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Subject: SPACE Digest V11 #38

SPACE Digest                                      Volume 11 : Issue 38

Today's Topics:
               NACA/NASA Wing sections
          Re: Galileo Update - 02/06/90 (Forwarded)
          Re: Spacecraft drives and fuel efficiency
               Re: Recreation in Space
               Re: SSX and Propellants
  Vice President emphasizes White House space commitment (Forwarded)
          Re: Galileo Update - 02/06/90 (Forwarded)
          Re: Spacecraft drives and fuel efficiency
               Re: Spacewarps?
            Re: Kepler fudged the Numbers?
            Compromising Humanity
          Re: Spacecraft drives and fuel efficiency
           Payload Status for 02/12/90 (Forwarded)
----------------------------------------------------------------------

Date: 12 Feb 90 15:38:34 GMT
From: fe2o3![e-mail]  (Michael Katzmann)
Subject: NACA/NASA Wing sections

I am looking for information on building wing sections for the least
aerodynamic drag. (not for lift).

Does anyone know of a publication that shows in detail the NACA and
NASA wing sections?  I have seen some books that show the coefficient
of drag for the various 4 and 5 digit NACA wings but none that show
you the detail the wing shape itself. Is there a publication where
this is defined (perhaps available from NTIS).

Please e-mail me any replys as I do not get a feed of this group.

                    Thanks in advance.

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Ph: [phone]

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

Date: 12 Feb 90 17:36:04 GMT
From: usenet.ins.cwru.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Galileo Update - 02/06/90 (Forwarded)

In article <[e-mail]> [e-mail] (Richard A. Schumacher) writes:
>This is also the first time a probe will approach the earth-moon
>system from a great distance, which should permit the best determination
>to date of the Earth's mass (right, Henry, Ron?)

Wrong twice, I think. :-)  For one thing, I think Giotto's Earth encounter
will be well before Galileo Earth encounter number one.  And second, I
think the numbers for Earth's mass are already ridiculously accurate as
a result of long-term tracking of high-orbit satellites.

(An amusing sidelight on this, by the way, is that the people involved
in this sort of thing won't tell you planetary masses in kg -- the numbers
they give you are always mass times G, the gravitational constant.  Why?
Because that's what they're directly measuring, to seven or eight digits,
and G is only known to about five digits!)
--
SVR4:  every feature you ever |     Henry Spencer at U of Toronto Zoology
wanted, and plenty you didn't.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 12 Feb 90 20:05:36 GMT
From: portal!portal!cup.portal.com![e-mail]  (H Keith Henson)
Subject: Re: Spacecraft drives and fuel efficiency

Since others on this thread have discussed Forward's method, I will
mention Drexler's method for stoping a light sail starship.

What you do is fire probes ahead to the target star system.  On the
way there, the (robot) probes reorganized themselves as very long
electrostatic accelerators.  When they are in the right place, they
fire bacteria sized reentry vehicles backwards, reducing the velocity
to interplantary speeds.  The bacteria sized reentry vehicles are
slowed by planetary atomospheres, drift down to the surface, and take
root.  Using local materials they grow something similar to a Niven
"stage tree," leave the planet, process an asteriod or two and
build a deceleration laser for the passenger ship which follows them.
Any information that the probes need which cannot be sent internally
can go by microwave later if the probes know how to grow an antenna.
What happens if the crop fails, or there is no place to plant it?
Details, details.  :)   Keith Henson

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

Date: 12 Feb 90 17:24:24 GMT
From: attcan!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Recreation in Space

In article <[e-mail]> [e-mail] (bill davidsen) writes:
>  Let me give you a hint... if I were going to be on a multiyear
>mission, I would want female astronauts.

I dimly recall seeing an account from one of the Skylab astronauts which
commented on this. :-)  He said that NASA told them they had a mass
budget of 60-odd kg for recreation, and "after management rejected our
unanimous first suggestion", this was used on games, tapes, etc.
--
SVR4:  every feature you ever |     Henry Spencer at U of Toronto Zoology
wanted, and plenty you didn't.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 13 Feb 90 02:03:57 GMT
From: agate!bigbang.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: SSX and Propellants

My work shows that for any given altitude there is a pretty straight
tradeoff between using higher density fuels [less tankage] and
final payload to that altitude.  When you go for a larger tank and LH2 you
get higher payload, offsetting the increased costs for the tank.

-george

[again, if someone has in-depth analysies that they want to post showing me
wrong, i'll recant.  But i haven't seen them.]

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

Date: 13 Feb 90 01:18:29 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Vice President emphasizes White House space commitment (Forwarded)

Jeff Vincent
Headquarters, Washington, D.C.                  February 12, 1990


RELEASE:  90-22

VICE PRESIDENT EMPHASIZES WHITE HOUSE SPACE COMMITMENT


     Vice President Dan Quayle met today with NASA's senior
management and gave the agency a resounding vote of confidence.
Speaking at an informal luncheon at NASA Headquarters,
Washington, D.C., the Vice President emphasized that the White
House "is committed to making space a priority."

     The Vice President told NASA officials that their immediate
challenge is to "reignite interest and energy in the space
program beyond the Beltway."  He characterized the civil space
program as being of "critical importance" to the nation.

     Vice President Quayle is the Chairman of the National Space
Council, which is charged with overseeing the President's
national space policy and coordinating interagency space
issues.  He met with NASA Administrator Richard H. Truly, Deputy
Administrator J. R. Thompson Jr. and the associate administrators
who oversee the agency's various programs.

     The Vice President discussed the value of new technology
that flows from the space program and how it makes the United
States more competitive in the world market.  He also spoke at
length on the link between NASA and education and, in particular,
how the space program can inspire students to study science and
math.

     On January 26, the Administration announced it was seeking a
23 percent funding increase for NASA in FY 1991, the largest
increase for any major agency.  The President's budget message
said that, "The exploration of space has benefits for the United
States that go far beyond the quantifiable.  There are specific
payoffs in the form of new materials, technological discoveries
and microgravity research.  But no price can be put on the
lifting of the spirit of people everywhere ... And no
quantitative measure of any kind can capture the benefit of
expanding human horizons, human dreams and the human domain."

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

Date: 13 Feb 90 15:46:10 GMT
From: munnari.oz.au!csc![e-mail]
Subject: Re: Galileo Update - 02/06/90 (Forwarded)

In article <[e-mail]>, [e-mail]
    (Henry Spencer) writes:
> I think the numbers for Earth's mass are already ridiculously accurate as
> a result of long-term tracking of high-orbit satellites.
>
> (An amusing sidelight on this, by the way, is that the people involved
> in this sort of thing won't tell you planetary masses in kg -- the numbers
> they give you are always mass times G, the gravitational constant.  Why?
> Because that's what they're directly measuring, to seven or eight digits,
> and G is only known to about five digits!)

There's even a theory (``fifth force'') that gravity has short-range (~100m?)
components, so that the value of G measured in a laboratory might be ~1%
different from the value relevant for interplanetary work. I haven't heard much
of these measurements recently, did the theory die?
------------------------------------------------------------------------------
David Bofinger    ACSNet:    [e-mail][.au]
                Snail:    Dept. of Theoretical Physics, RSPhysS, ANU, ACT, 2601
------------------------------------------------------------------------------
"Through the night of doubt and sorrow
 Onward goes the pilgrim band.
 Counting photons very slowly
 On the fingers of one hand."        -- The Lay of the Gamma-Ray Astronomer

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

Date: 12 Feb 90 07:57:57 GMT
From: mcsun!sunic!chalmers!mathrt0.math.chalmers.se!hacke1![e-mail]  (Bertil Jonell)
Subject: Re: Spacecraft drives and fuel efficiency

In article <[e-mail]> [e-mail] (Tim Maroney) writes:
>Unfortunately, the speculative "gate" approaches such as the Kerr
>metric warp are even worse.  Has anyone done any estimates on the
>energy needed to keep a Kerr warp contained and spinning?

Ok, Enlighten us. What is a metric Kerr warp and how can it be used for
interstellar travel?

Bertil K K Jonell @ Chalmers University of Technology, Gothenburg
NET: [e-mail]
VOICE: [phone] / [phone]     "Don't worry,I've got Pilot-7"
SNAILMAIL: Box 154,S-43900 Onsala,SWEDEN      (Famous last words)

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

Date: 12 Feb 90 05:20:44 GMT
From: zaphod.mps.ohio-state.edu!usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Spacewarps?

In article <[e-mail]> [e-mail] writes:
>What is a "Kerr metric warp", who is Kerr, and what sort of physics
>  does this involve?  Is this merely some science fiction conjecture
>  or is it based on reputable theory?

Folks interested in this should proceed immediately to the November issue
of JBIS [the Journal of the British Interplanetary Society], which contains
a paper by Robert Forward reviewing space warps [!].  At least one of the
concepts -- the Morris-Thorne Field-Supported Wormhole -- involves no
neutronium, no singularities, *comparatively* modest masses, no tidal
effects, a warp large enough to pass a spacecraft, and generally quite
tractable problems assuming you can build a structure the size of the
inner solar system [sigh, you knew there was a catch, didn't you?].
--
SVR4:  every feature you ever |     Henry Spencer at U of Toronto Zoology
wanted, and plenty you didn't.| uunet!attcan!utzoo!henry [e-mail]

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

Date: 12 Feb 90 13:30:56 GMT
From: mentor.cc.purdue.edu!bank.ecn.purdue.edu![e-mail]  (Ingo Cyliax)
Subject: Re: Kepler fudged the Numbers?

In article <[e-mail]>, [e-mail] (Robert
M. Panoff) writes:
> I have heard (or read) recently that Kepler fudged his numbers.
> He claimed to have an independent check on his theory, but the charge
> is used the theory to calculate the numbers he said verified his theory.
>
I always thought he made several mistakes in his math, some of which cancelled
each other out.


-ingo

/*                Ingo Cyliax    ECN, Electrical Engineering Bldg.          *
 *      [e-mail]    Purdue University, W. Lafayette,IN 47907   *
 *          [e-mail]    Work: [phone]                       *
 *         [e-mail]    Home: [phone]                       */

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

Date: 12 Feb 90 17:40:02 GMT
From: snorkelwacker!usc!zaphod.mps.ohio-state.edu!uwm.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!m.cs.uiuc.edu!p.cs.uiuc.edu![e-mail]
Subject: Compromising Humanity


Probably the most dangerous gift you could give an extraterrestrial
being would be a digital watch.

An alien could learn a lot from a digital watch.  The watch
demonstrates a mastery of integrated circuits (and thus computers),
material science (the LCD display), an understanding of non-silicon
molecular particles and their behavior (a watch depends upon the
stability of an oscillating quartz crystal, and a lithium battery).

It also demonstrates our engineering expertise at ruggedizing small
objects (waterproofing and shockproofing), simplifying complicated
devices, and perhaps even a bit of ergonomics (that is, if you
happened to know what a human being looked like).  My TIMEX Ironman
watch is made of a tough resin to achieve light weight.  If an alien
analyzed the material, he could probably infer that our culture had
developed airplanes or at least advanced composite materials.

I imagine that a timepiece would tell him how to distinguish our
planet from most of the other terrestrial bodies in the galaxy.

Nothing else as small is so indicative of the state of humanity today.

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

Date: 12 Feb 90 14:33:57 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Spacecraft drives and fuel efficiency

In article <[e-mail]> [e-mail] (Tim Maroney) writes:

>No, I think we're getting into absolutes.  It takes so much antimatter
>to send a one-ton probe to the nearest star in 22 years that the same
>amount of antimatter would cause a mass extinction event if it were to
>strike the earth.  In other words, the energy of 350,000 Hiroshima
>bombs.  That's a lot of energy for any biological species to be dealing
>with, period.

That's a lot of energy, yes.  But it is small compared to that
available.

BTW, 1 ton of antimatter, completely annihilated, liberates about 43
gigatons of energy.  The Hiroshima bomb was 13 kT, about 3 million
times less.  However, even 43 gigatons is small compared to the energy
liberated by the impact of an asteroid of the size of one consistent
with the K/T iridium layer; a 10 km asteroid hitting at 20 km/s would
liberate about 20,000 gigatons.  I don't think a mere 43 gigatons
could cause a global mass extinction event.

>>The energy resources of the solar system are more than adequate for
>>interstellar travel, given sufficiently massive engineering.  The sun
>>produces about 4e26 watts of power.  At 100% efficiency, this power is
>>enough to launch, every *second*, a 15 million ton starship at half
>>the speed of light.  Implementation details are left to the reader :-).
>
>Sure -- all you have to do is capture all of it with a Dyson sphere,
>then convert it to antimatter at 100% efficiency, then figure out some
>way to control all the antimatter without blowing your Dyson sphere
>into the Oort cloud.  That's not an awful lot of energy to be messing
>with; it's all relative.  No problem at all....

Making antimatter is horribly inefficient; I would not choose to use
it as a fuel.  Laser sails seem more practical.  You don't need a
Dyson sphere (the numbers I gave were only to show how great the upper
bound on interstellar traffic could be); if we launch one 15,000 ton
vehicle every 3 years the power is down by a factor of 10^10, even if
the laser propulsion system is only 10% efficient overall.

    Paul F. Dietz
    [e-mail]

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

Date: 13 Feb 90 01:16:24 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Status for 02/12/90 (Forwarded)

Daily Status/KSC Payload Management and Operations 02-12-90



- STS-36 (at Pad-A) -

MMSE operations at the pad were completed Friday.


- STS-31R HST (at VPF) -

At the VPF, HST stand alone confidence test was completed
Friday.  End-to-end 6 was completed third shift Saturday.
Today preps for the CITE confidence test will be worked.


- STS-32R SYNCOM/LDEF (at SAEF-2)

LDEF deintegration continues.


- STS-35 ASTRO-1/BBXRT (at O&C) -

Bond jumper repair and P-clamp installation will be worked
today.  Paper closure also continues today.


- STS-40 SLS-1 (at O&C) -

Preps for systems test were worked Friday, Saturday, and Sunday
and will continue today.  This work includes mating racks 3, 4,
5, 8, 9, and 11 to the floor, RAU installations, P-clamp
inspection, HDRR EU mods, aft end cone harness installation,
ECS preps, EU installation, and CCTV preps.


- STS-42 IML (at O&C) -

Racks 5 and 8 structural mods were worked Friday.  Rack 11
staging activities will be performed today.


- STS-45 Atlas-1 (at O&C) -

No activity.

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

End of SPACE Digest V11 #38
*******************