NASA Sticking To Imperial Units For Shuttle Replacement

JerryQ sends in a story at New Scientist about the criticism NASA is taking for deciding to use Imperial units in the development of the Constellation program, their project to replace the space shuttle. "The sticking point is that Ares is a shuttle-derived design — it uses solid rocket boosters whose dimensions and technology are based on those currently strapped to either side of the shuttle's giant liquid fuel tank. And the shuttle's 30-year-old specifications, design drawings and software are rooted in pounds and feet rather than newtons and meters. ... NASA recently calculated that converting the relevant drawings, software and documentation to the 'International System' of units (SI) would cost a total of $370 million — almost half the cost of a 2009 shuttle launch, which costs a total of $759 million. 'We found the cost of converting to SI would exceed what we can afford,' says [NASA spokesman Grey Hautaluoma]."

Comments

Horses Asses

[the phantom]

This email goes around archaeological circles every once in a while (I'm sure it goes around other circles, too), and I just got a new copy of it from my uncle yesterday, so it seems as good a time as any to share:

People are always asking why we do things the way we do. Well, here is the reason: railroad tracks.

The US standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That's an exceedingly odd number.

Why was that gauge used? Because that's the way they built them in England, and English expatriates designed the US railroads.

Why did the English build them like that? Because the first rail lines were built by the same people who built the pre-railroad tramways, and that's the gauge they used.

Why did 'they' use that gauge? Because the people who built the tramways used the same jigs and tools that they had used for building wagons, which used that wheel spacing.

Why did the wagons have that particular odd wheel spacing? Well, if they tried to use any other spacing, the wagon wheels would break on some of the old, long distance roads in England because that's the spacing of the wheel ruts.

So, who built those old rutted roads? Imperial Rome built the first long distance roads in Europe (including England) for the legions. Those roads have been used ever since.

And the ruts in the roads? Roman war chariots formed the initial ruts, which everyone else had to match for fear of destroying their wagon wheels. Since the chariots were made for Imperial Rome, they all had the same wheel spacing. Therefore, the United States' standard railroad gauge of 4 feet, 8.5 inches is derived from the original specifications for an Imperial Roman war chariot. Bureaucracies live forever.

So, the next time you are handed a specification/procedure/process and wonder 'What horse's ass came up with this?' you may be exactly right. Imperial Roman army chariots were made just wide enough to accommodate the rear ends of two war horses (two horses' asses). Now, the twist to the story.

When you see a Space Shuttle sitting on its launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are solid rocket boosters, or SRBs. The SRBs are made by Thiokol at their factory in Utah. The engineers who designed the SRBs would have preferred to make them a bit fatter, but the SRBs had to be shipped by train from the factory to the launch site. The railroad line from the factory happens to run through a tunnel in the mountains, and the SRBs had to fit through that tunnel. The tunnel is slightly wider than the railroad track and the railroad track, as you now know, is about as wide as two horses' behinds.

So, a major Space Shuttle design feature of what is arguably the world's most advanced transportation system was determined over two thousand years ago by the width of a horse's ass. And you thought being a horse's ass wasn't important? Ancient horse's asses control lots of things...

AND CURRENT HORSES' ASSES NOW ARE ARE CONTROLLING NEARLY EVERYTHING ELSE.

Re:Horses Asses

[Kjella]

That must be one of the weakest "false" results I've seen on Snopes. As it says itself:

Origins: This is one of those items that although wrong in many of its details isn't exactly false in an overall sense and is perhaps more fairly labeled as "True, but for trivial and unremarkable reasons."

In fact, it collaborates that the English railway was made in the same size as double-horse carriages, that the US share that width because they shared tools and that it's the dominant standard today since the northern US won the civil war. It's a bit of a stretch that double horse carriages were popular only because the romans did it, but they certainly did do it first and built a massive network of them.

Finally, on the space shuttle thing snopes is just being silly. The largest carriage in the table listed by snopes is 9-10 feet. According to wikipedia the shuttle boosters are a little over 12 feet. So while the part about being "slightly wider than the track" is a liberal description, it's certainly possible they couldn't be built bigger because the tunnels aren't bigger.

Re:If you give up the inch, they'll take the mile

[Arthur B.]

No it's not. I've was born and raised in France, moved in the US at 23, 4 years ago. The only unit I'm still uncomfortable with is F (also one of the stupidest) I have no problem thinking in inches, miles, gallons, ounces without converting.

Re:Oh the Humanity!

[gnick]

Wonderful +1 Welcome to the real world

Also, SI conversion with stimulus $$ is one of the better ideas I've heard. It creates jobs (and ones that require at least basic education instead of just the ability to pour and smooth asphalt.) Hell, we could have even have offered basic training for people that would be involved in the more trivial but labor intensive efforts.

Mass conversion to SI requires some manual labor (switching road signs, etc), a lot of public awareness stuff, and a lot of Associate-level tech folks (and probably higher-level for review). You know who building a duck pond employs? 4 guys with heavy equipment (or 50 with shovels) and some ducks.

Re:mod parent +1 realistic

[camperdave]

Yes the SI units are pegged to arbitrary things but they are not arbitrarily pegged to *eachother*.

Actually "imperial" units are pegged to SI units. Since July 1, 1959, the the inch, foot, yard, and mile have been defined on the basis of 1 yard = 0.9144 meters. The pound is defined as exactly 453.59237 grams.