In a remarkable feat of long-distance spacecraft maintenance, NASA engineers have successfully revived a set of backup thrusters on the Voyager 1 probe that had been dormant and considered inoperable for over two decades. This critical fix comes at a pivotal moment, as Earth-based communication with the iconic deep space explorer will soon be interrupted.

The Remarkable Revival

The interstellar spacecraft, launched in September 1977 and now roughly 25 billion kilometers (15 billion miles) from Earth, received commands to reactivate its backup roll thrusters, which had not been used since 2004. What makes this achievement particularly impressive is the extreme distance involved—signals traveling at the speed of light take nearly 23 hours to make the round trip between Earth and the spacecraft.

“I think at that time, the team was OK with accepting that the primary roll thrusters didn’t work, because they had a perfectly good backup,” explained Kareem Badaruddin, Voyager mission manager at NASA’s Jet Propulsion Laboratory (JPL), in comments shared by IFLScience. “And, frankly, they probably didn’t think the Voyagers were going to keep going for another 20 years.”

The timing of this engineering intervention was critical. NASA faces an impending months-long communication gap with both Voyager probes as the Deep Space Network antenna used to communicate with them goes offline for scheduled upgrades. The thrusters are essential for maintaining the spacecraft’s orientation, ensuring its antenna remains pointed toward Earth—the only way mission controllers can send commands and receive data.

Racing Against Time

The fix addresses a potential crisis that loomed on the horizon. The currently active thrusters were at risk of failing this fall due to the accumulation of residue in the thruster system. Under normal circumstances, all thrusters would be fired periodically to prevent such buildup, but in 2004, the main rolling thrusters experienced a significant issue when two small internal heaters lost power.

At that time, engineers considered the problem unfixable and relied on backup systems. Now, nearly 21 years later, with the spacecraft still operational far beyond its expected lifespan, the team has accomplished what was once thought impossible.

Engineering Across the Void

The resurrection of these thrusters represents another chapter in Voyager 1’s storied mission. Having completed its primary objective of observing the gas giants decades ago, the spacecraft has continued to function and provide valuable scientific data about the interstellar medium—the space between star systems.

Many of Voyager 1’s original components have been deactivated over the years. Some, like its cameras that captured the famous “Pale Blue Dot” image of Earth, were shut down to conserve power. Others have simply failed after decades of operation in the harsh environment of deep space.

A Legacy of Longevity

Voyager 1’s continued operation nearly 50 years after launch stands as a testament to NASA’s engineering prowess. The spacecraft relies on radioisotope thermoelectric generators (RTGs) for power, which continue to produce electricity from the heat of decaying plutonium, though at diminishing levels each year.

This latest success follows a pattern of creative problem-solving that has characterized the Voyager program. In 2022, engineers resolved a telemetry issue that had caused Voyager 1 to send back garbled data, demonstrating the team’s ability to troubleshoot complex problems across the vast distances of space.

As Earth’s most distant ambassador continues its journey into the unknown, this thruster revival ensures that humanity’s connection to its farthest-traveling creation remains intact—at least for a while longer. The Voyager mission continues to push the boundaries of what’s possible in space exploration, both in terms of distance traveled and engineering ingenuity.