Naked Numbers Cost NASA
Mars Climate Orbiter Gone Forever
After a nine month trip to Mars, the Mars Climate Observer
spacecraft was lost as a result of Naked Numbers. Numbers communicated from Lockheed
Martin in Colorado to NASA's Jet Propulsion Lab in California were left unit-less.
Naked numbers, being completely meaningless, left engineers to guess at their
meaning. The confusion created by improperly dressed numbers caused the loss of a
$125 million spacecraft and the waste of a 9 month journey to Mars. Thankfully, no
lives were lost.
Lockheed Martin was sending daily course adjustments to the Jet Propulsion Laboratory with numbers that should have been wearing the English units of "pound-seconds" to describe the amount of impulse which should be applied to the spacecraft to adjust its course. When these naked numbers arrived at the Jet Propulsion Laboratory engineers assumed that these were specifying the amount of impulse in metric units of "newton-seconds". Simply labeling the units that were being used would have prevented this tremendous loss. A group of physics teachers in Ithaca, New York hope to bring a proposal to Capitol Hill that would ban the use of naked numbers in the United States. Further efforts are being used to convince the United Nations to apply a similar law to the World. Until such a law is passed, physics teachers everywhere will have to settle for simply marking answers as wrong if they are not labeled with proper units. Math teachers are urged to contribute to the solution not the problem.
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Mars Climate Orbiter
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