The software of the Mars Climate Orbiter (MCO) performed an incorrect calculation due to a conversion error between force in pounds and newton. Resulting, an erroneous trajectory was computed using this incorrect data and communication with the MCO was lost.
The MCO library provides a means to correctly keep track of measured data and conversion between data types without worrying about using different types/units.
MCO is loosely based on JSR-275. Concepts have been re-used from this library.