HDTenEightyP/NetNews huggingface dataset:
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Shuttle computers
Date: Wed, 18 Nov 1992 18:51:47 GMT
Organization: U of Toronto Zoology

In article <Bxwy52.G3o.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:
>Is it at all possible to reprogram the GPCs from the ground, or does it
>have to be done from onboard?

They are routinely reloaded with different software from onboard storage
(tape, I think), but I don't think there is any remote-upload capability.
In an emergency, the astronauts can input patches manually -- NASA insisted
on this capability, over IBM's objections (the IBM folks say they considered
having the patch routine pop up a little flag saying "your warranty is void"
when it was used :-)) -- but that's not suitable for routine use.
-- 
MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
              -Hal W. Hardenbergh (1985)|  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.space
From: wjg@bluemoon.use.com (william grimm)
Subject: etc.
Organization: Blue Moon BBS ((614) 868-998[024])
Date: Wed, 18 Nov 92 22:43:51 EST

Mr. McElwaine, the reason the McLintock "Air Motor" isn't being used is 
that aliens from Tau Ceti hold exclusive patents on it for the next 1/2 
galactic rotation period.  Low-energy, but hey- those alien patent laws 
are rough :}.
Sorry for the waste of bandwidth.

 This is from
     wjg@bluemoon.use.com
who doesn't have his (or her) own obnoxious signature yet
Newsgroups: sci.space
From: roberts@cmr.ncsl.nist.gov (John Roberts)
Subject: Re: Hubble's mirror
X-Added: Forwarded by Space Digest
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Tue, 17 Nov 1992 04:56:29 GMT


-From: gsh7w@fermi.clas.Virginia.EDU (Greg Hennessy)
-Subject: Re: Hubble's mirror
-Date: 16 Nov 92 03:35:55 GMT
-Organization: University of Virginia

-Henry Spencer writes:
-#To the best of my knowledge, the only statement in my posting which is
-#not a solidly-established fact . . .

-I was referring to your statment implying that Dr. Jefferys was
-contributing to the "technological myth of the century." Correcting
-Dr. Jefferys on matters of the HST is like correcting Dennis Ritchie
-on matters of C. 

Careful yourself - Henry is an internationally recognized authority on
C - I wouldn't put it past him to correct Ritchie on some detail.
I have a book with a chapter entitled something like "Henry Spencer's
laws of C programming". :-)

-While certianly a very expensive end to end test would have caught the
-trouble, assuming that such a test is even possible (which I'm not
-convinced of given the difficulty), the set of tests that you develop
-to test a mirror BEFORE you know it has a certian problem is not
-necessarily the same as the set of tests that you develop AFTER you
-know it has a problem. PE developed a system of testing that they
-THOUGHT would be good enough. Unfortunately it was not. 

PE made themselves believe that there was no problem until after the launch.
The testing protocol used was robust, but not sufficiently robust to
compensate for people ignoring the test results.

-At least we can be pretty sure that this blunder won't be repeated.

PE (now Hughes Danbury) is reported to have cleaned up their act following
the discovery of the HST error - I think they're making a set of mirrors
for AXAF. I expect NASA will more insistent on full supervision in the
future (at least for contracts where they might take the blame :-).

John Roberts
roberts@cmr.ncsl.nist.gov
Newsgroups: sci.space
Subject: Human powered flight???
From: schiewer@pa881a.inland.com (Don Schiewer)
Date: 18 Nov 92 16:18:53 CDT
Organization: Inland Steel Company, East Chicago, IN
Nntp-Posting-User: skolly

I know there are some aeronautical engineer in the group.

I would like to know the current state of human powered flight.

I have heard of peddle-prop ultralight, but I would like to know
if any progress has been made with flap/soar type systems?

-- 
Don Schiewer   | Internet  schiewer@pa881a.inland.com    | Onward Great
Inland Steel   | UUCP:     !uucp!pa881a.inland!schiewer  | Stream...
Newsgroups: sci.space
From: pgf@srl03.cacs.usl.edu ("Phil G. Fraering")
Subject: Re: Satellite Photos of hurricanes...
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Wed, 18 Nov 1992 03:43:19 GMT



In article <16NOV92.12028663.0072@VM1.MCGILL.CA>, IEGS@MUSICB.MCGILL.CA (IEGS000) writes:
|>
|>COULD SOMEONE HELP ME: SUPPOSE A HURRICANE JUST BLEW IN! WHERE CAN I
|>FIND A SATELLITE PHOTOS OF IT'S PROGRESS?
|>PLEASE REPLY TO MC.BER
|>

>CNN

--
>Tim Fogarty
>FOGARTY@SIR-C.JPL.NASA.GOV

The cable was the first thing to go. Of course, the internet
connection to the school had been shut down early in the day.

The cable wasn't hooked up again until about three weeks
or so after the power was hooked up. The phones were up
all the time.

I don't really know why they want to keep the phone companies
out of the cable business.

-- 
Phil Fraering
In the country of the blind....
60 minutes doesn't run stories about people trying to ban hearing
Newsgroups: sci.space
From: vento@mars.lerc.nasa.gov (Dan Vento)
Subject: Re: Space suit research?
Followup-To: sci.space
Organization: NASA Lewis Research Center
Distribution: usa
Date: Fri, 20 Nov 1992 21:07:06 GMT

In article <1992Nov17.033954.4419@ucsu.Colorado.EDU>,
fcrary@ucsu.Colorado.EDU (Frank Crary) wrote:
> 
> Actually, Vail or Aspen at ~10 psi average, would be a better example
> than Denver (~12 psi...) I have never understood why NASA doesn't
> consider this fact relevant. I know the reason the Case for Mars IV
> conference endorsed 14.5psi for Mars missions: NASA apparently likes
> it and will probably be using that pressure in many existing systems
> by the time a Mars mission is launched. Having two different pressures
> is a _major_ pain, so the general consensus was to stick to 14.5psi...
> 
>                                               Frank Crary
>                                               CU Boulder


Another reason that NASA does not like low pressure high oxygen (e.g. 5 psi
pure oxygen) is the danger of fires in the crew cabin while in orbit. Most
materials don't burn easily in low g in "normal" air. Enriched oxygen
environments can be a serious problem for materials flammability. Needless
to say, this is a big driver in any decisions to be made about the cabin
environment for manned flight.  


Dan Vento
vento@mars.lerc.nasa.gov
Newsgroups: sci.space
From: hack@arabia.uucp (Edmund Hack)
Subject: Re: Lunar "colony" reality check, part 2
Organization: Lockheed ESC, Houston
Distribution: sci
Date: Thu, 19 Nov 1992 21:58:50 GMT

In article <BxwAKL.M5B.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:
> [regarding the need for spares for a lunar base]
>What can be done to help
>alleviate the problem? Breaking designs up into smaller modules, and having
>as many identical modules as possible might help. Using initially identical
>but reconfigurable modules could also be useful. (Earthbound example: I just
>finished a circuit design in which a high percentage of the logic is in
>identical reprogrammable logic devices, each one programmed differently.
>By keeping a relatively small number of spares on hand, I could replace
>any of these devices that might fail. If for some reason I had no spares 
>and really needed to use the circuit, I could cannibalize a component from
>a less-critical area, and use it to replace a failed device in a more-critical
>area.)

This is one idea that the NASA First Lunar Outpost has proposed. Even
Freedom has (partly) endorsed this, with only a few types of circuit
boards for the onboard computers. Having the ability to do sub-board
level repairs could greatly improve availability of the systems and
reduce the logistics burden, IMHO.  We are attempting to quantify this
in the future.
>
>As I posted long ago, I suspect a first mission would be likely to choose to
>start with a minimal set of spares, and hope to later build up a stock by
>periodic resupply. (Or they might send supplies ahead of them, by unmanned
>vehicle.)

Both are being looked at.  Also, most scenarios have the base landing
and auto-deploying a few months before the crew so that a couple of
night/day sequences happen, shaking early failures out.  Massis
allocated in the crew lander for last-minute spares to be included.


-- 
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"
Newsgroups: sci.space
From: kenl@larry.wes.army.mil ("Kenneth E. Lawrence")
Subject: message from Space Digest
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Fri, 20 Nov 1992 16:14:22 GMT


SUB SAPACEPACE Kenneth E. Lawrence


Newsgroups: sci.space,alt.sci.planetary
From: davem@ee.ubc.ca (david michelson)
Subject: Re: space news from Oct 23 Science (not AW&ST)
Organization: University of BC, Electrical Engineering
Date: Fri, 20 Nov 1992 20:47:05 GMT

In article <2421@usna.NAVY.MIL> wdw@math2.sma.usna.navy.MIL (Wm. Douglas Withers -- math  FACULTY <wdw@sma.usna.navy.mil>) writes:
>
>I wonder why the same techniques can't be used to shed light on the question
>of the presence of ice at the Moon's poles.  Comments, anyone?
>

It's a matter of the relative inclination of the orbits of Mercury and Earth.
 
From Slade, Butler, and Muhleman, ``Mercury Radar Imaging: Evidence for Polar
Ice,'' Science, 258, 635--640, 23 Oct 1992:
 
"On both days, the sub-earth latitudes were far enough north for our 
instruments to see over the north pole and into areas thought to be 
permanently shadowed from the sun."
 
Figures 1 and 3 in Harmon and Slade, "Radar Mapping of Mercury..." which
follows immediately after the Slade et al. paper, make this very clear.
 
We simply can't see the moon from the same aspect from the earth's surface.
 
We *really* need to get a lunar polar orbiting geochemical mapper built and
launched!
 
--
Dave Michelson
davem@ee.ubc.ca

Newsgroups: sci.space
From: dag@col.hp.com (David Geiser)
Subject: Re: ROTATION OF THE MOON
Date: Thu, 19 Nov 1992 14:44:41 GMT
Organization: HP Colorado Springs Division

> The same thing is happening, much more slowly, to the earth --
> friction with the tides and within the "solid" earth is slowing the
> rotation rate by something on the order of 1 sec every century. We can
> actually measure it (the slowdown) nowadays. Love those atomic clocks!

Do you know if that rate is constant?  Say around 63M years ago,
around the time of the end of the dinosaurs, the day would have
been 175 hrs longer!
-- 

 To the cat, the experimenter is problematic.
From: higgins@fnalc.fnal.gov (Bill Higgins-- Beam Jockey)
Newsgroups: sci.space,purdue.general
Subject: Party after Indianapolis NASA meeting
Followup-To: sci.space
Date: 18 Nov 92 20:44:43 -0600
Organization: Fermi National Accelerator Laboratory
NNTP-Posting-Host: fnalc.fnal.gov
Summary: Meeting 2-6:30 Friday at Walker Theater; reception at 7
Keywords: NASA town meeting Indianapolis party reception Higgins

Here's some news on the NASA Town Meeting to be held in Indianapolis
on Friday, 20 November.  I have learned that the meeting has been
moved to the Walker Theater at 617 Indiana Avenue.  It's no longer
scheduled for the IUPUI campus.

It still runs from 2:00 Friday afternoon till about 6:30.

Dr. Daniel Goldin, NASA Administrator, will be present for the first
half of the afternoon, and will answer some questions from the
audience after his talk.  A battery of other NASA officials will
review NASA's activities in the second half, along with short
presentations from a few Indianapolis-area people with some space,
aeronautics, or NASA connection.  (For instance, there's a company
named ARAC in the spinoff business which I expect will be represented.)

There will be a lot of open-microphone time so audience members can
sound off.

Now for the best part. I will be hosting a reception after the meeting
for anybody who wishes to keep talking about space.  It will start at
7 PM at the Slippery Noodle restaurant at 372 South Meridian in
Indianapolis, near Union Station and about a mile south of the Walker
Theater.  Everybody is welcome.  The Slippery Noodle's phone (I love
this name) is (317)631-6974.

I hope to distribute flyers at the meeting announcing this
reception (if they let me!).  But you heard it here first.

I figure people will enjoy meeting others with an interest in NASA.  
They can buttonhole each other, sign each others' petitions, get to
know one another, etc. It'll be real low-budget-- I expect people will
buy their own drinks-- and contributions will be welcome, but I'll be
providing the first round of snacks as long as my cash holds out. 
Just doing my bit for grassroots space activism in the Midwest...

Many thanks to Thomas Freebairn of IUIPUI for providing the legwork!

     O~~*           /_) ' / /   /_/ '  ,   ,  ' ,_  _           \|/
   - ~ -~~~~~~~~~~~/_) / / /   / / / (_) (_) / / / _\~~~~~~~~~~~zap!
 /       \                          (_) (_)                    / | \
 |       |     Bill Higgins   Fermi National Accelerator Laboratory
 \       /     Bitnet:     HIGGINS@FNAL.BITNET
   -   -       Internet:  HIGGINS@FNAL.FNAL.GOV
     ~         SPAN/Hepnet:      43011::HIGGINS 
Newsgroups: sci.space
From: dyson@sunfish.physics.uiowa.edu (Richard L. Dyson)
Subject: Re: Mars Simulation in Antarctica
Reply-To: dyson@sunfish.Physics.UIowa.EDU
Organization: Department of Physics & Astronomy
Date: Thu, 19 Nov 1992 14:28:29 GMT

In article <1992Nov19.054544.15772@ucsu.Colorado.EDU>, fcrary@ucsu.Colorado.EDU (Frank Crary) writes:
> In article <17547@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes:
> >        At one point I believe that the US was operating a small nuclear
> >reactor as a source of power and heat in one of their Antarctic bases.  Does
> >anyone know the details - this would be highly relevant to moon and or mars
> >bases (which of course would have to however have alternate methods of
> >rejecting heat).
> 
> MacMurdo Station, the main US base in the Antarctic, used to operate
> such a reactor. It was _not_ a space-related system such as the SNAP
> designs, just an ordinary, small, Earth-based system. I don't know
> if it is still opperational, but I doubt the assertion that Antarctica
> is now a "nuclear free zone": The only treaty on the subject of the
> antarctic is about 30 years old, and make no mention of such a thing 
> (In fact, I _think_ the treaty pre-dates the reactor at MacMurdo...)
> 
>                                                 Frank Crary
>                                                 CU Boulder
Frank is not completly correct.  The Antarctic Treay does not allow
nuclear testing (and I *believe* this includes USING nuclear devices)
anymore.  The OLD reactor system that was used at McMurdo was
decommissioned a LONG time ago and completely disassembled and brought
back to the US (probably stored up on the big nasty heap in Idaho...).
They even took out MANY barrels of surrounding volcanic dirt because it
showed a trace of low-level radiation.  Later, it was generally
determined that the entire continent has a higher background radiation
level than usual.  The reason the McMurdo reactor was allowed by the
treaty is because it was "grandfathered" in.

        This is what I recall from my discussions and conversations with
others when I lived there.

Rick
OAE, South Pole 83-84
-- 
Richard L. Dyson               INTERNET:  dyson@sunfish.Physics.UIowa.EDU

  Most people acknowledge that they will never see penguins in the wild.
               But just knowing that they are there is enough.

                                                --Frank S. Todd
From: keithley@apple.com (Craig Keithley)
Newsgroups: sci.space
Subject: Re: Shuttle computers
Date: 22 Nov 92 04:51:14 GMT
Followup-To: sci.space
Organization: Apple Computer, Inc.

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.
From: amon@elegabalus.cs.qub.ac.uk
Newsgroups: sci.space
Subject: Re: Shuttle computers
Date: 20 Nov 92 14:31:48 GMT
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

John:

TO my knowledge they only load the machines from tape on board. They  
do have the ability to override and to take out machines manually via  
a set of buttons at the front of the shuttle. I think they are in the  
center position, reachable from either left or right hand seat.

I'd have to pull out my copy of the control panel documentation (the  
REAL thing :-) to be sure.
Newsgroups: sci.space
From: roberts@cmr.ncsl.nist.gov (John Roberts)
Subject: Re: Shuttle computers
X-Added: Forwarded by Space Digest
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Wed, 18 Nov 1992 04:05:28 GMT


-From: prb@access.digex.com (Pat)
-Subject: Re: Shuttle computers
-Date: 17 Nov 92 04:58:22 GMT
-Organization: UDSI

-In article <BxsMA3.D2o.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:
->Do you recall how tight the lockstep is? I don't believe I've seen anything
->written on that since before STS-1.

-I think it was 1/2 a clock.  i believe every instruction is run at the same
-time on each processor and when a computation is ready they go to the master
-for comparison and validation.  

That *is* a tight lockstep - obviously a pure hardware implementation (at
least for detection). Do the processors have measurement "hooks" into
their internal workings for the lockstep comparison?

-one of the first shuttle flights was screwed up because IBM tested the
-software ona ground test bed which had different cable lengths then the
-shuttle and the propagation delay was putting the clock edges enough out that
-they kept locking out the slave in each pair.  i think it was something
-like this.  there are two control channels, each has a primary and backup
-computer.  the backups kept going off-line and the mission got scrubbed.
-i am sure henry knows the true details but thats how a guyt from IBM
-explained it to me.

If the new GPCs have a performance of 1.2 Mips, and the old GPCs have
"a third" of that, then it is very unlikely that the main processor clock
ran at more than a few megahertz. Since signals travel through cable at
roughly 1/2 - 1/3 of the speed of light, that sounds like either an
extraordinarily long cable or an unreasonably tight timing tolerance 
relative to the clock speed.

The first launch of the first Shuttle (STS-1) was delayed a few days
because when the system was powered up on the launch pad, an unacceptable
phase relationship was established between two of the system clocks. The
relationship was such that it was extremely unlikely to happen at any given
powerup, but no provision had been made to prevent it (the self-checks
*were* designed to detect it).

The solution at the time was to look at the phase relationship after powerup,
and if detected, the processors would be turned off and powered up again. :-)

John Roberts
roberts@cmr.ncsl.nist.gov
From: claudio@nmsb.larc.nasa.gov (Claudio Egalon)
Newsgroups: sci.space
Subject: Re: Where are shuttle research publications?
Date: 15 Nov 1992 21:07:53 GMT
Organization: NASA Langley Research Center, Hampton, VA  USA
Distribution: world
Reply-To: claudio@nmsb.larc.nasa.gov (Claudio Egalon)
NNTP-Posting-Host: b1230bmac9.larc.nasa.gov
Keywords: publications

I do not know any specific journal that publishes only Shuttle 
Research but I do remember  of having seen an issue of Science 
describing the research done during the  Spacelab-1 mission (do not 
remember the issue number but, for sure, it was published after the 
mission). It was a very comprehensive article and I recall that some of 
the authors were Bob Parker and Owen Garriott (crewmembers of the 
Spacelab mission).

May be another way of  finding out research articles of experiments 
performed during a Shuttle mission, would be to try to get one of 
these NASA booklets that are published just before a mission or even 
the NASA Press Kit of the mission itself. These publications include 
the name of the PI's and the experiments that are going to fly. By 
knowing at least the name of the PI you can later on make a literature 
search using the name of the PI and then get the article about the 
experiment that flew in the Shuttle. 

Another way to find out about that would be to contact anyone at 
University of Alabama in Huntsville. They have a lot of people there 
that fly experiments in the Shuttle and, for sure, they must have 
articles published in scientific, archival journals.

Claudio Egalon
From: jbh55289@uxa.cso.uiuc.edu (Josh 'K' Hopkins)
Newsgroups: sci.space
Subject: Re: Minority Kids into Techies (was Re: Free Middle/High School Broadcasts)
Date: 18 Nov 92 06:43:32 GMT
Article-I.D.: news.BxwG0M.LvD
Organization: University of Illinois at Urbana

higgins@fnalo.fnal.gov (Bill Higgins-- Beam Jockey) writes:

>I agree it's a damned shame more females, and members of American minority
>groups, don't take up these professions.  But sometimes I wonder...

>Would it be simpler to ask white males, politely, *not* to become
>engineers?  Or it might be even more effective to pay them.  "You
>don't want to be a scientist, kid!  Here's some cash."

Hmm... Seems to me that any scientist/techie type who is after money is in the
wrong field.  Be a sports hero or write a romance novel.      

>This would help make room for the ambitions of young people of other
>races, genders, or ethnic heritages to enter techie professions.

I don't have the stats to prove it, but I'm sure the ratios of fetal engineers
and scientists (those in school) are improving.  They still aren't great, but
they're far better than they used to be.

-- 
Josh Hopkins                                          jbh55289@uxa.cso.uiuc.edu

	"Why put off 'til tomorrow what you're never going to do anyway?"
Newsgroups: sci.space
From: hughes@gary.enet.dec.com (Gary Hughes - VMS Development)
Subject: ACTS Conference proceedings
Organization: Digital Equipment Corporation
Date: Fri, 20 Nov 1992 18:46:40 GMT


Do any of the NASA folks on the net know if there are proceedings and/or
'handouts' from the ACTS conference (Nov 18-19 I think) available and, if so,
who to contact?

tia

gary