Satellite Malfunction - Error In Units Used?
 

Hey, someone must know this off the top of their head.

Wasn't there a satellite, fairly recently, that malfunctioned because the engineers mixed up their units - inches to cm or something like that?

I am helping my 7th grade daughter learn to convert and proportion units. E.g. 55 miles/hour is how many kilometers/second? If 4 cakes require 16 eggs and 32 ounces of flour, how much eggs and flour for 3 cakes? And so on. It appears kids (or at least my kid) don't instinctively understand the need to be precise in carrying over and specifying their units. They abbreviate meters as "m" and then also abbreviate miles as "m", and don't get why I'm being such a stickler. So I thought there must be a really good story about Bad Things That Happen From Sloppy Units.

From memory that was one of the Mars landers.

Somehow converting meters to feet didn't quite go to plan.

Gimley Glider.

Fubar fuel gauge so they dipped the tank and calculated load.

Problem is they calculated kilos not pounds and ran out of fuel at 30,000 ft.

There was a movie about it.

It was a Mar's lander.

Everyone in astronomy uses metric. We don't even bother with units, because it's assumed.

Lockheed (I believe it was them) still works internally with Imperial, for some absurd reason. They sent acceleration data to NASA for the probe they built, without units. Each side assumed the other knew what they meant, and the result was a messy busted up field of broken probe parts scattered across the Martian landscape as the thing slammed into the ground at several times it's intended speed.

That was fast. Thanks.

Now we need a TI-84 Plus. Somehow hers is missing. Anyone got a used one to sell, let me know. Thanks.

Even beyond the imperial/metric transition, she can understand this:

A turtle might move at 5 feet per hour.
A person might walk at 5 miles per hour.

Even though the VALUE is the same, it's obvious that the turtle and the person are not pacing each other in that hour long race.

Now, understand how much faster the person is going than the turtle might be beyond her math level (dunno) but the concept would work.

For added fun, look up an Air Canada flight in a 767 from a few years back that flamed out both engines and was forced to land dead-stick due to fuel starvation. This was allowed to happen due to an error in using metric instead of imperial (or vise-versa, don't remember which) in calculating the temperature expansion of the fuel. Fortunately everyone survived.

Seriously bad things have happened because of unit conversion errors....

http://www.ima.umn.edu/~arnold/455.f96/disasters.html

http://news.bbc.co.uk/2/hi/uk_news/education/792162.stm

http://www.ima.umn.edu/~arnold/disasters/sleipner.html

http://www.cnn.com/TECH/space/9911/10/orbiter.02/