Voyager 1 was launched on 5 September 1977, i.e. almost 45 years ago.The probe is now just over 23.5 billion kilometers away, making it the furthest man-made object from home.The light takes just under 22 hours one way from the probe to Earth.Here you can see the status of Voyager 1 and 2 in real time.Nasa therefore became a little nervous in May 2022 when Voyager 1 suddenly started sending back telemetry data that was rather chaotic.Everything else worked as expected, and the probe not only sent back data and measurements, it also listened to commands sent from Earth.But the AACS system (attitude articulation and control system) sent back information that did not match what Nasa knew was happening on the probe.Most of all, it seemed like random data, and it couldn't possibly match any possible scenario for Voyager 1's internal systems.Another mystery was that the signals to Earth were actually as strong as before and arrived as expected.In addition to telemetry data, AACS is tasked, among other things, with ensuring that the Voyager probe's main antenna points towards Earth, so that signals are received and data is sent back.But if the AACS didn't work, it was strange that the antenna still seemed to point correctly.If not, the signal would vary in strength and perhaps also periodically cut out, but there were no signs of this.The probe had not gone into safety mode either.This means that only essential functions are maintained until the error can be found and fixed.But that hadn't happened either, so what was the real problem?When it takes almost a day to receive data from the probe, and another day to send it a new command, it is clear that the error fixing takes time.It's also not exactly appropriate to send a technician there to fix the problems, so you proceed slowly and methodically when making changes, so as not to make things worse and put yourself in a situation you can't get out of."A mystery like this is kind of expected at this stage of the Voyager mission," said Suzanne Dodd, project manager for Voyager 1 and 2 at NASA's Jet Propulsion Laboratory in Southern California.- The spacecraft are both almost 45 years old, which is far beyond what was expected.They are also in interstellar space – an environment with intense radiation, which no spacecraft has been in before.This means that there are some major challenges for the engineering team.But I believe that if there is a way to solve this problem with AACS, our team will find it.And found it they did.About three and a half months later, Nasa reported that the error had been found and corrected.The problem turned out to be that Voyager 1 suddenly started sending telemetry data through one of the craft's computers that had failed several years ago, and it was messing with the information.Data has since been sent via another computer on board.It is not known what caused Voyager 1 to suddenly start sending data via the wrong computer, but when Nasa began to suspect that this was what had happened, they decided to test a low-risk solution to the problem and sent the probe a command to send data via the correct computer.It turned out to do the trick and the telemetry data was meaningful again.But it has not yet been found out what happened.Voyager 1 probably received an incorrect command from another of the probe's computers.If so, it could be a sign that there is a problem in another system on the spacecraft.Nasa says it will continue to try to figure out the problem, but that it does not believe there is anything to indicate that Voyager 1 is in immediate danger.- We are happy to have the telemetry back, said Dodd.- We will do a full memory reading of AACS and look at everything it has done.That will help us try to diagnose the problem that caused the telemetry problem in the first place.So we are cautiously optimistic, but we still have more to investigate.With each passing year, the Voyager probes' systems will receive approx.4 watts less power to route with, and they therefore have to save power by turning off instruments.In total, such a probe needs 400 watts for instruments and their heating, but it is no longer possible to provide them with that.At launch, the systems were capable of delivering about 470 watts to each probe and its instruments, but now they deliver about 245 watts.Several systems have also been switched off because they are no longer needed or are no longer in working order.The antenna that sends data to Earth – a whopping 23.5 billion kilometers away, which corresponds to 157 times the distance between the Earth and the Sun – has an output of just 23 watts.Thus, sensitive antennas are required to pick up the signals.DSN's ("Deep Space Network") antennas with a diameter of 34 meters are needed to receive data 16 hours a day.The data transfer speed is not particularly high, either.Data transmitted in real time from Voyager 1 has a speed of only 160 bits per second.Six times a year, data is sent from the probe's recording system at a higher transfer rate of "a whopping" 2,800 bits per second.This data is written to the probe's tape recorder three times a week to be sent later.Then not only the aforementioned 34-metre antennas are needed, but also DSN antennas with a diameter of 70 metres.