NASA has successfully revived the thrusters aboard Voyager 1, the farthest spacecraft from Earth, just in time before a planned communications blackout. The thrusters, which were last used in 2004, had been out of action for nearly two decades due to power loss in internal heaters. Engineers at NASA’s Jet Propulsion Laboratory (JPL) managed to revive them by taking risks and trying new approaches.
Voyager 1 is a historic spacecraft that has been operating since September 1977 and uses more than one set of thrusters to function properly. The primary thrusters carefully orient the spacecraft so it can keep its antenna pointed at Earth, while the secondary thrusters control the spacecraft’s roll motion. If Voyager 1 can’t control its roll motion, the mission could be threatened.
The engineers had managed to avoid clogging the thrusters by commanding them to cycle between their original and backup systems for orientation. However, with a major communications blackout looming due to upgrades to an Earth-based antenna that sends commands to Voyager 1, the team had to act fast. They decided to switch on the primary roll thrusters and turn on the heaters before attempting to fix and restart the former.
The mission was a nail-biting test, as the team faced a time constraint and the risk of triggering a small explosion if the thrusters fired without the heaters being turned on. But the results showed that the thrusters were working again, with the temperature of the heater rising dramatically. The successful revival is considered a “miracle save” for Voyager 1 and has given the team more time to prepare for the upcoming communications blackout.
Source: https://edition.cnn.com/2025/05/14/science/voyager-1-thruster-fix