NASA's Deep Space Network could not detect Voyager 1's radio signal on Oct. 18 and 19, and communication resumed Oct. 20 before engineers sent commands. One thruster group went offline and backups turned on. Engineers are still investigating the cause.
NASA's Deep Space Network could not detect a radio signal from Voyager 1 during two scheduled communication attempts, 24 hours apart, on Oct. 18 and 19. The signal reappeared on October 20, and the team has stayed in touch with the spacecraft since then. The loss of contact resolved itself before the team sent commands to the spacecraft to troubleshoot.
What engineers have found
Engineers have determined that one group of Voyager 1's thrusters went offline during the communication loss, and backup thrusters turned on automatically. The swap is programmed to happen automatically if the spacecraft's computers detect something amiss with the active thrusters. JPL calls this automatic response fault protection, which puts the probe into a safe, stable configuration and pauses normal operations. The pattern could indicate that onboard computers detected a problem and put the spacecraft into a safe mode.
Engineers still do not know what caused the communication problem, and no outages have happened since. Kareem Badaruddin, Voyager mission manager at JPL, said this is the first time the team has seen the spacecraft do something like this.
Approaching one light-day
Voyager 1 is expected to reach one light-day from Earth on November 18, 2026, at a distance of about 16.09 billion miles (25.89 billion kilometers). One light-day is the distance light travels in 24 hours. Once the probe passes that point, a radio message from Earth will take 24 hours to reach it and the reply another 24 hours to return.
Voyager 1 launched in September 1977 and is the most distant human-made object from Earth, traveling at approximately 38,000 mph (61,155 kph).
Power-saving efforts
In September, the team completed a power-saving effort on Voyager 1 nicknamed the "Big Bang", switching off three devices and activating three lower-power alternatives. It was completed about six weeks after the same swap was performed on Voyager 2. Without the changes, NASA estimated it would have needed to shut down another Voyager 1 instrument as early as summer 2027.
The Voyager probes are powered by heat from decaying plutonium converted into electricity, and each loses about four watts of power a year. The dwindling power has forced the team to turn off two of the mission's 10 dedicated science instruments in recent years. Both Voyager spacecraft also carry a Golden Record, a 12-inch gold-plated copper disk with sounds and images selected to portray life and culture on Earth.
