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Date: Thu, 8 Oct 92 05:01:33
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #296
To: Space Digest Readers
Precedence: bulk
Space Digest Thu, 8 Oct 92 Volume 15 : Issue 296
Today's Topics:
Alleged Benefits of Military $
Drop nuc waste into sun (4 msgs)
Env. Satellites Shutdown in Dec. 1992
Final Round Sagan vs. LGM
Galileo Update - 10/07/92
HRMS
Pioneer Venus Out of Fuel, Orbit Deteroriating (2 msgs)
Sputnik I - 35th anniversary
UFO? REALLY?
Why not Mir? was(what use is freedom?)
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
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(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: Wed, 7 Oct 1992 15:29:17 GMT
From: Edmund Hack <arabia!hack>
Subject: Alleged Benefits of Military $
Newsgroups: sci.space
In article <1469100020@igc.apc.org> mwgoodman@igc.apc.org (Mark Goodman) writes:
[munch]
>
> But let me explain why
>I think the numbers are implausible. Military spending goes primarily
>to high income people in capital intensive industries.
Somewhat true. However, most defense workers are not high income except
by absurd standards. {What is the standard for "high income"? To Bill
Clinton, it is household income of about $55,000. To the IRS, while
perfoming "top heavy" benefits tests, it is salary of about $40k/yr. To
most people it is anyone making more than them ;-). } Given that median
salaries for _engineers_ in defence are in the low 40s and that
technicians and assembly line staff is lower, I don't think the industry
is mostly high income. Middle class income, yes.
>It is known to
>produce far fewer jobs (about a factor of 3, if I recall) than the same
>amount of money spend on public works or education. I haven't looked
>at this in a while, so I don't have references, but the Council on
>Economic Priorities will.
This may be due to the way that the accounting is done and salaries
involved. The overhead multiplier for DOD type work is on the order of 3
to 5, from what I have been told. That is, the DOD pays an hourly rate
3 to 5 times the worker's rate for his labor. This covers benefits
(insurance, Social Security, retirement) , rent, office supplies,
non-direct departments in the company (i.e. human resources, EEO
Compliance Officers, company managers, accountants, etc.), recruiting
costs and a % for internal R&D. This varies according to the contract
type. An order for bullets is different from a fighter prototype. Note
also that the single defense worker also "pays" for a part of other
workers. A job as a clerk in a Wal-Mart or a local small business will
have a lower multiplier - the benefits are not as good, the overhead in
consumer businesses is lower (not as much paperwork), salaries are
lower. The jobs that defense creates are mostly middle class jobs with
good benefits (and middlin' job security) as opposed to most small
business jobs that are entry level and poor in benefits.
>
>I believe it is also true that higher income people spend less of their
>money than low income people, so their money is likely to go into the
>economy fewer times.
The more you make, the more likely you are to invest and save. This is
(in the long term) good for the economy by making capital available for
job creation. However, most people don't save much. My wife and I are
unusual in that we are putting about 15% of our gross incomes into
savings (401(k), SEP, ESOP, etc.). We hope to be semi-retired by age
55. Most middle class persons have 2 major "savings" plans - a house
payment and Social Security. Their milage will vary - Social Security is
a very bad deal for the middle class, house values have had one big run
up recently, but future growth is unpredictable.
>I have heard this as an explanation for the fact
>that the increase in income during the Reagan years did not produce
>sustained increases in consumer demand; the increases went to people
>who spend less of their money. Not being an economist, I cannot vouch
>for the validity of this argument, but it tends to contradict what Gary
>said.
>
Much of what has been said about the "Reagan years" is very heavily
tinted by politics and agendas. I recently heard that the reason the
middle class shrunk in the 80s is that the "lost" members moved up, not
down. Is this true? I don't know. The man who said this had an axe to
grind. If consumer spending didn't go up, why is the retail business
expanding, mostly in new methods like "mega-stores"?
>It is important to note that military spending is essentially wasteful
>in the narrow sense that it produces no product or public resource with
>economic value. Building a highway contributes to the economy by
>facilitating transportation. Building a fighter aircraft does not.
I have no arguement here, aside from the commerce stimulating effects of
peace and stability.
>Technological spinoffs have become increasingly rare as military
>technology has become increasingly specialized and isolated from civilian
>technologies.
>
Please justify this. I see a lot of spinoffs all around me, especially
in the computer industry. The latest Aviation Week has a story on how
TI is turning NASP spinoffs into products that could bring in $200
million/yr by 2000. Not bad.
>In the broader sense, of course, military spending can be extremely
>valuable if it contributes to national security. I think the debate
>over military spending should rest on our security needs, not on
>disputed economic claims.
True, but unlikely to be implemented soon in Congress. Despite the lack
of need for most military bases in the US, it is almost impossible to
close them now. (The first wave was only closed due to extreme pressure
and arm-twisting, despite the obvious lack of utility they had to
national security.)
[munch]
>
>I don't understand why you think having a connection with Congress should
>associate me with any particular political agenda. Congressional staff
>members are not expected to pursue their own agendas, but those of their
>bosses.
<HA! HA! ROFL>
The staffers of the various subcommittees have agendas of their own and
pursue them with vigor. Ask around. Read the book "Hill Rat" that a
former staffer wrote. It is in hardback right now.
>Members of Congress have almost as wide a variety of agendas as
>those expressed on the internet. In any case, their agendas are a reflection
>of their constituents and (unfortunately) their campaign contributors and
^^^^^^^^^^^^ only if the district is unusual
>lobbyists, among whom military contractors are an especially influential
>group.
>
>I hope to help Congress develop better public policies by providing sound
>technical guidance where I can.
Good luck. Technical guidance is heeded as much in Congress as the 55 MPH
speed limit is on the Interstates.
>I may offer nontechnical judgments as well,
>but I will do my best to distinguish clearly between technical analysis and
>personal opinion.
Good. I wish you luck.
--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah..
Papoon for President - You Know He's Not Insane! - Endorsed by the
American Friends of the Martian Space Party, League of Winged Voters
------------------------------
Date: Wed, 7 Oct 1992 16:26:09 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Drop nuc waste into sun
Newsgroups: sci.space
In article <rabjab.10.718414104@golem.ucsd.edu> rabjab@golem.ucsd.edu (Jeff Bytof) writes:
>>... it would take more energy to
>>toss waste into the sun than it would to send it right out of the solar
>>system.
>
>Actually, I think you can leave Earth orbit at less than solar
>system escape velocity, and perform a Jupiter gravity assist ...
Unfortunately, then each waste package needs to have propulsion and guidance
systems that will function until Jupiter encounter, and considerable ground
support is needed for navigation and control. Launching them to solar escape
puts more demands on the launch system but greatly reduces complexity and
cost of the packages themselves.
--
There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: 7 Oct 92 17:12:25 GMT
From: Mark 'Henry' Komarinski <komarimf@craft.camp.clarkson.edu>
Subject: Drop nuc waste into sun
Newsgroups: sci.space
paul.nimmo@f635.n713.z3.fido.zeta.org.au (Paul Nimmo) writes:
>Original to: Hangfore@Spf.Trw.Com
>Hi all, now someone correct me if i'm wrong here, but, isn't the fundamentl
>problem with sending waste to the sun the energy requirements? If my
>schoolboy physics memory serves me correctly it would take more energy to
>toss waste into the sun than it would to send it right out of the solar
>system. this being true it certainly does *not* present itself as a fesible
>alternative.
>see ya, paul.
That shouldn't be a problem. The sun's gravity will pull it towards the
sun, saving energy. The problem is getting the radioactive crap into
space. If one of these rockets blows up, there will be mucho radiation
all over the place and the world will soon be glowing in the dark.
-Mark
P.S. I think sending the waste outside the solar system is like dumping it
in the ocean..it just sends the problem somewhere else.
--
- Mark Komarinski - komarimf@craft.camp.clarkson.edu
[MIME mail welcome]
Smile. It makes people wonder what you're up to.
------------------------------
Date: Wed, 7 Oct 1992 23:23:40 GMT
From: Nick Haines <nickh@CS.CMU.EDU>
Subject: Drop nuc waste into sun
Newsgroups: sci.space
In article <komarimf.718477945@craft.camp.clarkson.edu> komarimf@craft.camp.clarkson.edu (Mark 'Henry' Komarinski) writes:
paul.nimmo@f635.n713.z3.fido.zeta.org.au (Paul Nimmo) writes:
>Original to: Hangfore@Spf.Trw.Com
>Hi all, now someone correct me if i'm wrong here, but, isn't the fundamentl
>problem with sending waste to the sun the energy requirements? If my
>schoolboy physics memory serves me correctly it would take more energy to
>toss waste into the sun than it would to send it right out of the solar
>system. this being true it certainly does *not* present itself as a fesible
>alternative.
>see ya, paul.
That shouldn't be a problem. The sun's gravity will pull it towards the
sun, saving energy.
In the same way that the sun's gravity pulls the Earth towards the
sun? Wrongo. Whatever we launch from Earth starts off in solar orbit
(because the Earth is in solar orbit), and has to dump all of its
orbital velocity (i.e. 30 km/sec) in order to fall into the sun. This
is much more expensive than launching to solar escape velocity and
leaving the solar system. Do the sums.
Similarly I can't believe that the poster claiming that the vaporized
waste will end up back here can have been serious. The Earth covers
about one billionth of the sun's sky. So one billionth can be expected
to end up somewhere on Earth (uniformly distributed over 400 million
square kilometres of the Earth's surface). If you think this is going
to send us all into fallout shelters you must be completely insane.
Someone even suggested that we might turn the sun _out_. Good grief,
go get some education, why don't you?
The problem is getting the radioactive crap into
space. If one of these rockets blows up, there will be mucho radiation
all over the place and the world will soon be glowing in the dark.
This is only one problem. The real reasons why we shouldn't `dispose'
of nuclear waste by sending it into space are:
(1) it's far too expensive to do (even if we just want to leave it in
a parking orbit somewhere, the launch costs are absurd),
(2) we may well want the waste again in the future, and it's cheaper
to get to if it's on Earth,
(3) crazy politicians will scream blue murder because they think it'll
fall on their heads. It's not worth the trouble.
Any one of these reasons is more than enough. Three together shows
that it's crazy.
Again, _please_ think about doing some sums, or at least thinking
about physics, before posting to sci.space. These sums are _very_
easy. If you can't do them, don't try to answer questions that other
people post.
P.S. I think sending the waste outside the solar system is like dumping it
in the ocean..it just sends the problem somewhere else.
There are two fundamental differences between the ocean and
interstellar space: (1) the ocean supports life. (2) the ocean is
tiny. There is nowhere `else' (i.e. another solar system) that any
probe we can launch will reach within a span of tens of thousands of
years. We can choose a trajectory that will extend this timespan to
billions (or trillions...) of years if we want.
That statement betrays a complete lack of understanding of the scale
of space, so I'll post some basic numbers and ideas to help the
clueless.
radius of the earth: 6.4e3 km
(if you don't understand this notation, please go away
and take basic maths classes until you do).
surface area of the earth: 4e8 km^2
volume of the oceans: about 3e8 km^3
distance from the earth to the sun: 1.5e8 km
Pluto's orbit (characteristic size of the solar system): 6e9 km
`volume' of the solar system (within 1e9km of ecliptic): 4e27 km^3
(this is therefore ten billion billion times the volume of
earth's oceans)
other lifeforms within this space: none (best guess)
(so we won't affect anyone)
distance to the nearest star: 4 light years = 4e13 km
time to reach this at 10 km/sec (typical probe velocity): more than 10000 years
volume of "our" interstellar space (i.e. that which has the sun as the
closest star) : ~1e41 km^3 (i.e. about a million billion times the
volume of the solar system)
characteristic size of the galaxy: 1e19 km
There are a lot more numbers like this in the FAQ. I can't be bothered
typing in any more.
If the Earth were an apple, the whole biosphere shebang, including the
oceans, would be thinner than the skin on the apple. The sun would be
a 10-foot sphere about a mile away. The solar system would be forty
miles across. The nearest star would be on the moon (if you see what I
mean). And in all this space, there's _nothing_ except a few
basketballs (the gas giants), assorted small fruit (the other planets)
and a bit of dust. We can't pollute something that large.
_Please_, if you're going to post here, recognize that the Earth is
_tiny_. We could hide the whole damn _planet_ (never mind the tiny
fraction of the outermost skin which we might consider `waste') in
interstellar space and _nobody_ else (if there is anyone else) would
_ever_ notice.
Nick Haines nickh@cmu.edu
------------------------------
Date: Wed, 7 Oct 1992 19:27:53 GMT
From: Jordin Kare <jtk@s1.gov>
Subject: Drop nuc waste into sun
Newsgroups: sci.space
In article <komarimf.718477945@craft.camp.clarkson.edu> komarimf@craft.camp.clarkson.edu (Mark 'Henry' Komarinski) writes:
>
>That shouldn't be a problem. The sun's gravity will pull it towards the
>sun, saving energy.
Sigh. Presumably the waste is wearing heavy boots :-)
The problem is getting the radioactive crap into
>space. If one of these rockets blows up, there will be mucho radiation
>all over the place and the world will soon be glowing in the dark.
Sigh. An unprotected Russian reactor with a substantial waste burden
reentered a few years back over Canada. As far as I know, Canada only
glows in the dark when there's a good auroral display...
>
>-Mark
>
>P.S. I think sending the waste outside the solar system is like dumping it
>in the ocean..it just sends the problem somewhere else.
Except that in the ocean, it can come back to haunt you. Once it's
on a solar escape trajectory, it's _gone_. "But what" you ask "about
the alien beings around distant stars??" Well, given the velocities
waste packages would have (at most a few km/s once they're far from the sun;
why waste energy beyond what it takes to make sure they don't come back)
the travel times are of order 10^6 years. The aliens may wonder why we;re
sending them blocks of lead, but that's all...
>--
>- Mark Komarinski - komarimf@craft.camp.clarkson.edu
Why do we bother....
Jordin Kare
--
Jordin Kare jtk@s1.gov 510-426-0363
------------------------------
Date: Wed, 7 Oct 1992 16:34:32 GMT
From: gawne@stsci.edu
Subject: Env. Satellites Shutdown in Dec. 1992
Newsgroups: sci.space
In article <1992Oct6.232405.15250@news.arc.nasa.gov>,
rowland@zorba7.larc.nasa.gov (Michael W. Rowland) writes:
> We at Langley Research Center received news on Thursday, October 2,
> 1992 that NASA intends to shutdown the following satellites in
> December to save about $15M:
>
> NUMBUS-7
> ERBS
> NOAA-9
> NOAA-10
How is the money to be saved? Are they going to furlough all of the operations
staff? Will any health and safety telemetry still come down, or are they
to just fly free for a month?
Do any of these satellites use TDRSS?
The whole thing seems pretty disturbing to me. When will the satellites be
reactivated, if ever?
-Bill Gawne, Space Telsecope Science Institute
------------------------------
Date: Wed, 7 Oct 92 11:24:53 PDT
From: dkelo@pepvax.pepperdine.edu (Dan Kelo)
Subject: Final Round Sagan vs. LGM
>Robert E. McElwaine YELLS:
>I should think that by now he would have heard about the
>Roswell Incident in which UFO WRECKAGE and ALIEN BODIES were
>found on a ranch (in New Mexico, I think), gathered up by the
>U.S. military, and hidden away in an Air Force hanger
>somewhere. The wreckage included materials NOT KNOWN on
>Earth, and some of it even had ALIEN SYMBOLS written on it.
>All of this was witnessed by many People, both civilian and
>military. A couple of years ago, the TV program "Unsolved
>Mysteries" showed an excellent segment about the incident.
PLEASE stop YELLING AT US!!!! I AGREE with you 100 PERCENT.
UNSOLVED MYSTERIES is a literal FOUNTAIN of TRUTH, which is at
least the equal of the WEEKLY WORLD NEWS for PURE CREDIBILITY!
If OLD JOE out at the RANCH in NEW MEXICO said it, then its
GOOD ENOUGH for ME! What's DR. CARL SAGAN got that OLD JOE
AIN'T GOT? COME ON!!
________________________________________________________
All flamers are advised to re-read after installing #22-A
Dripping Sarcasm Filter set to "11"
Dan Kelo
dkelo@pepvax.pepperdine.edu
________________________________________________________
------------------------------
Date: 8 Oct 92 02:18:48 GMT
From: Ron Baalke <baalke@kelvin.jpl.nasa.gov>
Subject: Galileo Update - 10/07/92
Newsgroups: sci.space,sci.astro,alt.sci.planetary
Forwarded from:
PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
GALILEO MISSION STATUS
October 7, 1992
The Galileo spacecraft is less than 61 million kilometers (38
million miles) from Earth. It is just over two months to the
second and final Earth Gravity Assist that will set its course
leading to Jupiter arrival on December 7, 1995.
The spacecraft health and performance are excellent. Yesterday
the telemetry data rate was switched from 40 to 1200 bits per
second. This was the first time since June 1991 that the
spacecraft position allowed high-rate engineering telemetry.
Today the spacecraft reads out cruise-science data collected over
the last two and a half weeks.
Friday, October 9, Galileo will execute a small trajectory
correction maneuver, slightly increasing its speed and bending
its flight path to refine the Earth flyby conditions.
#####
___ _____ ___
/_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov
| | | | __ \ /| | | | Jet Propulsion Lab |
___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Einstein's brain is stored
/___| | | | ___/ | |/__ /| Pasadena, CA 91109 | in a mason jar in a lab
|_____|/ |_|/ |_____|/ | in Wichita, Kansas.
------------------------------
Date: 7 Oct 92 17:56:22 GMT
From: Millard Edgerton <millard@eos.arc.nasa.gov>
Subject: HRMS
Newsgroups: sci.space
eric@ils.nwu.edu (Eric Goldstein) writes:
>I guess I really wanted to know: Over what range of frequencies do we
>significantly leak, and are those frequencies capable of being detected
>by HRMS? The HRMS press kit that Ron Baalke posted (thanks Ron!)
>said that the targeted search would search at 1,000 to 3,000 MHz. I
>know we leak significantly on the TV bands, but TV is around 10 MHz,
>right? So, I was wondering if we also leak at detectable levels at
>1,000 to 3,000 MHz. And if we do, what is the source of the leakage?
>If I've displayed a real misunderstanding, please go easy on me -- this
>isn't my field -- and I'd genuinely appreciate any explanations.
> -- Eric
TV Low VHF is 60 - 88 Mhz( Channels 2 - 6), Hi VHF is 175 thru 216 Mhz,
(Channels 7 - 13). UHF (Channels 14 - 83) are 471 - 890 Mhz.
The search is first made at the "water hole". 21 cm where the ability
to penetrate to water/atmosphere is easiest.
Only tv carriers & other strong signals like radar would make it out very
far. The information(modulated sidebands) contain very little energy.
Cheers
***************************************************************************
* When I examine myself and my methods of | Standard disclaimers apply *
* thought, I come to the conclusion that the| Millard J. Edgerton, WA6VZZ *
* gift of fantasy ment more to me than my | millard@eos.arc.nasa.gov *
* talent for absorbing positive knowledge. A. Einstein *
***************************************************************************
------------------------------
Date: Wed, 7 Oct 92 17:45:21 GMT
From: "John P. Mechalas" <mechalas@gn.ecn.purdue.edu>
Subject: Pioneer Venus Out of Fuel, Orbit Deteroriating
Newsgroups: sci.space,alt.sci.planetary
In article <1992Oct7.143222.15439@ll.mit.edu> nates@ll.mit.edu ( Nate Smith) writes:
>In article <1992Oct7.004757.24245@gn.ecn.purdue.edu> mechalas@gn.ecn.purdue.edu (John P. Mechalas) writes:
>>Yes, but the radius to the spacecraft changes because of the drag forces.
>> When a s/c enters the atmosphere, the drag force cause the semi-major axis
>>to decrease by 4 * pi * Drag / n^2 per orbit (assuming a nominally cirular
>>orbit). The altitude of the s/c also decreases. Since orbital velocity is
>>inversely proportional to the semi-major axis and the radius, as those
>>terms decrease, the velocity must increase. Orbital energy is defined as
>>being inversely proportional to the semi-major axis as well, so energy
>>increases, too. The result is a more energetic, and more elliptic orbit.
>> It is very counter-intuitive, as is a lot of orbital mechanics. :)
>
>well, i'd like to add my 2 cents.
>for the purpose of this argument, do we consider the atmospheric drag to be
>negligible at a certain distance away from Venus? suppose we do. then we
>would need to know if the apoapsis is "outside" of the atmosphere. if so,
>then the drag effect will almost entirely be observed in the apoapsis height,
>as the semi-major axis shrinks. when all the orbit has fallen into the
>atmosphere, for drag purposes, then the periapsis height will be affected,
>but not in the way we would picture it. the argument of periapsis is the
>angle between the periapsis point on the orbit and the ascending node, where
>the satellite rises through the equatorial plane of the planet. this would
>be racing ahead of the satellite, in a mathematical sense, so that by the
>time the satellite reaches the old point of periapsis, that point will have
>advanced around the orbit to a new location. think of it as "the slowing
>down here reduces the height on the other side", sort of.
I was assuming the entire orbit was in the atmosphere, so drag was a present
effect over the orbit period. I don't know the specifics of the orbiter
in question...I was just referring to the question about the counter-intuituve
results of drag on spacecraft.
>but if the satellite only briefly dips into the atmosphere, then the effect
>will be as Shari described it: circularization. of course, by the time the
>apoapsis has been brought into a height equivalent to the original periapsis
>height, the whole orbit will be subject to drag forces.
Hence the term "aerocapture". :) It would be an interesting problem to
determine the "crossover" point where drag goes from "aerocapture" to
the other case. Meaning, how long in the atmosphere is too long?
>another point: the semi-major axis reduces, the energy is inversely
>proportional to the semi-major axis, but it is NEGATIVE. so its magnitude
>will increase, yes, but the satellite LOSES energy.
You are right of course...I did mean to say "magnitude of energy" in my
original post (honest! :). Either way, though, it's that increase in
magnitude that tends to be a surprise...at least it was to me when I first
learned it. *smile*
--
John Mechalas "I'm not an actor, but
mechalas@gn.ecn.purdue.edu I play one on TV."
Aero Engineering, Purdue University #include disclaimer.h
------------------------------
Date: 7 Oct 92 14:37:24 GMT
From: "Michael K. Heney" <mheney@access.digex.com>
Subject: Pioneer Venus Out of Fuel, Orbit Deteroriating
Newsgroups: sci.space,alt.sci.planetary
In article <1at959INNru4@darkstar.UCSC.EDU> bafta@cats.ucsc.edu (Shari L Brooks) writes:
>
>I am not sure I understand this. It seems to me that every time the S/C
>encounters atmospheric drag, the orbit should lose energy. I always thought
>that this would circularize the orbit (decrease the apoapsis) before
>significantly decreasing the periapsis. Where did I go wrong? Don't circular
>orbits of a given radius have less energy than an elliptical orbit with
>that same value as the periapsis?
>
The problem is, you're looking at this as if the only energy loss occurred
ONLY at periapsis. In reality, while the maximum energy loss occurs at
periapsis, there is a continuum (sp?) of energy loss before and after
periapsis.
Consider the point in orbit 5 degrees before reaching periapsis. In a
vacuum, you'd have a specific velocity profile leading to periapsis at
a certain altitude. However, at every point between our initial point and
periapsis, the velocity is lower due to drag, resulting in a lower
periapsis than the vacuum case. On each orbit, the fraction of the orbit
exposed to significant drag increases, resulting in an accelrating drop
in periapsis.
You are right that the orbit will tend towards circular. The apoapsis will
drop faster than periapsis; however, a circular orbit is the LIMITING case.
The orbit will approach circularity; however, before it achieves this, the
periapsis will have dropped to the point where the spacecraft will reenter
and burn up.
Sorry for the length on this - it's a lot easier to visualize the concepts
than to put them down in gleaming phosphors ...
--
Mike Heney | Senior Systems Analyst and | Reach for the
mheney@access.digex.com | Space Activist / Entrepreneur | Stars, eh?
Kensington, MD (near DC) | * Will Work for Money * |
------------------------------
Date: Wed, 7 Oct 1992 16:29:31 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Sputnik I - 35th anniversary
Newsgroups: sci.space
In article <164@newave.newave.mn.org> john@newave.newave.mn.org (John A. Weeks III) writes:
>> Today the earth has approximately 7000 moons.
>
>How many of these moons have stable orbits? In this case, I define stable
>to mean that they will stay in orbit for 100+ years without expending any
>fuel...
Most of them are in low orbit and will come down more quickly than that.
But orbital lifetimes up in Clarke orbit are millions of years.
>What would it take to build a sattelite that would stay up for a long time
>without having to be reboosted or carrying large amounts of fuel?
Just a fairly high orbit. Even 1000km would get you out of the worst of
the air drag and would probably be good for millennia (I don't have
numbers handy). Unfortunately, that *does* start to get you into the
inner Van Allen belt... it might be better to go all the way to Clarke
orbit if you want your satellite to *function* for a long time. Even
there you'd have to worry about degradation of solar arrays and such.
--
There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: 7 Oct 92 17:28:30 GMT
From: Gary Davis <gdavis@griffin.uvm.edu>
Subject: UFO? REALLY?
Newsgroups: sci.space
I've always been fascinated with the hypothesis that other civilizations
have visted Earth via a worm hole or other cosmic anomoly,but has anyone
ever with true open mind investigated the evidence? Most if not all of the
media have hopelessly been swallowed up in garbage. I am told that there
are at least a few unexplained events which Blue Book has classified as
unknowns. (Not that this in and of itself means we have been visted)
I wonder if anyone has information concerning the rather strange event
in New Mexico circ 1988. I think it involved a group of loggers with
one man disappearing for a week and then relating an abduction tale.
His companions,I believe were cleared on a polygraph and he later,taking
same showed ambiguous results. The first try was a flunk and second tries
passed. (Perhaps he was just nervous).
In any event,there most be some intermediate ground between the Amazing
Randy specticisms and the Inquirer tom foolery?
Is there any author who truly has investigated the issue with an open mind?
--
Gary E. Davis WQ1F (On AO13)
University of Vermont Land Liner's dial 802-656-1916
References " The Joys of Rumination Without The Cud", Elsie circa 1965
------------------------------
Date: Wed, 7 Oct 1992 16:22:59 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: Why not Mir? was(what use is freedom?)
Newsgroups: sci.space
In article <1992Oct6.171821.19794@yang.earlham.edu> yannb@yang.earlham.edu writes:
> I don't see why NASA, ESA, and the Japanese Space
>Agencies should spend all that money on this Space Station Freedom. My
>question is: why not spend less, and have each country but a module on
>the Mir? ...
Evidently you're under the impression that putting a useful space station
into orbit is the highest priority for SSF. This is technically sensible
but politically naive. SSF's first priority is full employment for the
NASA internal bureaucracy. Its second priority is major contracts for
a bunch of very hungry aerospace contractors. (The order of priorities
1 and 2 may be reversed depending on who you're talking to.) Putting
hardware into space is a distant third. This is how such megaprojects
work, unfortunately.
--
There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry
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End of Space Digest Volume 15 : Issue 296
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