idea that something they built could travel beyond the Sun’s empire and keep grinding away is impressive. Plenty of telescopes gaze at the far parts of the Milky Way, but Voyager 1 can now touch and feel the cold, unexplored region in between the stars and send back detailed dispatches about conditions there. It takes 17 hours and 22 minutes for Voyager’s signals to reach NASA’s Jet Propulsion Laboratory here.
“This is historic stuff, a bit like the first exploration of Earth, and we had to look at the data very, very carefully,” said Edward C. Stone, 77, NASA’s top Voyager expert, who has been working on the project since 1972. Ever the stoical scientist, he does get excited about what comes next. “It’s now the start of a whole new mission,” he said. “This is historic stuff, a bit like the first exploration of Earth, and we had to look at the data very, very carefully,” said Edward C. Stone, 77, NASA’s top Voyager expert, who has been working on the project since 1972. He said he was excited about what comes next. “It’s now the start of a whole new mission,” he said.
The lonely probe, which is 11.7 billion miles from Earth and hurtling away at 38,000 miles per hour, has long been on the verge of bursting through the heliosphere, a vast, bullet-shaped bubble of particles blown out by the sun. Scientists have spent this year debating whether it had done so, interpreting the data Voyager sent back in different ways. The lonely probe, which is 11.7 billion miles from Earth and hurtling away at 38,000 miles per hour, has long been on the cusp, treading a boundary between the bubble of hot, energetic particles around the solar system and the dark region beyond. There, in interstellar space, the plasma, or ionized gas, is noticeably denser.
But now it is official that Voyager 1 passed into the cool, dark and unknown vastness of interstellar space, a place full of dust, plasma and other matter from exploded stars. The article in Science pinpointed a date: Aug. 25, 2012. Dr. Gurnett and his team have spent the past few months analyzing their data, trying to nail down whether what they were seeing was solar plasma or the plasma of interstellar space. Now they are certain it was the latter, and have even pinpointed a date for the crossing: Aug. 25, 2012.
“This is the moment we’ve all been waiting for,” said Jia-Rui C. Cook, the media liaison at NASA’s Jet Propulsion Laboratory, in an e-mail to a reporter. “I can’t even sleep it’s so exciting!” At a news conference on Thursday, NASA scientists were a bit vague about what they hope to get from Voyager 1 from now on. The answer, to some extent, depends on what instruments continue to function as the power supply dwindles. Dr. Stone expects Voyager 1 to keep sending back data — with a 23-watt transmitter, about the equivalent of a refrigerator light bulb — until roughly 2025.
Coincidentally, the same month that Voyager 1 left the solar system, Curiosity, NASA’s state-of-the-art rover, landed on Mars and started sending home gorgeous snapshots. Soon afterward, Curiosity’s exploration team, some 400 strong, dazzled the world by driving the $2.5 billion robot across a patch of Martian terrain, a feat that turned the Red Bull-chugging engineers and scientists of Building 264 of the Jet Propulsion Laboratory campus into rock stars. One hope is that Voyager 1’s position will allow scientists to more accurately study galactic cosmic rays, which are high-energy particles that originate outside the solar system. They would use the information to make judgments about what interstellar space is like at even greater distances from Earth.
A spoof video, “We’re NASA and We Know It,” recorded to the beat of the song “Sexy and I Know It,” generated 2.8 million views on YouTube. In its heyday, Voyager 1 pumped out never-before-seen images of Jupiter and Saturn. But it stopped sending home pictures in 1990, to conserve energy and because there was no longer much to see. A companion spacecraft, Voyager 2, also launched in 1977, has also stopped sending back images. Voyager 2 is moving in a different direction but is also expected to exit the solar system.
Voyager, meanwhile, stopped sending home pictures in 1990, to conserve energy. In its heyday, it pumped out never-before-seen images of Jupiter and Saturn, but lately there has not been much to see. Eventually, NASA said, the Voyagers will pass other stars, coasting and drifting and being pulled by gravity. The next big encounter for Voyager 1, in around 40,000 years, is expected to be a dwarf star dispassionately known as AC+793888 in the constellation of Camelopardalis.
As the mission lost its sizzle, its 12-person staff was booted from the laboratory’s campus and sent to cramped quarters down the street next to a McDonald’s. Suzanne R. Dodd, the Voyager project manager, said that when she has attended meetings in Building 264, she has kept a low profile in deference to the Mars team. But already, Voyager 1 has achieved what Dr. Gurnett called “the holy grail of heliosphere research.”
Voyager 1 left the solar system the same month that Curiosity, NASA’s state-of-the-art rover, landed on Mars and started sending home gorgeous snapshots. Curiosity’s exploration team, some 400 strong, promptly dazzled the world by driving the $2.5 billion robot across a patch of Martian terrain, a feat that turned the Red Bull-chugging engineers and scientists of Building 264 of the Jet Propulsion Laboratory campus into rock stars. By comparison, the Voyager mission looked like a Betamax in the era of Bluetooth.
The 12-person Voyager staff was long ago moved from the Jet Propulsion Laboratory campus to cramped quarters down the street, next to a McDonald’s. In an interview last month at Voyager’s offices, Suzanne R. Dodd, the Voyager project manager, said that when she attended meetings in Building 264, she kept a low profile in deference to the Mars team.
“I try to stay out of the elevator and take the stairs,” Ms. Dodd said. “They’re doing important work there, and I’ll only slow them down.”“I try to stay out of the elevator and take the stairs,” Ms. Dodd said. “They’re doing important work there, and I’ll only slow them down.”
Now she and her team seem poised to be back in the spotlight, perhaps for years to come. Dr. Stone, vice provost for special projects at the California Institute of Technology and former director of the Jet Propulsion Laboratory, expects Voyager 1 to keep sending back data — with a 23-watt transmitter, about the equivalent of a refrigerator light bulb — until roughly 2025. At 52, Ms. Dodd is a relative newcomer to Voyager, first working on the mission in 1984. Now she and her team seem poised to return to the spotlight.
Not that the aging spacecraft has made things easy. An instrument that measures the energy of particles in plasma stopped working in 1980. But scientists still have access to a related sensor, a spindly antenna that records electron oscillations in plasma. The catch is that these oscillations don’t occur all the time; they typically happen when stirred up by a solar eruption. As the solar system’s edge grew tantalizingly close, NASA asked the Voyager scientists to increase the amount of data collection. The problem: the 8-track recorders from 1977 were not exactly bursting with extra space. Could Ms. Dodd even find anyone who specialized in that piece of technology and could coax it to record more?
Voyager 1’s plasma wave antenna picked up audible vibrations in April and May that allowed Dr. Gurnett and his colleagues to calculate the density of the plasma around the spacecraft, which would help them determine whether the craft was still in the solar system. “These younger engineers can write a lot of sloppy code, and it doesn’t matter, but here, with very limited capacity, you have to be extremely precise and have a real strategy,” she said.
“It was exactly what we expected for interstellar plasma,” Dr. Gurnett said. She was able to find her man: Lawrence J. Zottarelli, 77, a retired NASA engineer. He came up with a solution. But would it work?
Moreover, by combing through older oscillation data collected by Voyager 1, the team discovered that the edge of the solar system — the threshold that was crossed in late summer of 2012 — was roughly where Dr. Gurnett predicted it would be back in 1993 by using different solar storm calculations. With his striped suspenders and graying hair, Mr. Zottarelli waited at Voyager mission control one afternoon last month to find out. The first of the newly programmed data dumps was set to come down. Ms. Dodd, Dr. Stone and Mr. Zottarelli watched two old Sun Microsystems computers like children watching for a chick to peck through an egg. “Nine, eight, seven,” Dr. Stone counted down.
“Am I bragging here? No,” he said. “All right. I admit it. It’s bragging a little.”
As the solar system’s edge grew tantalizingly close, NASA asked Ms. Dodd and her team to increase the amount of data collection. The problem: 8-track recorders from 1977 are not exactly bursting with extra space. Could she even find anyone who specialized in that piece of recording technology?
“These younger engineers can write a lot of sloppy code, and it doesn’t matter, but here, with very limited capacity,” said Ms. Dodd, “you have to be extremely precise and have a real strategy.”
At 52, Ms. Dodd is a relative newcomer to Voyager, first working on the mission in 1984, when Voyager 2 — a companion spacecraft also launched in 1977 and still inside the solar system — was headed toward Uranus. But she was able to find her man: Lawrence J. Zottarelli, 77, a retired NASA engineer. He came up with a solution. But would it work?
Mr. Zottarelli waited at Voyager mission control one afternoon last month to find out. The first of the newly programmed data dumps was set to come down. Ms. Dodd, Dr. Stone and Mr. Zottarelli watched two old Sun Microsystems computers like children watching for a chick to peck through an egg. “Nine, eight, seven,” Dr. Stone counted down.
“Everything’s fine,” said Mr. Zottarelli, flashing a thumbs up and hiking up his trousers. “You’re on your own now.”“Everything’s fine,” said Mr. Zottarelli, flashing a thumbs up and hiking up his trousers. “You’re on your own now.”
The relief was written all over Ms. Dodd’s face, too. “It’s not easy flying an old spacecraft,” she said. The relief was written all over Ms. Dodd’s face. “It’s not easy flying an old spacecraft,” she said.
Her eyes moved to Dr. Stone, who was peering at a computer through his trifocals.Her eyes moved to Dr. Stone, who was peering at a computer through his trifocals.
“There are lots of old missions,” he responded, a sly smile taking over his face. “But not many are doing exciting new things.”“There are lots of old missions,” he responded, a sly smile taking over his face. “But not many are doing exciting new things.”

This article has been revised to reflect the following correction:

This article has been revised to reflect the following correction:

Correction: September 12, 2013Correction: September 12, 2013

A picture caption with an earlier version of this article referred incorrectly to Voyager 1. It is a spacecraft, not a satellite.

A picture caption with an earlier version of this article referred incorrectly to Voyager 1. It is a spacecraft, not a satellite.