@BlueSki - actually, the computers used to navigate to the moon and land there used metric internally, but converted to (and from) English units for the astronauts...
"With respect to units, the LGC was eclectic. Inside the computer we used metric units, at least in the case of powered-flight navigation and guidance. At the operational level NASA, and especially the astronauts, preferred English units. This meant that before being displayed, altitude and altitude-rate (for example) were calculated from the metric state vector maintained by navigation, and then were converted to feet and ft/sec."
The US has tried to convert to metric since I was a kid. Still not there, but some progress has been made (for example, my Jeep Grand Cherokee, Chevy Corvette and Cadillac SRX all use metric fasteners these days. Americans are a stubborn lot B)