Path: utzoo!attcan!uunet!samsung!brutus.cs.uiuc.edu!jarthur!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: sci.space.shuttle
Subject: Re: Spinning Shuttle
Message-ID: <6966@jpl-devvax.JPL.NASA.GOV>
Date: 1 Feb 90 22:07:47 GMT
References: <36192@cornell.UUCP> <19500002@hpfipgt.HP.COM> <48518e97.1766d@june.engin.umich.edu>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 20

In article <48518e97.1766d@june.engin.umich.edu> stealth@caen.engin.umich.edu (Mike Peltier) writes:
: In article <19500002@hpfipgt.HP.COM> pgt@hpfipgt.HP.COM (Paul Tobin) writes:
: >
: >							Standard
: >procedure is for the shuttle to echo the received data back down for
: >comparison with the original data.  This was done, but the HUMAN
: >operator failed to note the mismatch!  Somebody was asleep at the
: >wheel.
: 
: Why was a human relied upon to determine whether or not the data
: matches?  That seems sorta silly, when you can just do something
: similar to "cat echoed_data | diff - real_data | wc -l" and test
: that against zero.  If it's not, simply retransmit.  I don't see any
: need for a human in that loop.

Then some wise guy says "ls -l *_data" and discovers that neither file
has been modified in the last 11 months...

Or that echoed_data and real_data are hard links to the same file...

Larry Wall
lwall@jpl-devvax.jpl.nasa.gov