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NASA Moon Space

NASA Will Go Metric On the Moon 695

Posted by kdawson
from the late-conversion dept.
An anonymous reader writes "Space.com is reporting that NASA has decided to use the metric system for its new lunar missions. NASA hopes that metrication will allow easier international participation and safer missions. The loss of the Mars Climate Orbiter was blamed on an error converting between English units and metric units. 'When we made the announcement at the meeting, the reps for the other space agencies all gave a little cheer,' said a NASA official."
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NASA Will Go Metric On the Moon

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  • Re:Yay!!! (Score:5, Informative)

    by pilgrim23 (716938) on Tuesday January 09, 2007 @04:34PM (#17527882)
    as I recall, the fittings on the Apollo 13 launch were metric, the Comamnd Module English. Some fittings were square, others round.... If I was on the moon I would hate to need to change my O2 bottle and in an emergency, the one from contractor B has a English nozzle fitting. Consisitency is not just a good idea here....
  • Good start (Score:5, Informative)

    by gregmac (629064) on Tuesday January 09, 2007 @04:47PM (#17528284) Homepage
    .. but when is the rest of the USA going to follow suit?

    According to wikipedia, As of 2005 only three countries, the United States, Liberia, and Myanmar (Burma) [wikipedia.org] have not converted to metric yet. Canada officially converted in 1970, but both systems get used on a day-to-day basis. Most tape measures, rulers, etc have both systems. Most older people still use imperial for most things, and younger generations seem to be mixed.

    It's actually interesting that a lot of people here (Canada) use mixed units. Personally, I usually use feet if I'm estimating a distance (it's just a very convienient size - the closest metric equivalent is a decimeter, just doesn't quite cut it), and pounds and feet/inches for human weight/height. We still order a pound of wings and a pint of beer (I think you get beat up if you ask for 568mL of beer in a bar). Most other things are metric: road signs are km/h, the weather report is in celcius. Most stores sell things by the kilogram, meter, or liter/milliliter. I'm not sure what they teach kids in school now, but my generation (mid 20's) seems to be decently fluent in both systems (I remember learning how to add inches as part of learning fractions).

  • by wile_e_wonka (934864) on Tuesday January 09, 2007 @04:51PM (#17528378)
    I should preface this post with the fact that I'm in the US. When I took physics and chemistry in college we barely discussed English units. There was one class period that we talked a little about conversion from English to metric units (I don't believe we even did the opposite), and that was about it. It was just assumed that we knew metric very well already. If I graduated and went to work for NASA and had to use English measures, I think I would have to almost relearn some of the physics--it would be awkward for me to work with the non-SI units, and even more awkward to have to learn new constants (I learned the constants in metric units). So I assumed that NASA had moved away from English units long ago since it hasn't been taught in so long.
  • by PingSpike (947548) on Tuesday January 09, 2007 @04:55PM (#17528482)
    These NASA rebels must be stopped. The moon was claimed in the name of the United States by Neal Armstrong, we can't allow them to fruit it up by going all metric on its ass the next time they land there. We should nuke all of NASA's bases from orbit. Some one see about coordinating that with our national space agency.
  • Re:Good start (Score:3, Informative)

    by WarwickRyan (780794) on Tuesday January 09, 2007 @05:02PM (#17528660)
    Sounds just like England. Everything's in metric except drinking, driving and weight watchers.

  • by geekoid (135745) <dadinportland@ya ... m minus math_god> on Tuesday January 09, 2007 @05:07PM (#17528752) Homepage Journal
    And the fact that all the maerial he uses is probably cataloged as english unit.

    When you are in an industry that uses a standard, you can't be the sole guy using a different standard.

  • by mengu (452383) on Tuesday January 09, 2007 @05:10PM (#17528830)
    It was actually mandated back in 1975 that the US needs to convert to the metric system, check out http://www.pueblo.gsa.gov/cic_text/misc/usmetric/m etric.htm [gsa.gov] Quote: Congress passed the Metric Conversion Act of 1975 "to coordinate and plan the increasing use of the metric system in the United States." but it all fell apart since there where no deadline and all based onm voluntary conversion.
  • by mpe (36238) on Tuesday January 09, 2007 @05:27PM (#17529222)
    All of your current units of measurement have been defined relative to the metric system for the past 50 years or so. From the wiki: "One inch international measure is exactly 25.4 millimeters, while one inch U.S. survey measure is defined so that 39.37 inches is exactly 1 meter".

    Actually it's more like 60+ years. Originally the "English" and Imperial inches were slightly different. The 25.4 mm inch was a compromise between the two values, so as to ensure that parts manufactured for the war (WWII) effort would actually fit.
  • by Zackbass (457384) on Tuesday January 09, 2007 @05:33PM (#17529388)
    To follow up on this one of the other big difficulties with the switch is the need for metric tools. I'm not talking about a set of wrenches but the seriously expensive machine tools and metrology equipment that prototyping shops across the county rely on. I personally have several thousand dollars of just measuring equipment like micrometers, dial indicators, and gage blocks before even looking at the milling machine and lathe which have inch threaded screws. In a well equipped shop this could add up to several hundred thousand dollars of equipment that simply doesn't work in metric. To a shop that is perfectly happy using inch measurements there is no incentive to switch. On top of this, almost all machined parts are done in decimal inches. The whole power of ten advantage means nothing to a machinist because all the work is already done in decimal.

    As more modern NC equipment trickles down to the smaller shops that form of the base of American manufacturing the problem is getting less severe because it's as easy to programming a few lines to switch to metric or pressing a button on digital measuring equipment. I wouldn't hold my breath though.
  • Re:Yay!!! (Score:2, Informative)

    by MarcoAtWork (28889) on Tuesday January 09, 2007 @05:46PM (#17529710)
    I take it means that likely the instructions come on letter-formatted pdfs etc. and the printer (like most printers in Europe) only has a4 sheets loaded (hence the 'load letter' message)
  • by drinkypoo (153816) <martin.espinoza@gmail.com> on Tuesday January 09, 2007 @05:53PM (#17529846) Homepage Journal

    If you had ever done anything like engineering work you would realize just how stupid the Imperial/SAE system[s] is (are). When we do engineering work here in the states we use decimal inches anyway. 1/8" is never referred to as 1/8" on a blueprint for some bracket or something; it's always 0.125 inches. This just makes the whole thing confusing and so it makes much more sense just to finally go metric. Besides, frankly, a lot of people (including myself) have a hard time remembering how many cups in a pint, or how many volkswagens in a LOC, or how many quarts in a jeroboam... The metric system is simple and logical.

    Personally I seldom have a reason to measure anything but volume with SAE measurements. I seldom measure weight anyway (I don't even want to know what I weigh most of the time) and I've sworn off American cars since they're not worth buying anyway - although I guess a number of the new ones have gone metric, aside from certain things which are SAE even on Japanese cars - namely spark plugs (SAE flats, metric thread, this is typical for most spark plugs the world over) and the oil drain plug (which could have either metric or SAE thread, but which almost always has SAE flats.)

  • by maidopolis (197345) on Tuesday January 09, 2007 @06:09PM (#17530180)
    The fact that the US is non-metric means significantly increased costs for businesses and a barrier to trade. Considering the push in the US to globalise trade (and the realities of a global economy) it makes the most sense from an economic perspective to have the whole world on a single standard - and the rest of the world (as well as the scientific community) has clearly voted on what the standard should be. Furthermore, NASA's foibles show the obvious downside and potential expense of holding on to an outdated system.
  • Re:Yay!!! (Score:4, Informative)

    by Bent Mind (853241) on Tuesday January 09, 2007 @06:21PM (#17530444)
    It is plain old stupid. 60 sec for a minute, 60 min in a hour, 24 hours per day, 12 months? That is nuts. Why not use: 100 sec an hour, 10 hour a day, 100 hours a month and so on?

    Absolutely! I also don't know why we used such an awkward value for PI. It would make much more sense if PI = 1.

    On the other hand, I've always liked the idea of lunar months. Thirteen months of 28 days makes a lot more sense than twelve months that are anywhere from 28 to 31 days long.
  • Re:Yay!!! (Score:4, Informative)

    by Martin Blank (154261) on Tuesday January 09, 2007 @06:41PM (#17530840) Journal
    Better to use 100 hours per week, or tenday (some fiction writers have used this term, but I don't recall names offhand). I figure that you meant 100 seconds per minute, 100 minutes per hour, ten hours per day (which makes a metric second equal to 0.864 standard seconds). Otherwise, 100 seconds per hour makes for one metric second every 86.4 standard seconds.

    There are two problems with changing to metric time.

    1) The year does not fit neatly into a base-10 meter. You can do 36 tendays in a year, but there's still five days left to factor in, aside from the fact that 36 isn't really close to an exponentially-derived value of ten. This is the minor one, since the original 12 months of 30 days each didn't fit neatly into an actual year, either.

    2) Redefining the second means redefining a significant number of constants. The speed of light, for example, would go from 299,792.452 km/s to 259,020.684 km/s. That requires redefining the meter, which leads to redefinitions of even more things, and reprogramming vast amounts of software that makes use of these conversions. The short-term chaos probably would not be worth it.
  • by ZeroExistenZ (721849) on Tuesday January 09, 2007 @06:42PM (#17530854)
    You say it amuses you that Americans like to keep the imperial system but then go on to show that the one system is linked to the other

    Um. Imerial measurements are more like "hm. This is the size of a thumb. And that's the size of my foot." which is actually quite variable. The metric system is created with the idea to use a base that isn't variable. (as the speed of light.) Ofcourse, now you have agreements of how long one or the other is making it an common system (my foot is larger then yours. Whose measurements are we going to take?) but the irony remains that it's based on the metric system to define it.

    The meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second [nist.gov]
    As a kilo is a cubic decimeter or 1 liter of water.
    100C = boiling point of water
    0C = melting point of water
    and so on

  • by 808140 (808140) on Tuesday January 09, 2007 @07:03PM (#17531204)
    That boneheaded vendor being Lockheed Martin, unfortunately...
  • by justanyone (308934) on Tuesday January 09, 2007 @07:12PM (#17531358) Homepage Journal

    No one has actually answered this legitimate question.

    "PC LOAD LETTER" ==> (P)rint (C)artridge, (Load Letter) Sized Paper now!"
    "PC LOAD LETTER" ==> (P)rint (C)artridge, (Load Letter) Sized Paper now!"
    "PC LOAD LETTER" ==> (P)rint (C)artridge, (Load Letter) Sized Paper now!"
    "PC LOAD LETTER" ==> (P)rint (C)artridge, (Load Letter) Sized Paper now!"
    "PC LOAD LETTER" ==> (P)rint (C)artridge, (Load Letter) Sized Paper now!"

    There's only 14 characters on the display, what should it say? "Put In Paper?" Where? The obvious place, of course. Stupid wording, but once you know what it means, it's obvious.

    I RTFM.
  • Beer (Score:3, Informative)

    by meringuoid (568297) on Tuesday January 09, 2007 @07:14PM (#17531386)
    So how do you measure beer?

    In pints.

    Note however that these are not pints as you know them. Not the pitiful 473ml servings that pass for pints in the colonies. Oh no. One proper pint is 568ml.

    This may be why we've never quite gone for the metric system here. We'd end up being served beer in 500ml glasses and that simply won't do. That extra 68ml is important, even if in most pubs it just accounts for the head...

  • by WebCowboy (196209) on Wednesday January 10, 2007 @01:09AM (#17535140)
    However, a pound of feathers weighs more than a pound of gold, because feathers are measured using the avoirdupois system (1 pound = about 453.59 g) while gold uses Troy (1 pound = about 373.24 g).

    Hold on a minute--I always thought that a pound was a pound was a pound, and that a "Troy ounce" was different from a "normal ounce" (1/12 of a pound vs 1/16 of a pound). Now, becaus of you and Wikipaedia I now know that not only are the ounces different AND the number of ounces in each pound are Different, but the size of each pound is different too!

    Even more perverse--a Troy Oz is HEAVIER than a normal ox, but a Troy pound is LIGHTER than a normal pound!

    It's no wonder y'all down there in the US crash your space probes into planets.
  • by YttriumOxide (837412) <[yttriumox] [at] [gmail.com]> on Wednesday January 10, 2007 @01:36AM (#17535340) Homepage Journal
    If I had mod points, I'd mod you up. This is something I've been trying to tell people for a LONG time (every time I have this discussion - be it on slashdot or elsewhere)... just because we use metric, it doesn't mean we can't use fractions! A "half metre" makes perfect sense... and most people in Europe are more than familiar with buying half-litres of beer (although that said, it sounds you do something different in Sweden! 40cL, I'm not familiar with - generally 30cL or a half-litre (50cL) when I'm in Europe)

    As a note, I do the same thing with height - estimate to the nearest 5cm.

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