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Date: Fri, 12 Feb 93 10:11:10
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V16 #146
To: Space Digest Readers
Precedence: bulk
Space Digest Fri, 12 Feb 93 Volume 16 : Issue 146
Today's Topics:
algorithm needed
An 'agitator' replies (was: Clinton's Promises...)
Are Landsat Satellites receivable?
Challenger mistake (was re: Remember the Challenger...)
Electronic Journal of the ASA (EJASA) - February 1993
Fred is dead again.
Henry Spencer and stamps
Ideal fuel for 'anti-matter' engine
kerosene/peroxide SSTO (2 msgs)
Lurid Space Fantasy USPO stamps
NASA Seeks WAIS Volunteers
NF-104 (was Re: kerosene/peroxide SSTO)
Precursors to SSF/ST: TNG Data Ports.
Russian Solar Sail Results and Obervations pointers
Satellite Imagery
Solar wind nits
Space Calendar - 01/28/93
Space Colonies
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: 5 Feb 1993 18:40 CST
From: "Danny Bruton, Texas A&M University, Physics" <wdb3926@zeus.tamu.edu>
Subject: algorithm needed
Newsgroups: sci.space,sci.astro
Earl W Phillips <ephillip@magnus.acs.ohio-state.edu> writes...
>Does anyone happen to have an algorithm
>to convert RA & Dec to altitude & azimuth,
>as measured by a compass & quadrant?
>
>*****************************************************************
>* | ====@==== ///////// *
>* ephillip@magnus.ircc.ohio-state.edu| ``________// *
>* | `------' *
>* -JR- | Space;........the final *
>* | frontier............... *
>*****************************************************************
The lines below were cut from a FORTRAN program used to calculate
the Altitude (AL) and Azimuth (AZ)....using LATitude, LONgitude,
DEClination, Right Ascsnsion, and Hour Angle. Hour Angle can
be computed from Universal Time.
LAT=31
LON=-96.5
P=3.1415927/180
AL=(SIN(DEC*P)*SIN(LAT*P))+(COS(DEC*P)*COS(LAT*P)*COS(HA*P*15))
AL=ASIN(AL)/P
AZ=SIN(DEC*P)-(SIN(LAT*P)*SIN(AL*P))
AZ=AZ/(COS(LAT*P)*COS(AL*P))
IF (SIN(HA*P*15).GT.0.) THEN
AZ=360.-AZ
ENDIF
Dan
------------------------------
Date: Sat, 6 Feb 1993 06:39:06 GMT
From: "Edward V. Wright" <ewright@convex.com>
Subject: An 'agitator' replies (was: Clinton's Promises...)
Newsgroups: sci.space
In <1kugvoINN4l@phantom.gatech.edu> matthew@phantom.gatech.edu (Matthew DeLuca) writes:
>>Don't forget that it takes a week or two to really adapt to free fall and
>>get good at working there, even if you don't get spacesick. At just about
>>the time when a shuttle crew is becoming really effective, the mission ends.
>Agreed. However, next time they go up they're way ahead of the game and
>can adapt much more quickly.
Uh, no, it doesn't work that way. Once you come back to Earth, you
have to start all over again.
------------------------------
Date: Sat, 6 Feb 1993 00:41:47 GMT
From: Willie Smith <wpns@miki.pictel.com>
Subject: Are Landsat Satellites receivable?
Newsgroups: sci.space
ggjns@knuth.mtsu.edu (John Schmidt) writes:
>araichel@cser.encore.com (Alan Raichel) writes:
>> I have seen some pretty high resolution pictures taken by
>>the Landsat satellites. I think that these have a resolution of
>>something like 100 feet or so. I know that the NOAA HRPT satellites
>>have a resolution of about 2 Km. I think that it would be interesting
>>to see if I could get more.
>As far as this hobbyist is concerned, I think I won't be able to afford
>the reverse engineering; I'd be better off spending the money (up to
>$5000 for a full-scene digital image) to just buy the desired data from
>EOSAT.
>Since this system was designed beginning in the late 1970s and launched
>with your and my tax dollars in 1982/1983, (speaking strictly about the
>LANDSATs 4 and 5) I would suppose somewhere in an archive the documents
>exist.
There _is_ an archive of older images from back when the government
was gathering the data that's available for purchase at a modest cost.
The digital images are still pretty expensive (probably due to the
cost of making you the copies of the tapes), but color photos are
pretty cheap (around $25?). Now of course I forget _where_ you get
this stuff, but schools and govt researchers put up a big stink when
EOSAT started charging an arm and a leg for the taxpayer's data, so
they set up an archive somewhere. Try asking EOSAT or write me a note
if you can't find it, and I'll dig it up from home.
Willie Smith
wpns@pictel.com
--
Willie Smith wpns@pictel.com N1JBJ@amsat.org "I'll make
Beelyuns and Beelyuns from the book contract and the TV show with
government funding for looking for the nothing in the void where The
Bang caused the hole in the middle of it all" Frank Hayes - Cosmos.
------------------------------
Date: Fri, 5 Feb 1993 23:11:00 GMT
From: shanleyl@ducvax.auburn.edu
Subject: Challenger mistake (was re: Remember the Challenger...)
Newsgroups: sci.space,sci.space.shuttle
>>>(Simon E. Booth) writes:
>>>
>>> Just a reminder- 7 years ago today- 11:38am EST....
>>> So, where were you when the Challenger disaster took place
>> For the past few days, I've read responses to this post and have hoped
>>the flurry of responses would die down. Each post stirs up emotions most
>>of us would rather forget and I've been reluctant to add my experiences
>>to the heap. My feelings were, "It's over and we've finally put it
>>behind us. Let's get on with it."
>>
>> Well, last night I was walking past my bookshelf and next to the 20 or
>>so books I have about the accident in my SPACE collection, I remembered a
>>book I have called "To Engineer is Human". I bought it because it had a
>>picture of Challenger on the cover. It was mostly about other notable
>>failures in our transportation system, primarly the failure of bridges.
>>The reoccurring theme of the book was that engineering design is a cyclic
>>process of inovation and optimization followed by catastrophic failure.
>>The author stated that we learn more from any one failure than we do from
>>an entire string of successes. I suppose Challenger is the "Talcoma Narrows"
>>of our generation and something that none of us will ever be allowed to
>>forget.
While I wouldn't want to compare (no implications to this poster's comment)
the Challenger mistake to and us being able to "get over it" to the saying...
"no use crying over spilt milk", I would agree Jim and his suggestion that we
put the Challenger mistake behind us in terms of it having any impetus in the
way of needlessly obstructing further exploration...
...however, this was no"Tacoma Narrows". It was not engineers doing what
engineers do. It was not even a bunch of similar and disimilar 'problems'
that all came to a head at T+0000:00:00:01 seconds into the launch on a
pretty lousy day in January, 1986.
No, I do not have any conspiracy fodder for wasted bandwidth or "TOP SECRET"
information for the gullible to feed on. I do have the power of logic and
hopefully some rather stringent fallacy [sic?] failsafes to see the logic
through.
The Solid Rocket Boosters (SRB's) were manufactured by then Morton Thiokol
(now Thiokol Inc.). They were designed to be segmented which presented numer-
ous engineering problems in flight but many bonuses ("cost savings") in the
manufacturing and delivery process. Just imagine the casting hole that would
be required for a " 45.46 meters (146.6 foot [feet]) long" solid rocket booster
solid fuel component. Actually, the three segments that have fuel cast in them
will be approximately 36 meters long, or 120 feet. Still pretty big and then
you have to transport it. So, engineers did what engineers do and came up with
a more "convenient" structure but had to compromise on integrity. I (having no
power, authority, or consequence in these matters anyway) can accept the trade-
offs that are sometimes necessary. Integrity of the structure insofar as its
intended use (a pressure and propulsion vessel), was compromised by design and
several "fixes" were involved in man-rating* it. These include joint overlap
devices (clevis and tang) 1) --- >--- 2) --->--- and "torturous" or
labyrinthal (word?) segment insulation shapes, that when joined, made it very
difficult for efollow a straight (energy efficient) path
in the segment joint or "seams". The notorious "O"-rings are also part of the
seal at each joint and are strategically place in the clevis/tang joint to act
as final "roadblocks" for escaping plasma/gas.
* much less FLIGHT rating it!
The problem (sorry, I realize it's about time I got to it) :
The original design called for a "clevis and clevis" with an additional O-ring
______
=======< ------z========
\_____ /
_____/
placement. This design "ensured" a redundant seal when the SRB ignited due to
bowing forces that acted on the joints as the SRB became "pressurized" (yes with
a big hole at one end, but still pressurized). Otherwise, in a single "tang"
in double "clevis" structure, one of the overlapping flanges (sorry for all the
jargon) would bow out, actually causing the joint to be less sealed. Blow by
of the three O-rings becomes even easier in the clevis/tang set-up but the
clevis/clevis arrangement was given up for "performance" reasons. Yes, this
weight savings and the weight savings gained by shaving the SRB's were heralded
as Morton Thiokol PR coup to NASA by selling themselves as "High Performance
Solid Rocket Boosters". I do not know the total weight reduction due to these
and possibly other factors but weakinging a joint to save weight in an already
untried, borderline integrity structure, to me, is wrong. This seemed
motivated more by greed and deceit in the original performance claims than
anything else.
I say, the Challenger mistake was not "unavoidable" and the great NASA and con-
tractor soul-searching that went on after that ended with the wrong fingers
pointing at secondary reasons, not primary reasons for this, criticality one
failure.
Just a thought (a rather long one...).
>>The entire experience and the years of recovery leading up to STS-26R
>>deeply affected everyone here and thru failure has made space transportation
>>a little safer.
>>--
>>--------------------------------------------------------------------------
>> Jim Dumoulin INTERNET: DUMOULIN@TITAN.KSC.NASA.GOV
>> NASA / Payload Operations SPAN/HEPnet: KSCP00::DUMOULIN
>> Kennedy Space Center
>> Florida, USA 32899
No flames intended towards Jim Dumoulin and I would say that I appreciated his
accounting of a day he'd rather leave behind....
Sincerely,
Paul Sylvester Shanley
Researcher ad Infinitum et al
School of Human Sciences
Auburn University
308 Spidle Hall
Auburn University, Alabama 36849
United States of America
VOICE: 205 844 1339 office
VOICE: 205 887 7440 home
FAX: 205 844 1340 office
e-mail pshanley@humsci.auburn.edu
shanleyl@ducvax.auburn.edu
ad astra per Mylanta
------------------------------
Date: Fri, 5 Feb 1993 23:56:35 GMT
From: Jeff Bulf <jbulf@balsa.Berkeley.EDU>
Subject: Electronic Journal of the ASA (EJASA) - February 1993
Newsgroups: sci.space
Revolving around a small yellow star between the celestial paths
of a crater-scarred world called Mercury and our blue-white Earth lies
the planet known as Venus.
As I understand it, isn't the Sun a considerably larger-than-average star?
Recent articles in Astronomy have gone into this some. Apparently average
is around red-dwarf size.
Unfortunately I have no references on hand. Anybody have serious information?
--
dr memory
jbulf@kpc.com
------------------------------
Date: 6 Feb 1993 06:27:44 GMT
From: Jeff Foust <jafoust@cco.caltech.edu>
Subject: Fred is dead again.
Newsgroups: sci.space,talk.politics.space
In a recent article aws@iti.org (Allen W. Sherzer) writes:
>There was a meeting on the NASA budget last weekend when Clinton was
>at Camp David. Director of OMB Panetta is proposing (and Clinton seems
>to be accepting) a $12 billion NASA budget. The money is to come from
>ending Freedom and ASRM.
According to a report on CNN this evening, George Stephanopolous (White House
Comm. Director) said that the President was considering substantial cuts
to both SSF and SSC, but was not considering scrapping either project. This was
a change from previous reports.
>[on savings from scrapping Fred and ASRM]
>However, sources say that this may be used to do a serious re-write
>of the NASA Act over the next two years.
Interesting... any idea what changes/additions/deletions are being considered?
--
Jeff Foust Senior, Geophysics/Planetary Science, Caltech
jafoust@cco.caltech.edu jeff@scn1.jpl.nasa.gov
Final score of the Interstellar Space Deep Space 9
Station Championship Softball Game: Babylon 5
------------------------------
Date: Sat, 6 Feb 1993 00:29:21 GMT
From: Josh Hopkins <jbh55289@uxa.cso.uiuc.edu>
Subject: Henry Spencer and stamps
Newsgroups: sci.space
18084TM@msu.edu (Tom) writes:
>>>|> He's *ba-a-a-a-ck-k-k...*
>>>|> :) And we're all glad!
>>>who's back ?
>>>Elvis ?
>>Is there a Henry Spencer stamp yet? Which Henry picture did they use? ;-)
>No, but I just went down to the post office to get some stamps, and, being
>tired of ducks, asked what they had.
>I got this cool set of 'Space Fantasy' stamps.
>But Henry Spencer wasn't anywhere on them! :-)
Hmm. We could lobby the postal serivce (oxymoromn?) to make a Spencer stamp.
However, we'd have to kill him and then wait ten years so I don't think it's
worth it. Oh well, we'll just have to wait.
--
Josh Hopkins jbh55289@uxa.cso.uiuc.edu
Q: Why did the chicken cross the mobius strip?
A: To get to the other... er, uh...
------------------------------
Date: 6 Feb 93 04:40:38 GMT
From: fred j mccall 575-3539 <mccall@mksol.dseg.ti.com>
Subject: Ideal fuel for 'anti-matter' engine
Newsgroups: sci.space
The subject pretty much says it all. If you had close to unlimited
energy for input to the fuel (say from anti-matter reactions) as you
exhausted it, what would be the best fuel to carry from a performance
standpoint? Would you go for something relatively dense like mercury
and superheat it to a plasma, do something like a buckyball
massdriver, or still go for the light-weight atoms like hydrogen for
maximum exhaust velocity?
--
"Insisting on perfect safety is for people who don't have the balls to live
in the real world." -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me.
------------------------------
Date: Sat, 6 Feb 1993 00:06:04 GMT
From: Paul Dietz <dietz@cs.rochester.edu>
Subject: kerosene/peroxide SSTO
Newsgroups: sci.space
In article <C1zvyB.Ho5@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
> Higher molecular weight in the exhaust is what hurts the exhaust velocity,
> but it actually helps on thrust. In that department, you're ahead. The
> same number of engines with the same size and chamber pressure will give
> more thrust, not less, with JP-5/peroxide than with LH2/LOX. Alternatively,
> the engines can get smaller or you can use lower pressures, either of which
> is definitely useful.
Is this right? The coefficient of thrust doesn't depend on molecular
weight, only on pressures, throat area and specific heat ratio k. Perhaps
JP5/peroxide will produce gas with a lower k than LOX/LH2, but that
won't be enough to triple the thrust.
Paul F. Dietz
dietz@cs.rochester.edu
------------------------------
Date: 6 Feb 93 04:58:38 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: kerosene/peroxide SSTO
Newsgroups: sci.space
In article <1993Feb6.000604.18749@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes:
>> Higher molecular weight in the exhaust is what hurts the exhaust velocity,
>> but it actually helps on thrust...
>
>Is this right? The coefficient of thrust doesn't depend on molecular
>weight, only on pressures, throat area and specific heat ratio k...
Hmm, I think you're right. Somewhere I picked up the belief that there
was a dependence, but I'd never taken a hard look at the equations to
try to find it, and it doesn't seem to be there.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360. | henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: Fri, 5 Feb 1993 23:29:02 GMT
From: "Frank R. Dana Jr." <danaf@bray1b.its.rpi.edu>
Subject: Lurid Space Fantasy USPO stamps
Newsgroups: sci.space,rec.arts.sf.fandom,rec.arts.sf.misc,rec.arts.sf.marketplace
In article <1993Feb4.172915.1@fnalf.fnal.gov>, higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes:
|> Anybody seen the U.S. Post Office's new "Space Fantasy" stamps?
|> I just got mine.
[...]
|> Does anybody know who the artist is? Hmm, there's a philately list on
|> Bitnet, maybe I'll check there.
Hey! None of that philately stuff here! How disgusting!
...kids these days. Next thing you know, we'll have mastication at the dinner
table! Mark my words...
8) for the humour-deficient
|> --
|> O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/
|> - ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap!
|> / \ (_) (_) / | \
|> | | Bill Higgins Fermi National Accelerator Laboratory
|> \ / Bitnet: HIGGINS@FNAL.BITNET
|> - - Internet: HIGGINS@FNAL.FNAL.GOV
|> ~ SPAN/Hepnet: 43011::HIGGINS
--
/////////////////////////[[[[[[[[[[]]]]]]]]]]\\\\\\\\\\\\\\\\\\\\\\\\\
(718) (212) (516) (518)
=======Amiuser============Frank R. Dana, Jr.============Doc Ami=======
--------My opinions rarely reflect those of any sane person,----------
living, dead, or undead... that's gonna CHANGE.
------------------------------
Date: Sat, 6 Feb 1993 00:15:44 GMT
From: kjenks@gothamcity.jsc.nasa.gov
Subject: NASA Seeks WAIS Volunteers
Newsgroups: comp.infosystems.wais,sci.space,sci.space.shuttle
In a joint development effort between NASA's Johnson Space Center and
the Space Shuttle Program office, we are developing an X Windows/MOTIF
version of the Wide Area Information Servers (WAIS) client which allows
storage and retrieval of "metadata" (like Author, Title, Keywords,
Document Number, etc.) in addition to the usual "search by contents."
This new client talks to standard WAIS servers, but requires several
extra index files (for the metadata fields) in addition to the standard
WAIS index (which indexes the actual contents of the document).
In support of the Space Shuttle Program's multi-center implementation
requirements, we're looking for volunteers to help us test the new
client/server relationship between NASA Field Centers. This would
involve working with our developers to set up the necessary index files
on your existing WAIS server. We estimate that this will take at least
8 hours of your time over the course of a week, but I guarantee that
you'll learn something worthwhile in the process.
To keep the test as close as possible to actual operating conditions,
we'd prefer to find a volunteer who has a Sun at Kennedy Space Center,
Marshall Space Flight Center, and Rockwell International's Downey,
California, installation. Failing that, we'll take volunteers from
anywhere in the continental US. (I'm distributing this message to
"world" FYI only.)
If you are interested in participating in this project, please reply by
e-mail before 02/19/93.
Before you ask, no, the software is not available for anonymous FTP,
nor is it likely to be in the foreseeable future. Sadly, we're
restricted from distributing it this way.
-- Ken Jenks, NASA/JSC/GM2, Space Shuttle Program Office
kjenks@gothamcity.jsc.nasa.gov (713) 483-4368
"NASA turns dreams into realities and makes science fiction
into fact" -- Daniel S. Goldin, NASA Administrator
------------------------------
Date: 6 Feb 93 05:08:34 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: NF-104 (was Re: kerosene/peroxide SSTO)
Newsgroups: sci.space
In article <1993Feb5.215620.1@stsci.edu> gawne@stsci.edu writes:
>> Also of note were the peroxide monopropellant rocket engines used in the
>> NF-104 rocket-boosted aircraft flown by NASA and the USAF, which worked
>> quite well and were serviced and fuelled by ordinary USAF technicians.
>
>Isn't that the one Chuck Yeager almost killed himself in? Seems I recall
>somebody saying its flight envelope had more holes in it...
>I guess what I'm asking is did the engines work well, or the plane as
>a whole, or both, or neither?
Mitch's paper says "no rocket-engine-related emergencies were noted
during eight years of operation". (It also says that I misremembered
the engine cycle -- the NF-104 used peroxide monopropellant thrusters
for attitude control, but the main rocket engine was a bipropellant
engine, using jet fuel and peroxide.)
No version of the F-104 could be characterized as a gentle or forgiving
aircraft, and the NF-104 ballistic flights would have been hairier than
normal flying. Yes, it was an NF-104 in which Yeager had his close call,
I believe.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360. | henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: Sat, 6 Feb 1993 02:58:50 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Precursors to SSF/ST: TNG Data Ports.
Newsgroups: sci.space
In article <1993Feb5.034950.1@acad3.alaska.edu> nsmca@acad3.alaska.edu writes:
>In article <C1ynxG.L3B@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes:
>> Because, despite what you hear from people like Go Corp., it's still a
>> whole lot more convenient to carry a piece of paper around inside Spacelab
>> (for example) than to lug a portable computer around.
>
>Why muist it be a portable computer? Why not a data port as in Star Trek the
>Next Generation.. I know it is nice to have a hard copy, but.. Why not make the
>technology and computer better and have a real AI or combined system...
>Kind of liek ST:TNG...
Because the real world doesn't have movie special effects teams to make
such systems *seem* like they work. ST science and engineering shouldn't
be confused with *real* science and engineering. After 30 years of AI work,
you might as well ask for ST transporters as ST computer systems. Neither
is within the realm of real engineering today or any time in the foreseeable
future.
Gary
--
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary
534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244 | |
------------------------------
Date: Sat, 6 Feb 1993 05:33:15 GMT
From: Leigh Palmer <palmer@sfu.ca>
Subject: Russian Solar Sail Results and Obervations pointers
Newsgroups: sci.space
In article <C1zz0o.GMI.1@cs.cmu.edu> Glenn Chapman, glennc@cs.sfu.ca
writes:
>[a very helpful prediction report for Znamya, and] ...
>By the way on Radio Moscow they announced
>that the sail, when reflecting on an area, will illuminate a ground area
>4 km in diameter.
I guess I should point something out which has not been mentioned here,
perhaps because any physicist will say "of course" to this, and many
others don't care. That size is not a function of the size of this
particular sail; it is the minimum size spot the best optical converging
mirror in the universe could make from 400 km up, no matter how large you
make it. The minmum size depends only on the angular diameter of the sun
(which is approximately .01 radians) and the distance from the mirror to
the ground (400 km). The minimum spot size is the product of those two
numbers, and that would obtain not for Znamya, but for an ideally
focussed off-axis f/20,000 paraboloid of focal length 400 km. A floppy
mirror flat to a small fraction of a degree will produce an image a scant
twenty meters larger in diameter, so don't order a mirror from Roger
Angel's optical shop yet. The image on the ground is the same as would be
formed by a pinhole box camera 400 km long.
You terrified Yankee ants can come out of your bunker-anthills now.
Leigh
------------------------------
Date: 6 Feb 1993 07:11:51 GMT
From: Jody Fraser <fraserjo@nic.cerf.net>
Subject: Satellite Imagery
Newsgroups: sci.image.processing,sci.aeronautics,sci.astro,sci.geo.geology,sci.geo.meteorology,sci.misc,sci.space,alt.sci.image-facility
I am seeking information for a colleague concerning space borne
platforms for synthetic aperture radar imagery that is in the
public domain. As an example, SEASAT which I believe was orbited
in the mid 80's and managed by NOAA. If anyone out there on the
Internet either knows of or is involved with present or past
systems of this type, would they please email Richard Bence at
rbence@logiconultra.com to begin a dialog.
Also anyone with any information on side-looking synthetic
aperture radar implementations on air borne platforms would also
be welcome to communicate.
Thank you all in advance.
------------------------------
Date: Sat, 6 Feb 1993 00:25:21 GMT
From: Josh Hopkins <jbh55289@uxa.cso.uiuc.edu>
Subject: Solar wind nits
Newsgroups: sci.space
18084TM@msu.edu (Tom) writes:
>Tom said:
>>>Further nit: If light has momentum and protons have a wavelength,
>>>how do you classify one as wind and not the other? They are both
>>>"stuff emitted from the sun at supersonic velocities" after all.
I tried to explain this to Tom once and failed.
>I didn't call them the same. I suggested that the definition of solar
>wind is a bit arbitrary, since it's based on proton-ness, rather than
>wave-icle-ness. Does the difference in their momentum make the defintion
>any less arbitrary?
Tom, the solar wind is made up of protons AND electrons. If the sun were
selectively spewing protons out it would do some impressive things to its net
charge. Now there are fundamental differences between protons/electrons and
photons. Photons travel faster and have no rest mass. You can't fuse photons.
Please check your freshman chem or physics text for more information.
The fact that they can both be modeled as waveicles is irrelevant. You can be
modeled as a waveicle. However this would mean that you would increase the
solar luminosity or cause auroras.
>Aaaand, since we were talking about solar-sails, which are just ways
>of catching momentum, it doesn't matter what you use;
Solar sails (more properly "lightsails") just plain don't use the solar wind and
no amount of assertion will change that. The solar wind imparts a tiny fraction
of one percent of the momentum of the light. If you want to play with the
solar wind go build a magsail.
--
Josh Hopkins jbh55289@uxa.cso.uiuc.edu
Q: Why did the chicken cross the mobius strip?
A: To get to the other... er, uh...
------------------------------
Date: Fri, 05 Feb 1993 22:27:00 -0500
From: Mark Prado <Mark.Prado@f168.n109.z1.fidonet.org>
Subject: Space Calendar - 01/28/93
Newsgroups: sci.space
> January 1994*
> Jan 24 - Clementine Titan IIG Launch (Lunar Orbiter, Asteroid Flyby Mission)
Does anyone have more information the above?
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Date: Sat, 6 Feb 1993 03:55:27 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Space Colonies
Newsgroups: sci.space
In article <1kufceINNngn@digex.digex.com> mheney@access.digex.com (Michael K. Heney) writes:
>The L-5 society is not "moribund" - it merged with the National Space
>Institute in 1987(?) to form the Nationa Space Society (NSS). NSS is
>headquartered here in DC, at 922 Pennsylvania Ave SE, 20003; the phone
>number is (202) 543-1900. I don't know if there's an NSS chapter in
>your area; give 'em a call...
L5 isn't moribund; it's dead. NSS ate what was left of it. The chapter
organization is the only part of NSS that is recognizably a survival of
L5. I would second the recommendation to find a local chapter, if any.
The better local chapters are nearly the only thing about NSS that is
worth saving.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360. | henry@zoo.toronto.edu utzoo!henry
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From: Jeff Bytof <rabjab@golem.ucsd.edu>
Newsgroups: sci.space
Subject: SS Freedom and Supercollider again on chopping block
Date: Fri, 5 Feb 1993 21:21:46 GMT
Organization: sio
Lines: 7
Message-Id: <rabjab.48.728947306@golem.ucsd.edu>
Nntp-Posting-Host: lutherlab.ucsd.edu
Sender: news@CRABAPPLE.SRV.CS.CMU.EDU
Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU
I just heard on the radio that the Space Station and the Supercollider
are up for discussion by Clinton officials. The broadcast gave
little in the way of details. The report mentioned the "30 billion
dollar pricetag" for the space station. Curiously, Clinton's job
stimulus package is pegged at $31 billion...
-rabjab
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End of Space Digest Volume 16 : Issue 146
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