The space probe Voyager 1 is sending data back to Earth for the first time in five months, after engineers from NASA (United States space agency) come up with a creative solution to fix a communications problem aboard humanity's most distant spacecraft in the cosmos.
Voyager 1 is currently about 15 billion kilometers away, and at 46 years old, the probe has shown several quirks and signs of aging in recent years.
The most recent problem facing Voyager 1 first arose in November 2023, when the flight data system's telemetry modulation unit began sending an indecipherable repeating pattern of code.
Voyager 1's flight data system collects information from the spacecraft's scientific instruments and collates it with engineering data that reflects its current health status. Mission control on Earth receives this data in binary code, or a series of ones and zeros.
But since November, Voyager 1's flight data system has been stuck in a loop. Although the probe continued to relay a stable radio signal to its mission control team on Earth in recent months, the signal was not carrying any usable data.
The mission team received the first coherent data on the health and status of Voyager 1's engineering systems on April 20. Although the team is still analyzing the information, everything they've seen so far suggests that Voyager 1 is healthy and functioning properly.
“Today was a great day for Voyager 1,” said Linda Spilker, Voyager project scientist at the NASA-affiliated Jet Propulsion Laboratory (JPL), in a statement on Saturday. “We are back in communication with the spacecraft. And we look forward to receiving the scientific data back.”
The breakthrough was the result of intelligent trial and error testing and the unraveling of a mystery that led the team to a single chip.
Solving problems billions of kilometers away
After discovering the problem, the mission team attempted to send commands to restart the spacecraft's computer system and learn more about the underlying cause of the problem.
The team sent a command called a “poke” to Voyager 1 on March 1 to make the flight data system run different software sequences in hopes of figuring out what was causing the failure.
On March 3, the team noticed that activity in one part of the flight data system stood out from the rest of the scrambled data. Although the signal was not in the format that the Voyager team is accustomed to seeing when the flight data system is working as expected, an engineer with NASA's Deep Space Network was able to decode it.
The Deep Space Network is a system of radio antennas on Earth that helps the agency communicate with the Voyager probes and other spacecraft exploring our solar system.
The decoded signal included a readout of the entire flight data system memory.
By investigating the reading, the team determined the cause of the problem: 3% of the flight data system's memory is corrupt. A single chip responsible for storing part of the system's memory, including part of the computer's software code, is not working properly. Although the cause of the chip's failure is unknown, it may be worn out or may have been hit by an energetic particle from space, the team said.
The loss of the code on the chip rendered Voyager 1's scientific and engineering data unusable.
Since there was no way to repair the chip, the team chose to store the chip's affected code elsewhere in the system's memory. Although they could not find a place large enough to store all of the code, they were able to divide it into sections and store it at different points within the flight data system.
“For this plan to work, they also needed to adjust these sections of code to ensure, for example, that they all still worked as a whole,” according to a NASA update. “Any reference to the location of this code in other parts of the (flight data system) memory needed to be updated as well.”
After determining the code needed to package Voyager 1's engineering data, engineers sent a radio signal to the probe commanding the code to a new location in the system's memory on April 18.
Considering Voyager 1's immense distance from Earth, it takes approximately 22.5 hours for a radio signal to reach the probe and another 22.5 hours for the spacecraft's response signal to reach Earth.
On April 20, the team received feedback from Voyager 1 indicating that the clever code modification had worked, and they were finally able to receive readable engineering data from the probe once again.
Exploring interstellar space
In the coming weeks, the team will continue to relocate other affected parts of the system's software, including those responsible for returning the valuable scientific data that Voyager 1 is collecting.
Initially designed to last five years, Voyager 1 and its twin, Voyager 2, launched in 1977, are the longest operating spacecraft in history . Their exceptionally long lifetimes mean that both spacecraft have provided additional insights into our solar system and beyond, after achieving their preliminary goals of flying by Jupiter, Saturn, Uranus and Neptune decades ago.
Probes are currently venturing into uncharted cosmic territory along the outer reaches of the solar system. Both are in interstellar space and are the only spacecraft to operate beyond the heliosphere, the Sun's bubble of magnetic fields and particles that extends far beyond Pluto's orbit.
Voyager 2, which is operating normally, has traveled more than 12.6 billion miles (20.3 billion kilometers) from our planet.
Over time, both spacecraft faced unexpected problems and disruptions, including a seven-month period in 2020 when Voyager 2 was unable to communicate with Earth. In August 2023, the mission team used a risky “whooping” technique to restore communication with Voyager 2 after a command inadvertently oriented the spacecraft's antenna in the wrong direction.
The team estimates they are a few weeks away from receiving scientific data from Voyager 1 and are eager to see what that data contains.
“We never know for sure what will happen to Voyagers, but it constantly amazes me that they just keep going,” Voyager project manager Suzanne Dodd said in a statement. “We have had a lot of anomalies, and they are getting more difficult. But we have been lucky so far to recover from them. And the mission continues. And younger engineers are joining the Voyager team and contributing their expertise to keep the mission going.”
Source: CNN Brasil
Charles Grill is a tech-savvy writer with over 3 years of experience in the field. He writes on a variety of technology-related topics and has a strong focus on the latest advancements in the industry. He is connected with several online news websites and is currently contributing to a technology-focused platform.
