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Date: Sun, 22 Nov 92 05:05:23
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #448
To: Space Digest Readers
Precedence: bulk
Space Digest Sun, 22 Nov 92 Volume 15 : Issue 448
Today's Topics:
Minority Kids into Techies (was Re: Free Middle/High School Broadcasts)
Shuttle computers
Space BBS in Somerset, UK ?
Weekly reminder for Frequently Asked Questions list
Welcome to the Space Digest!! Please send your messages to
"space@isu.isunet.edu", and (un)subscription requests of the form
"Subscribe Space <your name>" to one of these addresses: listserv@uga
(BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: Sun, 22 Nov 1992 03:57:59 GMT
From: kjenks@gothamcity.jsc.nasa.gov
Subject: Minority Kids into Techies (was Re: Free Middle/High School Broadcasts)
Newsgroups: sci.space
In article <ppw1kvp@rpi.edu> kentm@aix.rpi.edu (Michael V. Kent) writes:
>In article <1992Nov16.184820.1@fnalo.fnal.gov> higgins@fnalo.fnal.gov (Bill Higgins-- Beam Jockey) writes:
>
>>Would it be simpler to ask white males, politely, *not* to become
>>engineers?
>
>This is already being done, on a large scale, in the aerospace industry,
>though hardly politely. Bottom left corner of sig says it all.
>
>Mike
>
>--
>Michael Kent kentm@rpi.edu
>McDonnell Douglas Rensselaer Polytechnic Institute
>
>Tute Screwed Aero Class of '92 Apple II Forever !!
I, for one, would like to hear that story.
I have been passed over for hiring and promotion at least twice at NASA
because I'm a white male, and "minorities" and women were needed to
meet a quota (which is currently called a "hiring goal" in Human
Resources euphamism). I will never file a complaint because of the
career-limiting aspects of arguing with HR policies. But I suspect
that the space program is not alone in having this problem, so this may
not be strictly a sci.space topic.
-- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office
kjenks@gothamcity.jsc.nasa.gov (713) 483-4368
"he (n.) The third person singular pronoun in the
nominative case, masculine gender. 1. Used to represent
the male person, animal or other being last mentioned or
implied. 2. Used to represent any person whose sex is not
specified: 'Everyone knows he is mortal.'"
-- American Heritage Dictionary
------------------------------
Date: 22 Nov 92 04:51:14 GMT
From: Craig Keithley <keithley@apple.com>
Subject: Shuttle computers
Newsgroups: sci.space
In article <Bxvr1K.36L@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry
Spencer) wrote:
>
>
> It's not a cycle-by-cycle lockstep like some redundant systems. Every
> couple of milliseconds, the four computers in the main redundant set
> compare notes; if one disagrees with the others twice in a row, the
> others declare it to have failed.
>
>
I seem to recall that this is correct; that the four computers running the
same code are on something like a 40ms main event loop, and that they check
their results at that point. I've also read/heard that the avionics
sensors transfer (using some forerunner to the MIL-STD-1553 communications
bus) their data at roughly the same time. This has something to do with
the incredible number of sensors throughout the spacecraft, and that the
data has to be multiplexed before the CPUs process it.
So at the beginning of every 40ms loop, the CPUs acquire data from the
multiplexed data stream, evaluate it, reach a decision, prepare to output
new commands to the servors/thrusters/etc., vote on those decisions, and
the winning decision is feed back out to the spacecraft systems.
Newer fly-by-wire systems need a faster communications bus and a shorter
main event loop.
I wish I could remember where I've read this...
Craig Keithley
Apple Computer, Inc.
keithley@apple.com
Anything not forbidden is mandatory.
------------------------------
Date: Friday, 20 Nov 1992 11:28:37 CET
From: PKRISTIA@ESOC.BITNET
Subject: Space BBS in Somerset, UK ?
Newsgroups: sci.space
Since I will move to the Somerset area in the UK next year I would
be interested in any information on Astro/Space BBS's in that area.
Especially BBS's carrying NASA 2-line satellite elements
Thanks in advance
Poul
------------------------------
Date: 22 Nov 92 05:49:05 GMT
From: Jon Leech <leech@mahler.cs.unc.edu>
Subject: Weekly reminder for Frequently Asked Questions list
Newsgroups: sci.space,sci.astro,sci.space.shuttle
This notice will be posted weekly in sci.space, sci.astro, and
sci.space.shuttle.
The Frequently Asked Questions (FAQ) list for sci.space and sci.astro is
posted approximately monthly. It also covers many questions that come up on
sci.space.shuttle (for shuttle launch dates, see below).
The FAQ is posted with a long expiration date, so a copy may be in your
news spool directory (look at old articles in sci.space). If not, here are
two ways to get a copy without waiting for the next posting:
(1) If your machine is on the Internet, it can be obtained by anonymous
FTP from the SPACE archive at ames.arc.nasa.gov (128.102.18.3) in directory
pub/SPACE/FAQ.
(2) Otherwise, send email to 'archive-server@ames.arc.nasa.gov'
containing the single line:
help
The archive server will return directions on how to use it. To get an
index of files in the FAQ directory, send email containing the lines:
send space FAQ/Index
send space FAQ/faq1
Use these files as a guide to which other files to retrieve to answer
your questions.
Shuttle launch dates are posted by Ken Hollis periodically in
sci.space.shuttle. A copy of his manifest is now available in the Ames
archive in pub/SPACE/FAQ/manifest and may be requested from the email
archive-server with 'send space FAQ/manifest'. Please get this document
instead of posting requests for information on launches and landings.
Do not post followups to this article; respond to the author.
------------------------------
End of Space Digest Volume 15 : Issue 448
------------------------------