Voyager 1, despite being billions of miles away, experienced an anomaly where its attitude articulation and control system (AACS) sent garbled telemetry data, even though the probe remained operational. Engineers diagnosed the issue as the AACS inadvertently sending data through a defunct onboard computer, which corrupted the information. The team successfully commanded Voyager 1 to switch back to the correct computer for telemetry, resolving the anomaly. Though the root cause of why the AACS routed data through the wrong computer remains unknown, Voyager 1 is now functioning as expected, sending back clear telemetry.
The author experienced system hangs on wake-up with their AMD GPU on Linux. They traced the issue to the AMDGPU driver's handling of the PCIe link and power states during suspend and resume. Specifically, the driver was prematurely powering off the GPU before the system had fully suspended, leading to a deadlock. By patching the driver to ensure the GPU remained powered on until the system was fully asleep, and then properly re-initializing it upon waking, they resolved the hanging issue. This fix has since been incorporated upstream into the official Linux kernel.
Commenters on Hacker News largely praised the author's work in debugging and fixing the AMD GPU sleep/wake hang issue. Several expressed having experienced this frustrating problem themselves, highlighting the real-world impact of the fix. Some discussed the complexities of debugging kernel issues and driver interactions, commending the author's persistence and systematic approach. A few commenters also inquired about specific configurations and potential remaining edge cases, while others offered additional technical insights and potential avenues for further improvement or investigation, such as exploring runtime power management. The overall sentiment reflects appreciation for the author's contribution to improving the Linux AMD GPU experience.
Summary of Comments ( 9 )
https://news.ycombinator.com/item?id=43732632
The Hacker News comments express admiration for the Voyager team's ingenuity and perseverance in diagnosing and fixing the anomaly from such a vast distance. Several commenters highlight the impressive feat of debugging a 50-year-old system with limited telemetry and communication. Some discuss the technical aspects of the problem and solution, including the use of the AACS's articulation test mode and the likely cause being a faulty component sending erroneous commands. Others reflect on the historical significance of Voyager and the dedication of the engineers involved, both past and present. A few commenters mention the emotional impact of the mission's continued success and the awe-inspiring nature of exploring interstellar space.
The Hacker News post "We Diagnosed and Fixed the 2023 Voyager 1 Anomaly from 15B Miles Away [video]" generated several comments discussing the impressive feat of engineering and the ingenuity involved in troubleshooting a problem so far from Earth.
Several commenters expressed awe and admiration for the engineers who designed and maintain Voyager 1. They marvelled at the longevity and resilience of the probe, highlighting the difficulty of diagnosing and fixing a problem billions of miles away with limited communication capabilities. The ingenuity of using existing hardware and software workarounds to solve the issue was a recurring theme of praise. Some users reminisced about the Voyager program's launch and their childhood fascination with space exploration, emphasizing the historical significance of the mission's continued operation.
Some comments delved into the technical details of the anomaly and the fix. They discussed the articulation and attitude control system (AACS), its role in orienting the spacecraft and its high-gain antenna towards Earth, and the challenges posed by the corrupted telemetry data. The commenters explained how the engineers were able to pinpoint the faulty component within the AACS and how they re-routed commands to a backup system. The complexity of achieving this with limited bandwidth and significant signal delay was highlighted.
A few commenters pointed out the unexpected benefit of gaining a deeper understanding of the aging spacecraft's systems through this troubleshooting process. They noted that this knowledge could prove invaluable for extending the operational life of Voyager 1 and potentially Voyager 2.
There was also discussion about the limitations of Voyager 1's communication systems, the diminishing power supply, and the inevitable end of the mission. Despite this acknowledgment, the prevailing sentiment was one of optimism and excitement for the continued data collection and the ongoing journey of these interstellar probes.
Finally, some comments touched upon the philosophical implications of the Voyager mission, reflecting on the vastness of space, humanity's reach beyond Earth, and the legacy of this iconic exploration endeavor.