# NASA Finally Switches to Metric

Countries primarily using non-metric systems of measurement (Liberia, Myanmar, Thailand, and the United States). Source: Wikipedia.

As reported in Space.com,

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.

This is welcome news. Readers may recall the loss of NASA’s Mars Climate Orbiter several years ago due to force data being provided in pounds when it was expected in newtons (the SI/metric unit of force). It’s about time NASA switches to an all-metric system, especially as we increasingly collaborate with other nations. I heard once, “The world speaks in English, and it measures in metric.” Even if I didn’t feel that the metric system had inherent superiority, it still remains that it is the international system of choice, and in our ever-shrinking world, it is vital that data be easily communicated using a common system.

More than that, the metric system (and now, SI) has long been the scientific community’s measurement system as well. Americans are at a considerable disadvantage growing up with the U.S. customary system since scientific data are always reported in metric units. In my line of work, medications are dosed in milligrams, intravenous fluids are given in milliliters, and body surface area is calculated in meters squared. There is still some usage of U.S. units for other measurements, like body temperature, and height and weight, though medications are always dosed in milligram per kilogram, requiring a conversion if the weight is given in pounds. My hospital recently switched all measurements to metric, a move with which I fully agree.

I hope that a way can be found to make a transition in the United States to the metric system. It will be difficult for a generation, but children growing up with the metric system will benefit. At the very least, metric units should be given alongside customary units—and I would suggest metric first, customary in parentheses; that’s what I have chosen to do on this weblog, despite my familiarity with (and therefore, preference for) U.S. customary units.

It’s time to switch.