Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_4/V15NO488.TXT

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Date: Thu,  3 Dec 92 05:00:28
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #488
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  3 Dec 92       Volume 15 : Issue 488

Today's Topics:
       Detonavion vs Deflagration (was Re: Shuttle replacement)
                             Foreign Soil
   NASA has 5 hand grenades still on the moon from Apollo missions
                     Shuttle replacement (5 msgs)
                      Space probe to pass Earth
                      spherical space structure
                 STS-48 and "SDI": Oberg vs. Hoagland

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Date: Tue,  1 Dec 92 12:39:25 +0100
From: "John D. Boggs" <erato!jdb>
Subject: Detonavion vs Deflagration (was Re: Shuttle replacement)
Newsgroups: sci.space

From article <[e-mail]>, by [e-mail] ():
> At least in the language of supernovae research, a detonation involves
> a flame front that propogates supersonically, whereas a deflagration has
> a subsonically propogating flame front.  In the case of supernovae you
> get a VERY big ball of fire in the sky.


Hmm.  And just how fast *does* sound move in space?

-John D. Boggs     uunet!erato!jdb

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

Date: 2 Dec 92 13:43:45 GMT
From: FRANK NEY <tnc!m0102>
Subject: Foreign Soil
Newsgroups: talk.politics.guns,sci.space

This is also one of the reasons why private space
exploration/exploitation will never get off the ground, at least those
attempts made by US citizens.

The Commercial Space Launch Act requires $3 billion in Liability
Insurance for a launch.  I called the NY office of Lloyd's once to
inquire on the rates for such a policy and was informed that they
would not write one.

Launching outside the US would not work, since the Foreign Practices
Act enforces the Commercial Space Launch Act wherever a US citizen
goes....even into outer space.

Your only alternative is to renounce US citizenship.

Frank Ney N4ZHG EMT-A  NRA ILA GOA CCRTKBA "M-O-U-S-E"
Commandant and Acting President, Northern Virginia Free Militia
Send e-mail for an application and more information
----------------------------------------------------------------
"Whether the authorities be invaders or merely local tyrants, the
effect of such [gun] laws is to place the individual at the mercy of
the state, unable to resist."
       - Robert Heinlein, in a 1949 letter concerning "Red Planet"
--
The Next Challenge - Public Access Unix in Northern Va. - Washington D.C.
703-803-0391 To log in for trial and account info.

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

Date: 2 Dec 92 13:13:47 GMT
From: "H.S. Doyle" <[e-mail]>
Subject: NASA has 5 hand grenades still on the moon from Apollo missions
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] ("Phil G. Fraering") writes:
>
>In article <[e-mail]>,
>[e-mail] (Bradford B. Behr) writes:
>> In article <[e-mail]>
>[e-mail] (Dave Jones) wrote:
>>>Wasn't there an Urban Legend to the effect that Armstrong & Co. were
>>>issued .45 automatics just in case?
>>
>> Just in case of bug-eyed moon monsters or giant mutant space goats or
>> secret Nazi bases? Not likely. It is quite possible that they had
>> sidearms in the command module in case they splashed/crashed down in
>> the wilderness somewhere and had to hunt for food or defend themselves
>> from ravenous but terran beasts.
>
>Ordinary firearms wouldn't work in a vacuum anyhow.
>The gunpowder couldn't burn. The same might be true at high
>altitudes on the Earth's surface, as I've heard that in a
>particular South American city (I think it was La Paz, Bolivia),
>there's not enough oxygen in the air for them to really require
>a fire department.

Gun propellant powder doesn't need oxygen to burn, it will explode quite happily
in a vacuum. The chemical reaction isn't an oxygen-carbon one. I thought this
would have been obvious due to the fact that the powder in a cartridge goes off
when the bullet is still in the cartridge case and thus blocking it from the air!

Harry.


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

Date: 2 Dec 92 01:58:05 GMT
From: Rich Kolker <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>>By the way Henry, I found out some interesting stuff there are three versions
>>of  the Saturn V first Stage. These are as follows
>>
>>S1C-T                   Test Stage for Manufacturing and Ground firings
>>                        This is the one at the Alabama Space & Rocket Center
>>
>>S1C-D                   Dynamic Test model. Was later scrapped at the end of
>>                        the program.
>>
>>S1C-1,2,3....           Flight Saturn S1 C stages.
>>
>
>I don't know the true designations, but I think that the S1C-D that you said
>was scrapped is presently on display near the VAB at Kennedy Space Center.
>It was part of the AS-500F vehicle used to test the Kennedy facilities in
>1966. At least, I'm pretty sure that AS-500F is on display at the Cape.
>
>-Brian

I checked this out a while back.  The Apollo 19 Saturn is at KSC, the Apollo
20 Saturn is at JSC (I could check out the actual SV designations in Starges
to Saturn, but you get the idea).  The Saturn V at MSFC is the Engineering
test model, not a flight article.
-------------------------------------------------------------------
   rich kolker       [e-mail]
                          It's been a long, long time
--------------------------------------------------------------------

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

Date: 2 Dec 92 02:14:19 GMT
From: Rich Kolker <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>>>A bit less zenophobia please! what the hell do you think an airliner is?
>>>
>>>Something with *wings* on it.
>>
>>Just think of DC-1 as a high-performance helicopter.
>
>Even they have rotary wings. The reason I keep harping on this is that
>landing *on* a ball of fire is too damn near landing *in* a ball of fire
>for my tastes. I've been in a helicopter with in flight power failure;
>I've been PIC of a fixed wing aircraft with in flight power failure; and
>I walked away from both. I don't see any margin for error in setting down
>on rocket exhaust. Either everything works perfectly and you survive, or
>something fails and you topple over and burn, or if you're higher you
>smack in hard and burn.
>

So long as your engines fire through the CG, the engine redundancy of
DC-1 as currently planned (and understand the whole idea of X and Y is
to change that paper design based on flight testing...like they do with
aircraft) will not easily allow "topple over and burn" any more than a
properly trained pilot will "spin out and burn" in a twin with an engine
out.

-------------------------------------------------------------------
   rich kolker       [e-mail]
                          It's been a long, long time
--------------------------------------------------------------------

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

Date: 2 Dec 92 02:47:26 GMT
From: Rich Kolker <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>>Please dont confuse the re-entry phase from the  landing hover phase.
>>certainly a phine guidance error at re-entry results in  hundreds of
>>miles in terminal descent.  but shuttle has that same problem and you
>>dont seem to scream about that.  the key point that DC-1 will have
>>over STS is that when they punch out of the blackout zone they can
>>get a guidance update from GPS,LORAN, Ground radar or visual and if they
>>are significantly off course  they cna look for a convenient emergency
>>descent location and make a powered landing.
>
>    The Space Shuttle no longer has a 'blackout zone'. The TDRS satellites
>    eliminated it. I don't know about the DC, but it probably will avoid
>    a blackout zone, too, if Mc-D leases TDRS space from NASA or something.
>

The space shuttle does too have a blackout zone.  The Zone of Exclusion is
over the Indian Ocean, and the exact size depends on shuttle altitude.
In addition, the shuttle can be out of radio touch due to attitude
requirements that block the Ku Band antenna.  There is a blackout due to
atmospheric ionization during reentry.  Finally, during the entry after
that point, there have been certain high inclination flights that,
due to the approach path, have been out of comm range during much
of the run across the US into KSC.

-------------------------------------------------------------------
   rich kolker       [e-mail]
                          It's been a long, long time
--------------------------------------------------------------------

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

Date: Wed, 2 Dec 1992 13:58:21 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Shuttle replacement
Newsgroups: sci.space

In article <qg#[e-mail]> [e-mail] (Greg Moore) writes:

>>Amounts to the same thing. Most of the Shuttle flights which have ever been
>>scheduled have been cancled. That's not reliable service.

>    This comment bears a little explaining I think.  What exactly has
>beed cancled that has actually been scheduled...

Check out the table in the Nov. 12, 1990 issue of Avation Week on Page 27.

In ten years of operation this is the first year where Shuttle has gotten
even close to projected flight rates.

>However, if something DOES go wrong, or for some reason you want a
>person on sight, then the shuttle wins.

Maybe even not then. It depends on the cost of failure.

>For something like Hubble, or
>some other unique satellites, I'd prefer the Shuttle.

One reason Hubble is unique is that Shuttle eats almost a third of
NASA's budget. I hope you consider this when measuring Shuttle utility.

If YOU where paying for Hubble, which would you pick?

>    Allen, they haven't made a profit in 6 years (since Challanger).

Largely because they are forced to compete with government subsidized
competition.

The point still remains that the commercial providers are REDUCING the
cost of access to space; Shuttle increases it. Commercial launchers spend
investors money, Shuttle spends MY money. Given a choice between a cheaper
option which costs me nothing and a more expensive one I need to pay for
I would pick the former. How about you?

>>But what would have happened if we developed a commercial based infrastructure
>>back in 1980? Much furthur I'll bet.

>Let's argue today, not the past.

One thing we need to do to make progress is understand the mistakes of
the past and then have the courage to correct them.

  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------143 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Wed, 2 Dec 1992 11:55:26 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Shuttle replacement
Newsgroups: sci.space

Nonflamable materials only in this post. :-)

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:
>
>>Now here's a question: How is the DC to be refuelled and reloaded
>>between missions? That is, it won't necessarily land on a pad and it
>>has no wheels (?) so how will the ground crew handle it?
>
>I believe current plans are to put weels on it after it lands and tow it
>to a hanger or the launcher. Empty weight is only 80K pounds so this isn't
>hard.

What's the height/width of the projected DC? What I'm asking is how
stable is this thing on just wheels? Would a bracing structure be
helpful or required when moving it over ordinary rough concrete surfaces?

>>Does it need a gantry to load heavy payloads or will a
>>mobile crane be used?
>
>A mobile crane will be fine. Payload are put into a standard pallet and the
>pallet has standard interfaces with the vehicle. This means that the complex
>integration tasks can be done offline and payload/vehicle integration will
>take a few hours at most. Max payload weight is 20K pounds so a mobile crane
>is no problem.

Are the payload/pallet integration costs included in DC flight costs,
or are they offloaded onto the customer? Standards help, of course,
but payload integration costs are a significant part of spaceflight
costs. Also, I'd expect a mobile gantry platform would be better than
having a ten ton pallet swaying on the end of a crane cable. Costs
for a ten ton mobile gantry platform shouldn't be that high, just
a glorified forklift.

Gary

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

Date: Wed, 2 Dec 1992 01:04:18 GMT
From: "Carlos G. Niederstrasser" <phoenix.Princeton.EDU![e-mail]>
Subject: Space probe to pass Earth
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (UPI) writes:
>
>     PASADENA, Calif. (UPI) -- NASA's Galileo space probe will zip past
> Earth and the moon next week to use the planet's gravity to fling it
> toward an exploration of Jupiter beginning in three years, officials
> said Tuesday.
>     ``We are now just one week from the Earth-II flyby, the gravity
> assist, that will send Galileo to Jupiter,'' said project manager
> William O'Neil during a briefing at NASA's Jet Propulsion Laboratory.
>     Galileo will pass within about 68,000 miles of Earth's moon at 10:58
> p.m. EST Dec. 7 and pass within 190 miles of Earth at 10:09 a.m. EST the
> next day, he said. The pass will increase the probe's speed by 8,280
> mph, whipping it out toward the asteroid belt between Mars and Jupiter
> at about 87,190 mph.
>     Scientists plan to use the pass by the atomic-powered, $1.4 billion
> spacecraft to calibrate the probe's instruments by using the various
> sensors and cameras to study and photograph the Earth and moon.

190 miles ?!?!  Isn't that even closer than the normal shuttle orbit?  Are they
missing a few zeroes?  I mean, at 190 miles I would expect air resistance
(considering the high speed) to be quite detrimental.

And on a 'whine' note, once again the press trying to scare ignorant fools by
stating that the spacecraft is atomic-powered.  Was that reference really
necessary in the context of the article?  I think not!
--
---------------------------------------------------------------------
| Carlos G. Niederstrasser        |   It is difficult to say what   |
| Princeton Planetary Society     | is impossible; for the dream of |
|                                 | yesterday, is the hope of today |
|                                 |   and the reality of tomorrow   |
| [e-mail]   |---------------------------------|
| [e-mail]     |    Ad Astra per Ardua Nostra    |
---------------------------------------------------------------------

--
---------------------------------------------------------------------
| Carlos G. Niederstrasser        |   It is difficult to say what   |
| Princeton Planetary Society     | is impossible; for the dream of |
|                                 | yesterday, is the hope of today |

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

Date: 2 Dec 92 04:12:38 EST
From: andrew busigin <[e-mail]>
Subject: spherical space structure
Newsgroups: sci.space

DW> But spherical shapes for space stations aren't as efficient as you
might
DW> hope. The thickness of the material that would be required for
DW> the wall of a sphere containing a 20 kPa (or whatever) pressure
DW> increases with the diameter of the sphere. If I remember aright,
DW> directly proportional to the diameter, so a sphere 100 metres in
DW> diameter, say, would need walls twice as thick as a 50m sphere.
DW> Thus the mass of material needed for the walls would be directly
DW> proportional to the volume of the sphere, rather than increasing
DW> more slowly as you might expect and hope.
DW>
DW> Oh well...

Perhaps you should re-examine your assumptions on efficiency, David.

There is no geometric shape with

          1  -  a more efficient ratio of volume to surface area, or
skin
          mass, in the case of a hollow spheriod.

          2  -  a greater strength to mass ratio, for a container under

                 pressure.

          3  -  a simpler method of erection than inflation.
                 (Please Mr. Lurker, restrain yourself! )

The fact is that space station freedom is based on technology anchored
in lego blocks and mechano sets. Nature tends to use sacs to contain
pressure. Hmmm...

Examination of the technologies deemed critical for Freedom, revealed
that they felt that structural members needed to be extruded on site.
This manufacturing technique, together with the spelunkers' dream castle
architechture, creates a formidable amount of construction effort in open
space.

Spheres, on the other hand, might be manufactured on earth, a number at
a time, as large as football fields, and shuttled up. Reinforcing and
insulative materials would ride up compressed, ie - honeycomb, resins,
foils, and applied to a surface from inside, and perhaps outside.

As for pressure, the spheroid would initially probably be fabric based,
perhaps related to tevelec. The thickness of the skin could be built up
in the same fashion that a Harrier Jet's Wing is constructed, from
advanced composites.

As for the pressures involved, the spheroid could be initially inflated
to 1psi, rigidized, the skin built up, and gradually pressurized to
10psi as another post'r suggested is required for the N2 O2 mix now thought
proper by NASA.

One final, very important note. Your reaction, "Oh Well...", is a
problem. Ceative thought must be encouraged especially in the science and
space conferences. Good science demands that problems be exposed to the
light of reality. But good scientists, and engineers can usually find their
way around problems. We have to get the youngsters out there thinking!
Between all the people in these conferences, we ARE capable of BUILDING
on new ideas, not just critiqueing them.

BTW, I do appreciate your post.

Best Regards,


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

Date: 2 Dec 92 06:12:12 GMT
From: Robert Sheaffer <[e-mail]>
Subject: STS-48 and "SDI": Oberg vs. Hoagland
Newsgroups: sci.skeptic,sci.astro,sci.space,alt.alien.visitors

I am posting the following file that I received from James Oberg, a
well-known writer on the space program. He is discussing the same
videotaped footage from NASA's STS-48 mission that has been endlessly
showen as a supposed "UFO." Richard Hoagland, a major promoter of the
"Face On Mars," claims that NASA cameras accidentally caught a secret
"star wars test". Here is Oberg's rebuttal.


        James Oberg, Rt 2 Box 350, Dickinson, TX 77539
        Re: Did STS-48 view a "Star Wars" test?


        The  STS-48 mission was the 43rd shuttle launch, the 13th  flight
        of OV-103 Discovery, with the Upper Atmosphere Research Satellite
        (UARS).  The crew was John Creighton, Ken Reightler, Jim  Buchli,
        Mark  Brown,  and Sam Gemar. It was launched from KSC  Pad  A  at
        2311GMT Sep 12, 1991 (twilight),landed at EAFB on Sep 18, 0738GMT
        (night), duration 5d08h27m. The orbit was inclined 57 degrees  to
        the  equator at an altitude of about 570 km, second only  to  the
        616  km altitude of the Hubble deploy mission a year and  a  half
        earlier.  Due  to  radar  experiments  with  the  deployed   UARS
        satellite,  I  was present in the control room for  two  planning
        shifts  (my  job  was as "Guidance and  Procedures  Officer"  for
        actions  related  to  orbital rendezvous,  such  as  the  planned
        checkout  of the radar which had shown performance  anomalies  on
        several earlier missions).

        I  have reviewed the videotape by Richard Hoagland alleging  that
        the  notorious STS-48 videotape shows a "Star Wars" weapons  test
        against  a  target  drone  with  astounding  propulsion.  In   my
        judgment,  the facts, analysis, and conclusions presented by  Mr.
        Hoagland are entirely wrong.

        Is  the object really very far away? Hoagland's argument  depends
        on proving that the object is at or beyond the physical  horizon,
        "1713  miles away". Proving this depends on optical  analysis  of
        the  image  and  of its motion. All  of  Hoagland's  analysis  is
        invalid.

        First,  Hoagland  alleges  that the videotape  shows  the  object
        suddenly appearing at the edge of the Earth, as if it had  popped
        up  from behind the horizon. But a more cautious viewing  of  the
        tape shows this is not accurate.

        The  object does NOT rise from "behind the horizon".  It  appears
        (arguably,  it  becomes  sunlit) at a point  below  the  physical
        horizon,  just slightly below, to be sure, but  measurably  below
        the edge of the Earth (the "limb").

        It  has  been  suggested  (Dipietro)  that  the  object's  sudden
        appearance  is  due to sunrise. This is plausible.  I  suggest  a
        variation  on this, that the object became visible when it  moved
        up  out  of the shuttle's shadow just after  sunrise.  Since  the
        video  was taken near sunrise, the shuttle's shadow was  pointing
        back nearly parallel to Earth's horizon, and the ground was still
        dark  (bright  ground reflection later lights up debris  even  if
        they are in the shuttle's sun shadow). This would require that it
        be close to the shuttle. The proximity to the horizon line  would
        be coincidental.

        Note  that the bright light in upper left is some sort of  camera
        anomaly  and  is not an electronic horizon marker as  alleged  by
        Hoagland. There is no such thing as an electronic horizon marker.
        Is  the  object  behind  the  atmosphere?  Hoagland  argues  that
        analysis of the imagery shows the object is physically behind the
        atmosphere.   But  I  disagree.  It  is  NOT  seen  through   the
        atmosphere:

        First,  consider  the brightening effect.  Computer  analysis  is
        shown  which  alleges that the brightening of  the  object  while
        below the airglow layer is analogous to the brightening of  stars
        setting behind the airglow layer. This allegedly implies that the
        object, like the stars, is behind the airglow layer.

        This argumentation is false because it posits the wrong causation
        mechanism   for  brightening  ("passage  of  the  light   through
        atmosphere").  This  should  be  obvious  since  at  the  airglow
        altitude  (40-60 miles) the atmosphere is already extremely  thin
        and the lapse rate (the drop in pressure per rise in altitude) is
        already much reduced over the value at lower altitudes (that  is,
        crossing the "airglow boundary" does NOT significantly change the
        atmospheric density the light ray is passing through). If density
        WERE  the  true cause of brightening, the effect  would  markedly
        peak  at a lower altitude (as soon as the beam rose  above  total
        obscuration),  then drop rapidly as atmospheric density  dropped,
        and  show NO NOTICEABLE CHANGE in dimunition rate as  it  crossed
        the  airglow layer because the density of traversed air  wouldn't
        change much either at that region.

        The  actual  connection  for  the  object's  brightening  is  the
        absolute  brightness of the airglow layer in the background.  The
        object  is brighter when it is against a bright background,  just
        as  stars  are  brighter. This is not an effect of  a  light  ray
        transiting  the  airglow region and somehow  being  strengthened.
        Instead,  I believe it is an effect on the camera optics  of  the
        summing,  pixel by pixel, of all brightness within the  field  of
        view.  A bright object with a dark background will not  throw  as
        many  photons on the individual pixels of the camera as  would  a
        bright object with a half-bright background. The camera's vidicon
        system will respond to light in the background by brightening the
        small point-source objects observed in that region, either  lying
        behind or crossing in front of that background. Repeat:  crossing
        in front of that airglow.

        This is confirmed by other checks. Observers can note that  other
        drifting  point-source objects, clearly starting well  below  the
        horizon line, also brighten as they traverse the airglow region.
        NOTE:  Hoagland's  argument that the dimming beyond  the  airglow
        disproves NASA's contention that the object is nearby and sunlit,
        since  as it gradually rose "higher into the sunlight" it  should
        brighten,  not dim, is false. Once in full sunlight,  no  further
        brightening  occurs. Sunrise only lasts as long as it  takes  for
        the  sun  (0.5 degrees wide) to rise above the  horizon,  at  the
        orbital  angular  rate  of 4 degrees per  minute  (that  is,  360
        degrees  in a 90-minute orbit), which comes to just 7-8  seconds,
        which anybody should have been able to figure out. Of course this
        is  different  from  ground rates, which depends  for  the  sun's
        angular motion on earth's rotation rate (4 minutes per degree, 16
        times slower than spaceship orbital rate). This argument  reveals
        Hoagland's unfamiliarity with basic orbital flight conditions and
        implications.

        Notice  that no mention is made by Hoagland of the clear  absence
        of expected refractive effects of being behind the atmosphere. As
        is  known  by  anybody who's watched  sunset/moonset  at  a  flat
        horizon,  the  atmosphere creates significant distortion  in  the
        bottom .2-.4 degrees of the image. The lowest layers  demonstrate
        a  vertical compression of 2:1 or greater. This is also shown  on
        pictures  of  "moonset"  from orbit. If the  STS-48  object  were
        really  travelling nearly parallel to the horizon  but  somewhere
        behind  the  atmosphere, this would be visible by  analyzing  its
        flight path. As it rose its line of travel would markedly  change
        as  atmospheric  refractive effects disappeared.  This  does  not
        happen, which strongly suggests that the object is NOT behind the
        atmosphere.

        Since  the arguments for great range to the object all fail,  the
        conclusions based on angular motion converted to physical  motion
        also fail.

        What  is  the "flare" in the camera that precedes the  change  in
        motion of all the objects? I believe the flare in the lower  left
        camera   FOV  is  an  RCS  jet  firing,  not  per   Hoagland   an
        electromagnetic pulse effect. There are several reasons: it  does
        not  look like any known electromagnetic video  interference;  it
        looks  just  like previously seen RCS flares;  and  the  Hoagland
        counterargument  about an alleged need for pointing  changing  is
        not valid.

        First, while it is true that EMI can affect electrical equipment,
        such pulses would not lie in any localized region of a television
        screen but would blitz the whole image. Anybody whose TV has ever
        been blitzed by lightning knows that the effect does not  confine
        itself  to  the  corner nearest the  lightning.  Also,  far  more
        sensitive  electronic  equipment aboard  the  shuttle,  including
        computers  which  were counting the pulses of  individual  cosmic
        rays  striking  their circuits, were not affected  by  the  event
        (otherwise,  the entire television transmission would  have  been
        knocked   out).   So  Hoagland's  explanation  is   magical   and
        unrealistic.

        Second,  the optical appearance of RCS jet firings is well  known
        and  familiar to experienced observers, and they look  just  like
        the flash in question. These have been observed and videotaped on
        every shuttle mission, from the crew cabin, from payload bay  and
        RMS  cameras, and from cameras on nearby free-flying  satellites,
        and from ground optical tracking cameras as well.

        Third, Hoagland's argument that the line of travel of stars  down
        to the horizon should have been kinked by the jet firing is plain
        ignorant.  During  attitude  hold  coast  periods,  the   shuttle
        autopilot  maintains  a  "deadband" of  several  degrees,  slowly
        drifting  back  and  forth and, when  the  attitude  exceeds  the
        deadband  limit,  a  jet is pulsed to  nudge  (NOT  "shove")  the
        spaceship  back  toward the center of the deadband.  The  angular
        rates induced by these 80-msec pulses are as follows:

             ROLL               .07 deg/sec
             PITCH              .10 deg/sec
             YAW                .05 deg/sec

        Note  that the star motion would have changed direction  ONLY  IF
        the orbiter's pointing attitude was shifted to the right or left.
        If  shifted up or down, only a slight change in star motion  rate
        would occur (this appears to be the way the jet plume is actually
        directed)  but  so  would horizon motion, so  it  would  have  to
        measured  as absolute screen position. If shifted in or  out,  no
        change  at  all would be observable. This is all  based  on  pure
        geometric considerations overlooked by Hoagland.

        After ten seconds, even in the worst case (pitch motion  inducing
        pure  crossways angular motion), the star track would  only  have
        diverged  a single degree from the former straight line. This  is
        visually undetectable on the images shown by Hoagland.

        So the fact that he sees no change in the star motion tracks does
        not disprove that the pulse was an RCS jet.

        Video  Encryption:  Hoagland  alleges  that  since  STS-48,   all
        external  STS  video has been encrypted and will be  viewed  only
        after NASA review and approval. I have checked with a NASA Public
        Affairs  official, and have personally verified, that things  (as
        usual)  are not quite what Richard Hoagland alleges.  On  STS-42,
        the  second  flight  after STS-48 (the STS-44  DoD  mission  went
        between   them),   the  International   Microgravity   Laboratory
        (Spacelab)  science  group requested that medical  video  imagery
        from  the cardiological studies (sonogram images) be  treated  as
        privileged   medical   information,   as   all   previous   audio
        conversations with doctors had been. NASA discovered that  having
        to  continuously reconfigure the White Sands TDRSS site  and  the
        TDRSS satellites back and forth for encrypted video  transmission
        was  a laborous process. Rather than spend all that time, it  was
        decided  to go into encrypted mode continuously and  decrypt  the
        raw  video at NASA Goddard for immediate release over  the  "NASA
        Select"  circuit.  Normally, when there was  shuttle  video,  the
        White  Sands to Goddard raw video link had been unencrypted,  and
        the   Goddard  relay  to  "NASA  Select"  required   no   further
        processing;  but  when  medically-privileged  video  was  to   be
        transmitted  (a  new innovation on STS-42,  planned  for  years),
        complex encryption processes had to be initiated on the  shuttle,
        on  the  TDRS  satellites, at White Sands, and  at  Goddard.  The
        procedure  for constant encryption was implemented to  avoid  the
        cost of many switchovers between modes. But the NASA Select video
        from  Goddard  was  to continue to be decrypted  except  for  the
        medical  transmissions, which were to be openly announced on  the
        audio  feed,  just  not piped into a million  homes  and  schools
        nationwide.  Since  then, the NASA Select video  (originating  at
        NASA  Goddard,  and containing other sources of video,  too)  has
        continued to be transmitted as before, with the only change  that
        the  White Sands to Goddard link (which viewers could  previously
        observe  when it was active) is now encrypted. There is  no  hint
        from air-to-ground conversations that anything other than the new
        (and long scheduled) medical video imagery is being  interrupted.
        And  although  it is encrypted, the White Sands raw feed  can  be
        observed  to tell if there is a video signal or not on the  feed,
        so I am told.

        Conclusion:  The standing explanation, that the objects are  near
        the  shuttle, are sunlit, and are affected by the plume field  of
        an RCS jet firing, remains valid.

        P.S. Hoagland made a number of other factually erroneous comments
        about  live  planetary  image transmissions.  He  says  that  all
        previously  NASA  planetary  probes  transmitted  live   imagery.
        Actually,  only fly-by probes did that, particularly  the  fly-by
        probes which had slow transmission rates which took many  minutes
        to build up each image. Probes orbiting other planets (Venus  and
        Mars,   for  example),  do  not  (and  I  believe,  never   HAVE)
        transmitted  live imagery, since they are frequently occulted  by
        the planet's mass. Each orbit's imagery is stored and dumped over
        a short portion of each orbit, and the imagery data is  initially
        decoded over the next hours and days. Live coverage of the actual
        image transmission would usually be blank, but for a few  minutes
        every few hours would show images flipping across the screen at a
        very fast rate, if there was enough computer power to decode them
        in  this  "real  time" speed. There is no  practical  reason  why
        computers have to be built so powerful to keep up with the  high-
        speed  dump rate for a few minutes, then rest idle for  the  next
        several  hours.  Outside  of avoiding  whines  about  censorship,
        there's no reason to do so.
--

        Robert Sheaffer - Scepticus Maximus - [e-mail]

 Past Chairman, The Bay Area Skeptics - for whom I speak only when authorized!


     "Mystical explanations are considered deep. The truth is that
      they are not even superficial."

                   - Friedrich Nietzsche    (The Gay Science: 126)

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End of Space Digest Volume 15 : Issue 488
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