Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_6/V13_608.TXT

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Subject: SPACE Digest V13 #608

SPACE Digest                                     Volume 13 : Issue 608

Today's Topics:
               Re: Calculating delta-V
              Re: Budget Numbers Wanted
      Re: Crater Found From 65-Million Year Old Asteriod
       Re: Laser launchers (really microwave launchers)
              Re: Privatization
               Amateur Telescope Making
           Re: Rational next station design process
              Mars Info Requests
          Re: vacuum energies for propolsion
           Re: Rational next station design process
              Asteroid Hazard Avoidance
              Glavkosmos Joint Ventures
              Re: Budget Numbers Wanted
            Re: Asteroid Hazard Avoidance

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription requests,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 24 May 91 03:21:48 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Calculating delta-V

In article <[e-mail]> [e-mail] writes:
>... My question is what is the
>standard (if there is one) that rocket scientists use for g? ...

You just have to look at the fine print in whatever document you are using.
Sutton says the "standard" is 9.8066 m/s^2, but (for example) the Thiokol
solid-motor catalog specifies 9.80665.

>A good solution is to give SI as the ratio of thrust (in Newtons) to
>propellant consumption (in kg/s). This will give SI in m/s ...

In fact, this amounts to forgetting specific impulse entirely and simply
stating the effective exhaust velocity.  Definitely the right approach.
--
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  [e-mail]  utzoo!henry

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

Date: 24 May 91 03:16:46 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Budget Numbers Wanted

In article <[e-mail]> [e-mail] (Stephen Walton) writes:
>My letter did not bash Fred.  I mentioned no other government programs,
>merely wrote a short letter stating my support for the Augustine
>Commission recommendations...

Unfortunately, this is naive.  As I've mentioned before in other connections,
you must always consider not just the wording of what you are signing, but
how it will be perceived and used.  You may not have *said* "kill Fred",
but your letter was almost certainly counted in the "kill Fred" column.
Don't delude yourself; this is politics, not mathematics.
--
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  [e-mail]  utzoo!henry

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

Date: 22 May 91 14:47:32 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Crater Found From 65-Million Year Old Asteriod

In article <[e-mail]> [e-mail] (John A. Weeks III) writes:

>what I read (and partly understand).  The dinosaurs did not die out in
>one instant.  The extinction appears to have taken hundreds if not thousands
>of years.  This could be consistant with a climate change, but one might
>expect the effects of a major impact to be more immedieate.

This reasoning is odd indeed.  The dinosaurs were around for more than
100 million years.  Impacts (or whatever) on the scale of the KT
boundary (CT refers to another boundary) are very rare, as has been
confirmed by the absence of similar iridium anomalies elsewhere in
sediments.  It would be an enormous coincidence indeed if the were to
die out within a few hundred or thousand years of such a rare event,
unless the extinction and the iridium event are causally connected.

I suspect the answer is that the dinosaurs were not dying out at
the time; I understand sampling errors near sharp cutoffs can give
the illusion of slow decline when none exists, especially in large,
rare organisms such as dinosaurs where the spacing between fossils is
large (and the temporal resolution is therefore low).  Oceanic
microfossils of other kinds of organisms appear to document a
knife-sharp discontinuity, as do pollen grains in continental
fossils.

    Paul F. Dietz
    [e-mail]

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

Date: 21 May 91 18:27:53 GMT
From: cis.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!uupsi!cci632!ritcsh!ultb![e-mail]  (K.R. Flanagan )
Subject: Re: Laser launchers (really microwave launchers)

In article <[e-mail]> [e-mail] (Paul Blase) writes:
>to: [e-mail] (Thomas Johnsson)
>
> TJ> I wonder if anyone has considered beaming the power to the
> TJ> launch vehicle using microwaves instead of a laser. Presumably
> TJ> power can be converted to microwaves with greater efficiency
> TJ> than laser light.  In the vehicle end, the beamed power could
> TJ> either heat up a medium direcly, or be converted to electricity
> TJ> (a lot!) with a rectenna to drive a mass driver.
>
>The trouble is the size of the rectenna required.  NASA has already built a
>microwave powered airplane, for long-duration upper atmospheric studies.
>The thing (unmanned, of course) looks like a cross between a U-2 and
>an AWACS, the big circular thing being the rectenna
>
>--- via Silver Xpress V2.26 [NR]
>--
>Paul Blase - via FidoNet node 1:129/104
>UUCP: ...!pitt!nss!Paul.Blase
>INTERNET: [e-mail]

    Sounds interesting, detials, details please, and references if
possible.
        Just another college student during finals;
            -Kevin Flanagan
            [e-mail].

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

Date: 22 May 91 17:21:31 GMT
From: agate!spool.mu.edu!rex!rouge![e-mail]  (Fraering Philip)
Subject: Re: Privatization

Would people please be careful with the nested attributations?

The post by H. Rubin may or may not have attributed something
Jonathan Leech wrote to me (although perhaps not; I sort of
wonder who that Fraering Philip person is who keeps posting
the same things I do).

--
Phil Fraering || Usenet (?):[e-mail] || YellNet: 318/365-5418
''It hardly mattered now; it was, in fact, a fine and enviable
madness, this delusion that all questions have answers, and nothing is
beyond the reach of a strong left arm.`` - Larry Niven and Jerry
Pournelle, _The Mote in God's Eye_

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

ReSent-Message-ID: <[e-mail]>
Resent-Date:  Thu, 23 May 91 09:17:09 EDT
Resent-From: Harold Pritchett <[e-mail]>
Resent-To: Space discussion group <[e-mail]>
Date:         Wed, 22 May 91 12:40:29 CDT
From: THE GAR <[e-mail]>
Subject:      Amateur Telescope Making

A trip to a nearby library at lunch yielded three books in my search:

Amateur Telescope Making:  Book One  (1959) from Scientific American
Amateur Telescope Making:  Book Two

Standard Handbook for Telescope Making  by N.E.Howard (also 1959)

I look forward to hearing any comments on my chosen (by availability) texts
and suggestions regarding new techniques or sources which may have emerged
in the last 32 years.


 /++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++\
!  Later        +   Systems Programmer                                 !
!  Gary Warner  +   Samford University Computer Services               !
!               +   II TIMOTHY 2:15                                    !
 \+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++/

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

Date: 21 May 91 18:33:53 GMT
From: van-bc!rsoft!mindlink![e-mail]  (Nick Janow)
Subject: Re: Rational next station design process

[e-mail] (George William Herbert) writes:

> This isn't how space programs funding is done now...

That's your argument?  We should decide to go ahead with a vague project,
_then_ decide the details, like who can/will use it and who might be willing to
pay for the services, just because "that's the way they do it now"?

> The President and VP seem to want Freedom, whatever the cost.

Political advertising is a really poor excuse for an otherwise unrelated
engineering project.

> ) we've already decided how much one is worth.

Really?  I thought the project was still undefined, so how could there be a
firm cost to be accepted?  The cost projections seem more like tools used for
the current round of budget fighting, with no real meaning beyond that.

[e-mail]

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

Date: 21 May 91 07:57:29 GMT
From: pdn![e-mail]  (Steve Moody)
Subject: Mars Info Requests


I am about to embark on a research endeavour to aquire as much information as I can about Mars, Future Mars Missions, Theories and Proposals for Colonization,
and or Exploration of our sister planet. I need to point out that this is a
personal project, and not one that is affiliated with any organization. I also
wish to point out that it is nonetheless important to me and I intend to treat
it as such. I have access to ftp sites only through mailservers, so any bulk
information must either be sent to me directly or directions to acess it
through the mail system must be prescribed. It  is my hopes that eventually thisdata gathering will culminate in some writing submissions.
I appreciate any help given and my thanks to all who help. Steve Moody



--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Steve Moody                              AT&T Paradyne                       ~~ [e-mail]
adyne.com                   Mail stop LG-130                    ~~                                          P.O Box 2826                        ~~                                          Largo, Fla 34649-2826               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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

Date: 21 May 91 15:45:15 GMT
From: agate!spool.mu.edu!think.com!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!sun-barr!ccut!wnoc-tyo-news!astemgw!kuis!rins![e-mail]  (will)
Subject: Re: vacuum energies for propolsion

In article <[e-mail]>, [e-mail] (will) writes:
>all the oceans of Earth. Another estimate by Jojn Wheeler gives

    Sorry, should be John Wheeler.

    Also, does anyone know where Dr. Robert Forward is and how to contact
    him?



                                        William Dee Rieken
                                        Researcher, Computer Visualization
                                        Faculty of Science and Technology
                                        Ryukoku University
                                        Seta, Otsu 520-21,
                                        Japan

                                        Tel: [phone](direct)
                                        Fax: [phone]
                                        [e-mail]

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

Date: 21 May 91 22:39:51 GMT
From: agate!headcrash.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: Rational next station design process

In article <[e-mail]> [e-mail] (Nick Janow) writes:
>I agree with Nick Szabo: you have decided the project will go ahead, and are
>looking for ways to justify it.

No, but anyway...

>IMO, the proper approach is to first find out who is wiling to pay for a space
>station; then how much are they wiling to pay, for how much/what kind of
>service.  It may be that the taxpayers are willing to pay $x billion for
>research, exploration and national pride.  The "Industrial Competitiveness"
>branch of the government may be willing to allocate $x billion for
>space/power/time in microgravity for materials and biological research.  Some
>private corporations might also be willing to spend $x billion for <specific
>services>.  The military may allocate a certain amount of funds for aerospace
>R&D, certain services, etc.
>Once you find out who is willing to pay for what sort of services, you can
>start defining what sort of structure is required to meet those demands and
>whether or not they can be provided at the price offered.

    This isn't how space programs funding is done now...
    Besides which, we've already Heard how much we're willing to spend.
Depending on who you listen to, (congress wants something at or under the
NASA estimate (30-50 billionish) as opposed to the Congressional estimate of
about 100 billionish.  The President and VP seem to want Freedom, whatever
the cost.) we've already decided how much one is worth.

    -george william herbert
    [e-mail]

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

Date: 23 May 91 17:02:20 GMT
From: [e-mail]  (Robert F. Stengel)
Subject: Asteroid Hazard Avoidance

According to Aviation Week (6/4/90):  "Asteroids hurtling toward Earth are suff
iciently large and numerous that the (AIAA) persuaded Vice President Dan Quayle
 to mention the threat in a recent speech.  The impact of an asteroid that whiz
zed by in 1989 would have equalled 1,000-2,500 one-megaton hydrogen bombs.  The
 AIAA says the asteroid passed through Earth's orbit just 6 min. after the plan
et was there, and no one saw it coming."
    How about some discussion ...

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

Date: Wed, 22 May 91 08:09:24 PDT
From: [e-mail]
X-Vmsmail-To: UTADNX::UTSPAN::AMES::"[e-mail]"
Subject: Glavkosmos Joint Ventures

I found an interesting tidbit in _Soviet Business & Trade_, Vol.XIX,
Iss.6, April 17, 1991.  News of this may have appeared on the net
before, but if it did I missed it.

  The Soviet commercial space agency Glavkosmos is codeveloping
  four 18 ton satellites which are ultimately intended to provide
  direct-broadcast television to homes throughout the USSR.
  Unnamed German coporations are participating in the design,
  development, and financing of the satellites, which will be five
  times heavier than any other satellite launched into a
  geosynchronous orbit.

  The project was revealed by Mr. Alexander Dunaev, chairman of
  Glavkosmos, before an audience of US aerospace executives.  He
  said Glavkosmos is willing to consider additional foreign
  participation in the project, including American coporate
  participation.  The preliminary timetable calls for launching the
  first of the satellites in 1994.

  Three satellites will suffice for broadcasting television
  throughout the USSR, and the fourth would provide global
  coverage.  Their signals are intended to be received by satellite
  dishes 1.5 feet (0.5 meter?) in diameter located on rooftops of
  houses and apartment buildings.

  Mr. Dunaev also said the Almaz radar mapping system would go
  commercial.  Almaz images will have a resolution of 20 meters and
  will be marketed in the US by the Texas based Space Commerce
  Corporation.

_____________
Dale M. Greer, whose opinions are not to be confused with those of the
Center for Space Sciences, U.T. at Dallas, UTSPAN::UTADNX::UTDSSA::GREER
"Mars is essentially in the same orbit as the Earth.  Mars is somewhat
 the same distance from the Sun, which is very important.  We have seen
 pictures where there are canals, we believe, and water.  If there is
 water, there is oxygen.  If oxygen, that means we can breathe."
 -- J. Danforth Quayle, 18 November, 1989

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

Date: 23 May 91 22:45:48 GMT
From: sequent!muncher.sequent.com![e-mail]
Subject: Re: Budget Numbers Wanted

In article <[e-mail]> [e-mail] (Frank Crary) writes:
>As can be seen from Stephen Walton's post, most programs did not recieve
>"the money taken away from Freedom" the following items are the only ones
>to recieve more money without Freedom as opposed to with Freedom:

[3 items, including LANDSAT]

>The following did not LOOSE money, as a result of the deletion of Freedom:

[11 items, including SETI, SIRTF, AXAF, EOS, CRAF, and NASP]

What is the difference between not losing money to Fred, and
getting money taken away from Fred?  _Both_ of these categories --
a good chunk of NASA's valuable programs -- have greatly benefited in
this budget from the Fred cut.  Drawing any other conclusion is, to
quote some nay-sayer, "dreaming".



--
Nick Szabo                [e-mail]
"If you understand something the first time you see it, you probably
knew it already.  The more bewildered you are, the more successful
the mission was." -- Ed Stone, Voyager space explorer

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

Date: 24 May 91 01:08:43 GMT
From: [e-mail]  (Jonathan Leech)
Subject: Re: Asteroid Hazard Avoidance

In article <[e-mail]> [e-mail] writes:
>that has already been made during the last decade by the great explorers
>Eleanor Helin and Eugene Shoemaker.

    Don't forget Carolyn Shoemaker while you're at it.

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

End of SPACE Digest V13 #608
*******************