(j3.2006) (SC22WG5.5067) [ukfortran] J3 work plan

[Van Snyder]

On Tue, 2013-08-06 at 08:35 -0400, Tom Clune wrote:
> Hi Van,
> 
> 
> I'm curious - how does the software get re-certified when new features
> are added?  That would seem to be the opportune time to include
> recertification for pruning high-priority legacy features.

New features are not necessarily added to every one of the sixty or so
subsystems to support each mission.  For example, Cassini navigation
needed a better model for the gravitational attraction of Saturn's
rings, but no changes were needed in the Kalman filter that ingests
tracking data.  Re-certification is only necessary if something changes,
and then only for the changed subsytem.  The (maybe fortunate) reason
that the suite is sixty-some subsystems instead of one massive program
is that it was impossible to run programs bigger than 32k on the IBM
7094, and difficult to run programs bigger than 65 K on the Univac 1108.

> 
> 
> - Tom
> 
> 
> 
> 
> 
> On Aug 6, 2013, at 3:55 AM, Van Snyder <Van.Snyder at jpl.nasa.gov>
> wrote:
> 
> > On Tue, 2013-08-06 at 08:31 +0100, N.M. Maclaren wrote:
> > > In the world of today, writing a Python (or whatever) script to
> > > replace all arithmetic IFs (including 3 label ones) by logical IFs
> > > isn't even hard.
> > 
> > That's not the hard part.  The hard part is getting a few tens or
> > hundreds of thousands of dollars to re-certify six million lines of
> > mission-critical software.
> > 
> > 
> > _______________________________________________
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> > J3 at mailman.j3-fortran.org
> > http://mailman.j3-fortran.org/mailman/listinfo/j3
> 
> Thomas Clune, Ph. D.  <Thomas.L.Clune at nasa.gov>
> Chief, Software Systems Support Office Code 610.3
> NASA GSFC 301-286-4635
> MS 610.8 B33-C128 <http://ssso.gsfc.nasa.gov>
> Greenbelt, MD 20771
> 
> 
> 
> 
> 
> 
> 
> 
> 
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