Against all odds, NASA engineers brought back to life a set of Voyager 1’s thrusters thought to be dead since 2004.
Reviving “Dead” Voyager 1 Thrusters In a remarkable engineering feat, NASA scientists at the Jet Propulsion Laboratory (JPL) in Southern California have reactivated a set of thrusters on the Voyager 1 spacecraft that hadn’t worked since 2004.
But on Voyager 1, the primary roll thrusters stopped working in 2004 after losing power in two small internal heaters.
Engineers determined the broken heaters were likely unfixable and opted to rely solely on Voyager 1’s backup roll thrusters to orient the star tracker.
It was yet another miracle save for Voyager.” More About Voyager Voyager 1 and 2 are NASA’s iconic deep space explorers, launched in 1977 to study the outer planets—Jupiter, Saturn, Uranus, and Neptune.
Despite all odds, a set of Voyager 1 thrusters believed to be dead since 2004 were revived by NASA engineers.
Growing worries that the spacecraft’s current thrusters might soon fail, given that it is now in deep interstellar space, prompted the fix. The team made a bold and complex attempt to revive the dormant system in a race against time before a protracted communications blackout. Just in time, their innovative theory transformed a system that was all but forgotten into a backup that saved the mission.
Reviving the “Dead” thrusters of Voyager 1.
NASA engineers at the Jet Propulsion Laboratory (JPL) in Southern California have accomplished a remarkable engineering feat by reactivating a set of thrusters on the Voyager 1 spacecraft that had not functioned since 2004. For twenty years, these thrusters were regarded as being out of service. Although restoring them required some risk and some ingenuity, the team wanted a solid backup. This is because there are indications that the primary thrusters that are currently in operation are clogged with residue, which could prevent them from operating as early as this fall.
It was crucial to time. Before May 4, when the potent Earth-based antenna that transmits commands to Voyager 1 and its twin, Voyager 2, would go offline for several months of planned upgrades, NASA needed to restart these backup thrusters.
Interstellar Roll Control Navigation.
Currently traveling at approximately 35,000 miles per hour through interstellar space, both Voyagers were launched in 1977. They use little thrusters to change their orientation so they can send and receive signals, and they keep their antennas pointed directly at Earth.
Every Voyager has a set of primary thrusters that regulate movement in several directions in addition to separate thrusters for roll motion, a particular kind of movement. This roll appears to Earth as the antenna spinning like a vinyl record. The spacecraft locks onto a guide star to maintain proper alignment thanks to that subtle motion.
For roll control, the spacecraft are also equipped with backup thrusters. In 2018 and 2019, they restored a third set that had been utilized for their planetary flybys. Nevertheless, roll adjustments—which are essential for preserving contact with Earth—cannot be handled by those thrusters.
Thruster Failure and Contingency Plan.
The engineers alternate between the primary, backup, and trajectory thruster sets of both Voyagers in order to handle the clogging tubes in the thrusters. However, Voyager 1’s main roll thrusters failed in 2004 as a result of two tiny internal heaters losing power. Engineers decided to use Voyager 1’s backup roll thrusters exclusively to orient the star tracker after concluding that the damaged heaters were probably irreparable.
Kareem Badaruddin, Voyager mission manager at JPL, which oversees the mission for NASA, stated, “I believe the team was comfortable with acknowledging that the primary roll thrusters didn’t work at that time, because they had a perfectly good backup.”. They also likely didn’t believe the Voyagers would survive for another 20 years, to be honest. “”.
Ancient Hope Is Rekindled by New Theory.
The engineering team chose to reexamine the 2004 thruster failure because, in the absence of control over the spacecraft’s roll motion, a number of problems could occur and endanger the mission. They started to suspect that a switch had been inadvertently flipped to the incorrect position due to an unforeseen alteration or disruption in the circuits that regulate the heaters’ power supply. The heaters might function again if they could flip the switch back to its initial setting. This would allow them to use the primary roll thrusters again in the event that the backup roll thrusters, which have been in use since 2004, become totally clogged.
Dangerous Restart With Limited Time.
It took some puzzle-solving to figure out the solution. After turning on the inactive roll thrusters, the team would need to attempt repairing and restarting the heaters. During that period, the spacecraft’s programming would cause the long-dormant roll thrusters to automatically activate if the star tracker strayed too far from the guide star. Additionally, the team needed to point the star tracker as precisely as possible because if the heaters were still off when they fired, it might cause a minor explosion.
Why a single antenna could make all the difference.
Deep Space Station 43 (DSS-43), a 230-foot (70-meter) wide antenna in Canberra, Australia, which is a part of NASA’s Deep Space Network, would be undergoing upgrades from May 4, 2025, to February 2026, so the team would be under even more time pressure. With brief outages in August and December, it would be offline for the majority of that time.
DSS-43 is the only dish with sufficient signal power to transmit commands to the Voyagers, despite the fact that the Deep Space Network has three complexes evenly distributed throughout the world (in Goldstone, California, and Madrid, in addition to Australia) to guarantee continuous contact with spacecraft as Earth rotates.
The director of the Interplanetary Network at JPL, which oversees the Deep Space Network for NASA, and Voyager project manager Suzanne Dodd stated, “These antenna upgrades are important for future crewed lunar landings, and they also increase communications capacity for our science missions in deep space, some of which are building on the discoveries Voyager made.”. Since this kind of downtime has happened before, we’re just making every preparation we can. “”.
Because the thrusters currently in use on Voyager 1 may be fully clogged by the time the dish briefly returns online in August, the team wanted to ensure that the long-dormant thrusters would be available.
A long shot of 20 years pays off.
The team’s efforts paid off on March 20, when they saw the spacecraft carry out their instructions. Everything the team witnessed had happened nearly a day earlier because of Voyager’s distance, which causes the radio signal to take more than 23 hours to reach Earth from the spacecraft. Voyager may have already been in danger if the test had been unsuccessful. However, the team realized they had succeeded when they noticed a sharp increase in the thruster heaters’ temperature within 20 minutes.
“It was such a wonderful occasion. That day, team morale was really high,” stated Todd Barber, the JPL mission’s propulsion lead. They were regarded as dead thrusters. And it was a valid conclusion. Just one of our engineers thought that perhaps there was another potential reason, and that it could be fixed. Save for Voyager, it was another miracle. “.”.
Learn More About Voyager.
NASA’s famous deep space explorers, Voyager 1 and 2, were launched in 1977 with the goal of studying Jupiter, Saturn, Uranus, and Neptune. Currently situated approximately 15 billion miles away from Earth (Voyager 1) and 13 billion miles away from Earth (Voyager 2), the spacecraft have made the most extensive journey of any man-made object in history.
Following their planetary missions, both Voyagers were the first and only spacecraft to enter and send data from interstellar space, which is the vast area outside the heliosphere, the Sun’s protective bubble of particles and magnetic fields, and beyond the planets of our solar system. They continue to offer ground-breaking discoveries about the far reaches of our solar neighborhood.
