NASA engineers fix Voyager 1 telemetry transmission problem

NASA knows the ‘how’ but not the why of a telemetry data routing snafu that caused ‘garbled’ information about the position of the 45-year-old Voyager 1 probe to be sent to space controllers. ground mission.

Space agency engineers announcement a fix for the problem last night, saying they discovered data was being routed through the wrong place – an on-board computer which the team said was ‘known to have stopped working years ago’ , which then “corrupted the information”.

Calling the fix billions of miles away the “ultimate telesurgery”, Voyager propulsion engineer Todd Barber said the team was “thrilled” after being “baffled” by the nonsensical attitude control telemetry . “We were unable to obtain any health and safety information regarding the pointing of the spacecraft or any of the thruster operations,” he noted.

The ground crew needs Articulation and Attitude Control System (AACS) data from the venerable 1970s probe to control the orientation of the spacecraft. One of the most crucial functions of AACS is to keep Voyager 1’s high-gain antenna pointed precisely at Earth, otherwise it won’t send any data home.

When the problem first surfaced in “March or April,” Pasadena technicians were quick to point out that the craft, which entered interstellar space in 2012 and is currently the most man-made object farther from Earth, was functioning normally.

It was receiving commands from Earth and executing them, as well as collecting and returning scientific data, all without any compromise in signal, suggesting that these AACS values ​​were in fact in good condition. The team said that at the time the data they were receiving did not in fact reflect ‘any possible state the AACS might be in’, adding: ‘Voyager 1’s signal has not weakened neither, suggesting that the high-gain antenna remains in its prescribed orientation with the Earth.”

Suzanne Dodd, Voyager’s project manager, said that because the team had suspicions about the underlying problem, they opted to try a low-risk solution: order the AACS to resume sending the data to the correct computer – confirming their thesis as it apparently worked.

It’s not yet clear why the probe started sending telemetry to the wrong case, but NASA says it’s likely it received an erroneous command generated by another onboard computer. “If so, that would indicate there is a problem elsewhere on the spacecraft,” the JPL team added, saying they would continue to look for the underlying problem, but did not believe that it was a “threat” to long- term health.

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The fact that we are still receiving data 45 years later of the craft, currently 22.5 billion kilometers (14 billion miles or about 20 light hours) from Earth, is extraordinary, and some of the original team members were on hand to discuss it yesterday .

Voyager probe.  Image: NASA/JPL-Caltech

NASA builds forever: Voyager mission still underway after 45 years


Propulsion engineer Barber then listed the craft’s current problems. “We lose 4 watts [of power] a year on the spacecraft; things are incredibly cold; thruster lines are about to freeze; we had computer chip issues,” he said, adding that it was “kind of like running an old car — they’re geriatric by NASA standards and it’s the most engineering toughest I’ve done in my entire career, but also the most fun.”

The probe, launched in 1977 and featuring a 3.7-meter-wide (12-foot) radio antenna, was originally designed to last the five years the agency thought it would take to conduct studies closer to Jupiter and Saturn, Saturn’s rings and the larger moons of the two planets.

The register found it interesting that the telemetry issue was disclosed in May, but when the Voyager engineers appeared live yesterday, it looks like it started much earlier, in March or April, which makes us wonder about the process of verifying information, even on veteran ships. Barber also noted that “we announced the fix today.”

Speaking more broadly about Voyager’s resiliency, the project’s assistant scientist, Linda Spilker, said during the live Q&A session yesterday: “All computers are redundant on Voyager and we knew from an earlier flyby of Pioneer passing through Jupiter, that the radiation environment of Jupiter was quite harsh did a lot of things to harden the radiations of the two Voyagers and it helped them a lot not only for their flybys of Jupiter, but now in interstellar space , where those cosmic rays or high-energy radiation are more important – that little extra shield is always at work.”

When was the last time you performed troubleshooting on 1970s technology? Let us know in the comments below. ®

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