AstronomyTeacher

SPACE.com -- NASA Finally Goes Metric: "When NASA returns astronauts to the Moon, the mission will be measured kilometers, not miles.
The agency has decided to use metric units for all operations on the lunar surface, according to a statement released today.
The change will standardize parts and tools. It means Russian wrenches could be used to fix an air leak in a U.S.-built habitat. It will also make communications easier, such as when determining how far to send a rover for a science project.
NASA has ostensibly used the metric system since about 1990, the statement said, but English units are still employed on some missions, and a few projects use both. NASA uses both English and metric aboard the International Space Station."