How We Diagnosed and Fixed the 2023 Voyager 1 Anomaly from 15 Billion Miles Away
Why Hacker News recommends it
Commenters recommend it for the remarkable remote reverse engineering done on decades-old hardware with no simulator.
What it is
JPL's David Cummings presents at the 2025 Flight Software Workshop how the team diagnosed and fixed the 2023 Voyager 1 anomaly from billions of miles away. It walks through the flight computer and the memory fix.
Recommended by 2 HN commenters across 2 different months, 2026 to 2026.
What Hacker News said
Strong rec wanderingmind · 2026-08 · on “NASA to keep its 48-year-old Voyager 2 probe running for yet another year”
A slight tangent here is a technical deep dive on Voyager 1 fixing a memory corruption error in 2023 by hand 15 billion miles away. Blows my mind of the reverse engineering done to achieve this [this video]
Recommends ndiddy · 2026-04 · on “NASA Shuts Off Instrument on Voyager 1 to Keep Spacecraft Operating”
Here's a talk about how the Voyager team fixed the flight data computer on Voyager 1 when a memory chip went bad on it a few years ago. It goes over how the flight computer works and he walks through a few assembly routines. [this video] Some of the challenges they had to deal with while developing the fix: - The only source code they had for the flight data software was an OCR'd Microsoft Word document (with typos) that was likely scanned from a hard copy assembler listing printout. - The processor runs a custom instruction set developed by JPL for the Voyager mission. The documentation they had on the processor was incomplete. - Everybody who had designed the flight software was dead. - They ha
Cites zerd · 2026-03 · on “Voyager 1 runs on 69 KB of memory and an 8-track tape recorder”
Based on the communication fix, they also didn't have a simulator, or tests, or complete source code, on a custom instruction set that wasn't well documented, so they had to reverse engineer how it worked. [this video]