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From: "Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>
Subject: Re: How would Ariane 5 have behaved if overflow checking were not turned off?
Date: Mon, 14 Mar 2011 20:25:04 +0100
Date: 2011-03-14T20:25:04+01:00	[thread overview]
Message-ID: <op.vsclj2zhule2fv@index.ici> (raw)
In-Reply-To: 2442baf5-d53e-4e9a-bbe6-6803feead512@r19g2000prm.googlegroups.com

Le Mon, 14 Mar 2011 17:17:10 +0100, KK6GM <mjsilva@scriptoriumdesigns.com>  
a écrit:
> It really all comes back to the essential question, if variable X is
> known, PROVEN, to never exceed the range A..B, and suddenly it does
> exceed that range, what is the correct action?  You can't just throw
> it away and read it again, since in the Ariane 5 case it would have
> continued to exceed its proven valid range.  So what do you do?
Seems the proof was rather weak there ;)

I suppose the “proven” here mean “physically proven” (by some physic  
properties of the engine) and not “logically proven” as impossible to  
happen in the driver software. Defensive programming may have been an  
option here; if there was something wrong in the input, may be that was  
because the engine behave unexpectedly. Such a case (just like erroneous  
human input would be) should be caught by defensive programming. What to  
do next ? Well, first raise an alarm (to the control center), then trigger  
some automatic urgency sequence.

Any way, the way this happened, that seems unlikely the ship could be  
saved (any urgency sequence could perhaps attempt to avoid collateral  
damages, no more)

Seems relevant or not ?

-- 
Si les chats miaulent et font autant de vocalises bizarres, c’est pas pour  
les chiens.

“I am fluent in ASCII” [Warren 2010]



  reply	other threads:[~2011-03-14 19:25 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-14 15:49 How would Ariane 5 have behaved if overflow checking were not turned off? Elias Salomão Helou Neto
2011-03-14 16:17 ` KK6GM
2011-03-14 19:25   ` Yannick Duchêne (Hibou57) [this message]
2011-03-14 19:28     ` Vinzent Hoefler
2011-03-14 20:28     ` KK6GM
2011-03-15  4:02       ` Yannick Duchêne (Hibou57)
2011-03-15  4:53         ` Shark8
2011-03-14 18:29 ` Vinzent Hoefler
2011-03-16 10:41   ` How would Ariane 5 have behaved if overflow checking were notturned off? robin
2011-03-16 15:16     ` Simon Wright
2011-03-17 11:48       ` robin
2011-03-16 16:58     ` Martin Krischik
2011-03-16 23:39       ` How would Ariane 5 have behaved if overflow checking werenotturned off? robin
2011-03-17 18:48         ` Vinzent Hoefler
2011-03-18 12:06         ` Alex R. Mosteo
2011-03-18 21:15           ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-20 10:42             ` Vinzent Hoefler
2011-03-20 17:06         ` How would Ariane 5 have behaved if overflow checking werenotturned off? Martin Krischik
2011-03-20 17:11         ` Martin Krischik
2011-03-20 18:10           ` Dmitry A. Kazakov
2011-03-21 13:24         ` Leif Roar Moldskred
2011-03-20 13:07       ` How would Ariane 5 have behaved if overflow checking were notturned off? Florian Weimer
2011-03-20 17:00         ` Martin Krischik
2011-03-20 20:17           ` Florian Weimer
2011-03-20 20:37             ` Vinzent Hoefler
2011-03-20 20:14         ` Vinzent Hoefler
2011-03-16 18:20     ` Vinzent Hoefler
2011-03-16 18:29       ` Hyman Rosen
2011-03-16 18:55         ` Vinzent Hoefler
2011-03-16 19:40         ` KK6GM
2011-03-16 20:52           ` Hyman Rosen
2011-03-16 21:02             ` KK6GM
2011-03-16 21:09             ` Shark8
2011-03-16 21:13               ` Hyman Rosen
2011-03-16 21:35                 ` Shark8
2011-03-16 22:27             ` Vinzent Hoefler
2011-03-16 21:04           ` Shark8
2011-03-16 21:10             ` Hyman Rosen
2011-03-16 21:27               ` KK6GM
2011-03-16 21:31               ` Shark8
2011-03-16 22:32               ` Vinzent Hoefler
2011-03-18 21:14           ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-16 23:46       ` How would Ariane 5 have behaved if overflow checking werenotturned off? robin
2011-03-17  0:26         ` Simon Wright
2011-03-17 11:01           ` Georg Bauhaus
2011-03-17 11:04           ` robin
2011-03-17 13:36             ` Niklas Holsti
2011-03-18 21:13               ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-19 10:12                 ` Niklas Holsti
2011-03-17 22:51         ` How would Ariane 5 have behaved if overflow checking werenotturned off? Vinzent Hoefler
2011-03-18 21:13           ` How would Ariane 5 have behaved if overflow checking were not turned off? robin
2011-03-20 10:42             ` Vinzent Hoefler
2011-03-15  6:28 ` Stephen Leake
2011-03-15 17:32   ` Keith Thompson
2011-03-15 17:40     ` KK6GM
2011-03-15 19:44     ` Robert A Duff
2011-03-15 19:12   ` Florian Weimer
2011-03-15 19:45     ` KK6GM
2011-03-15 19:57     ` Vinzent Hoefler
2011-03-20 13:00       ` Florian Weimer
2011-03-20 20:13         ` Vinzent Hoefler
2011-03-15 19:42   ` John B. Matthews
2011-03-17 11:44   ` robin
2011-03-17 18:37     ` Vinzent Hoefler
2011-03-17 23:04       ` How would Ariane 5 have behaved if overflow checking were notturned off? robin
2011-03-18 15:55         ` Vinzent Hoefler
2011-03-17 21:37     ` How would Ariane 5 have behaved if overflow checking were not turned off? Vinzent Hoefler
2011-03-16 10:33 ` robin
2011-03-16 15:08   ` Simon Wright
2011-03-17 12:39     ` robin
2011-03-17 13:41       ` Georg Bauhaus
2011-03-17 23:34         ` How would Ariane 5 have behaved if overflow checking were notturned off? robin
2011-03-18 12:57           ` Hyman Rosen
2011-03-18 16:49             ` KK6GM
2011-03-18 17:18               ` Dmitry A. Kazakov
2011-03-19 17:55                 ` Keith Thompson
2011-03-20 18:39                   ` Robert A Duff
2011-03-17 18:43       ` How would Ariane 5 have behaved if overflow checking were not turned off? Vinzent Hoefler
2011-03-17 20:58       ` Simon Wright
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