Even the Moon's Gone Metric!

Tom's Astronomy Blog (emphasis mine):

Do you know how many countries besides the U.S. that either can’t or won’t think in the metric system? How about two: Liberia and Burma.

Recently, in terms of their lunar missions, NASA has declared the moon metric, so all operations on the lunar surface as NASA puts it, will be in the metric system. You might think, well big deal they do that metric stuff anyway. The truth is they do some of that, and have since 1990, however NASA admits English units still linger in the aerospace industry and some missions are using mixed units.

In 1999 the Mars Climate Orbiter mission failed primarily due to a mistake in part of the navigation related mission software related to an English to metric units translation error. Looking at one of the mission web pages, I was amused see on the left under Science, the caption reads “What will we learn?”. I bet they didn’t expect “We” would learn mistakes do happen and not even an organization which most people think of as the epitome of a cutting edge scientific organization, is immune.

While I’m wondering which missions might be subject to possible failure because of a blown conversion or translation between units, I’m not blaming NASA. The whole country is behind the times here. I’ve been hearing “we will be going to the metric system” for years. What are we waiting for? We just got to do it once and for all and get it over with, we’d figure it out. Big talk, I flip flop between units everyday at work. I don’t even use the metric system here, I use English as the primary unit and metric unit are secondary in posts. Okay I’ll change and join the rest of the world, at least here, how hard can it be?

I'd have to disagree with Tom's final analysis. I do blame NASA if they get conversions wrong. That's one of the things that separates a good engineer from a bad one is the ability to convert from one set of units to another with accuracy. (I spent many hours in engineering school trying to master this.) Most private companies seem to handle those conversions with precision and efficiency -- why can't we expect NASA to do the same? (I'm sensing a public choice story could be told here.)

My take on why the US hasn't switched to metric yet is a simple economic one: The benefits do not outweigh the costs. The US faces very high switching costs (higher than any other country) and most Americans are not engineers, so calculation benefits only impact a small segment of society. It's a typical path dependency story. Most manufacturing and construction are done in English units in the US and the cost of switching to metric could be astronomical. Just think about all the machine shops, mechanics, and guys with workshops you know -- all of their tools would have to be replaced with metric tools and dual sets would have to be kept during the transition phase. The capital investments necessary don't seem to justify the switch.

Additionally, the US has a less centralized government than most countries, so a switch is less likely to be successfully decreed by the US government than by governments of other nations.

As an engineer, I'd love to see the swtich. As an economist, I think it would probably be a bad idea. (As an MBA, if it happens, I'd want to start up a consulting firm to help people with the transition...)

My guess is the US will probably eventually phase towards the metric system, but it won't be anytime soon. As our proportion of global GDP shrinks, it will pay off more to go the route everyone else has gone. Until then, it will remain miles to go before I sleep and not kilometers.