NASA's fight to save a spacecraft 24 billion kilometers away

For about 5 months, experts tried every way to fix the error and restore communication for Voyager 1, a ship that had been operating for nearly half a century .

After five months of work to reestablish contact with the farthest-flying man-made object, the Voyager 1 spacecraft, NASA announced that the spacecraft finally "phoned" home on April 20. For the engineers and scientists working on NASA's longest-running space mission, it was a moment of immense relief and excitement.

Simulation of the Voyager 1 spacecraft entering interstellar space.

"That Saturday morning, we all arrived, sat around boxes of donuts and waited for the data to come back from Voyager. We knew exactly when it was going to happen, it was all very quiet, everyone just sitting there and looking at the screen ," recalls Linda Spilker, Voyager 1 mission scientist at NASA's Jet Propulsion Laboratory (JPL).

When the spacecraft finally answered the call, the room erupted with celebration. "There were cheers, people raised their hands in the air, there was also a sense of relief. After all the hard work, from the near impossibility of receiving Voyager's signal to re-establishing communications, It was a huge relief and a great feeling ," Spilker shared.

Voyager 1's problem was first discovered last November. At that time, NASA still kept in contact with the ship and could see it receiving signals from Earth. But what was sent back to the control station - including scientific data, information about the health of the ship and its onboard systems - was distorted, unreadable. This launched a months-long " war" to determine what happened and save Voyager 1.

Spilker and his colleagues remain hopeful and optimistic, but they face enormous challenges. First, engineers must try to fix the problem as the spacecraft moves through interstellar space, more than 24 billion kilometers from Earth.

Members of the Voyager team celebrate in the conference room at NASA's Jet Propulsion Laboratory (JPL) on April 20. (Photo: NASA)

"With Voyager 1, it took 22.5 hours to transmit the signal and another 22.5 hours to receive the signal back. So we prepared the commands, transmitted them and received them about two days later. get the answer to see if it's effective or not ," Spilker said.

Ultimately, the team of experts determined that the problem originated from one of three computers on the ship. A hardware error - most likely due to aging or radiation - could have messed up a piece of code in the computer's memory, Spilker said . This malfunction prevented Voyager 1 from transmitting clear information regarding its health status and scientific observations.

The NASA engineering team determined that they would not be able to repair the damaged software storage chip. The faulty code was also too large for Voyager 1's computer to store both it and any new instructions that arrived. Because the technology on Voyager 1 existed in the 1960s and 1970s, computer memory was worse than today's smartphones. It is roughly equivalent to the memory capacity in an electronic car key, Spilker said.

Finally, the team of experts found a solution. They divide code into smaller parts and store them in different areas of the computer's memory. They then reprogram the part that needs fixing while ensuring the entire system operates seamlessly. That's a feat, since Voyager 1 was built so long ago and there were no test platforms or simulators on Earth to test new code before sending it on board.

"There were three people looking at every line of the code we were sending, looking for anything that might have been missed. It was like a visual inspection ," Spilker said. This hard work has finally paid off, with Voyager 1 being restored.

To date, the research team has determined that Voyager 1 is still in good condition and operating normally , NBC News reported on April 27. The spacecraft's scientific instruments are still on and appear to be working, but it will take some time for the spacecraft to resume transmitting scientific data, Spilker said.

The Titan/Centaur-6 launch vehicle launched Voyager 1 from Kennedy Space Center on September 5, 1977. (Photo: NASA)

Voyager 1 and its "twin brother" Voyager 2 launched into space in 1977 with a mission to study the outer Solar System. According to Spilker, the ships could last into the 2030s. Eventually, they will run out of power or their parts will become too old to continue operating.

The day Voyager 1 and 2 are decommissioned will be a very difficult day, but they will continue to exist as "silent ambassadors". Both ships carried valuable messages on the Golden Record. The discs contain images and sounds representing life on Earth and human culture, including music, animal sounds, laughter, and greetings recorded in multiple languages. The spacecraft duo will carry these messages until they are discovered by astronauts in the distant future.

"Maybe in about 40,000 years, they will come quite close to another star. Then, they can be found ," Spilker said.