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Comment by nemo44x | Hacker News Reader

There is the old joke: “there’s 2 types of countries on this planet - those that use metric and those that put man on the moon.”

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I agree, the Liberian space program simply doesn’t get the respect it’s due.

... and pissed away $193M when they missed/crashed into Mars because a US made spacecraft was using metric units while US-ground control was using Imperial (ironic because I thought we fought a Revolution to get out from under the Empire). By the 1990s when that loss occurred, there was no scientific or business reason for the US space program to be using Imperial units: except maybe in press releases that no one read. Generations of machine tools, dies, moulds and instruments have come and gone since the 1970s push for metrification. It's all about as rational as people insisting on only buying incandescent light bulbs. Oh wait.

The primary cause of this discrepancy was that one piece of ground software supplied by Lockheed Martin produced results in a United States customary unit, contrary to its Software Interface Specification (SIS), while a second system, supplied by NASA, expected those results to be in SI units, in accordance with the SIS. . . .

. . . The discrepancy between calculated and measured position, resulting in the discrepancy between desired and actual orbit insertion altitude, had been noticed earlier by at least two navigators, whose concerns were dismissed because they "did not follow the rules about filling out [the] form to document their concerns".

https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...

> whose concerns were dismissed because they "did not follow the rules about filling out [the] form to document their concerns".

Typical government bureaucracy.

Communication within large groups of humans is difficult. I think the examples that NASA provides are enlightening and occur occluded in many places but NASA bares all. Below are examples from the Challenger and Columbia disasters.

It was not the Morton Thiokol engineers who made the decision to go ahead with the ill-fated launch. It was NASA. The engineers, meeting in Utah, communicated two messages from their meeting to their local managers. First, they produced the a formal, abstract result: "With the data available to them, and with NASA knowing as well as they that the design was flawed and that temperature might be a causal factor, the engineers argued that the Challenger ought not to fly so far out of the field database, the firmest evidence available." --Robison, et. al.

https://www.asktog.com/books/challengerExerpt.html

This fourth-level bullet concluding the slide says that, by the way, the debris that struck the Columbia is estimated to be 1920/3 = 640 times larger than data used in the tests of the model! Thus a better headline would be "Review of Test Data Indicates Irrelevance of Two Models." There is an interesting dynamic to this slide: the headline is an exercise in misdirection, which the text then awkwardly and slowly eviscerates.

https://www.inf.ed.ac.uk/teaching/courses/pi/2016_2017/phil/...

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