From: "J. Ward" <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] To: "U.S. Metric Association" <[email protected]> Subject: [USMA:32502] It's impossible to not use metric units Date: Fri, 18 Mar 2005 20:06:48 -0800
Stephen Humphreys wrote:
The best example in the US was the Mars Orbiter fiasco.
Some might say that 'it was all imperial's fault - if they hadn't have used imperial this would never had happen'
That's plain daft - as you could easily (and equally wrongly) substitute 'imperial' with 'metric'.
Some might say it was due to mixing systems - equally wrong IMHO.
It's effectively impossible to design a spacecraft of this nature without using metric units to a large extent. Most calculations involving optics, electronics, and scientific instruments must be done in metric units. Chemistry is all-metric, which includes batteries and rocket fuel. Device physics is all-metric, including solar cells, cameras, and transistor electronics. The underlying science the spacecraft is attempting to do is calculated all-metric. Some of the detailed engineering such as integrated circuit design and fabrication is always done metric. Power budgets are all-metric. Thermal design is done all-metric. Calculations involving thrust and orbital mechanics are simpler in metric. I could go on....
After the core requirements and specifications are determined in metric, the results can be to a large extent converted to customary units for detailed designs. However, speaking as a working aerospace engineer, it's less work to keep everything metric rather than convert back and forth.
A fair point and a perspective technologically deeper than I could ever go.
I think I was talking in terms of distances, speeds etc. but again I'm not of an engineering background. I believe good communication is key.
I have to say that I've always been an advocate of metric in the science world, but in this case there is more to it that "blaiming imperial"
