Nasa claims converting to SI would cost $370,000,000

[zahc]

http://www.newscientist.com/article/dn17350-nasa-criticised-for-sticking-to-imperial-units.html

I don't understand why it was built in English units in the first place. Didn't scientists use metric units in the 60s or whenever it was made? How many mars probes have to crash before they get their heads on straight? In 20 years, they will be using the same argument for building the Ares replacement in English dimensions.

[AZRedhawk44]

I don't see how it takes 370 million dollars to do a find-replace for key words in engineering documents... replacing feet with meters, pounds with newtons or kilograms (depending on usage), and convert all the numbers.

I personally favor the Imperial units myself and I love that my truck uses "STANDARD" units rather than metric.   Since I'm unlikely to actually work on a space vehicle of any type though, I could care less as long as the US stays as top dog in the arena.

[Headless Thompson Gunner]

<Shudder>

I would NOT want to be involved in any project to change the units on systems as elaborate and complex as the various NASA vehicles.

[roo_ster]

"We in the private sector are doing everything possible to create a global market with as much commonality and interoperability as possible," says Mike Gold of the US firm Bigelow Aerospace, which hopes to fly commercial space stations in orbitMovie Camera. "But NASA still can't make the jump to metric."

What a drama queen^^^.

If it were a clean-slate design, converting NASA over to metric would be a fine idea.  Since it is not, run with what you got.

Choosing the standard system will in no way effect civvies making their way to space, who can use whatever system they prefer.

Personally, I prefer the metric system for my engineering calculations.  Doesn't mean I can't do them in standard.  Anyways, I prefer the standard system for everyday use.

[AJ Dual]

Working in IT and having helped with certain similar projects, I can say that the lions share of that budget NASA made for a metric conversion isn't for the actual conversion.

It's for the verification.

And now that I'm peripheraly involved with defense/aerospace Quality Assurance, I'll wager that with manned spaceflight, and with multi-million.. billion dollar probes that are launched on one way missions forever out of reach of any repair, that they can't just do a statistical sample of all the documentation and code to "verify" things.

They'll have to go through every piece of data they have line by line. And it's not just simply going though and saying "Okay, 1 inch equals 25.4 millimeters...", they'll need to figure out significant digits, and acceptable tolerances for each conversion, for some things like laying out the roadway for the crawler-transporter, it won't matter. For others like a space probe trajectory to an outer planet where a difference of .00000001 of whatever unit will stack up every second like "compound interest", that can be a problem.

And then they'll need to test some of those conversions in simulations, or actual engineering studies, static models, wind tunnels, with supercomputer time etc..

I'm certain there's a fair amount of padding for fed.gov cost-plus contracting in that estimate, but IMO, even the leanest and meanest private sector conversion budget for an enterprise the size of NASA would probably surprise you.

[Gewehr98]

Depends on the tolerances built-in, too.

It's not as easy as just plugging in the 25.4 ratio and running with it.

That's not even figuring in the conversion of existing blueprints from English to Metric.

[ilbob]

Depends on the tolerances built-in, too.

It's not as easy as just plugging in the 25.4 ratio and running with it.

That's not even figuring in the conversion of existing blueprints from English to Metric.

I'd be willing to bet a fair number of the blueprints were hand drawn too.

People that don't get involved in large projects have no feel for what it can take to make even a small change. I don't work on really huge billion dollar type projects, but the million dollar and less ones I do work on often end up with change orders that sound insane for what is being changed. But once something is already there, changing it can be insanely expensive.

Thats one of the main reasons to have design freeze dates where you don't make any more changes no matter how nice it would seem to be.

[Marvin Dao]

Rule of thumb from what I've seen is minimum $5k labor cost between engineering, verification, drafting, and document management for even minor drawing changes. Yeah, I can see reworking every document at NASA reaching $370M pretty danged easily.

[MechAg94]

Hell, a sizable percentage of my job is Management of Change paperwork for even small changes and all that stuff is very necessary.  I have no doubt that our procedures are child's play compared to what NASA has, and that is just for very minor changes. 

[seeker_two]

Nasa claims converting to SI would cost $370,000,000

Wow!  Who knew Sports Illustrated was that expensive....must be one heck of a swimsuit issue.....

[AJ Dual]

Wow!  Who knew Sports Illustrated was that expensive....must be one heck of a swimsuit issue.....

I think NASA is also factoring in lost productivity from all the engineers on uh.. "bathroom breaks".

[Thor]

Let's not forget all of the re-tooling and new tools required for the conversion.