Date: Sun, 22 Nov 92 05:05:23 From: Space Digest maintainer 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 " 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 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 Subject: Shuttle computers Newsgroups: sci.space In article , 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 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 ------------------------------