Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V08/V8_285.TXT

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Subject: SPACE Digest V8 #285

SPACE Digest                                      Volume 8 : Issue 285

Today's Topics:
              Re: Space cities--replies
            Re: NASA news - Seasat
                Re:  NASA news
                 OZONE cont.
                  New Ideas
               OZONE depletion
 NASA Deep Space Network to support Soviet Phobos mission (Forwarded)
----------------------------------------------------------------------

Date: 29 Jun 88 16:58:00 GMT
From: mcvax!ukc!dcl-cs!nott-cs!pyr1.cs.ucl.ac.uk![e-mail]
Subject: Re: Space cities--replies


Very interesting.  Only one quibble ...

In reply to John Turner's contribution, is it true that spin gravity
is not similar to real gravity?  This city would have to be some
miles in diameter (I assume - I didn't get the original posting)
so I would have thought the variation in the effective gravity would be
minute over small movements.

As (I think!) the effective gravity is proportional to the distance
from the centre, a 10cm head-nod on a 5km radius ring would cause
a force variation of 2e-5.  Could a human detect this change?
Of course, if you had a small radius and used a long cylinder then
you would definitely get some effect.

            ... Bill

************************************************************************
Bill Witts, CS Dept.     *
UCL, London, Errrp       *       Don't believe everything you hear,
[e-mail](UK) *       or anything you say.
[e-mail](US) ***********************************************

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

Date: 1 Jul 88 00:31:39 GMT
From: aplcen!aplcomm!stdc.jhuapl.edu![e-mail]  (Jim Meritt)
Subject: Re: NASA news - Seasat

In article <[e-mail]> [e-mail] (Mike Wooding) writes:
}In article <[e-mail]>, [e-mail] (Eric Behr) writes:
}< Downloaded from NASA SpaceLink BBS, Huntsville, Ala. [phone]
}< a radar altimeter to
}< measure the height of the ocean surface and waves;
}
} How does the radar altimeter decouple its "height" above ocean
} surface from the "height" of the ocean's surface? What scales
} are involved (+-10 meters)? A reference point?


There is an altimeter on the geosat that is a follow-up to the seasat
one.  I do the real-time processing of the data - you not only get
"height above ocean", but significant wave height, winds, and a measure
of roughness off the altimeter.  (probably more, but that is all I lift).
This can be used to get current "edges", fronts, eddy locations, and all
kinds of neat stuff.  I asked about satellite oceanography earlier, but
didn't hear about anyone else using altimeter data for oceanography.

Anyone else?

(geosat is run from here at APL, the only ground station)

oh yes - changes in ocean height varies greatly with where on the ocean
you get 'em.  Biggest off japan.....


Disclaimer: Individuals have opinions, organizations have policy.
            Therefore, these opinions are mine and not any organizations!
Q.E.D.
[e-mail] 128.244.65.5  (James W. Meritt)

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

Date: Fri, 1 Jul 88 13:14:31 PDT
From: Eugene N. Miya <[e-mail]>
To: [e-mail]
Subject: Re:  NASA news
Cc: [e-mail]

A tie?

You wore a tie today?

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

Date: 2 Jul 88 14:08:00 GMT
From: mailrus!uflorida!novavax!ankh![e-mail]  (Laurie Forti)
Subject: OZONE cont.


      Internationally, NRDC is urging the State Department to make
ratification and reassessment of the Montreal agreement a top priority
in dealings with our European allies and Japan, who with the U.S.
account for the bulk of world production of CFC's.  NRDC is also
pressing for passage of legislation now pending before Congress which
would phase out CFC's over 6-8 years and take away the producers'
windfall profits."
.
.
      The Natural Resources Defense Council is a not-for-profit member
supported organization dedicated to protecting America's natural
resources and to improve the quality of the human environment through
scientific research, legal action, and citizen education.  Memberships
are $10 per year.  NRDC, POBox 37269, Washington, DC 20013.
.
.
      (Why is the ozone layer so important??  Stress on the plant
biomass by increased UV only adds to the attack on same by pollution,
chemical agricultural systems, global deforestation, and
desertification.  Thousands of plant (and animal) species have already
been destroyed by human activity, and there very well may be a
threshold level of stress beyond which major areas of plant material
are
destroyed leading to loss of atmospheric oxygen and collapse of
agricultural and other ecosystems.  Read this as global famine and
major depopulation of the planet.  Let's hear it for technology, folks
.... Laurie)
--
 FidoNet : 369/6     the Eye of Osiris   -   305-973-1947  -     OPUS/UFGATE
 UUCP    : ...!{gatech!uflorida!novavax, hoptoad, umbio, attmail}!ankh

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

Date: 3 Jul 88 17:09:26 GMT
From: fluke!ssc-vax![e-mail]  (Dani Eder)
Subject: New Ideas

In article <[e-mail]>, [e-mail] (Ralf Brown) writes:
 In article <[e-mail]> [e-mail] writes:
  There's also an interesting proposal to use a tether concept to deorbit
  the space shuttle from the space-station, simultaneously reboosting
  the station every time you drop a shuttle off.

 This isn't all that new an idea.  See the SF novel "Descent of A????" (it's
 been at least five years since I read it), which gives a nice account of
 using just this concept to deorbit a shuttle (though the other end was its
 payload, rather than the space station).  Written ca. 1980.
 --

There has been observed by myself and others a 'signal delay' of about five
years within NASA for new ideas.  Hypotheses to explain this delay range
from the 'Not Invented Here' syndrome, to there not being a significant
'office of new ideas'.  At the same time, the past few years has
had an explosion of new ideas in space development.  In the propulsion
area alone, my friends and I have catalogued over fifty ways to get to
and around in space (see the book "Mirror Matter" by Forward and Davis
for a list).  Only a few (chemical rocket, airbreathing, ion) are receiving
non-trivial attention.

Expect a revolution in the 'Paradigm' for space development over the
next few years, as all the new ideas, not just the propulsion ones,
but the extraterrestrial materials and energy, closed life support,
seriously smart computers and robots, teleoperation, etc. get folded
into the mix, and interact.  For refernce the current paradigm:

Space Shuttle launches Space Station
Space Station is a staging base for chemical Orbit Transfer Vehicle
Lunar Surface Station is Set up from Space Station using OTV
All this occurs over now-2010 time period.
Over next ten years (2010-2020) a few (3) manned mars missions
are mounted from space station using large chemical rockets and
aerobraking for arrival.



--
Dani Eder / Boeing / Space Station Program / uw-beaver!ssc-vax!eder
[phone](w) [phone](h) 1075 Dockside Drive #905 Huntsville,
AL 35824  34 40 N latitude 86 40 W longitude +100m altitude, Earth

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

Date: 2 Jul 88 14:04:00 GMT
From: mailrus!uflorida!novavax!ankh![e-mail]  (Laurie Forti)
Subject: OZONE depletion

This article excerpted from the NRDC Newsline Vol. 6, No.2, May/Jun
1988
.
"Ozone Depletion Worsens, NRDC Leads drive for Total CFC Phase-out"
.
      Stratospheric ozone depletion is dramatically worse than we
thought, according to a new report just issued by an international
panel of more than one hundred scientists.  The report prepared under
the auspices of the National Aeronautics and Space Administration
(NASA), documents an unexpectedly rapid thinning of the stratospheric
ozone shied all over the globe, with chlorofluorocarbons (CFC's) the
likely cause.  The alarming findings add new urgency to NRDC's drive
for a total phase-out of CFC's and other ozone-depleting chemicals.
      According to the scientists report, even after natural factors
are accounted for, satellite and ground-based monitors show ozone
losses since 1969 as high as 3% over the heavily populated regions of
North America and Europe and 5% over parts of the southern hemisphere.
What's more, depletion is occurring at 2 to 3 times the rate predicted
by computer models scientists have previously relied on.
      "We are facing a global emergency," NRDC senior attorney David
Doniger testified before the Senate Environment and Public Works
Committee on March 30.  Doniger called for immediate steps to
strengthen the international agreement reached last September in
Montreal -- which the Senate ratified by a vote of 83-0 just one day
before the new scientific report was issued -- as well as
Environmental Protection Agency regulations proposed last December
under a court-ordered deadline won by NRDC.  "The Montreal accord and
the proposed EPA rules will cut CFC's (production) by less than 50%
over 10 years.  The world has _already_ suffered more ozone depletion
than EPA predicted would occur under that level of cuts _by the year
2050_.  Safeguarding the ozone layer requires a rapid and total CFC
phase-out, not just a 10 year halfway measure."
      The findings of global ozone losses follow on the heels of
proof, gathered by NASA last year, that CFC's are the cause of the
massive Antarctic ozone "hole" that opens each year when spring returns
to the southern hemisphere.  Ozone levels over Antarctica plummeted by
more than _50%_ last September and October.
      Ozone depletion will allow more ultraviolet (UV) radiation to
penetrate to the Earth's surface, causing tens of thousands of extra
skin cancers, cataracts, and immunological diseases in the U.S.
(alone) over the coming decades.  More UV also damages crops and
other vegetation and endangers the marine food web.  Even the Earth's
climate may be changed.
      The new scientific report prompted a surprise announcement from
du Pont, the world's largest CFC producer, which had led the industry
_opposition_ to controls on these chemicals for more than a _decade_.
Du Pont stated a "goal" of totally phasing out its CFC production and
called for immediately reassessing the Montreal agreement once it
takes effect next year.  "While du Pont's new position is welcome, its
conversion is far from complete," said NRDC's Doniger.  "Du Pont has
set _no schedule_ for its own actions, and it still opposes any move
to phase-out U.S. production and use prior to reaching a new
international agreement.  In addition, du Pont and other CFC producers
stand to make billions of dolFrom [e-mail]  Tue Jul  5 08:55:20 1988
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Date: 3 Jul 88 05:01:00 GMT
From: a.cs.uiuc.edu!m.cs.uiuc.edu![e-mail]
Subject: Soviet space station elements
Message-Id: <[e-mail]>
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Salyut 7
1 13138U          88179.68414465 0.00010405           33290-3 0  1404
2 13138  51.6128 239.0138 0001070 150.7375 209.3187 15.32968712353693
Mir
1 16609U          88179.75592934 0.00050649           35750-3 0  2763
2 16609  51.6160  13.0567 0003430 100.9284 259.3027 15.73519445135493
Satellite: Salyut 7
Catalog id 13138
Element set 140
Epoch: 88179.68414465
Inclination:  51.6128 degrees
RA of node: 239.0138 degrees
Eccentricity:  0.0001070
Argument of perigee: 150.7375 degrees
Mean anomaly: 209.3187 degrees
Mean motion: 15.32968712 revs/day
Mean motion acceleration: 0.00010405 * 2 revs/day/day
Epoch Revolution: 35369

Semimajor axis:    6845.05 km
Apogee height*:     467.63 km
Perigee height*:     466.16 km


        Source: NASA Goddard via T.S.Kelso's `Celestial RCP/M'

* Apogee and perigee altitudes are referred to the mean radius of the
  Earth (6378.15 km), and not to the local radius of the geoid.  They
  are only approximate, and should not be used for orbit prediction.
Satellite: Mir
Catalog id 16609
Element set 276
Epoch: 88179.75592934
Inclination:  51.6160 degrees
RA of node:  13.0567 degrees
Eccentricity:  0.0003430
Argument of perigee: 100.9284 degrees
Mean anomaly: 259.3027 degrees
Mean motion: 15.73519445 revs/day
Mean motion acceleration: 0.00050649 * 2 revs/day/day
Epoch Revolution: 13549

Semimajor axis:    6726.94 km
Apogee height*:     351.09 km
Perigee height*:     346.47 km


        Source: NASA Goddard via T.S.Kelso's `Celestial RCP/M'

* Apogee and perigee altitudes are referred to the mean radius of the
  Earth (6378.15 km), and not to the local radius of the geoid.  They
  are only approximate, and should not be used for orbit prediction.

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

Date: 3 Jul 88 15:59:07 GMT
From: [e-mail]  (Peter E. Yee)
Subject: NASA Deep Space Network to support Soviet Phobos mission (Forwarded)

Charles Redmond
Headquarters, Washington, D.C.
                                                     July 1, 1988

Jeff Vincent
Headquarters, Washington, D.C.

Jim Wilson
Jet Propulsion Laboratory, Pasadena, Calif,


RELEASE:  88-87

NASA DEEP SPACE NETWORK TO SUPPORT SOVIET PHOBOS MISSION

     When the USSR's Phobos 1 spacecraft lifts off for Mars on
Thursday, July 7, it will be headed not only for a landing on the
tiny Martian moon Phobos but also for a radio rendezvous with
NASA's Deep Space Network (DSN).

     Phobos 1 and Phobos 2, scheduled for launch a week later,
each carry 100-pound landers designed to analyze the 17-mile-
long, potato-shaped moon, and the DSN's role in the mission is to
provide essential tracking data to permit their landing on
Phobos.  The DSN then will shift to enabling a key scientific
goal of the mission, to track Phobos very precisely.  The DSN's
230-foot dish antennas in California, Spain and Australia, as
well as a Soviet radio telescope in the Crimea will be used.  The
landings, and the special DSN tracking, are expected to begin in
April 1989.

     Scientists are interested in the orbit of Phobos because it
appears to be decaying.  They believe tidal forces, the unequal
attraction of gravity between different parts of two bodies, are
making the moon spiral very slowly toward Mars and eventual
destruction.  Optical tracking is barely accurate enough to
detect this phenomenon.  Only active radio tracking, with a
spacecraft on the site, can measure the orbit's decay rate.

     The Deep Space Network, developed and operated by NASA's Jet
Propulsion Laboratory over the past 3 decades, has built up
unique expertise in determining the distance, within yards, and
the velocity of spacecraft billions of miles from Earth.
    - more -






    - 2 -


     During the passage of Comet Halley in 1986, JPL and Soviet
scientists cooperated to pin down the location of the comet's
nucleus for the European spacecraft Giotto by precisely locating
the Soviet Vegas spacecraft while they were photographing the
nucleus, then reckoning from known camera locations and angles to
find the target for Giotto's later flyby.

     This time, U.S. scientists will use a radio-astronomy
technique called very long baseline interferometry (VLBI), which
employs widely-spaced, paired ground antennas, as well as doppler
and range tracking to pinpoint the position and motions of the
moon Phobos.

     The Deep Space Network will receive telemetry, including
images and other scientific measurements, from the two landers,
but its principal responsibility will be the ranging and VLBI
measurements.  These will be complicated by the moon's rapid
rotation once every 7 hours, 37 minutes and the fact that the
lander antenna will be fixed, rather than tracking the Earth.
Scientists expect to be able to track lander and moon for only
about 17 minutes out of each rotation period, without the DSN's
worldwide facilities, this would be still further reduced.
Lander telemetry, like that from the Phobos orbiters, also will
be collected by Soviet receiving stations.

     Between October 1988 and year's end, Phobos project and DSN
scientists will check the VLBI technique under space flight
conditions.  Hardware was checked at the Goldstone tracking site
in April.

     Then, after the Phobos spacecraft go into Mars orbit in late
January, precise tracking by the DSN will help first Phobos 1 and
then Phobos 2 edge down very close to the moon's orbit so that
the manifold scientific operations can begin.

     The Phobos mission involves more than three dozen
experiments, with scientists representing nations of Eastern and
Western Europe as well as the United States and the U.S.S.R.  Two
orbiters and two landers, consisting of a long-lived scientific
package and a 100-pound hopper which measures surface properties
at several positions 20 to 40 yards apart, carry the instruments.

    - end -

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

End of SPACE Digest V8 #285
*******************