Originally Posted by
Marcus_Ti
Except...NASA has used metric units for decades....it is only the tool citizenry and Congress and companies that insist on using it. The USA has among its distinguished list of accomplishments...being the only country to kill a $300,000,000USD Martian orbiter probe....due to the continued corporate use of Imperial units (Lockheed used them in their firmware, and didn't tell NASA).
This of course ignores the fact that Imperial units are defined by metric units, and have been since the late 1950s by international treaty. It is why 1 "inch" equals exactly 2.54cm....as opposed to the centimeter which is actually defined by a real physical phenomenon. So, strictly speaking, the USA is and has been using metric units for decades---just with an added layer of obfuscation on top.
The metric system is almost always superior to whatever it is you call the customary system (English or imperial or whatever) and yet it hangs on. In aviation, a mixed system of units is used. My favorite example is that lapse rate is sometimes given in official documentation as deg C/1000 ft.
As for the Martian probe cock up, the failure was that NASA did not publish and enforce standards. The SNAFU happened to be use of the customary units -- it could have been using something like kgf instead of N or Bar instead of Pa or g/cc instead of kg/m^3.