Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_4/v9_405.txt

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Subject: SPACE Digest V9 #405

SPACE Digest                                      Volume 9 : Issue 405

Today's Topics:
Re: McBride to leave NASA; Brand named commander of STS-35 (Forwarded)
        Re: Earth based - will it always win?
           NASA Prediction Bulletin Format
        Re: Earth based - will it always win?
    Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!)
    Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!)
               Re: wireless electricity
            Re: Asteroid Encounter
              Re: Re: Asteroid Encounter
----------------------------------------------------------------------

Date: 30 Apr 89 15:45:41 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Re: McBride to leave NASA; Brand named commander of STS-35 (Forwarded)

In article <[e-mail]> [e-mail] (Paul S. R. Chisholm) writes:
>In article <[e-mail]>, [e-mail] (Peter E. Yee) writes:
>>      Astronaut Jon A. McBride (Captain, USN) has announced his
>> intention to leave NASA effective May 12, 1989.
>>      McBride was named last year to command the STS-35 (ASTRO-1)
>> mission, scheduled for launch in March 1990.
>
>If an astronaut with a guaranteed seat isn't interested in sticking
>with the program, imagine how the rest of NASA (orbit-bound and
>otherwise) must feel!

I believe the three men who left NASA were doing so because of a new law
that takes effect next month governing NASA employees and their ability to
take jobs in industry.  By leaving now, they beat the deadline and will
not have problems getting new jobs.

Also, please remember, that the first 'A' in NASA stands for Aeronautics.
We do more than space flights.

                            -Peter Yee
                            [e-mail]
                            ames!yee
PS Standard disclaimers.

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

Date: 30 Apr 89 23:38:03 GMT
From: [e-mail]  (Rick Francis Golembiewski)
Subject: Re: Earth based - will it always win?

From: [e-mail] (Tom Neff)
>Should we concentrate on ground based work and de-emphasize space based
>observation until some smart cookie makes it a lot cheaper and easier
>to get up there? I hope I have framed the question usefully.

For some things, definately yes, for others no... Ideally we should
only use space for the experiments/manufacture etc. that is cheaper,
then Earth based, or that is impossible from earth (ie, how does one
simulate 0 G for a long period of time on earth?).  There are a few
important realities to keep in mind: If space is de-emphasized, the
chances are that very few 'smart cookies' are going to be working on
making it a lot cheaper and easier to get up there.  Also remember
 that putting money into research won't necessarily get you the desired
 results (NASA has shown this many times, remember how the shuttle was
 supposed to be INEXPENSIVE?), so if all the money that went into say
 HST or Magellian, may not have produced the necessary technology, the
 people who had the $$$ made the descision to us space, and you can be
 fairly certain that they made the descision for a reason. They knew
 they could build a space telescope, and that there is already a
 shuttle system to deploy it etc.  Did they consider an earth based
 telescope?  Probabily, however the problems associated with the
 atmosphere can not be eliminated easily, it may well take more $$$
 invested in R&D in order to get a system that is not nearly as good as
 HST.  In science there are alaways a few ways to do a particular experiment,
 and a few different experiments to learn the same thing, so you have
 to learn to pick the best that you can within your resources.
 Remember that money isn't the only resource, manpower and time are two
 other important ones, so if you only have a staff of say 10 people,
 then you can't expect to develope new areas of technology in a reasonable
 amount of time, however if you have the money you can have some engineers make
 a satellite for you, and have NASA launch it...  It is up to the
 scientists to pick the most efficient way to learn new information,
 however scientists are people too, so they might just make a mistake
 and end up spending more then they though...

//     Rick Golembiewski  [e-mail]  \\
\\       #include stddisclaimer.h               //
 \\  "I never respected a man who could spell" //
  \\               -M. Twain                  //

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

Date: 30 Apr 89 15:26:12 GMT
From: [e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletin Format


As a service to the satellite user community, the following description
of the NASA Prediction Bulletin's two-line orbital element set format is
uploaded to sci.space on a monthly basis.  The most current orbital elements
from the NASA Prediction Bulletins are carried on the Celestial RCP/M, (513)
427-0674, and are updated several times weekly.  Documentation and tracking
software are also available on this system.  The Celestial RCP/M may be
accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop
bit, no parity.

==============================================================================

Data for each satellite consists of three lines in the following format:

AAAAAAAAAAA
1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN

Line 1 is a eleven-character name.

Lines 2 and 3 are the standard Two-Line Orbital Element Set Format identical
to that used by NASA and NORAD.  The format description is:

Line 2
Column     Description
 01-01     Line Number of Element Data
 03-07     Satellite Number
 10-11     International Designator (Last two digits of launch year)
 12-14     International Designator (Launch number of the year)
 15-17     International Designator (Piece of launch)
 19-20     Epoch Year (Last two digits of year)
 21-32     Epoch (Julian Day and fractional portion of the day)
 34-43     First Time Derivative of the Mean Motion
        or Ballistic Coefficient (Depending on ephemeris type)
 45-52     Second Time Derivative of Mean Motion (decimal point assumed;
           blank if N/A)
 54-61     BSTAR drag term if GP4 general perturbation theory was used.
           Otherwise, radiation pressure coefficient.  (Decimal point assumed)
 63-63     Ephemeris type
 65-68     Element number
 69-69     Check Sum (Modulo 10)
           (Letters, blanks, periods = 0; minus sign = 1; plus sign = 2)

Line 3
Column     Description
 01-01     Line Number of Element Data
 03-07     Satellite Number
 09-16     Inclination [Degrees]
 18-25     Right Ascension of the Ascending Node [Degrees]
 27-33     Eccentricity (decimal point assumed)
 35-42     Argument of Perigee [Degrees]
 44-51     Mean Anomaly [Degrees]
 53-63     Mean Motion [Revs per day]
 64-68     Revolution number at epoch [Revs]
 69-69     Check Sum (Modulo 10)

All other columns are blank or fixed.

Example:

NOAA 6
1 11416U          86 50.28438588 0.00000140           67960-4 0  5293
2 11416  98.5105  69.3305 0012788  63.2828 296.9658 14.24899292346978

Note that the International Designator fields are usually blank, as issued in
the NASA Prediction Bulletins.

--
Dr TS Kelso                           Asst Professor of Space Operations
[e-mail]          Air Force Institute of Technology

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

Date: 30 Apr 89 19:39:37 GMT
From: uflorida!haven!uvaarpa!hudson!bessel.acc.Virginia.EDU![e-mail]  (Greg Lindahl)
Subject: Re: Earth based - will it always win?

In article <[e-mail]> [e-mail] (Tom Neff) writes:

> [discussion of radar at arecibo looking at venus]

> All of which brings me to a question I've often wondered about. Given
> enough time and ingenuity can't we nearly always do better here on
> Earth?

Depends. At some wavelengths you can see through the atmosphere, no matter
how much time and ingenuity you put into it. And to consider a few
silly and/or serious cases:

    you can't take a picture of the far side of the moon from the earth :-)
    you can't put two radio interferometer elements farther apart than
      one earth diameter on the earth (oh, QUASAT, when will you fly)
    you can't pick up soil samples on mars and return them to the earth
      without leaving your living room
    you can't measure cosmic rays out at Neptune without going there

Finally, one might note that Aricebo would be expensive to build today,
and the radio astronomy community probably could never get they money ---
the Air Force originally built it for ionospheric research.

> (The antenna can't even
> collapse a la Greenbank, Arecibo's a mesh bowl dug into the ground.)

See that big receiver thingie sitting 500 feet off the ground in
the middle? Wonder how much that weighs? It's only held up by a few
cables... fortunately it was probably built with a larger safety margin
than the 300'.

> Should we
> concentrate on ground based work and de-emphasize space based
> observation until some smart cookie makes it a lot cheaper and easier

Some things must be done from space. Some things are cheaper to do from
space than from the ground.

------
Greg Lindahl                |
gl8f@virginia.{edu,bitnet}  |   Veraj Programistoj ne uzas PASCAL-on

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

Date: 30 Apr 89 05:38:09 GMT
From: att!pegasus![e-mail]  (Paul S. R. Chisholm)
Subject: Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!)

In article <[e-mail]>, [e-mail] (Diana L. Syriac) writes:
> UFOs are definitely pertinent to Space....last I heard, most of
> them are from OUTER SPACE.

UFO's are, by definition, unidentified.  Some are natural phenomena,
seen in unexpected ways.  I've seen a couple of those myself, such as an
airliner at sunset, reflecting light to look like windows in a flying
saucer.  None are clearly, indisputably from outer space.

As for "close encounters of the third kind" . . . I remember reading a
serious book on UFO's, by someone who thought some of them really were
spacecraft from Out There.  His section on personal encounters ended by
saying that such stories "travelled at the speed of lie."  The rest of
us are even more skeptical.  Certainly, no one to my knowledge has
increased our understanding about space (or our ability to go there) by
studying UFO's.

Most of us aren't interested in hearing about flying saucers, and most
"flying sorcerers" aren't interested in what we talk about here.

> Diana L. Syriac, {decvax,linus,mit-eddie,masscomp}![e-mail]
That should be either [e-mail] or {decvax,linus,...}!genrad!dls
(mixing at's and bang's can be hazardous to your e-mail's health).

Paul S. R. Chisholm, AT&T Bell Laboratories
att!pegasus!psrc, [e-mail], AT&T Mail !psrchisholm
I'm not speaking for the company, I'm just speaking my mind.

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

Date: 30 Apr 89 14:03:15 GMT
From: usc!nunki.usc.edu![e-mail]  (Mark Anderson)
Subject: Re: Censorship ( was Space Shuttle Attacked by 200-foot UFO!)

>In article <[e-mail]>, [e-mail] (Diana L. Syriac) writes:
>> UFOs are definitely pertinent to Space....last I heard, most of
>> them are from OUTER SPACE.
>
>Most of us aren't interested in hearing about flying saucers, and most
>"flying sorcerers" aren't interested in what we talk about here.
>
>Paul S. R. Chisholm, AT&T Bell Laboratories

UFO's can't be any more far out than some of the more "scientific"
arguments posted here, such as blowing up the Sun or mining asteroids.
Loosen up a little.
                    Mark

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

Date: 30 Apr 89 03:41:40 GMT
From: att!pegasus![e-mail]  (Paul S. R. Chisholm)
Subject: Re: wireless electricity

<"Would you like me to summon Data so he could offer a few dozen synonyms?">

In article <[e-mail]>, [e-mail] (S Millington) writes:
> There have been recent sugestions that a satellite in a
> geostationary orbit could use a high power microwave transmitter to
> transmit power to earth, this would mean that the solar cells picked
> up more light than they would on earth.

Recent?  These proposals were first made in the seventies.  The
original proposal was made by Peter Glaser (of Arthur Little, I think).
Princeton's Gerard K. O'Neill suggested that, rather than lifting all
that mass from the Earth, it would be cheaper to build a lunar colony,
get all the mass from the Moon, and build the solar power satellites
from space habitats.  I did my term paper for Engineering Economics on
O'Neill's proposal back in 1977 or 1978.

What effect would that kind of microwave flux have on birds, crops,
people, and the environment in general?  No one knows.  Terrestrial
fusion might well be cheaper, and looks from here to be much simpler.

Please follow-up to sci.space.

> Stuart Millington.

Paul S. R. Chisholm, AT&T Bell Laboratories
att!pegasus!psrc, [e-mail], AT&T Mail !psrchisholm
I'm not speaking for the company, I'm just speaking my mind.

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

Date: 1 May 89 15:21:07 GMT
From: hp-pcd!hpcvlx![e-mail]  (Greg Goebel)
Subject: Re: Asteroid Encounter

I have a set of old photocopies and clippings at home that I have slowly
been "digitizing" (the hard way -- eyes on text, fingers on keyboard)
as a means of keeping them organized.

I have two on meteor strikes.  They're a little old, but as long as I'm
writing them up I might as well post them, since they're still interesting.

This one's on Dr. Shoemaker of the USGS.  I have a SKY & TELESCOPE article
on the Tunguska strike which I'll post later this week.

    | Greg Goebel
    | INTERNET: cwo_online@hp-pcd

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

Date: 1 May 89 15:21:48 GMT
From: hp-pcd!hpcvlx![e-mail]  (Greg Goebel)
Subject: Re: Re: Asteroid Encounter

Dealing With Threats From Space

   Michael Lemonick

   TIME / 9 JUN 86 / P 65

   It is a sunny afternoon in Karachi, and streets of Pakistan's largest
   city are crowded with shoppers, apparently unconcerned about the rising
   tension between Pakistan and India.  Suddenly a second sun bursts into
   view overhead, so bright it temporarily blinds thousands and so hot it
   blisters the skin.  Thirty seconds later, the shock wave hits,
   crumbling buildings and throwing people to the ground.  To the
   Pakistanis, only one explanation is possible for the tremendous blast:
   India has launched a nuclear attack.  They immediately order their bombers,
   armed with atomic bombs, to strike back at India, which responds in kind.
   Only later do the surviving officials learn of their mistake.  The
   object that exploded over Karachi was not a nuclear weapon but a large
   meteor hurtling in from outer space.

Though this sounds like the plot for a TV movie, Eugene Shoemaker, a respected
US Geological Survey scientist, is concerned that just such an event -- and an
unwarranted reaction -- could occur.  Shoemaker expressed his fears at a
Baltimore meeting of the American Geophysical Union (AGU):  "The effect of a
meteor blast appears the same as a high-altitude nuclear explosion," he said.
"If this happens in the wrong place, people will think they've been nuked."

Meteors, which are asteroids or cometary debris that has entered the
atmosphere, continually shower the Earth.  Most of them are small and either
break up or are burned to ash by friction.  But, explains Shoemaker, the
incineration of larger asteroids is far more violent.  As asteroid 80 feet
across, striking the atmosphere at 50,000 MPH, compresses the air in its path
so much that in effect the asteroid is stopped dead in its path, converting
kinetic energy almost instantaneously into heat, light, and a powerful shock
wave.  That causes a tremendous explosion, in this case equivalent to a
one-megaton bomb.

If a meteor were to burst in the atmosphere tomorrow, Shoemaker says, "the
Soviets and the US would know what it was" and not react militarily.  Their
detectors could distinguish between a nuclear explosion -- which generates
million-degree temperatures, X-rays, and gamma rays -- and an exploding meteor
-- which would produce considerably lower temperatures and no deadly radiation.
But smaller nations, unaware of the nature of the blast, might react violently.
Says Shoemaker:  "Suppose it happens over Syria or Pakistan?"  He proposes that
the US immediately try to determine whether the explosion was of cosmic origin
and notify the affected nation.

Since 1973, Shoemaker has been photographing the sky in search of asteroids
that periodically cross the Earth's orbit and thus pose a danger of collision.
To date, he says, 57 such asteroids at least 1 km in diameter have been
catalogued.  In addition, about three Earth-crossing comets are detected each
year.  From the rate at which new Earth-crossers are detected, Shoemaker
estimates that there are some 2,000 asteroids in this category and that 100
comets intersect the Earth's orbit every year.

His calculations suggest that asteroids packing the explosive energy of one
megaton should enter the atmosphere on an average of once every 30 years,
larger asteroids with a 20-megaton punch every 400 years, and a 1 km, 10,000
megaton comet or asteroid once in 100,000 years.

This century has already seen a major meteorite blast.  In 1908, either an
asteroid or comet exploded about five miles above the remote Stony Tunguska
River region of Siberia, igniting and flattening trees over hundreds of square
miles.  From descriptions of the blast and photographs of the damage,
scientists have estimated that the object was at least 200 feet across and
caused a 12-megaton explosion.

Depending on their velocity, size, and composition, some meteors survive the
fiery trip through the atmosphere at hit the ground, at which point they are
called meteorites.  Most are in the form of pebbles or small rocks, but
occasionally they are much larger.  Scientists think it was a 130-foot chunk of
meteoric iron that hit Arizona with a force of 15 megatons between 20,000 and
50,000 years ago, digging a crater three-quarters of a mile across and 600 feet
deep.

But even greater menace lurks in the darkness of space.  Scientists have
speculated that objects as large as several miles across have crashed into the
Earth, spewing millions of tons of debris into the atmosphere, blotting out the
Sun for months or years, and causing mass extinctions of life -- including,
many believe, the dinosaurs.  Of the known larger Earth-crossers, none seem to
pose a threat in the near future.  But, says Shoemaker, "until we have tracked
all of them, something could sneak up on us."

What if a large asteroid or comet is discovered heading for the Earth?  At the
AGU meeting, Shoemaker and colleage Alan Harris, of the Jet Propulsion
Laboratory in Pasadena, California, suggested that the intruder could be
diverted by landing a thrusting device on it.  As a last-ditch effort, a small
nuclear warhead could be detonated on or near it.  Says Shoemaker:  "We have
the technology to do that right now."  But if the explosion simply broke the
meteorite into large chunks, the danger would only be multiplied.  "The more
prudent solution," says Harris, "is to burrow a substantial charge into the
object and blow it to smithereens."

[<>]

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

End of SPACE Digest V9 #405
*******************