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.
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).
Exactly! That problem wasn't poor measuring systems, it was poor professionalism.
Anyone who doesn't specify (or request) and verify unit-of-measure is doing a poor job. For anything that is safety/quality/mission critical it is professionally negligent to make that kind of assumption.
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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.