home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Space & Astronomy
/
Space and Astronomy (October 1993).iso
/
pc
/
text
/
spacedig
/
v16_2
/
v16no235.txt
< prev
next >
Wrap
Internet Message Format
|
1993-07-13
|
10KB
Date: Sun, 28 Feb 93 05:14:08
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V16 #235
To: Space Digest Readers
Precedence: bulk
Space Digest Sun, 28 Feb 93 Volume 16 : Issue 235
Today's Topics:
Blimps
forwarded message
Gore on Today tomorrow
Harwood Station design (was Re: Alternative Space Station designs)
Spaceflight for under $1,000?
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: Thu, 25 Feb 1993 18:51:43 GMT
From: Josh Hopkins <jbh55289@uxa.cso.uiuc.edu>
Subject: Blimps
Newsgroups: sci.space
nsmca@acad3.alaska.edu writes:
>(Frank Crary) writes:
>>
>> Balloons are somewhat more difficult on Mars than on Earth, but they
>> are very feasible. There will be one on the Russian Mars 94 mission
>> (or so they say...)
>>
>I more like rigid balloons (deridgebles(sp)). Powered by beamed microwaves
>either from the ground or from orbit..
A _dirigible_ is a steerable vehicle. It doesn't have to be rigid. Rigid
dirigibles are generally just called "rigids" (after you've established the
context) or occasionally zeppelins after Count Ferdinand von Zeppelin.
>Don't need to beam power directly at the Blimp, just to the tether that follows
>behind..
If you were going to use beamed power (which isn't obvious to me) you would
almost certainly use the huge surface area of the thing to mount your receiver.
Lighter than air vehicles do indeed have lots of potential for Mars, though the
difficulties can't be ignored. It is however _far_ easier than floating a
balloon on Jupiter, something Bill Higgins and I have been puttering around
with.
--
Josh Hopkins jbh55289@uxa.cso.uiuc.edu
You only live once. But if you live it right, once is enough.
In memoria, WDH
------------------------------
Date: 25 Feb 93 17:45:50 GMT
From: BAIRD <wbaird@dante.nmsu.edu>
Subject: forwarded message
Newsgroups: sci.space
From ruden@essvax.plk.af.mil Thu Feb 25 09:40:11 1993
Received: from NMSU.Edu by dante (4.1/NMSU)
id AA29246; Thu, 25 Feb 93 09:40:08 MST
Message-Id: <9302251640.AA29246@dante>
Received: from dante (dante.NMSU.Edu) by NMSU.Edu (4.1/NMSU-1.18)
id AA12277; Thu, 25 Feb 93 09:40:10 MST
Received: from essvax.plk.af.mil by dante (4.1/NMSU)
id AA29219; Thu, 25 Feb 93 09:39:54 MST
Date: 25 Feb 93 09:40:00 MDT
From: "RUDEN, EDWARD" <ruden@essvax.plk.af.mil>
Subject: please POST, I can't from here
To: "wbaird" <wbaird@dante.nmsu.edu>
Status: R
In article <C1Mx3z.7Lq@uceng.uc.edu> rbatra@uceng.uc.edu (Rajesh Batra)
writes:
> Hi,
>
> Here's a problem that I'm just plain stuck on, see if you can help.
>
> Scenerio: You're on the moon, a 1700 m/s container (containing ice)
>which
> weighs approximately 120 kg is hurled at you. How do you catch it such
> that you can salvage the ice? You have free reign over the container-
> hence the size/material.
Launch the ice from space in a lunar orbit which is tangent to the
lunar surface at the orbit's perigee. This is possible since there is
no atmosphere to bring the load down prematurely. Your "catcher" then,
regardless of its nature, can be laid out along a great length of
the lunar surface since the load will be coming in horizontally.
This will keep the decellaration of (and therefore forces on) the load
to a minimum. A very desirable feature of the catcher would be that
it be moving at about the same velocity as the load at the point of contact.
this means, of course, it will have to run along and catch it before
pulling it down to rest.
Another idea:
The ice is launched as a sphere of, say, 1m diameter, and is
accurately aimed at a long, narrowly tapered conical hole in the lunar
surface. The cone openning is about 10m in diameter, is heavily lined
with steel, and sunk into solid bedrock for strength. The cone angle is
sufficiently small that the ice sphere, coming in parrallel to the cone
axis, will not dent the steel wall upon grazing angle impact. The ice,
however, may at that point disinitigrate into ice cubes. The cone is used
to inject the ice into a steel tube somewhat over 1m in diameter which is
also sunk into the bedrock for strength. The tube is bent to give a radius
of curvature of about 100 m. The centripital acceleration of the ice fragments
will be on the order of 1000 g's. The tube can be built to withstand this
since ice on steel has very little abrasiveness and the pressure is
tolerable for steel in bedrock. The ice, however, will melt and vaporize
from the friction. The tube can curve back on itself so that the H2O
can race around in a loop until its kinectic energy is expended.
Within the first second or less of injection, a vacuum tight gate valve
closed off the conical injectors throat so that the water vapor doesn't
escape. The tube is kept warm enough to prevent condensation while
the water vapor is pumped out of the tube with a condensation (cryo)
pump to slake the thirst of the colonists.
Side note: there may (still) be some advantage to having the ice
come in horizontally by having the collection point at perigee. The
steel ring could then be layed flat, with the tubing at a nominally
constant depth below the lunar surface. This reduces construction costs
Also, if terminal guidance is needed for the ice to hit the hole,
the carrier can release the ice about 1 km from the hole, give itself
a small boost to miss the lunar surface, and return to space for reused.
Edward Ruden
------------------------------
Date: 25 Feb 93 18:58:59 GMT
From: "Russell J. Pagenkopf" <cs000rjp@selway.umt.edu>
Subject: Gore on Today tomorrow
Newsgroups: sci.space,talk.politics.space
Hahahahaha, read that subject line with a small "g". I think I'm gonna
laugh all day about that one. Thanks Allen. :-}
--
Russ Pagenkopf "Heading, Sir?"
cs__rjp@lewis.umt.edu "Out there. Thataway."
cs000rjp@selway.umt.edu "A most logical choice, Captain."
------------------------------
Date: 25 Feb 1993 10:17 PST
From: "Horowitz, Irwin Kenneth" <irwin@iago.caltech.edu>
Subject: Harwood Station design (was Re: Alternative Space Station designs)
Newsgroups: sci.space
In article <1993Feb24.113327.15711@doug.cae.wisc.edu>, wrighte@hp-3.cae.wisc.EDU (Edward Dansavage Wright) writes...
>
>Info request to the net....
>
>I am interested in space station designs not based on the
>"power tower" concept as was/is Freedom. I am interested in
>alternative designs such as inflatable structures, geodesic
>dome configurations etc. Could someone please provide a starting
>place to look for this information? Is there a particular NASA
>installation I should contact?
>
You might want to look up the paper by ex-Rockwell engineer Oliver Harwood
on an "evolutionary" space station design. It appeared in the Journel of the
British Interplanetary Society in 1985 (I believe). The basic structure was
based on the more rigid tetrahedron rather than the cube-like structure of
SSF.
-------------------------------------------------------------------------------
Irwin Horowitz |
Astronomy Department |"Whoever heard of a female astronomer?"
California Institute of Technology |--Charlene Sinclair, "Dinosaurs"
irwin@iago.caltech.edu |
ih@deimos.caltech.edu |
-------------------------------------------------------------------------------
------------------------------
Date: Thu, 25 Feb 1993 18:39:12 GMT
From: Josh Hopkins <jbh55289@uxa.cso.uiuc.edu>
Subject: Spaceflight for under $1,000?
Newsgroups: sci.space
fcrary@ucsu.Colorado.EDU (Frank Crary) writes:
>>Is it really possible for a small organisation to launch a man into space, if
>>that is all it intends doing? I know this has shades of "The Mouse That Roared
>I think it would be very easy for a company to make a one way launch
>and then hitch a ride back to Earth with (say) the Russians.
>The total price (including a ride with the Russians)
>would probably be under $100 million. Possibly under $50 million.
>I haven't checked the rates for 30-second ads during the Superbowl,
>but I think a $50 million publicity stunt might not be unrealistis
>for a major company.
Asking whether they could spend that much and whether the actually would are
two completely different questions. First, $50 million is _lots_ of money.
That's enough to make one of those huge megamovies that nobody will watch. It's
enough to hire a big star for a few movies or enough to buy advertising space
on the next hundred Conestoga launches. In short, it's probably not the best
investment someone could make even if they have the money lying around. Besides
why putz around with your own tin can when you can go up with the Russians for
a mere $15 million?
--
Josh Hopkins jbh55289@uxa.cso.uiuc.edu
You only live once. But if you live it right, once is enough.
In memoria, WDH
------------------------------
End of Space Digest Volume 16 : Issue 235
------------------------------