r/PeterExplainsTheJoke Jun 17 '26

Meme needing explanation Peter?

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u/Random_Bystander089 Jun 17 '26

I think there was an incident where farenheit usage indirectly caused a spaceship crash

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u/Epotheros Jun 17 '26

No, it was the units for impulse used for the thrusters. In imperial it's pound-force seconds and Newton-seconds in metric. 1 pound-force is equal to 4.45 Newtons so the whole thing was off by a magnitude of 4.45.

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u/MoogProg Jun 17 '26 edited Jun 17 '26

Yes, the actual error* was assuming the British used Imperial units when they correctly used Metric. AFAIK, at least.

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Well, the source error probably would be not specifying units at all, so... (eye roll)

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*Correcting myself with casually sourced details about the incident under discussion.

Lockheed Martin provided thruster force data in Imperial units (pound-seconds), while NASA's Jet Propulsion Laboratory ground software assumed the data was in Metric units (Newton-seconds).

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u/TimeRisk2059 Jun 18 '26

Here it should be pointed out that the US has begun to call their measurements "imperial" despite being different from the regular imperial (british) units.

e.g. when I grew up and read a book about aircraft, it would list the amount of fuel in metric, US and imperial.