[time-nuts] Standards for units

[Magnus Danielson]

From: SAIDJACK at aol.com
Subject: Re: [time-nuts] Standards for units
Date: Wed, 4 Apr 2007 01:46:57 EDT
Message-ID: <d4f.603e679.334495d1 at aol.com>

Said,

> In a message dated 4/3/2007 19:29:25 Pacific Daylight Time, didier at cox.net  
> writes:
> 
> An  Arianne 5 rocket had to be destroyed with its cargo when it veered 
> off  course because of a faulty conversion from English to metric in the  
> guidance software. What a bummer!
> I hate it when that  happens!!!
> 
> 
> Hi Didier,
>  
> actually unless there was a second explosion I don't know about, the first  
> Arianne-5 proto-rocket exploded due to a variable parameter overflow  (missing 
> saturation check) in a calculation.

A very spectacular overflow indeed.
http://www.around.com/ariane.html

> The conversion problem you mentioned happened on a Mars mission.

This should shed some light over the manuvering details of that particular
mission:
http://lamar.colostate.edu/~hillger/toles-orbiter.gif
(From http://lamar.colostate.edu/~hillger/cartoon.htm)

> BTW: I didn't expect my email about our strange US units to start such a  
> lengthy discussion on the board...

OK, thanks for reminding us who's fault it is. :)

Cheers,
Magnus