Due to problems with the main radio transmitter , the Voyager 1 spacecraft sent a signal to Earth via an auxiliary module that had not been powered up since 1981. This is reported by the Space.com portal, referring to a statement by the American space agency NASA.
In mid-October, the interstellar probe experienced problems with its primary communications equipment, after which it automatically entered a safe operating mode to conserve power. The problem was discovered after a signal was sent over the Deep Space Network (DSN) to the spacecraft to turn on one of its heaters on October 16, and the mission team did not receive a response to that.
After sending new instructions to Voyager 1 on October 16, the mission team expected to hear back with data from the device in the next few days. Normally, it takes about 23 hours to transmit a signal to a probe located more than 24 billion kilometers from Earth. The same amount is needed by the device to transmit a signal to Earth.
On October 18, however, the mission team did not detect a signal from Voyager 1 at X-band frequencies using the DSN antennas. This happened due to the fact that the X-band signal turned out to be lower in power, as the emergency failure protection system reduced the power of the main transmitter as well. The mission team was later able to receive a signal from the probe, but on October 19 communication with Voyager 1 was completely lost as the probe completely shut down the X-band signal transmitter.
Mission engineers believe that after this failure, the ship's emergency protection system was activated several more times, eventually causing the probe to switch to an additional signal transmitter operating in S-band frequencies. The latter has not been used by the probe since 1981. Considering the fact that Voyager 1 is now much further from Earth than it was 43 years ago, the mission team feared that the signal from Earth simply would not reach S -the transmitter of the device, since the transmitter itself and its antenna use much less power than the X transmitter.
However, mission specialists also did not want to risk sending a signal to the X-band transmitter, which could potentially lead to reactivation of Voyager 1's emergency damage protection system. As a result, the signal from Earth on 22 October was sent right to the S-transmitter. Two days later, on October 24, the mission team was finally able to re-establish communication with the probe.
„The shutdown of the main transmitter appears to have been caused by an emergency failure protection system that autonomously resolves problems the device may encounter. The team is now gathering all available information that could help determine the source of the problem and return Voyager 1 to normal operation, NASA said in a statement.
Activation of Voyager 1's emergency collision protection system can be caused by a variety of reasons. One of them, for example, is the possible excessive power consumption of the device. If this happens, the probe automatically turns off the non-key systems to save energy.
Mission engineers are now trying to determine what caused the vehicle's defense system to activate, given that Voyager 1 had to have enough power to activate the heater. However, the NASA report notes that finding the source of the problem could take several weeks.