Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_1/V15NO180.TXT

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Date: Thu, 10 Sep 92 05:00:26
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #180
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 10 Sep 92       Volume 15 : Issue 180

Today's Topics:
            20 Questions About the Delta Clipper (2 msgs)
Article (part) on Gore's support for NASA from 9/5/92 Birmingham News
             Climate cycles from Earth's orbital geometry
                     Clinton/Gore Space Position
         Is NASA really planning to Terraform Mars? (9 msgs)
                        Pluto Direct/ options
                              Relativity
 Shuttle tank for habitation; was Inflatable Space Stations (2 msgs)
                          Special Relativity
                              Star Chart
                             TSTO vs SSTO

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

Date: Wed, 9 Sep 92 12:31:24 BST
From: [e-mail]
Subject: 20 Questions About the Delta Clipper

> actual wear and tear on the engines.  You may find the atmospheric
transit
> has strange affects (look at the British Comet) that negatively
affect
> wear and tear, requiring more maintainance than required.  And this

>


The problem with the Comet had nothing at all to do with engines. It
had to do with metal fatigue on the fuselage and an insufficient
number of rip stops. This is not likely to be a problem on DCX as
materials are much better understood now. Not to mention that
simulation, while not perfect, allows problems like this to be
uncovered before prototyping. It even eliminates the need for
fullscale models (as has been noted by Dani I believe) and thus cuts
cost at the same time it cuts design risk.

The DCX is a simple craft using off the shelf parts and well
understood technology. There may be some flight regimes in which
there is something to be learned, but I suspect there is not much
from a science viewpoint. Unlike other vehicles built in the past,
its design is not a research project. This is a skunkworks aviation
project whose only goal is operational hardware.

If you want to find out everything there is to know about DCX that is
in the public domain, pickup the last couple volumes of SpaceDigest
from the archives.

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

Date: 9 Sep 92 13:04:21 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: 20 Questions About the Delta Clipper
Newsgroups: sci.space

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

>Good article.

Thanks.

>question 21:  What type of system does DC use to maneuver in space?

It uses its main engines for orbital changes. The RCS is based on gaseous
oxygen and hydrogen.

>22: How does it deorbit?

It fires the main engines to slow down and enters on one side which
is made of materials able to stand the heat. At about 50,000 feet it
flips over so the base is down and fires the main engines again to
come in for a landing.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------227 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 9 Sep 92 08:24:27 GMT
From: Gerald George Marfoe <[e-mail]>
Subject: Article (part) on Gore's support for NASA from 9/5/92 Birmingham News
Newsgroups: sci.space

Since there's been more discussion of pro-space statements by the Democrats
in this newsgroup than in talk.politics.space, I thought I'd post this
article from the Birmingham News/Birmingham Post-Herald of September 5, 1992.
Come to think of it, this is probably the first story I've seen in the general
media concerning how the candidates regard the future of space exploration.
(I don't consider Aviation Week & Space Technology to be the "general media".) ;-)

If someone from Huntsville could post an article from the Huntsville papers
of last week, when Vice-President Quayle visited Marshall Space Flight
Center, I'd appreciate it. All I saw from the TV news was Quayle's remarks
bashing Murphy Brown, but nothing about his support for the space program.
(All flames will be ignored.)

The following article is partially reprinted without permission from the
Birmingham News/Birmingham Post-Herald of Saturday, September 5, 1992.
----------------------------------------------------------------------------

"HE AND CLINTON BETTER FOR NASA, GORE SAYS IN VISIT"

-----------------
By Justin Fox
News staff writer
-----------------

  America's space program would fare much better under Bill Clinton than it
has under President George Bush, Democratic vice presidential candidate
Al Gore said at a campaign stop in Birmingham Friday.

  "My position on this is not one that comes out of a sudden foxhole
conversion", the Democratic senator from Tennessee said of his support for
space exploration. "I've been fighting in the trenches for many years."

  Gore, in town for two evening fundraisers, talked of little else but space
in a brief news conference at the Birmingham Airport.

  The vice presidential hopeful, who is chairman of the Senate subcommittee
that oversees the space agency NASA, said he "fought tooth and nail with the
Bush administration" to keep alive a space shuttle booster plant in Iuka,
Miss.
(Note: This refers to the Advanced Solid Rocket Motor (ASRM) program.)

  In a July 16 letter, Vice President Dan Quayle said the administration
opposed continuing to fund the plant, which employs hundreds of Alabamians.
But during a visit to Huntsville Monday, Quayle said he supported funding
the plant as part of "a strong and vigorous space exploration program."

  Said Gore: "Anybody who believes that, I've got a bridge in Brooklyn to
sell you."

  Gore aimed other remarks at Alabama interests as well. Speaking about
the Star Wars missile defense program, which employs many researchers at
Huntsville's Redstone Arsenal, he said, "Bush and Quayle have tried to take
money away from Huntsville and steer it to their pie-in-the-sky Brilliant
Pebbles program."

  He also complimented medical research efforts at the University of Alabama
at Birmingham and said he is "extremely optimistic" about the Clinton/Gore
ticket's chances in the state.

  Gore was greeted at the airport by Alabama U.S. Senators Howell Heflin
and Richard Shelby and more than 200 other supporters. Scores of others
were turned back at the gate of the private hangar - on orders of the
hangar company and the fire marshal, campaign aides said.
-----------------------------------------------------------------------------

The remainder of the article dealt with Gore's stand on environmental issues
and economics, and fundraising details which I won't bore you with.

---

-------------------------------------------------------------------------------
Gerald G. Marfoe                    |"Mirabile visu. Mirabilia/Et itur ad astra
InterNet: [e-mail]    |... Suus cuique mos. Suum cuique.../
          [e-mail]   |Memento, terrigena./Memento, vita brevis."
          [e-mail]  |- "Afer Ventus", Enya, "Shepherd Moons"

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

Date: 9 Sep 92 14:42:00 GMT
From: [e-mail]
Subject: Climate cycles from Earth's orbital geometry
Newsgroups: sci.geo.geology,sci.astro,sci.space,sci.geo.meteorology

In article <[e-mail]>, [e-mail] (Joe Cain) writes...
>
>    We were just going over some sedimentary cycles in a class
>today which related to an article in EOS.* I would
>like to find some material which discusses the Milankovitch-type
>forcing functions which lead to climate cycles. i.e.
>
>precesssion of the equinoxes  19, 23 K years
>obliquity of Earth's axis     41, 54 K years
>eccentricity of orbit         95, 123, 413, and 2035 K years
>
>I am looking for something about the level of Scientific American with
>some pretty pictures that discusses the geologic findings in this
>area.  This is for a beginning planetary geology class for
>non-scientists. Has anyone seen anything recently?
>
>*Olsen, P. E. and D. K. Kent, Continental coring of the Newark Rift,
>EOS April 10, 1990, pp 385,394.
>Joseph Cain        [e-mail]
>[e-mail]        scri::cain



           Try the article entitled "Orbital geometry, CO2, and
        Pleistocene climate," by Nicklas G. Pisias and John Imbrie
        in _Oceanus_, Vol. 29, No. 4, Winter 1986/87.  The _Oceanus_
        articles are comparable to those in _Scientific American_
        in difficulty level and are nicely illustrated.

                                                S. Baum
                                                [e-mail]

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

Date: Wed, 9 Sep 1992 15:09:03 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Clinton/Gore Space Position
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Mike Van Pelt) writes:

>How has he [Gore] voted on the various attemts to scuttle DCX?

To date he hasn't had a chance to vote. The Sanate will be considering
the defense appropriation later this year. That will be his earliest
opportunity.

However, the other senator from Tenn. *IS* on the Defense Appropriations
Subcommittee and is therefore in a position to vote yes or no on September
15. One way to support DCX would be to write Gore and ask him to convince
Senator Sasser to support DCX.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------227 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Wed, 9 Sep 92 12:54:46 BST
From: [e-mail]
Subject: Is NASA really planning to Terraform Mars?

> I don't believe that Venus could ever be made earthlike. I see the
chance, however, of seeding life there and letting it make it's own
way.
>

I would be careful with such strong statements about times far in the
future.

> The same with Mars. All of the grandiose plans aside I can't see
> the bulk of the necessary machinery being transported to Mars to
> terraform it and then the project continued for thousands of years.
>

If done in the far future I expect at least some or all of it to be
done using nanotechnology. If started near term it would be a
bootstrapping operation with small initial equipment from Earth and
everything else done indigenously. And somewhere in between there
will be a time when space transport is common enough that maybe even
the massive loads would be possible. After all, with Orion we could
have put the weight of a naval destroyer on Mars by the late 60's or
early 70's. What might be possible in a century by colonists who have
escaped the fearful, inward looking societies of Earth?

And if it takes thousands of years, so what? It will just be a day to
day matter for the millions living there, something to be cared for
like the dikes of Holland or the Mississippi levees. Each generation
(assuming lifespans are not drastically increased in the near future)
will know that the gains it has from the previous generation must be
preserved to keep things at least as comfortable as they are, and
improvements might be rapid enough that small effects would be seen
over a lifetime.

If you refer to Dr. Robert Zubrin's work and agree with his results,
then we find that the turnover to a warm, wet CO2 planet is rapid
compared to a human lifespan, ie a few decades at most. The turnover
to an Earthlike world using plants and genetic engineering would
indeed be the work of many generations (if you assume serious limits
to the eventual capability of nanotechnology).

Martians would also need to find a way to solve problem of success
(as I noted before). An O2 atmosphere will become transparent and
will lose much of it's greenhouse capacity.

Maybe it will be the patriotic duty of every Martian to own a leaky
CFC refrigerator, raise cattle and drive a poorly tuned 1950's
Cadillac. :-)



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

Date: 9 Sep 92 05:44:28 GMT
From: Frank Crary <[e-mail]>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas H. Kunich) writes:
>>Not that we know of, just water ice and permafrost. There is some,
>>distant theoretical possibility of sub-surface water (liquid). But
>>the evidence for this isn't too substantial...

>Frank, I seem to remember clouds at the atmospheric boundary
>on Olympus Monds (sp?). Certainly that indicates that there is
>some water vapor there.

There is water vapor (most of Mars is very near the dew point,
so condensation is common, even though the aboslute humidity is
extremely low.) Unfortunately, the martian atmospheric pressure is
below the triple point: Water in the liquid phase doesn't exist
(the vapor condenses out directly into ice, and ice sublimates
into a vapor instead of melting.)

There are a few spots with average atmospheric pressure _just_
above the triple point (Hellas Basin, fro example). Here, there
is a five degree difference between the melting and freezing points.
While it is _theoretically_ possible for liquid water to exist
here, the conditions required would be fairly rare (liquid water
might exist less than one day out of each year, and even then
not in any real quantity: Hellas isn't near the polar caps...)

                                              Frank Crary
                                              CU Boulder

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

Date: 9 Sep 92 14:41:21 GMT
From: Nick Szabo <[e-mail]>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas H. Kunich) writes:
>(I am reposting this at request)

>Of course it would be unethical to interfere with any life
>there may be already there.

"Of course?"  Has our civilization changed so much that this notion
is not only accepted, it is taken for granted?


--
[e-mail]  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at [phone] (1200/2400, N81)

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

Date: 9 Sep 92 10:25:13 GMT
From: Richard Nickle <trystro!rick>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <jvrnh5#[e-mail]> [e-mail] (Thomas H. Kunich) writes:
>Without references it is difficult to remember, but isn't there
>water, water vapor and possible liquid water along the interface of
>the Martian north pole?
>
>If so, shouldn't this represent a possible seeding area for life forms?
>
>I also seem to remember that the upper atmosphere of Venus was
>mostly water vapor even though the bulk of the atmosphere was
>sulphuric acid.
>
>Perhaps I didn't make myself clear enough. I don't believe that
>Venus could ever be made earthlike. I see the chance, however,
>of seeding life there and letting it make it's own way.
>
>The same with Mars. All of the grandiose plans aside I can't see
>the bulk of the necessary machinery being transported to Mars to
>terraform it and then the project continued for thousands of years.
I never understood this machinery bit though...my understanding of
Martian terraforming was that the timescale would be large, but the
steps taken would be rather simplistic:  slamming large ice blocks
from the belt or Saturn's rings (though why anybody would want to
throw away all that nice water, I don't know...maybe they could just
send the low-grade ore towards mars), using orbiting mirrors to melt
the poles, or covering the poles with dark matter to assist in raising
the surface temperature.  Once you begin to raise atmospheric pressure
and water vapor content, you can begin seeding microbes....

But all of these steps, no matter how gartantuan the time scale, are
pretty passive.  You just build the stuff and leave it operating autonomously,
and fiddle with it every decade or so.  No massive focus of manpower,
just one hell of a long view would be necessary.

--
richard nickle        [e-mail]    617-625-7155 v.32/v.42bis

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

Date: 9 Sep 92 15:01:42 GMT
From: Nick Szabo <[e-mail]>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John F. Woods) writes:

>One suggestion I heard was to slam a few large comets into Venus, thus adding
>hydrogen and blowing off big chunks of the atmosphere in one fell swoop.
>Not exactly a low-budget operation, mind you...

Not at all as expensive as you might think.  The comets provide their own
propellant, so what we need are solar-powered ice processing facilities,
to convert the dusty ice into purified propellant, and several small,
low-thrust nuclear- or solar-thermal rockets.  I've worked out several
spreadsheets for various scenarios, and the method is far superior to,
for example, moving around asteroids with mass drivers, in terms of
equipment mass launched from Earth.  The big markets are much
nearer term, though: just about any kind of transportation between
planets and many kinds of space industries benefit from the method.
The industry will be quite well-developed, with bootstrapped
ice costing a few cents per thousand tonnes, before it comes time to
terraform Venus.


--
[e-mail]  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at [phone] (1200/2400, N81)

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

Date: 9 Sep 92 15:05:40 GMT
From: Nick Szabo <[e-mail]>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <jvrnh5#[e-mail]> [e-mail] (Thomas H. Kunich) writes:

>Without references it is difficult to remember, but isn't there
>water, water vapor and possible liquid water along the interface of
>the Martian north pole?

There is water ice (as well as CO2 ice) at the north pole, and ice
clouds and water frost in many parts of the planet.  There is no known
liquid water; the temperature and pressure are both too low.


--
[e-mail]  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at [phone] (1200/2400, N81)

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

Date: 9 Sep 92 15:12:36 GMT
From: Nick Szabo <[e-mail]>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <samw.715971213@bucket> [e-mail] (Sam Warden) writes:

>As for the morality of this sort of thing, I don't share the
>comfortable expectation that we as a civilization _have_
>future centuries at our disposal for a conservative planetary
>exploration.  The spread of terrestrial life to other
>now lifeless environments seems _very_ moral to me, even a
>moral imperative, given a possibly limited window of ability
>to do so.  My opinion; others of course are free to differ.  ;-)

Even while perhaps disagreeing about the size of that window, I wholeheartedly
agree that this is a moral imperative, not "pollution" or "ruining the planet"
as the politically correct would have us believe.


--
[e-mail]  Public Access User --- Not affiliated with TECHbooks
Public Access UNIX and Internet at [phone] (1200/2400, N81)

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

Date: 9 Sep 1992 11:39 EST
From: WENDY WARTNICK <[e-mail]>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Edmund Hack) writes...
>In article <[e-mail]> [e-mail] (Barry Kort) writes:
>
>The probable origin of this rumor is a book by a contractor at
>JSC (Jim Oberg) on how to terraform Mars. There have also been a few
^^^^^^^^^^^^^^^


Jim Oberg...now there's an interesting guy!  When I was but a lowly coop at
JSC I heard a talk by a guy (I believe it was Jim Oberg) about the Soviet
Space program and, specifically, about all the sneaky things the Soviets
did to hush up/erase/deny things they didn't want us or even their own
people to know about.  Apparently Soviet Space program was a bit of a hobby
for him...he would do research to find out about cosmonauts who suddenly
didn't exist anymore.  He has some great before and after slides--slides
where guys were literally erased from the photo and a shrub painted in (a
badly painted shrub, I might add).  To make the picture all the more
laughable, the one fellow standing next to the erased guy originally had
his arm draped across the guy's shoulder--his arm now just sort of ends at
the shrub.

Anyway, I think Jim Oberg was the guy who dug up all this stuff and gave
lectures on it.

                WEndy

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

Date: Wed, 9 Sep 1992 17:15:12 GMT
From: Andreas Michael Weder <[e-mail]>
Subject: Is NASA really planning to terraform Mars?
Newsgroups: sci.space

>If you refer to Dr. Robert Zubrin's work and agree with his results,
>then we find that the turnover to a warm, wet CO2 planet is rapid
>compared to a human lifespan, ie a few decades at most. The turnover
>to an Earthlike world using plants and genetic engineering would
>indeed be the work of many generations (if you assume serious limits
>to the eventual capability of nanotechnology).

Did Dr.Robert Zubrin simply stop the simulation/calculation as soon
as the Marsian atmosphere reached earthlike temperatures and compo-
sition or did he continue?
The athmosphere, as we all now, seems to be an enourmously complicated
system. It gets kicked out of balance due to meteor impacts, changes
to the angle of Earth's axis and the like.
So if you would be able to heat up this system in a few decades it
probably wouldn't be stable at all. It would cool out, heat up
again and maybe would never ever find it's balance again.
I'm very suspicious if a "solution" to a problem like this turns out
to be a brute-force method.


Andrew

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

Date: Wed, 9 Sep 92 13:00:38 BST
From: [e-mail]
Subject: Pluto Direct/ options

> Sun than Neptune and will not cross back over until February 10, 1999, and
> this is the closest Pluto will be for another 248 years.  The proposed plan
>


Not really relevant. In 248 years we'll have people living furthur out than
that. The real reason is that if a probe doesn't get there by 2010 or so, the
atmosphere will be condensing again. This IS our last chance for about 248
years to study the atmospheres of Pluto/Charon.

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

Date: 9 Sep 92 07:21:06 GMT
From: Alan Barclay <[e-mail]>
Subject: Relativity
Newsgroups: sci.space

4318602 from David Meiklejohn:

DM>No, his time measured is 1.95 years, as you say.  What you're missing is
that
there is no favoured frame of reference, given that he's not accelerating.
Therefore, as far as our astronaut is concerned, he's stationary, and the
universe is rushing by at 0.9 c.  Now, when you move, the only relatavistic
effect isn't time dilation.  You gain mass, and your metrics contract in the
direction of motion.  This last effect means that the observer measures the
distance between the stars as 2.17 ly.  As far as he's concerned, he's taken
1.95 years to travel between two objects 2.17 ly apart, so he's measured his
speed as 0.9 c.

DM>So, it all works out.



Yes, I sort of suspected that within the subjective relativistic frame my
observer would make measurements consistent with 0.9C.

I guess I included an assumption I failed to mention.  My observer had
measured the distance between the two stars before accelerating to 0.9C,
thus he got the result of 4 ly.  He did not measure distance during flight.

I'm trying to get at something more complicated I can't do the math for.
What I was trying to simplify is the following:


1) Observer starts at v=0 relative to stars A and B.  He starts at Star A.

2) Observer measures distance to star B = 4 ly.

3) Observer accelerates to a high relativistic speed travelling towards
star B, turns over halfway and decelerates to v=0 relative to star B
adjacent to star b.  During this time he makes no measurements except to
keep track of subjective time passed.

4) When he steps onto the surface of a planet around star B, he can look
back at star A, measure it as 4 ly away, and know it took him less than
four (subjective) years to get there.

It seems to me that it is possible to travel at greater than 1 ly per
year FROM A CERTAIN POINT OF VIEW, and that point of view is valid,
in that it would have real experiential consequences on a traveller.

You mentioned something about "no favored frame of reference."  I guess
my little idea only works if you use data from two different frames.
However, my observer is present in both frames, and can trace his history
from one to the next.  Is there then a dynamic frame of reference
from his point of view?


Alan

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

Date: 5 Sep 92 01:45:29 GMT
From: USENET System Software <[e-mail]>
Subject: Shuttle tank for habitation; was Inflatable Space Stations
Newsgroups: sci.space

Why not orbit the tank with solid fule trap-on boosters and
build them with an access hatch?

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

Date: 5 Sep 92 01:49:11 GMT
From: USENET System Software <[e-mail]>
Subject: Shuttle tank for habitation; was Inflatable Space Stations
Newsgroups: sci.space

Sorry, typo, trap-on should have read strap-on solid fule
boosters.

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

Date: 08 Sep 92 19:31 PDT
From: Mark Goodman <[e-mail]>
Subject: Special Relativity
Newsgroups: sci.space

Reply-To: [e-mail]

Alan Barclay writes

>A recent SF book used relativistic mass to produce black holes.
>i.e. accelerate a spaceship until it's massive enough to collapse
>into a singularity.  Something seems missing in this equation.
>Could it happen?

The short answer is no.

It is a common (because it appears in many textbooks) misconception
that the mass of an object changes when its velocity changes.  In
fact, what increases is the time component of the energy-momentum
4-vector (E,p ,p ,p ).  The invariant mass is defined by
             x  y  z

   2  2    2
  m =E -|p|

and is independent of the frame of reference.  The confusion is
caused by Einstein's famous identity

      2
  E=mc

which holds only in an object's rest frame.  It would be more
precise to write this explicitly as

       2
  E =mc
   0

where E  is the energy of the object at rest.
       0

Mark W. Goodman

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

Date: 9 Sep 92 06:48:56 GMT
From: David Bell <dcb@mulka>
Subject: Star Chart
Newsgroups: sci.space

[e-mail] (Ridley McIntyre) writes:
: Hi,
:
: Is it possible for me to find a star chart (or set of charts) that show
: Sol's position in the Milky Way compared to other stars? All I can find
: here are charts of the Milky Way *from Earth* which don't actually show
: where we fit in to the rest of the universe. Is there one on archive
: somewhere?
:
    There was some time ago (~1985) an article on the Universe in
National Geographic, this issue came with a wall map that had our universe
on it and our solar system in relation to the universe.
    The map was more of an artistic illustration than a technical map
but could perhaps be referenced to a actual starchart or maps.
    It is also just good to look at and I think it is still available
from the National Geographic Society.
    Regards,
    David
    [e-mail]

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

Date: 9 Sep 92 13:11:49 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: TSTO vs SSTO
Newsgroups: sci.space

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

>In article SECRET AIRCRAFT ENCOMPASSES QUALITIES OF HIGH-SPEED LAUNCHER
>FOR SPACECRAFT (Aviation Week & Space Technology, August 24, 1992)
>William B. Scott writes:...

>If this is not fiction, but reality, could this (or an improved
>version) be a rival of the SSTO ?

Perhaps but my gut reaction is no. If nothing else, this violates
the KISS principle. With this you have two separate systems to develop
and then build and maintain.

>Have the U.S. enough money to make both the TSTO and the SSTO ?

Sure, depends on your priorities. I don't know about TSTO but SSTO
could be funded by the interest off an investment the size of a single
year NASA budget.

   Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "If they can put a man on the Moon, why can't they     |
|  [e-mail]     |  put a man on the Moon?"                               |
+----------------------227 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

End of Space Digest Volume 15 : Issue 180
------------------------------