Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!swrinde!ucsd!nosc!spectra!morgan
From: morgan@spectra.com (Mike Morgan)
Newsgroups: sci.space.shuttle
Subject: Re: New Shuttle Computers
Message-ID: <1991Mar20.155334.13624@spectra.com>
Date: 20 Mar 91 15:53:34 GMT
References: <1991Mar9.044834.27802@cimage.com> <430@daisy.WichitaKS.NCR.COM> <1991Mar18.231328.24932@ncsu.edu>
Organization: Spectragraphics Corporation
Lines: 21

In article <1991Mar18.231328.24932@ncsu.edu> eagle@garfield.catt.ncsu.edu (Daniel L'Hommedieu) writes:
>msjohnso@daisy.WichitaKS.NCR.COM (Mark Johnson) writes:
>>I wonder if they've considered using CD-ROM as a storage medium for the control
>>programs. It's rugged, the drives can be lighter than tapes, the media is
>>not alterable except by drastic accident on-board, etc.
>
>Have you ever used a CD player?  I don't think a CD-ROM is a viable
>alternative, as it is very easy to "skip" a CD player (for instance,
>just tap or hit the desk near a CD player and listen to it skip).  I
>should think that the g-forces and vibrations experienced during launch
>would be too harsh for the CD-ROM drive.
>
>>Well, maybe someday.... 

And that some day is today. Already companies such as Hewelett Packard and
Meridian Data already produce CD-ROM publishing systems. I believe manuals
for Boeing Jets are one such application. The big problem is not the skip
that occurs on many of the poorly made musical CD players, but the seek and
retrieve time required by the CD-ROM drives. Also, the inability to record
reduces their desirability. However, I would not be surprised if they become
standard fare on future missions.