Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_4/v9_431.txt

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Subject: SPACE Digest V9 #431

SPACE Digest                                      Volume 9 : Issue 431

Today's Topics:
           Re: citizens in space -- risk silliness
             Re: Magellan update
             BITNET mail follows
                  Re: memes
            spaceplane propulsion
               Re: more 747 drop tests?
                Wyoming Bolide
              Re: Wyoming Bolide
        Re: Does anyone know *why* the USAF did this?
              Re: spaceplane propulsion
       Re: Private spending for space science (summary)
           Re: citizens in space -- risk silliness
----------------------------------------------------------------------

Date: 9 May 89 18:55:11 GMT
From: hpfcdc!hpfcdj![e-mail]  (Bob Myers)
Subject: Re: citizens in space -- risk silliness

>>...simply too blinkin' expensive to be able to justify a joy ride for an
>>"ordinary citizen", even if we had a system which was 100% safe (which we
>>most certainly do NOT have at present)...

>Leaving aside the debate about whether this use of a shuttle seat is worth
>the money, I've always been puzzled by the "but it's not safe" bullpucky
>offered as an argument against private citizens in space.  Of course it's
>not safe; so what?  Don't you think Christa McAuliffe understood that?


I should reiterate that the "safety argument" is NOT my basic objection to the
"ordinary citizen in space".  My objection is solely due to a belief that such
flights cannot be justified either in monetary cost or in the terms of putting
the "ordinary citizen" in space instead of a more qualified specialist (and
THAT really boils down to monetary cost, anyway!).

However, many of those who are lined up for the chance to get in to space
have all the appearances of kids itching for that first spin in the car
without Dad in the right seat.  They're the "joy riders", who have no
reason or justification at all for *why* they should go to space, they just
wanna "do it."  In their cases, we should wait until United Airlines is
offering children's discounts on orbital trips.  This is NOT a blanket
condemnation of those who want to travel to space; as mentioned in my original
posting, I would definitely love the opportunity, but cannot presently
give any justification for my travelling to orbit.  I admit that I'd be a
"joy rider" myself - but I also voluntarily take myself out of the line for
that very reason.


Bob Myers            | "What is wanted is not the will to believe, but the
{the known universe} |  will to find out, which is the exact opposite."
!hplabs!hpfcla!myers |          - Bertrand Russell, _Sceptical_Essays_, 1928.

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

Date: 6 May 89 16:16:31 GMT
From: shlump.dec.com!jfcl.dec.com!imokay.dec.com![e-mail]  (Doug Borsom)
Subject: Re: Magellan update

Can anyone tell me what advantages were gained by launching Magellan
from the space shuttle?  Is there any (nonpolitical) reason why
Magellan couldn't have been launched by an expendable (assuming
we had some) vehicle?

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

Date: 10 May 89 09:39-GMT
From: [e-mail]
Subject: BITNET mail follows

Subject: Re: More 747 Drop Tests?

In Vol 9., Issue 422 (10th May), Doug Davey (grits|[e-mail]) writes:
 writes:
>In article <[e-mail]> [e-mail] (Henry Spencer)
> writes:
>> ...Radical, innovative thought: if they want landing and braking tests, why
>> not dust off Enterprise and run some more 747 drop tests?...
>...
>... commmentary on 747 as critical point in testing...
>...
>Since there is at least a possibility of doing crosswind landings
>and/or hard surface braking tests each time the orbiters land, without
>risking the 747, it would be imprudent to revive the drop tests until
>a second ferry vehicle is available.

A related question - how consistent has NASA been in upgrading the steering
and braking systems of Enterprise?  I was under the impression that this
was a continuous process, starting with major modifications to Columbia
in the 1983 - 84 time frame (remember when she just kind of "dissapeared"
for a while?).

Would it be feasible for NASA to upgrade Enterprise with the new braking
steering upgrades?  It would seem to me that they would have to make a
judgement call between the added cost and the extra margin of safety
that additional drop testing would allow.

              --Bruce A. Tankleff  <67372111@NMSUVM1>
                New Mexico State University
                Las Cruces, NM, USA

Disclaimer:  My mom thinks I ran down to the 7-11 3 years ago to get
             a gallon of milk.  Please don't tell her otherwise...

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

Date: Wed, 10 May 89 12:17:52 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: memes


It seems to me that the concept of the "meme" is similar to the concept
of the Petri net: an unconventional approach used in an attempt to model
complex systems. The question is whether this approach is useful in obtaining
a simpler or more accurate model than is available from conventional methods.

The meme model seems to be an attempted mapping of the behavior and propagation
of ideas to the behavior and propagation of living organisms. I suspect that
some of the more outlandish operations of ideas, such as the fusion of
numerous well-developed ideas to form a new product, are such that finding an
exact biological analogy would be stretching things quite a bit. One can
suppose, therefore, that a reasonable model for memes would have to be based
mostly on its own set of internal rules rather than an exact biological analogy.

Even when this is done, the model of a meme must be very complex in order to
produce a good model of human thought and behavior. There are many different
kinds and even classes of ideas that can be spread from person to person,
among which are:

- factual statements of existing conditions
- factual statements of past events
- speculations
- well-founded rumors
- poorly-founded rumors
- principles/ideals
- methods/techniques
- personal impressions
- prejudices/opinions
- lies/fiction

These different types of ideas behave in different ways, and have different
kinds of influence on the host humans and on other ideas. In addition, the
model must be "stretched" to include the various methods of propagation.
I suppose a book would be a collection of "dormant" memes. (How about
encrypted text for which the key is missing?) Does a piece of information
being processed by a computer count as a meme? Also remember that a meme
will "mutate" just about every time it propagates through a human. If
intelligent aliens exist (to return to the original topic), there must be
some reasonable model for their reaction to memes.

My question is not whether the concept of memes can be used to form a
model of the spread and application of ideas, but whether such a model
would be of any actual use, for predicting future events or for some
other application, which it can handle better than conventional methods.
                                      John Roberts
                                      [e-mail]

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

Date: 10 May 89 12:43:51 GMT
From: thorin!lhotse![e-mail]  (James Symon)
Subject: spaceplane propulsion

Ramjet vs rocket? Ramjet sounds great but from what's been said on the
net, high mach numbers bring on very tricky engine issues. Couldn't a
hybrid be built in which oxidizer injection is gradually increased as
altitude and speed begin to cause combustion problems? Eventually the
intake ports are closed and the motors are straight liquid fuel rocket
motors. (Don't the Russkies use kerosene in liquid rocket motors?) The
oxidizer doesn't begin to be consumed until most of the atmosphere is
behind you. Also you've made good use of atmospheric oxygen on the way
up (from air launch to start the ramjets and get above of the real
muck.) You avoid the really exotic realms by moving to well known
rocket technology as you begin to leave the well understood envelope
in ramjet technology.

Can you get really cheap air launch by dropping from a B52 or 747 and
diving this slippery little devil to reach ramjet ignition speeds?

jim
[e-mail]
{decvax uunet}!mcnc!unc!symon

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

Date: 10 May 89 15:51:43 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: more 747 drop tests?

In article <[e-mail]> [e-mail] (Mike Ekberg, Sun {GPD-LEGO}) writes:
>Er...Pardon the dumb question, but what is the use of the
>crosswind tests?

Establishing how well the shuttle lands in crosswinds.  This is of some
importance for using the runway at KSC, since it frequently has crosswinds.
--
Mars in 1980s:  USSR, 2 tries, |     Henry Spencer at U of Toronto Zoology
2 failures; USA, 0 tries.      | uunet!attcan!utzoo!henry [e-mail]

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

Date:         Wed, 10 May 89 08:21:02 EST
From: Morven Wilson <[e-mail]>
Subject:      Wyoming Bolide

     Several people have asked for details of a bolide (bright meteor)
seen over the Teton range in western Wyoming a few years ago.
     You can find a picture of it (streaking across the sky) in the
National Geographic's book "Our Universe" (published in 1980, and again
in 1986; author Roy Gallant).  The picture is on page 148 in the 1986
edition, and about the same page in the original edition.
     The bolide is estimated at 1000 tons, 10m in diameter, 60Km altitude,
and travelling at 15Km per second.  It was seen and photographed by
several people, and a an amateur movie clip was shown on TV some years ago.
     The picture shows little more than a bright head and a long trail, but
it's enough to make you pause and think what might have happened if the
orbit/trajectory had been even slightly different.
     (PS: the book is intended for kids ... but it's still worth browsing!).

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

Date: 10 May 89 19:53:03 GMT
From: vsi1!v7fs1![e-mail]  (Mike Van Pelt)
Subject: Re: Wyoming Bolide

In article <[e-mail]> [e-mail] (Morven Wilson) writes:
>The bolide is estimated at 1000 tons, ...
>and travelling at 15Km per second.

Quick calculation, kinetic energy = 1/2 mv^2, I get about
10^14 J.  About 23 kilotons if it had hit, about the
energy released by the Hiroshima bomb.
--
"I hate trolls.  Maybe I could metamorph it into    | Mike Van Pelt
 something else -- like a ravenous, two-headed,     | Video 7
 fire-breathing dragon."  -- Willow.                | ...ames!vsi1!v7fs1!mvp

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

Date: 10 May 89 14:39:29 GMT
From: cs.utexas.edu!ut-emx![e-mail]  (Ed Nather)
Subject: Re: Does anyone know *why* the USAF did this?

In article <[e-mail]>, [e-mail] (Stuart Warmink) writes:
> [e-mail] (CUP/ML, MLO5-2/G1 8A, 223-3283) writes:
> >  (1963)   The U.S. Air Force launches 400 million tiny copper needles
> >           into Earth orbit, despite protests they might play havoc with
> >           radio and optical astronomical observations.
>
> Passive radio reflector, along similar lines to the "Echo" mylar "balloon"
> satellites.
> --

The "Echo" mylar balloon was used for a short time as a passive reflector and
it worked (sort of) but got punctured by dust grains (meteorites) and turned
from a sphere into a potato chip.  The microwave receiver built to detect
signals bounced off of it became "surplus" and was later used by Penzias and
Wilson to detect the 3 degree microwave background radiation -- residue of the
cosmic fireball from the Big Bang.

--
Ed Nather
Astronomy Dept, U of Texas @ Austin

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

Date: 10 May 89 21:31:36 GMT
From: rochester![e-mail]  (Brian Yamauchi)
Subject: Re: spaceplane propulsion

In article <[e-mail]> [e-mail] (James Symon) writes:
>Can you get really cheap air launch by dropping from a B52 or 747 and
>diving this slippery little devil to reach ramjet ignition speeds?

Why not just use conventional jets to get up to altitude, then power
dive straight down to ignite the ramjets?

(It would make for an exciting ride, at least :-)

_______________________________________________________________________________

Brian Yamauchi                University of Rochester
[e-mail]        Computer Science Department
_______________________________________________________________________________

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

Date: 10 May 89 18:55:58 GMT
From: uflorida!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Private spending for space science (summary)

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>Actually, such a project has already been funded, and points up the
>problems with private efforts.  The Spacewatch telescope in Arizona
>was (is?) getting funds from the Planetary Society...

Credit Where Credit Is Due Dept.:  it is all too seldom acknowledged
(especially by the Planetary Society!) that private funding of this effort
was started by the World Space Foundation, with the Planetary Society
joining later.
--
Mars in 1980s:  USSR, 2 tries, |     Henry Spencer at U of Toronto Zoology
2 failures; USA, 0 tries.      | uunet!attcan!utzoo!henry [e-mail]

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

Date: 9 May 89 20:39:56 GMT
From: hpfcdc!hpldola!hpctdlb!hpctdke![e-mail]  (Richard Katz)
Subject: Re: citizens in space -- risk silliness

-Two, I think she understood the risks fully.  During her training, she was
-taught about the various aborts that were possible; abort on pad (get the
-hell out of the shuttle...), RTLS, AOA, ATO...you get the picture.  Somehow,
-I think she got the picture that things *could* go wrong.  I feel sure she
-knew the risks and was willing to accept them.


-On the contrary, I think shuttle crew probably know better than anyone, what
-risks they are taking. ...


-Is that really important?  I wonder if good old Chris Colombus got any
-estimates of his chances of success before he charged off?  At some
-point in life, people have to take responsibility for their actions.  She
-CERTAINLY had enough information available to her to make a decision. Can
-you imagine a test pilot's family suing the government because he wasn't
-shown a metallurgical report about a rivet contained in his airplane  that
-caused a catastrophic failure?  ...
-   ...           They may not know ALL of the risks, no one EVER does, but
-they do know that what they are doing is dangerous, and THEY have made the
-decision (not their lawyers).
        If it was known that there was a problem with the rivet, and
        that fact was concealed from the pilot/commander of the
        aircraft for political gain, I see nothing wrong with seeking
        compensation.  This is not a risk taken by a pilot testing an
        aircraft.  It would be a risk taken by the "manager."  The
        gain would be "meeting schedule," and the cost would be the
        pilot's life.  The parallel to the challenger is clear.
        Manager's made the decision about the risk, not the
        astronauts.




        I think that the above opinions are confusing two issues, so
        I'll add my two cents.  The manned space program, and the
        shuttle program in particular, has rules governing the design,
        test, operation, certification, etc. for the entire program.
        Indeed, this is one factor that makes manned space flight very
        expensive.

        Even with the best of engineering and diligence on the part of
        all personnel, there is the risk of an _accident_ as a result
        of the unforseen or mistake.  It happens.  If this was indeed
        the case, then I agree, there would be no basis for lawsuits,
        etc.  Test pilots take these risks as well as astronauts.  It
        is part of the job.

        However, the Challenger disaster was not an accident.  There
        were many things wrong.  First, the SRB's were not qualified
        to the shuttle system's design temperature.  Maybe someone out
        there could state how this "fell through the cracks."  Flight
        hardware should be designed and tested to assure that it meets
        the operational requirements with margin.  Arguing about it
        the night before a launch is ludicrous.  I doubt that the
        shuttle astronauts and passengers were aware that the SRBs
        were not qualified.

        Second, there was a known (to some) problem with the SRBs.
        The astronauts were unaware of this, too.  Also, flying with
        this problem required a waiver.  Signing the waiver allowed
        the launch to be attempted.  So again, the assumptions about
        the risks were not valid.  The shuttle didn't meet the
        "advertised requirements."

        If the crew was aware of all the signed waivers, then ok, it
        was a concious decision to take the risks.  If not, then their
        families actions are justified, the courts can decide the
        issue according to law, and hopefully this will cause people
        to think about "breaking the rules" for political gain.

        rich katz
        hewlett packard
        p o box 7050
        colorado springs, co
        80933-7050

        email: [e-mail]

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

End of SPACE Digest V9 #431
*******************