NASA Still Can't Get That Metric Stuff Right

From Wayne Hale's blog post on human rating referenced here recently:

> I can remember one shuttle issue with the agency tribology expert (that's lubrication to most folks). The technical expert would not budge a millimeter (0.254 inch) in requiring servicing of a part almost inaccessible deep in the bowels of the orbiter.

millimeter (0.03937 inch)

I always try to do conversions two different ways, then multiply by another known factor to get a different value that can be checked for consistency. e.g.: 0.254 * 25.4 mm/inch does not equal the expected one inch.

Unit conversions are fundamental, not easy.

If you want the general public and kids to understand, you relate in English units..I know at my house the kids know what a gallon of milk is and reasonably adept at guaging the length of bugs in inches.

I don't think Keith (after watching the last year or so) can post a good story on NASA. Always negative slants, always the same nagging, tiring rhetoric. I b**ch about NASA on a daily basis (the bureaucracy et al), but Keith reminds me of the nagging mother who does nothing but tear down. Must have been one mediocre engineer; see why they got rid of you. B**ch, B**ch..moan moan. Offer something up.

Maybe something nice or positive for a change?

Editor's note: Bad Keith. BAD Keith.

He likes Avatar!

That really pisses me off...really does make me angry! NASA hasn't set deadline or a target for their programs but they give educational organizations and non-profits less than 60 days to come up with an idea and $30,000 for a research satellite?!

What a great educational opportunity flushed down the toilet. Once again NASA shoots itself in the foot with a cannon! >:-(

@Incredulous One: I agree that relating to meaningful measures adds context. However, I don't want to live anywhere that the bugs are measured EITHER in inches or too many millimeters:)

Cube Sats aren't new. They have been around for more than 10 years according to Wikipedia.

KC: The purpose of this particular program and the constraints are pretty clearly laid out in the linked article. If you don't already have a CubeSat in development, you can't possibly help them determine how many CubeSats are interesting and also available now, and decide the priority for near term launch opportunities. To repeat, the intent seems to be to decide amongst the most worthy existing CubeSats for new near term launch opportunities.

"There are organizations that have been waiting a long time for a chance to see their satellites fly in space."

And $30k isn't what the projects selected get - it is what they _pay_. And frankly, if a group can't respond to a request for proposal in 45 days, what is the chance they can realistically be ready to launch their already existing CubeSat _next year_?

This is a pilot program, and if successful, could perhaps be continued so groups that aren't ready now can eventually participate on later launch opportunities. (One of the things NASA specifically ask is if you aren't ready for this pilot program, then tell NASA when would you be available.)

Keith's note: yes, I am aware of CubeSats and their history. I am not certain why you needed to assume that I do not.

Sorry for the confusion. My post closest above was in response to poster KC several above. (The initials probably didn't help either ;) )

Keith,

Thanks for bringing up the metric problem again. This site is not to cheer NASA it's to analyze it. I've waited 25 years for this supposedly forward looking country to go metric and use metric. NASA is supposed to use metric, it's a directive. Can't someone hire people in PR that will use metric?

Again 95% of the world uses the metric system. We are the only crybabies left. We purchase two sets of tooling in this country so we can work on Imperial and metric. IT COSTS TWICE AS MUCH. 1/4-20 or 4-40? how about M2, M3, M4, M5? What rational is there to use Imperial other than Americans are too Wussie to change?

Yeah, CubeSats have been around a while ... the implication is that they're new.

When I took high school physics in 1964-65, we used the metric system. Then when I got to college, they used English, and it was a bit of a change since I was already familiar with physics constants, etc., being metric. A bit backwards there. :)

Doesn't a cube have the same dimensions on all sides? :)

Keith wrote: So ... did someone in PAO translate from metric units back into English units? Wacky.

I'm really missing something. Keith: you complain about NASA PAO a fair bit, but here they finally do something right by communicating with the US public in their own language. And you're complaining about that?

Yes sorry perhaps a poor choice of 'nickname'. Matt's response was for me.

I was not aware CubeSat was an existing program.

Still it ticks me off when NASA announces deadlines for projects and programs and grant opportunities which have such great potential but are sabotaged by short deadlines.

First let me say I agree we should go to SI units. I was hoping that for Constellation we would. As a mechanical engineer it isn't a big deal to me which I use. I am limited to the material we buy. So you might get W-beams that are based on an english unit standard but the AISC has an ISO conversion we could use.

But you are wrong that is costs twice as much. Even if you have to buy two sets of taps they don't last that long and you have to replace them anyway. Same with drill bits. Things like mills and lathes it doesn't matter because they are mostly CNC so it doesn't matter what units you use. Also as for threaded fasteners there are also fine and course pitch metric fasteners. So you don't get away from that.

There are millions of people in the U.S. who would be happy to convert to metric. Unfortunately, there are over 300 million people who won't and never will, period. We tried it in the 1970's. I still remember my introduction to metric was my dad driving us to may grandmother's house and we'd always pass a sign that said "62 miles / 100 km". That's how I started. Now, if that had been done everywhere, over time we would have gotten used to metric. Seeing that one sign as an 8 year-old enabled me to convert miles to km and then feet to cm, etc. I assimilated the knowledge; it wasn't forced on me or beaten into my head in school. It was just there and it sunk in my head.

Still, I chuckled when Wayne Hale tweeted the tribology anecdote and then a few minutes later tweeted his correct cm-inches conversion. It's a pain when the conversions aren't exact. In fact, the OFFICIAL conversion for centimeters to inches is 2.54 cm / inch. That is the international standard that is to be used by everyone. However, if you actually measure it, the ratio is actually 2.54-more-numbers-etc. But it's difficult to work with a ratio that has a never-ending fraction that, by beauracratic fiat, the ratio is hard-set to 2.54.

Imagine if a NASA safety document was "translated" to metric and that cm/inches conversion standard applied. That could kill people.

English to metric is easy in theory, but tedious and inexact in practice.

I have read NASA Watch for some time and frankly am a bit tired of so-called "experts" and their opinions. Let me tell you why NASA hasn't made the switch to metric, it's because NASA owns SO MUCH infrastructure that wasn't built in metric units. Facilities at the Johnson Space Center in Houston were originally built for APOLLO, same for Marshall. Kennedy still has stuff hanging around from the programs BEFORE Apollo! Why, because the budgets they get simply don't include the $ needed to upgrade or replace this aging infrastructure, much needing work starting at the "foundation." Until this can be addressed, NASA is wiser to avoid living "half slave and half free" lest we all get more incidents like the poor Mars Orbiter.

It's really a shame we didn't just take the plunge in the 1970s. Converting to different units is best done quickly - like ripping off a band aid.

People would have complained but eventually would have gotten used to it.

Now - forget it. Christ years later people are still bitching about Pluto! The right would have an absolutely conniption like you wouldn't believe. They'd be saying crap like: "First Obama tried to socialize health care now he's socializing everything!!"

The future of space exploration is with international partners that use the metric system.

Get with the program or someone will make a conversion mistake that kills people. Pick one

The American public absolutely refuses to convert to metric. Perhaps we should be addressing that issue rather then NASA using English units in a solicitation.

CubeSat is not a NASA program and the young engineers at CalPoly have done a excellent job getting the program off the ground. pardon the pun. If you go to a CubeSat event, you will find lots of organizations involved in the project.

As best as I can tell, the NSF has been much more supportive of the program in real financial and program terms.