Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_2/V16NO274.TXT

Internet Message Format | 1993-07-13 | 31KB

Date: Fri,  5 Mar 93 05:05:25
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #274
To: Space Digest Readers
Precedence: bulk


Space Digest                Fri,  5 Mar 93       Volume 16 : Issue 274

Today's Topics:
                   Alternative space station design
                                Blimps
                           Columbus project
                            Deahead space
                            Fallen Angels
               Galileo Earth-Moon Animation, AVI Format
                      Gravity-NEUTRALIZING Spac
                 I have a dream! People into Space..
                        Japan's space program
       Jupiter and Venus followons (was Re: Refueling in orbit)
                          Latest on Geminga
                          military aircraft
          Misconceptions about SSTO (was Re: Fallen Angels)
                        Research opportunities
            Soviet Energia: Available for Commercial Use?
                           Space Scientists
                              Starprobe
                          The Future of Fred

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

Date: Thu, 4 Mar 1993 08:11:39 GMT
From: Hugh Emberson <[e-mail]>
Subject: Alternative space station design
Newsgroups: sci.space

>>>>> "NLF" == Dr. Norman J. LaFave <[e-mail]> writes:
NLF> * Primary power source---NOT solar arrays!
NLF>   RTG pallet---known technology...not subject to shadowing
NLF> problems...  eliminates primary plume impingement
NLF> problems....eliminates largest flexibility problems, both control
NLF> and structural....proven safety.

Why not solar arrays?  Couldn't you just wrap solar cells around all
of your modules, or have lots of small rigid wings.  Some cells will
be in shadow some of the time, but if you have enough of them then it
won't be a problem.  Over-engineer!

Another solution would be to have a big array (as big as Freedoms
arrays or bigger) attached to your station by a short tether (~100m).
The drag and the gravity gradient would probably produce a couple of
microgees though.  You would need some way of controlling it, stopping
it spinning and getting tangled up.  Perhaps the array could be flown
like a kite, deflect one half of the array slightly so that its drag
produces a torque in the opposite direction to the rotation you want
to control.

NLF>   Secondary source: Thermal gradient power generation---This is

Cool idea.

Hugh
--
Hugh Emberson -- CS Postgrad
[e-mail]

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

Date: 3 Mar 93 20:57:16 GMT
From: Henry A Worth <[e-mail]>
Subject: Blimps
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
> TS.ccc.amdah
> Reply-To: [e-mail] (Gary Coffman)
> Organization: Destructive Testing Systems
> Lines: 23
>
> In article <[e-mail]> [e-mail] (Josh Hopkins) writes:
> >It would certianly be possible to actively heat the lifting gas. However, given
> >that Mars has an atmosphere of CO2 and probably has plenty of native Hydrogen
> >available for use I don't forsee a real need for active heating.  Passive lift
> >should be just fine thank you.
>
> Given that a blimp flies by displacement bouyancy, and given the low
> density of Mars' atmosphere, active heating could be very valuable
> in increasing the lift capacity of a Mars blimp. Even with hydrogen
> as the displacement gas, you don't get a lot of lift. Therefore the
> structural mass and payload of the blimp are extremely limited. If
> you can heat the hydrogen, according to PV=nRT your displacement,
> and hence your lifting capacity, increases in direct proportion to
> the displacement gas temperature. Raise the gas temperature to 200C
> and you would almost double the lifting capacity of the blimp over
> that of an unheated system.
>

   Another area that hot gas would help besides lift is to reduce the
difficulties of landing and securing an airship. One of the biggest costs
associated with airship use is the ground crew, on Mars such manpower would
be prohibitively expensive. An unheated airship can vary lift only slightly
by blowing air into ballast conpartments or in extreme conditions venting
lifting gas. With the ability to more significantly vary lift, such as with
active heating and cooling, it becomes possibile to operationally "hard
land" an airship, eliminating the complexity of airship capture. Hot-air
blimps are much more manuverable and more easly handled than gas airships
-- part of this is also due to small size and an abundance of vectored
thrust -- but the amount of fuel required severely limits range.

   Other approaches to controllably vary lift have been tried: attached
helicopters, rotating envelope with lifting airfoils, rotating envelope
exploiting the Magnus(?) effect.  Unfortunately, the dynamics of the
first two have been too complex for their limited development efforts
to overcome. Does anyone out there know anything about the status of the
Canadian Magnus project? I've only seen a couple of pictures and have
never heard how it worked out, it wasn't nearly as dynamically complex as
the other two.
--
Henry Worth
No, I don't speak for Amdahl... I'm not even sure I speak for myself.

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

Date: Thu, 04 Mar 93 17:19:12 EST
From: Tom <[e-mail]>
Subject: Columbus project

>BH>What's the message here?  If Clinton kills Fred, Columbus is sunk?

>I suspect that Columbus could be sent into a 51 degree orbit
>in case of no America station being available.

I assume this is a distinct project from the proposed Columbus Binocular
Telescope.  So what project is it?

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: Thu, 04 Mar 93 19:19:31 EST
From: Tom <[e-mail]>
Subject: Deahead space

>>>Are you postulating that the typical Shuttle launch will be going to
>>>the station with over 20% deadhead carge space?  Sounds like time to
>>>build another vehicle and switch to it, to me, if that's the case then it
>>>is time to switch to another launch vehicle

>>Hey Fred if you look at the Expendables, most of them go up with anwhere from
>>5 to 25% deadhead.

>No doubt.  And the smaller the payload the larger that percentage
>probably is.  After all, if you're launching on a booster that can
>loft 40k and you're only using 25k of that, why not use a cheaper
>booster that can lift less in the first place?

Yes, it would be much less of a waste to use a cheaper launcher.  But
how many different launchers are we talking about?  One for every
possible payload size would be required to avoid any wasted space
whatsoever.  Maybe a SRB with 6-inch disk-shaped modules that you can
stack for each 10kg :-)

Also, if Pegasus is a good model, aren't smaller launchers more
expensive, per unit weight, than larger?  Maybe a good solution would
be to put the original paylod into a larger, more expensive launcher,
increasing the extra space to 50%, allowing a second payload, and
decreasing the cost/weight.

On the bright side, extra payload capacity is also extra manuvering
capability, which is nice.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: 4 Mar 93 07:45:46 GMT
From: Daniel Pawtowski <[e-mail]>
Subject: Fallen Angels
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (FRANK NEY) writes:
>
>In the SF book 'Fallen Angels' by Larry Niven & others, a launch
>vehicle named PHOENIX was described.  In the afterward, it was claimed
>that such a launch vehicle (SSTO/VTOL) could be build for $50M-200M.
>
>Anyone have information on the design of this critter?
>
  Yes, the "Phoenix" vehicle mentioned in the book is based on a real
launch system.  It was picked up by the DoD in the 80's as the "Spaceship
Experimental", or SSX, has gone though several re-designs.  It is know part
of SDI and is known as the McDonald Douglas Delta Clipper, or DC-X.
(The initial's resemblance to commerical airliners are NOT conincidental).
Specs, off the top of my head:
  20,000 lb payload including crew.
  Single-Stage-To-Orbit, entire vehicle completely re-useable.
  Manned or unmanned operation.
  No major overhauls between each flight.  They hope to eventually get launch
turnaround to less than one day with a ground crew of fewer than 30.

I haven't actually heard anything about the project since last fall.  At
that time, they were halfway through construction of the DC-Y test vehicle, a
1/3 scale test vehicle using engines from an existing rocket.  The DC-Y
is not manned and does not have orbital capability.  The first DC-Y
test flight was set for April 1993, and they were running ahead of schedule
and under-budget.  Constrction of the first DC-X was set for early 1994,
first launch in 1997.  Cost of the program is insanely low, on the order of
the $200 Mil mentioned in the book.  If they go into commercial production,
launch costs should easily fall below $1 mil.  So far, Northwest Airlines
has shown extreme interest in buying the first production-line DC-X's for
commercial space use and possible passenger service by 2010.
The fuel used by the real DC-X is a little more complicated than the
Phoenix.  That ship used straight hydrogen and oxygen.  The real one will
use "slush hydrogen" fuel for greater energy density.
As of last Fall, the people at the project said their biggest problem
was some of the folks at NASA who wanted to kill it in favor of the
National Launch System.  Of course, other folks at NASA loved the Delta
Clipper.  Of course, there is a very good chance Bill Clinton will scrub
the whole thing because of its SDI origins.

                                              Daniel Pawtowski
                                               VTAS Commando
[e-mail]
Obnoxious .sig:  Come to Technicon 10, April 9-11!  SF&F con in SW VA!
(Somehow, Frank, I suspect you're coming :)

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

Date: Thu, 4 Mar 1993 07:53:39 GMT
From: Andreas Hestermeyer <[e-mail]>
Subject: Galileo Earth-Moon Animation, AVI Format
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>The hqx file for the Galileo Earth-Moon animation was inadvertently ftp'd
>to Ames in binary mode, and this has caused some problems with some of the
>uncompressors such as Stuffit and Compact Pro.  The file has been
>ftp'd in ascii to rectify the problem.  I apologize for any inconvenience
>this may have caused.  The animation can be run using either NIH Image
>or Quicktime 1.5.  A fli version of the animation is expected to be ready
>by this Friday (March 5).  Thanks again to Paul Geissler and Larry Kendall
>for creating the animation and making it available.
>
Is there anybody who could convert the animation to the Microsoft Video for Windows format ?

Andreas Hestermeyer

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

Date: Thu, 4 Mar 1993 15:38:40 GMT
From: Dillon Pyron <[e-mail]>
Subject: Gravity-NEUTRALIZING Spac
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Roland Dobbins)  writes:
>M >Date: 1 Mar 93 17:24:25 -0600
>M >
>M >     The ZERO/REDUCED-Gravity Chamber described below has obvious p
>M >applications for Chemistry, Biology, Biophysics, Biochemistry, Medi
>M >Research, etc., allowing experiments which now can be done ONLY on
>M >Shuttle, AT GREAT EXPENSE!
>M >
>M >
>M >                       Gravity-NEUTRALIZING Air/Spacecraft
>M >                         or ZERO/REDUCED-Gravity Chamber
>M >
>M >               NASA should build an experimental spacecraft based o
>M >          U.S. Patent #3,626,605 [at least $3.00 per complete copy
>M >          U.S. Patent Office, 2021 Jefferson Davis Hwy., Arlington,
>M >          22202; correct 7-digit patent number required.  Or try ge
>M >          it via your local public or university library's inter-li
>M >          loan dept..], titled "METHOD AND APPARATUS FOR GENERATING
>M >          SECONDARY GRAVITATIONAL FORCE FIELD", awarded to Inventor
>M >          Henry W. Wallace on Dec. 14, 1971.
>M >
           [deleted]
>M >
>M >
>M >               UN-altered REPRODUCTION and DISSEMINATION of this
>M >          IMPORTANT Information is ENCOURAGED.
    oops.   So sue me.
>M >
>M >
>M >                                        Robert E. McElwaine
>M >                                        B.S., Physics and Astronomy
     We all know what BS stands for, MS is more of the same and Ph.D. is pile
it higher and deeper.
>M >
>M >
>
>That's nuts . . .
No, nuts are tasty little things found on trees or in the ground.  He's crazy.

The patent office issues patents based on technical novelty and uniquness.  The
only invention they currently want a working copy of is a perpetual motion
machine.

I'm in a foul mode today.  I thought it was Friday.
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |When in fear, or in doubt
[e-mail]          |Run around, scream and shout.
PADI DM-54909                     |

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

Date: Thu, 4 Mar 1993 07:32:31 GMT
From: Josh Hopkins <[e-mail]>
Subject: I have a dream! People into Space..
Newsgroups: sci.space

[e-mail] (Gary Coffman) writes:

> What we need is a small core group
>of Germans who have a tightly focused mission objective, a hard deadline,
>and a relatively free hand and cubic money to accomplish it.

Hmm.  I'll have to warn my relatives to move out of London :-)

--
Josh Hopkins                                          [e-mail]

    You only live once.  But if you live it right, once is enough.
            In memoria, WDH

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

Date: 4 Mar 93 07:28:45 GMT
From: Josh Hopkins <[e-mail]>
Subject: Japan's space program
Newsgroups: sci.space

(fred j mccall 575-3539) writes:

>(Kenji Saito) writes:

[Someone else asked ..]

>>>In the close-up GIF of the space station,
>>>on the one module, what does NASDA stand for ?

>>NASDA is the Japanese version of NASA. I do not know what the name stands
>>for, but it must be something like National AeroSpace D? Agency.

>I would be inclined to suspect the "N" is for Nippon;

Folks, If you don't know, don't speculate.  Henry will explain eventually :-)

NASDA = National Space Development Agency
ISAS  = Institute for Space and Astronautical Science
NAL   = National Aerospace Laboratory

NASDA runs the big applications projects, like H-2 and JEM.  Note the word
"Development" in their name.  It's there for a reason.

ISAS is somewhat smaller and runs the science projects, like the probes to
Halley's comet and the Moon.  They have their own smaller rockets.

NAL does some space related research, notably on aerospace planes.

Naturally, like any political beast, the boundries between organizations are
a little fuzzy.  For example, Bill thinks that NASDA and ISAS are in their
own race to the Moon.
--
Josh Hopkins                                          [e-mail]

    You only live once.  But if you live it right, once is enough.
            In memoria, WDH

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

Date: Thu, 4 Mar 1993 07:01:36 GMT
From: Josh Hopkins <[e-mail]>
Subject: Jupiter and Venus followons (was Re: Refueling in orbit)
Newsgroups: sci.space

[e-mail] (Pat) writes:


>Actually Bill, I would Posit, that the Discovery Series are The follow
>Ons to Mariner/Voyager/Pioneer.   Mariner really started off as a
>series of Light fast missions to single targets,  they just got a little
>ambitious in voyager, but I think?????? they all used pretty mcuh the
>same vehicle bus.

>Magellan, I think used the the Mariner Mk II bus

Sorry.  Wrong on both counts.  The various Mariner, Pioneer and Voyager missions
used distinctly different hardware.  Magellan was made from spare parts off
Voyager and Galileo.  The Cassini and CRAF missions were designed to use the
Mariner Mk II but CRAF has been canceled and there aren't likely to be any
other missions in that class for a while, so Mariner Mk II will probably never
see the light of day in a form resembling the original concept.
--
Josh Hopkins                                          [e-mail]

    You only live once.  But if you live it right, once is enough.
            In memoria, WDH

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

Date: Thu, 4 Mar 1993 16:16:45 GMT
From: Henry Spencer <[e-mail]>
Subject: Latest on Geminga
Newsgroups: sci.space,sci.astro

In article <[e-mail]> [e-mail] (Keith Mancus) writes:
>> ...Neil Gehrels and Wan Chen of NASA/Goddard suggest that the
>> supernova that created Geminga also created the "Local Bubble," the
>> hot, low-density region of interstellar space containing our solar
>> system.
>
>  Does this mean the density of hydrogen in interstellar space near
>the solar system is significantly lower than the average density across the
>Milky Way galaxy?

Yes.  It's obviously due to a recent close supernova, and people have been
interested in finding the leftovers for some time now.

The existence of the Local Bubble is the only reason why EUVE (the Extreme
UltraViolet Explorer satellite) can function at all.  The normal interstellar
medium is opaque at those wavelengths.
--
C++ is the best example of second-system| Henry Spencer @ U of Toronto Zoology
effect since OS/360.                    |  [e-mail]  utzoo!henry

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

From: Dillon Pyron <[e-mail]>
Subject: military aircraft
Newsgroups: sci.space

Organization: TI/DSEG VAX Support
References:  <[e-mail]>
Date: Thu, 4 Mar 1993 15:31:16 GMT
Source-Info:  Sender is really [e-mail]
Source-Info:  Sender is really [e-mail]


In article <[e-mail]>, [e-mail] (Roland Dobbins)  writes:
>MC>In article <[e-mail]> [e-mail] (Brian Stua
>MC>
>MC>As for rumoured replacement. The SR-71, the A-12, the F117A were se
>MC>many years before they went public. So it is reasonable to assume t
>MC>the USA has a replacement.  After all the original designs for the
>MC>dated from the late 40's. You decide.
>MC>
>MC>Yours in Paranoia
>MC>Chris
>
>Er . . . the original SR-71 designs aren't from the 1940s, I think.
>Kelly Johnson built the SR-71 during 1961-1962 at the Lockheed Skunkworks,
>if I'm not mistaken . . .

Are not.  The first SR-71 flew in the summer of 1902.  It is probably the best
kept secret, after the Martian space craft, or the fact the aliens took JFK to
their planet to fix him up, or...  oh God, next time I go to the grocery store,
I'll look at candy bars  :-)
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |When in fear, or in doubt
[e-mail]          |Run around, scream and shout.
PADI DM-54909                     |

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

Date: 4 Mar 93 09:57:05 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: Misconceptions about SSTO (was Re: Fallen Angels)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Daniel Pawtowski) writes:
> In article <[e-mail]> [e-mail] (FRANK NEY) writes:
>>
>>In the SF book 'Fallen Angels' by Larry Niven & others, a launch
>>vehicle named PHOENIX was described.  In the afterward, it was claimed
>>that such a launch vehicle (SSTO/VTOL) could be build for $50M-200M.
>>
>>Anyone have information on the design of this critter?
>>
>   Yes, the "Phoenix" vehicle mentioned in the book is based on a real
> launch system.  It was picked up by the DoD in the 80's as the "Spaceship
> Experimental", or SSX, has gone though several re-designs.  It is know part
> of SDI and is known as the McDonald Douglas Delta Clipper, or DC-X.
> (The initial's resemblance to commerical airliners are NOT conincidental).

This is really distorted, as Phoenix, SSX, and Delta Clipper are
indeed all SSTO proposals (DC-X in certainly not, as it will never get
anywhere near orbit!), but they are all DIFFERENT proposals from
different people, and there are marked technical differences between
them.  Mr. Pawtowski has blurred them seriously.  Yes, there may be
some historical and political influence that one had on the other--
but then one could say that they share a common descent from Phil
Bono's Pegasus/Hyperion/ROMBUS/etc. proposals of the Sixties.

> I haven't actually heard anything about the project since last fall.

Many people have posted much technical detail here in sci.space on
DC-X and its possible successors.  Send a request to Allen Sherzer
([e-mail]) if you want more information.

> The fuel used by the real DC-X is a little more complicated than the
> Phoenix.  That ship used straight hydrogen and oxygen.  The real one will
> use "slush hydrogen" fuel for greater energy density.

Hmm, slush hydrogen technology is not mastered yet-- there's some
research on it going on under the NASP program-- and I very much doubt
that McDonnell Douglas is counting on it for DC-Y and operational DC
ships.  Correct me if I'm wrong.

I'm pretty sure Gary Hudson's defunct Phoenix proposal was intended to
use slush hydrogen.  But Gary can be awfully optimistic at times...

Bill Higgins, Beam Jockey              | Bartlett's
Fermi National Accelerator Laboratory  | Most Familiar Quotation
Bitnet:           [e-mail]  | (according to W. H. Leininger):
Internet:       [e-mail]  | "Say, that's pretty good!
SPAN/Hepnet:           43011::HIGGINS  | Mind if I use it?"

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

Date: Thu, 04 Mar 93 20:45:33 EST
From: Mike Perry <[e-mail]>
Subject: Research opportunities

I am an undergraduate physics major interested in obtaining information concern
ing appropriate research opportunities for undergrads.  I am interested in anyt
hing remotely concerning the space program sponsored by NASA, the armed forces,
 or other private or public agencies.  Please e-mail me.

                             Thank you
                                  Michael Perry
                                   kyl118 at uriacc.uri.edu

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

Date: 4 Mar 93 11:41:32 GMT
From: Nick Szabo <[e-mail]>
Subject: Soviet Energia: Available for Commercial Use?
Newsgroups: sci.space

[e-mail] (Garret W. Gengler) writes:

>Can anyone tell me if the Soviets are still offering their launch vehicles,
>specifically the Energia, for commercial use?

The Russians, new to capitalism, have offered to sell all sorts
of strange things that are only in demand in a warped command
economy, but even so I doubt they're seriously considering this.
The commercial space sector has never been interested in HLVs. They
also never used Saturn or even the semi-heavy Titan IV, and only breifly
used Shuttle when >3/4 of its cost was subsidized by the U.S. govnt.  The
military of USSR and US also had no use for Energia and Saturn respectively,
despite being by far the largest space users.  The only people still
interested in HLVs are those astronaut fans who (a) lack imagination
to figure out ways to get their heros up there with commercial/military
rockets, and (b) have no understanding of economics, so that they
fantasize that astronauts are "the" space program, with an enending
infinite supply of pork, and can afford to build their own special
purpose, oversized infrastructure which in turn is supposed to
magically expand the capability of the actual users of space,
military and commerce, even though these users are the last thing
in mind when HLVs, shuttles, space stations, and other sacraments
of the astronaut cult are designed.


--
Nick Szabo                     [e-mail]

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

Date: Thu, 04 Mar 93 17:37:43 EST
From: Tom <[e-mail]>
Subject: Space Scientists

David Lai ([e-mail]) wrote:
: I'm interested in becoming a space scientist, like those who work for
: NASA.  I want to know what qualifications I need.  Do those scientists who
: work for NASA are all Ph.D.s?  Is there any recommendations for what degrees
: to get?  Thanks!

Ken Jenks;
>We have many different kinds of people whom you might call "space
>scientists."  The minimum qualification is a BS in any SCIENCE.  ...

Depending on how loosly you define 'space scientist', you don't even
need a B.S.  I was a still a Junior (or maybe a sophmore, it gets a
little muddled around here :-) when I was hired and started programming
for the SOI Helio-seismography project.  The project will study the
Sun, and the programming included data-analysis and tracking for the
satellite, so it fulfils the criteria of science realted to space.

Of course, should I graduate or stop pursuing my BS, that job would
either end or be filled by someone who had at least a B.S, so my
example is of little use for David's search.

-Tommy Mac
-------------------------------------------------------------------------
Tom McWilliams | 517-355-2178 (work) \\     Inhale to the Chief!
[e-mail]  | 336-9591 (hm)\\  Zonker Harris in 1996!
-------------------------------------------------------------------------

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

Date: 4 Mar 93 09:59:52 GMT
From: Del Cotter <[e-mail]>
Subject: Starprobe
Newsgroups: sci.space

<[e-mail]> [e-mail] (Mark D. Looper) writes:
>[e-mail] (Bill Higgins-- Beam Jockey) writes:
>>... 4. How *do* you engineer a spacecraft to go arbitrarily close to the
>>Sun?  (Spare me Brin's "refrigerator laser,"  I already know about it
>>and his ship uses magic technology for its other systems.)
>
>The Solar Probe spacecraft, a proposed mission to whip by the sun at about
>3 solar radii above the photosphere, will hide behind a big conical heat
>shield of "carbon-carbon" (whatever that is) composite material.  It will
                            ^^^^^^^^^^^^^^^^
Exactly what it says: a composite of carbon fibres in a carbon matrix.
For example, "fibreglass" or Glass Reinforced Plastic (GRP) is a
composite of glass fibres in a resin matrix.

Incidentally, the factor limiting the lifetime of such a probe close to the
Sun is the *evaporation* of carbon from the surface - Eeek!

>It will
>not take pictures of the sun, but rather will carry instruments to measure
>fields and particles that can come behind the shield to be observed;

My impression of Starprobe was that a camera would be positioned to take
pictures of the Sun through a small hole in the apex of the cone.

>Of course, in order to kill its angular momentum enough
>to get that close to the sun, it may make use of Jupiter for a gravity assist
>(as Ulysses did to get kicked out of the ecliptic plane), at which distance
>it'd need RTG's anyway.

Another disadvantage is that subsequent encounters occur at intervals of
about eight years.  One idea that was considered was an *aerogravity*
manoeuvre in the atmosphere of Venus, obviating the need for RTGs and giving
encounters at intervals of about six months.  You need a helluva heatshield
for this trick, though, not to mention a glider with a lift/drag ratio of
about 10 (!).
--
 ',' ' ',','  |                                                  |  ',' ' ',','
   ', ,','    |       Del Cotter       [e-mail]      |    ', ,','
     ','      |                                                  |      ','

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

Date: Thu, 4 Mar 1993 11:13:04 GMT
From: Nick Szabo <[e-mail]>
Subject: The Future of Fred
Newsgroups: sci.space,talk.politics.space

[e-mail] (Gary Coffman) writes:

>Freedom was scheduled for first launch in late 95 with PMC in 97, and
>*was on schedule* (+/- 3 months). So it looks like any new station will
>*delay* our chances of having an operational facility. And will definitely
>*reduce* our on orbit capabilites if built.

It's disappointing to see Gary passing on NASA-bureaucrat excuses.
Reagan called in 1984 for the station to be completed "within a
decade" and the advertised cost was $8 billion.  Today independent
cost estimates are well over $100 billion, we've spent $8 billion
already, the design has been stripped of most of its promised
functionality, and anti-Reagan Democrats control both the White
House and the Hill, probably for many years to come.

NASA screwed up by putting all its marbles into an obsolete concept.
Unless you just want to see another decade of failure at NASA, it's
time to stop making excuses and start helping to reform NASA and
create a new vision for the next century instead of pursuing
religious sacraments springing out of the early part of this
(mercifully soon ending) century.

>throws away ... upfront costs just as they are getting ready to pay off.

There isn't any signficant pay off even if SSF is completed, and
massive amounts of lost opportunity in other parts of the space
program while the money and the effort pursuit this futile
banging of the head against a wall.


--
Nick Szabo                     [e-mail]

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End of Space Digest Volume 16 : Issue 274
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