The Voyager 1 space probe disappeared from NASA's view for two days, then restored contact on its own. Engineers established that the spacecraft automatically switched to backup thrusters, but the cause of the failure remains unknown.
On 18 and 19 October 2026, the antennas of NASA's Deep Space Network twice failed to receive a signal from Voyager 1. The spacecraft is more than 25 billion kilometres from Earth, so it was impossible to quickly establish what had happened. On 20 October the signal reappeared, before NASA specialists had sent commands to fix the fault. Since then, the connection has remained stable.
Telemetry data showed that one of the attitude control thruster groups, which help the spacecraft point its antenna at Earth, had shut down. The onboard computer then brought the backup group into operation. The switch was carried out by a built-in protection system: when a fault is detected, it puts the probe into a safe state to prevent more serious breakdowns. Engineers have not yet determined what triggered the protection system. Mission manager Kareem Badaruddin of NASA's Jet Propulsion Laboratory said that specialists are seeing this behaviour from Voyager 1 for the first time.
The spacecraft's energy resources are gradually running down. Voyager 1 receives electricity from radioisotope thermoelectric generators, which convert heat released by the decay of plutonium into energy. Their output is declining, and the spacecraft loses roughly four watts a year. To prolong the work of its scientific instruments, in early September engineers carried out the "Big Bang" operation: they simultaneously switched off three heaters that maintain temperature and replaced them with less power-hungry ones. Without this, the next scientific instrument would have had to be shut down in the summer of 2027.
On 18 November 2026, Voyager 1 will become the first human-made object to move one light-day away from Earth, a distance of about 25.9 billion kilometres. A radio signal will need 24 hours to travel from Earth to the spacecraft, and another 24 hours to return with a reply. A full exchange of messages will take two days.
Voyager 1 launched in 1977, explored Jupiter and Saturn, and in 2012 became the first spacecraft to enter interstellar space. In recent years, engineers have more than once had to solve technical problems. The present case differs in that the spacecraft dealt with the malfunction on its own, without intervention from Earth.
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