Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v16_0/v16no065.txt

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Date: Wed, 20 Jan 93 05:10:09
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #065
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 20 Jan 93       Volume 16 : Issue 065

Today's Topics:
                        ** BUSSARD RAMSCOOP **
           Antarctic meteorites (was Re: Cheap Mars Rocks)
Earth's rotation rate may be due to early collisions [Release 93-12] (Forwarded)
                     Handling Antimatter (2 msgs)
                        Oxygen in Biosphere 2
                            Parting Words
                    Planetary Ephemeris Routines?
          Sabatier reactor? (was Re: Oxygen in Biosphere 2)
                           Soyuz as an ACRV
                        Territorial conquest?
                  Toutatis Captured by Radar Images
             Two-Line Orbital Element Set:  Space Shuttle
                       Znamya: Orbiting mirror.

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----------------------------------------------------------------------

Date: 20 Jan 93 03:56:00 GMT
From: Josh Hopkins <[e-mail]>
Subject: ** BUSSARD RAMSCOOP **
Newsgroups: sci.space

[e-mail] (Jason Cooper) writes:

>Hmm, can anybody here think of a way to retract a HUGE sail that's giong
>to be external of all tanks, etc, down close to the hull?

Depends on the sail.  Heliogyros are fairly trivial to deploy and retract
(although of course "trivial" is comparative in this case).  Other types are
more difficult.

The next question though is _why_ you want to combine a solar sail with a
ramjet.  Solar sails are fairly slow and ramjets have to be moving very quickly
to work.  Solar sails have to be near the sun for efficiency whereas I suspect
bussard ramjets benefit from being outside the solar system (someone want to
back me up or shoot me down on this one?).  Get a first stage with more thrust.
Or better yet, build a big laser in the solar system and just use the sail for
propulsion.  It may well be easier than trying to build an interstellar ramjet.

>  Okay, anyways,
>(no more parentheses anymore) does anybody know of a way to retract this
>solar sail (which must be rigid (but possibly foldable), as it will
>contain solar panels VERY useful for the initial approach

I'd be very impressed if you could combine the function of pv cells with solar
sail material.  The sail material must be very thin and strong (as well as a
few other requirements) and should be reflective to a very high degree.  Solar
cells must absorb light, and tend to be to thick and heavy to be very useful.
Besides, even if you could make a solar sail the generated power you'd have a
hard time figuring out what to do with it all.  A sail big enough to boost an
interstellar probe up to the speeds you require would be intercepting enough
light to power a good sized planet.
--
Josh Hopkins                                          [e-mail]

Q:  How do you tell a novice from an expert.
A:  A novice hesitates before doing something stupid.

------------------------------

Date: Tue, 19 Jan 1993 16:47:08 GMT
From: [e-mail]
Subject: Antarctic meteorites (was Re: Cheap Mars Rocks)
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]>, [e-mail] (Kevin W. Plaxco) writes:
> In article <[e-mail]> [e-mail] (S.J. Morden) writes:

>>Similar situations occur in the Nullabor Plain in Western Australia, and in
>>"blow-outs" in the Southern U.S., where the ground is eroded away, leaving
>>concentrated meteorites.
>>
>>Any questions?
> Yup.  What is the concentration mechanism on the Nullabor Plain?

For the last n thousand years, wind and thermal cycleing. " Null Abor " literaly
"no trees" is a *VERY* apt name. A typical day/night cycle would be 35-40C day
to -15-0C overnight. Geologicaly it is the oldest part of the earths crust
overlaid with soft lime-stone, full of HUGE cave systems. The rainfall is
sporadic thunderstorms, which may deliver several years rain in 1/2 an hour!

My mother was a teacher at Rawlinna in the 30s, so if you would like details,
let me know.

~Paul

------------------------------

Date: Tue, 19 Jan 1993 18:08:43 GMT
From: "Robert F. Drury" <[e-mail]>
Subject: Earth's rotation rate may be due to early collisions [Release 93-12] (Forwarded)
Newsgroups: sci.space

In article <[e-mail]>,
[e-mail] (Ray Davis) wrote:
>
> >     "A popular theory holds that the collision of a Mars-sized planetary body
> > with the Earth threw considerable debris into orbit, which then came together
> > to form the moon," Dones said.  "Thus, the same impact which gave Earth its
> > spin, could also have formed the moon."
>
> How does this popular theory account for the moon having zero spin?
>
>   Ray Davis ([e-mail])
>    hplabs!hp-pcd.cv.hp.com!rayd

The moon doesn't have "zero spin"; the period of rotation just matches the
period of revolution.  With zero spin, we'd get to see the "darkside" every
month.  My understanding is that this situation arose due to the frictional
effects of tidal forces, and had nothing to do with the spin states of
Earth and Moon upon formation. (in other words, the moon's rotation slowed
down to its
current equilibrium state).

Standard disclaimer--my opinions are my own.

------------------------------

Date: 19 Jan 93 19:18:13 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Handling Antimatter
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mark Budd) writes:
>
>This whole approach has the problem of equipotential within a spherical
>shell.  It has been long known that there is no gravitational gradient
>within a uniform spherical shell of mass.  The intuitive reason for this
>is the counteracting of the 1/r^2 distance factor and the r^2 mass factor
>within a cones on either side of any point within the shell.  (Did this
>make any sense without an ascii drawing?)  The same would be true for
>a charged sphere.  Of course this assumes that the sphere is uniformly
>charged, but for an electron confined to the atoms of the shell (but not
>to any individual atom) this would essentially be the case.

I'm not sure this would be true. Certainly we are dealing with quantum
events on this scale. The electron "wavicle" is going to be smeared out
with probability lumps at the bond angles. I don't think a uniform
spherical cloud shape can be assumed.

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: 20 Jan 93 00:15:22 GMT
From: Sam Warden <[e-mail]>
Subject: Handling Antimatter
Newsgroups: sci.space

--

[e-mail] (Sam Warden) -- and not a mere Device.


------------------------------

Date: 19 Jan 93 21:16:33 GMT
From: Pat <[e-mail]>
Subject: Oxygen in Biosphere 2
Newsgroups: sci.space

Bill Higgins asked me to post a little bit on the Sabatier reaction
and on how it could be made in a small facility.   Now I am not a chemical
engineer or a chemist.  Actuually my total knowledge of this is mostly
bounded by a talk i went to given by Robert Zubrin PhD.  and some
dinner conversation with him.

Basically  if CO2  + H   (Over Iron Catalyst)   --> H2O + Carbon.
You crack  Electrolytically  H2O  -->  O2 + H.

Free Hydrogen  is then  Brought  back to the carbon to get  CH4.

I cant remember the exact details,  but basically for a small
amount of starting hydrogen, you can take CO2 and make methane.
or you can run  the different reaction  and just keep
scraping  carbon off the catalyst bed.
Now as to size,

    Zubrin implied that the process plant only needs to
    be no larger then 1-2 CF in scale, because you run
    the gear more or less continously.  B2 has lost appx
    9000 liters of o2 over 1 year????  if so we are
    talking about an imbalance of only 1-2 liters per hour.
    If you think about it, you can blow that amount of gas
    through a capillary tube in an hour, hence even if the
    reaction chambers are not large, they only need
    to process  10cc/min  appx.

Now maybe i lost an order of magnitude in there,  but i'd appreciate
anyone with better chemical engineering pointing it out.

thanks

pat

------------------------------

Date: 19 Jan 1993 13:59 EDT
From: Greg Macrae <[e-mail]>
Subject: Parting Words
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] ("F.Baube x554") writes...
>> "God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
>>        -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry
>
>Are these perhaps the *last* words spoken on the moon ?
>If not, what *were* the last ?
>
>--

One of my favorite lines from the space program were the last words spoken on
the moon.  A flowery speach was prepared for and read by the Apollo 17
astronauts.  It was intended as the last words spoken from the Apollo lunar
missions.  After reading the speach, the commander turned to the pilot and
said, over an open mike (ie. it was broadcast), "Let's get this mother out
of here."  Those were the last words spoken on the moon.

--------------------------------------------------------------------
     MacRae                  |       Darting dragonfly...
                             | Pull off its shiny wings and look...
  [e-mail]  |      Bright red pepper pod!
                             |                      -Kikaku
--------------------------------------------------------------------

------------------------------

Date: 19 Jan 1993 20:45:37 GMT
From: Jonathan Young <[e-mail]>
Subject: Planetary Ephemeris Routines?
Newsgroups: sci.space,sci.astro,comp.lang.c

I am trying to write a small program to add external computer control
to our existing telescope system. The current computer cannot
calculate planetary postitions but can accept coordinates from a
serial line. It would be pretty simple to write a program that would
present the user with a menu of planets and send the coordinates of
that planet to the telescope computer.

What I need are some routines which can calculate planet positions
with accuracy more important than speed. Since I'll have to put these
eventually onto a Macintosh, C code is preferred over Fortran although
I can try to translate others.

Thanks in advance
Jonathan Young
Williams College Astronomy Department

------------------------------

Date: 19 Jan 93 18:14:53 GMT
From: Willie Smith <[e-mail]>
Subject: Sabatier reactor? (was Re: Oxygen in Biosphere 2)
Newsgroups: sci.space

I'm not convinced that such a reactor would do any good in this case,
unless you had a _lot_ of them.  9,000 kilograms of LOX comes out to
something like (scribble, scribble) 50,300 cubic feet of oxygen gas.
At one cubic foot per hour, that's 5.7 years to make up the deficit...

On the other tentacle, it sounds like interesting technology, pleae
tell us more!  Startup costs, maintainance and operating costs,
reliability?

Willie Smith
[e-mail]

--
Willie Smith    [e-mail]    [e-mail]     "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: Tue, 19 Jan 1993 20:11:33 GMT
From: Edmund Hack <arabia!hack>
Subject: Soyuz as an ACRV
Newsgroups: sci.space

In article <[e-mail]>
      [e-mail] writes:
>AW>Oh, that's a given. The booster may be the Shuttle but we will see Soy
>AW>being launched for (at the very least) ACRV on US launchers.
>
>Under the terms of the Launch Services Purchase Act, NASA is prohibited
>from orbiting non-shuttle-specific payloads. Therefore,
>using the shuttle to orbit Soyuz spacecraft contravenes the LSPA.

Why do you assert that it is not STS specific, since the final design is
not yet established?  For example, the design might require a full
load of fuel/oxidizer to do safe deorbit and landing, so it would need
to be docked without using the propulsion system by placing it with the
RMS on the Shuttle.
>
>However, several U.S. commercial vendors can supply launchers that
>can easily orbit a Soyuz for a more reasonable price than the shuttle. As
>a nice side benefit, this would create a second means of access to space
>in the US, in case the shuttle fleet is grounded.

The cost to orbit might be cheaper by commercial carrier, depending on
how you do the accounting.  As we have seen here, the entire government
uses different procedures for figuring the "cost" of something.  If the
STS fleet is grounded, the only impact aside from STS-specific ops woud
be on Freedom.  This might or might not be critical.
--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - 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"

------------------------------

Date: Tue, 19 Jan 1993 17:55:17 GMT
From: Ed Faught <[e-mail]>
Subject: Territorial conquest?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Tom) writes:
>
>>>>The urge to colonize the universe seems to come from an urge for
>>>>territorial conquest that has been with us for a long time.  It is
>>>>interesting how old themes are constantly repeated in the present.
>
IMHO, territorial conquest was the politcal reason used to obtain funding.
--
Ed Faught  WA9WDM  [e-mail]
 Superconducting Super Collider Laboratory

------------------------------

Date: 20 Jan 93 01:46:48 GMT
From: Ron Baalke <[e-mail]>
Subject: Toutatis Captured by Radar Images
Newsgroups: sci.space,sci.astro,alt.sci.planetary

From the "JPL Universe"
January 15, 1993

Earth-approaching asteroid captured by radar images
By Mary Hardin

     Using a large radar antenna at the Goldstone Dep Space
Communications Complex in the Mojave desert, JPL astronomers have
obtained the sharpest images yet of an Earth-approaching
asteroid, 4179 Toutatis, as it passed extremely close to Earth
last month.
     "This is our first clear look at one of the many thousands
of asteroids whose orbits can intersect Earth's orbit," said Dr.
Steven Ostro of the Geology and Planetary Section 326 and leader
of the radar team.
     The radar images reveal Toutatis to be a "contact binary"
asteroid, consisting of two irregularly shaped, cratered objects
about 4 and 2.5 kilometers (2.5 and 1.6 miles) in average
diameter and rotating with a period between 10 and 11 days.
Toutatis passed 4 million kilometers (2.5 million miles) from
Earth on Dec. 8 -- less than 10 times farther away than the Moon.
     Discovered by French astronomers on Jan. 4, 1989, almost
nothing was known about Toutatis before the radar images were
taken. The asteroid has now been shown to have a jagged, cratered
surface which indicates a complex history of collisions.
     "The binary nature of Toutatis is the most important single
result of this radar experiment," Ostro said.
     Previous radar images taken by Ostro and his colleagues of
another Earth-approaching asteroid, 4769 Castalia (1989 PB), were
too crude to reveal surface details but did show the object to be
bifurcated into two 1-kilometer (0.6 mile) lobes. Radar echoes
bounced off of other asteroids have also contained hints of
contact-binary configurations.
     "Three years ago we were startled by the initial evidence
for contact-binary asteroids," Ostro said. "Now it seems that
double bodies might be very common in the Earth-approaching
asteroid population. If so, then their abundance has important
implications for theories of the origin and evolution of
asteroids and meteorite source bodies.
     "For example, sub-catastrophic collisions might play an
important role in delivering asteroidal bodies into the inner
solar system from the main asteroid belt between Mars and
Jupiter," he said.
     The two components of Toutatis probably joined in a
relatively gentle collision, but their origins and the times and
circumstances of events leading up to the asteroid's current
configuration are unknown, Ostro continued.
     "Toutatis may be two pieces of a much larger asteroid that
once orbited in the main belt between Mars and Jupiter, but was
disrupted in a catastrophic collision with another large object,"
Ostro speculated. Another possible scenario is that Toutatis was
split into two parts by a collision not quite energetic enough to
completely pulverize it.
     The best way to study the history of Toutatis would be
through the analysis of samples returned from both Toutatis
components. While there are no plans yet to rendezvous with
Toutatis, Ostro said it and dozens of other near-Earth asteroids
are leading candidates for robotic flyby, rendezvous and sample-
return missions because of the asteroids' small gravitational
fields and because of the ease of maneuvering spacecraft between
the orbits of Earth and the asteroids.
     For most of the radar observations, a 400,000-watt coded
radio transmission was beamed at Toutatis from Goldstone's main
70-meter (230-foot) antenna. The echoes, which took as little as
24 seconds to travel to Toutatis and back, were received by the
new 34-meter (112-foot) antenna and relayed back to the 70-meter
station where they were decoded and processed into images.
     Full processing of the Toutatis radar data over the next few
months is expected to reveal details of surface features less
than 100 meters (330 feet) across. Eventually a detailed three-
dimensional computer model of the object will be constructed from
the data, Ostro said. In addition to Ostro, members of the JPL
radar team include Dr. Raymond Jurgens, Keith Rosema, Ron
Winkler, Denise Howard, Randy Rose, Dr. Martin Slade and Dr.
Donald Yeomans.
                          ###
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Every once in a while,
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | try pushing your luck.
|_____|/  |_|/       |_____|/                     |

------------------------------

Date: 19 Jan 93 23:20:51 GMT
From: TS Kelso <[e-mail]>
Subject: Two-Line Orbital Element Set:  Space Shuttle
Newsgroups: sci.space

The most current orbital elements from the NORAD two-line element sets are
carried on the Celestial BBS, [phone], and are updated daily (when
possible).  Documentation and tracking software are also available on this
system.  As a service to the satellite user community, the most current
elements for the current shuttle mission are provided below.  The Celestial
BBS may be accessed 24 hours/day at 300, 1200, 2400, 4800, or 9600 bps using
8 data bits, 1 stop bit, no parity.

Element sets (also updated daily), shuttle elements, and some documentation
and software are also available via anonymous ftp from archive.afit.af.mil
(129.92.1.66) in the directory pub/space.

STS 54
1 22313U 93  3  A 93 19.25033564  .00058283  00000-0  18298-3 0   219
2 22313  28.4724 112.5776 0013729 296.3232 214.4186 15.89736109   902
--
Dr TS Kelso                           Assistant Professor of Space Operations
[e-mail]                    Air Force Institute of Technology

------------------------------

Date: 19 Jan 93 09:49:52 GMT
From: Dennis Newkirk <[e-mail]>
Subject: Znamya: Orbiting mirror.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:

>In article <[e-mail]>, [e-mail] (N T Clifford) writes:
>>
>> Apparently a recent Progress cargo ship (1992-71A?) currently docked
>>(or station keeping) with Mir is due (maybe next month) to unfurl a 65 foot
>>'space mirror' constructed from aluminium coated plastic film, in an
>>experiment known as `Znamya' (Banner).
>>
>> Apparently this is an attempt to extend the daylight hours of the
Siberian regions by reflecting sunlight to the required areas.
>>

>The information carried on our UK newsline (0891-88-1950) says that
>the last Progress in Oct'92 carried p an experimental solar sail perhaps
>this is where the confusion arises? Anyway, Mir will now be crossing UK and
>Ireland in daylight until it is visible in morning skies in early Feb. (and
>evening skies from early March) although such a large item could probably be

Progress M-15 launched on Oct 5 1992 is the ship in question. It will
remain docked to Mir through the Soyuz TM-16 docking and Soyuz TM-15
undocking. In February it will undock to begin several days of mirror
tests using its Znamya solar sail.

The tests were originally scheduled for October but were delayed due
to control and thermal reasons. This was reported in an Energiya-USA
press release. There are also reports of budget problems contributing
to the delay.

Source: James Oberg, a Houston space engineer and consulting speciallist
in Russian aerospace.

Dennis Newkirk ([e-mail])
Motorola, Land Mobile Products Sector
Schaumburg, IL

------------------------------

From: Ed Faught <[e-mail]>

Newsgroups: sci.space
Subject: Re: Antimatter
Message-Id: <[e-mail]>
Date: 19 Jan 93 17:47:52 GMT
References: <[e-mail]>
Sender: News Admin <[e-mail]>
Reply-To: [e-mail]
Organization: Superconducting Super Collider Laboratory
Lines: 8
Nntp-Posting-Host: berserk.ssc.gov
Source-Info:  Sender is really [e-mail]
Source-Info:  Sender is really [e-mail]

In article <[e-mail]>  writes:
>Does anyone have any proposals for how the actual matter/antimatter "reaction"
>would be regulated.

Dilithium crystals, of course!
--
Ed Faught  WA9WDM  [e-mail]
 Superconducting Super Collider Laboratory

------------------------------

End of Space Digest Volume 16 : Issue 065
------------------------------