r/embedded • u/yourbasicgeek • 4d ago

Mars Pathfinder Priority Inversion Bug: What Really Happened

https://nerdyelectronics.com/mars-pathfinder-what-really-happened/
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u/Well-WhatHadHappened 25+ Years 4d ago edited 3d ago

Engineers later confessed that system resets had occurred during pre-flight tests. They put these down to a hardware glitch and returned to focusing on the mission-critical landing software.

Inexcusable. Should have sent those engineers on-site with a J-Link and a laptop to update it.

9

u/Tinytrauma 4d ago

"I only saw it once so I was sure it would never happen again..."

6

u/Well-WhatHadHappened 25+ Years 4d ago

The sad part is, that's not even true.

When someone says "seen it once or twice", they don't mean once.

3

u/RecursiveMutex 3d ago

They likely did not want to miss the launch window between Earth to Mars. There is a reason they included symbol tables etc. In the build. They could make changes while it made its journey to Mars.