What's New With Voyager 1?

 Voyager 1 is no Longer Sending Home Garbled Data!

This aging and still-valuable spacecraft has been exploring the outer parts of the solar system since its launch in 1977, along with its twin sibling, Voyager 2. They each traveled slightly different trajectories. Both went past Jupiter and Saturn, but Voyager 2 continued on to Uranus and Neptune. They’re both now outside the solar system, sending back data about the regions of space they’re exploring.

Voyager 1 flew past Jupiter in March 1979, and Saturn in November 1980. After its close approaches to those two gas giants, it started a trajectory out of the solar system and entered interstellar space in 2013. That’s when it ceased to detect the solar wind and scientists began to see an increase in particles consistent with those in interstellar space.

These days, Voyager 1 is more than 157.3 astronomical units from Earth and moving out at well over 61,000 km/hour. It’s busy collecting data about the interstellar medium and radiation from distant objects. If all goes well, the spacecraft should continue sending back data for nearly a decade. After that, it should fall silent as it travels beyond the Oort Cloud and out to the stars.

Earlier this year, however, the teams attached to the Voyager 1 mission noticed that the spacecraft was sending weird readouts about its attitude articulation and control system (called AACS, for short). Essentially, the AACS was sending telemetry data all right, but it was routing it to the wrong computer, one that had failed years ago. This corrupted the data, which led to the strangely garbled messages the ground-based crew received.

Once the engineers figured out that the old, dead computer might have been part of the problem, they had a way forward. They simply told the AACS to switch over sending to the correct computer system. The good news was that it didn’t affect science data-gathering and transmission. The best news came this week: team engineers have fixed the issue with the AACS and the data are flowing normally again.

The ongoing issue with AACS didn’t set off any fault protection systems onboard the spacecraft. If it had, Voyager 1 would have gone into “safe mode” while engineers tried to figure out what happened. During the period of garbled signals, AACS continued working, which indicated that the problem was either upstream or downstream of the unit. The fact that data were garbled provided a good clue to related computer issues.




This adapted article appeared in Universe Today. Click through for the full thing.