NASA’s Voyager 1, the most distant spacecraft from Earth, continues to send cogent science data after a months-long disruption in communication.
Voyager 1’s four instruments are back in business after a computer problem in November, officials at Jet Propulsion Laboratory confirmed this month.
The agency reported back in April that the spacecraft appeared to be back online — and the communication appears to remain solid. On May 19, JPL announced that they were receiving science data from two of the four instruments aboard the 46-year-old spacecraft. On June 13, JPL said that all four instruments were functioning.
The JPL crew recently commanded it to start studying its environment again.
Launched in 1977, Voyager 1 is drifting through interstellar space, or the space between star systems. Before reaching this region, the spacecraft discovered a thin ring around Jupiter and several of Saturn’s moons. Its instruments are designed to collect information about plasma waves, magnetic fields and particles.
Voyager 1 is more than 15 billion miles from Earth. Its twin Voyager 2 — also in interstellar space — is more than 12 billion miles (19.31 billion kilometers) away.
At Jet Propulsion Laboratory in La Canada Flintridge, months of concern and intense troubleshooting resulted from the spacecraft going off-line.
The Voyager team at the sprawling Southern California lab on April 20 finally heard back from Voyager 1 again, in a way that was more than just gibberish.
For the first time since November, Voyager 1 was once again returning usable data about the health and status of its onboard engineering systems.
After losing contact with the space probe in November, the team back in March received the first signs of Voyager 1 being back online in five months. It took some clever computer engineering and an ongoing emergency operation from 15 million miles away.
The break in communication came due to malfunction in one of the spacecraft’s three onboard computers, called the flight data subsystem, which is responsible for packaging the science and engineering data before it’s sent to Earth. With the data system unable to function, the space probe was receiving data and sending it back to NASA, but it was essentially unreadable gibberish.
Voyager 1 could hear the messages being sent from Earth but couldn’t respond coherently, providing no information on its health or status.
However, the fact that the ever dependable Voyager, now years past its expected useful life, was still operating gave the team enough hope to attempt what would essentially be brain surgery on the space probe to get it communicating properly again.
Unable to simply repair the part, the team decided to place code elsewhere in the flight data subsystem memory, but since it was too large to put in any single location, they had to break it up in sections — requiring them to adjust the code to ensure it all worked together functionally and update the system.
The team started by singling out the code responsible for packaging the spacecraft’s engineering data, which they completed April 18.
It took nearly a day for NASA’s radio signals to reach the probe and another day to hear back while scientists listened intently for a message from deep space, but finally they heard a familiar response.
The team has been working to adjust the other affected portions of the FDS software.
“We never know for sure what’s going to happen with the Voyagers, but it constantly amazes me when they just keep going,” Voyager Project Manager Suzanne Dodd said in a statement.
Voyager 2, meanwhile, continues to operate normally, though last year JPL engineers used a longshot maneuver to get it to begin returning data again, too.
Launched more than 46 years ago, the twin Voyager spacecraft are the longest-running and most distant spacecraft in history — or at least our history.
Before they ever got to interstellar space, both probes flew by Saturn and Jupiter, and Voyager 2 flew by Uranus and Neptune.
Voyager 1 discovered a thin ring around Jupiter and two new Jovian moons: Thebe and Metis. At Saturn, the craft found five new moons and a new ring called the G-ring.
By February of 1998, it had become the most distant human-made object after overtaking NASA’s Pioneer 10. And by 2012, it entered a whole new ballgame: interstellar space.
Interestingly, according to JPL, Voyager 1 was launched after Voyager 2, but because of a faster route, it exited the asteroid belt earlier than its twin, having overtaken Voyager 2 on Dec. 15, 1977.
The Associated Press contributed to this report.
