NASA’s Voyager 1 spacecraft, a remarkable feat of engineering, has been journeying through the vastness of space for nearly 50 years. Launched in 1977, less than a month after its twin probe, Voyager 2, this spacecraft has survived the harsh conditions of interstellar space, all while NASA teams on Earth work diligently to extend its operational life. Recently, engineers achieved a significant milestone by successfully reviving a set of thrusters on board Voyager 1 that had been inactive for decades.
This week, NASA announced that its engineers managed to restore functionality to Voyager 1's primary roll thrusters, which had been out of service since 2004 due to power loss in two small internal heaters. This revival is crucial as the spacecraft prepares for a period of downtime while a 230-foot-wide (70-meter-wide) antenna in Canberra, Australia, undergoes necessary upgrades. This antenna is part of NASA’s Deep Space Network and serves as the only communication dish powerful enough to send commands to the Voyager probes.
The primary roll thrusters play a vital role in maintaining the spacecraft’s orientation, allowing it to keep its antennas aligned towards Earth for data transmission and command reception. While Voyager 1 has been relying on its backup thrusters for the past 20 years, the revival of the primary roll thrusters adds an extra layer of security as the spacecraft continues its journey through interstellar space, currently positioned an astounding 15.14 billion miles (24.4 billion kilometers) away from Earth.
NASA’s engineering team had long accepted the failure of the primary roll thrusters, as the backup units were functioning adequately. “At that time, the team was OK with accepting that the primary roll thrusters didn’t work, because they had a perfectly good backup,” stated Kareem Badaruddin, Voyager mission manager at NASA’s Jet Propulsion Laboratory. “And, frankly, they probably didn’t think the Voyagers were going to keep going for another 20 years.” However, as the mission extended far beyond initial expectations, engineers decided to revisit the issue of the primary roll thrusters.
The need for this repair became urgent as the communication pause is set to last until February 2026, with only brief operation periods in August and December. During this downtime, any failure of the backup roll thrusters could pose a serious risk to the mission, potentially resulting in catastrophic challenges. The engineers had to ensure that Voyager 1 was capable of handling any issues that may arise during this extended silence from Earth.
After careful analysis, engineers suspected that a disturbance in the circuits controlling the heaters’ power supply might be the root cause of the thrusters’ malfunction. If they could reset this circuit, it was possible to reactivate the primary roll thrusters. On March 20, a significant breakthrough occurred—the primary roll thrusters came back online after years of dormancy. “These thrusters were considered dead. And that was a legitimate conclusion,” remarked Todd Barber, the mission’s propulsion lead at JPL. “It’s just that one of our engineers had this insight that maybe there was this other possible cause and it was fixable. It was yet another miracle save for Voyager.”
As the first spacecraft to cross into interstellar space, the Voyager probes have been on a historic journey, exploring the unknown for nearly 48 years. Voyager 1, in particular, has contributed significantly to our understanding of the outer planets, including the discovery of moons like Thebe and Metis, and a new ring around Saturn. Meanwhile, Voyager 2 continues its trajectory toward the solar system’s gas giants, Jupiter and Saturn, before venturing into the icy realms of Uranus and Neptune.
The revival of Voyager 1’s primary roll thrusters not only showcases the resilience of this aging spacecraft but also highlights the ingenuity of NASA's engineering teams. As they continue to push the boundaries of space exploration, the legacy of the Voyager missions will undoubtedly inspire future generations of scientists and explorers.
