Talks to Watch

How We Diagnosed and Fixed the 2023 Voyager 1 Anomaly from 15 Billion Miles Away

17K views · Apr 16, 2025 · 1:03:45 · 2 HN recommenders · 3 mentions · discussed 2026

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.

Why Hacker News points people here: Commenters recommend it for the remarkable remote reverse engineering done on decades-old hardware with no simulator.

“Blows my mind of the reverse engineering done to achieve this”HN comment, 2026

What Hacker News said 3

Strongly recommendswanderingmindAug 2026

“Blows my mind of the reverse engineering done to achieve this”

Technical deep dive on fixing Voyager 1 remotely.

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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

in “NASA to keep its 48-year-old Voyager 2 probe running for yet another year” · view on HN
RecommendsndiddyApr 2026

“It goes over how the flight computer works and he walks through a few assembly routines.”

Walkthrough of the flight computer and the memory chip fix.

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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 had no assembler, no debugger, and no processor simulator. They had no testbed, the only two FDS processors were in space.

in “NASA Shuts Off Instrument on Voyager 1 to Keep Spacecraft Operating” · view on HN
Cites itzerdMar 2026

Talk on fixing Voyager without simulator, tests, or complete source.

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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

in “Voyager 1 runs on 69 KB of memory and an 8-track tape recorder” · view on HN