Voyager 1 began transmitting incorrect telemetry – Kiri2ll – LiveJournal

Voyager 1 mission escort team faced with a riddle. The device, located in interstellar space, functions normally, continues to receive signals from the Earth and send scientific information collected by its instruments. But at the same time, recently, its attitude control system (AACS) began to transmit “garbage” telemetry, which does not correspond at all to what is happening on board the probe.


The AACS system controls the orientation of Voyager 1. Among other tasks, it keeps the probe’s high-gain antenna pointed accurately at Earth, allowing it to communicate. All indications are that AACS is still working because the device remains in touch. But at the same time, the telemetry transmitted to it does not make any sense. The data looks like it is generated randomly or does not represent any possible state of the AACS.

The telemetry problem has not yet triggered any of the onboard defense systems designed to put the craft into safe mode. Voyager 1’s signal has also not weakened, suggesting that its antenna remains pointed exactly at Earth. So far, mission specialists are trying to figure out what is the source of the problem – the AACS itself or some other system of the device, as well as how the current situation may affect the further operation of the probe.

At the moment, Voyager 1 is at a distance of 23.4 billion km from the Sun, being the most distant spacecraft in history. Its signal takes over 21.5 hours to reach Earth.

According to mission specialists, the problem with telemetry is to some extent expected. In August, Voyager 1 will turn 45 years old, which is an order of magnitude longer than the nominal life for which the probe was designed. During this time, he experienced a large number of various failures and technical problems. In addition, now the earthly messenger is in interstellar space – an environment with a high level of radiation in which no spacecraft has ever flown before.

However, engineers are hoping to find the cause of the AACS data issue and resolve it, perhaps by using a spare system or making changes to the software. In case this is not possible, the engineers will try to adapt to the anomaly.

The Voyager devices receive energy from radioisotope thermoelectric generators (RTGs). Over 45 years of flight, their power has almost halved due to the gradual decay of plutonium-238 and the degradation of the thermocouple. Probes lose another 4 watts each year. However, for now, they have enough energy to keep active scientific instruments running. The project staff hope to find a way that will allow the devices to continue working until the end of the current decade.

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