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Subject: SPACE Digest V12 #454

SPACE Digest                                     Volume 12 : Issue 454

Today's Topics:
          Re: ulysses and galileo questions
     Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)
         NASA Headline News for 10/12/90 (Forwarded)
        Re: Cost comparison: Apollo/Saturn vs. Shuttle
          Re: ulysses and galileo questions
            Re: Voyager Update - 10/11/90
         Please include me in this news group
         Re: Disposal of N-waste into the Sun
           Re: disposal of N-waste into sun
            Re: Ulysses Update - 10/06/90
             Re: Nerva rockets...

Administrivia:

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

Date: 12 Oct 90 21:14:23 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: ulysses and galileo questions

In article <[e-mail]> [e-mail] (Fraering Philip) writes:
>In article <[e-mail]> [e-mail] (Perry G Ramsey) writes:
>
>PR>In a sense, both spacecraft do use a three stage upper
>PR>stage, but Galileo needs to save its third stage until it gets to Jupiter.
>
>Does anyone know if the Galileo insertion stage was bought
>off-the-shelf, and if it will have a high acceleration
>(decelleration?) factor the same way the Magellan prode did?
>

Galileo will fire a 400 Newton retro engine for an hour, and use a gravity
assist from Io to get itself in Jupiter orbit.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 12 Oct 90 15:35:50 GMT
From: sdd.hp.com!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)

In article <[e-mail]> [e-mail] (Jim Barnes) writes:
>If Ulysses needs 8 hours per day of coverage, Magellan is returning radar
>images several times a day, and Galileo is doing some interesting things
>at the same time, are there enough minutes in the day? ...

Yes, although things are definitely going to be busy.  Bear in mind that
these birds are in different parts of the sky, so they are not competing
for the same antennas all the time.  Bear in mind also that DSN has several
sets of antennas; they've only got one set of real biggies, but there are
(I think) two sets of smaller ones.  My recollection is that the smaller
ones are quite adequate for Magellan work, which is just as well because
"several times a day" is a major understatement. :-)  (Magellan pours data
back on *each orbit*.)

The Voyagers and Pioneers are definitely not going to get a lot of DSN
coverage, but then they no longer need that much.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 12 Oct 90 23:44:31 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 10/12/90 (Forwarded)


              Headline News
Internal Communications Branch (POC) NASA HQ


Friday, October 12, 1990    Audio Service: 202/755-1788


This is NASA Headline News for Friday, October 12, 1990

U.S. and Soviet space and aeronautics officials will hold three
separate meetings next week.  Adm. Richard Truly will lead a
U.S. Government delegation to the Soviet Union for general
discussions on the U.S. - U.S.S.R. civil space programs and for visits
to Soviet space facilities.  The visit will occur Oct. 15 through 19.  In
addition, the fourth U.S.J- U.S.S.R. Solar System Exploration Joint
Working Group meeting will be held Oct. 15 through 22 in Crystal
City, Va.  A Soviet aeronautical group will also visit NASA
aeronautical centers to be briefed on our program from Oct. 15
through 22.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

Atlantis remains in the Vehicle Assembly Building.  It was
not rolled out to launch pad 39-A this morning, as planned, due to
severe weather associated with Tropical Storm Marco.  The storm
caused considerable heavy rain in the pad vicinity and that, plus
the threat of lightning, caused the launch team to re-plan Atlantis'
roll out for tonight at 9 pm EDT.

Columbia's roll out to launch pad 39-B is scheduled for 9 pm
EDT Saturday.  Servicing of the Astro-1 Broad Band X-ray
Telescope, inside Columbia's payload bay, is still set for Monday.

Discovery is expected to begin its flight back to the Kennedy
Space Center aboard the 747 Shuttle Carrier Aircraft on Monday.
The trip includes a scheduled refueling stop at Kelly Air Force Base
in San Antonio, and, weather permitting, should conclude with
Discovery's arrival at Kennedy Monday evening.

KSC and NASA Shuttle management are currently examining late
October dates for fuel tanking tests for both Atlantis and Columbia.
No specific date has been decided upon.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

Ulysses is now more than three million miles from Earth and
moving away from the Sun at an ever-increasing velocity.  It's
current speed, relative to the Sun, is over 91,000 miles per hour.
Jet Propulsion Laboratory Ulysses engineers have been tracking
the spacecraft continuously since its release from Discovery to
determine a precise trajectory.  This trajectory information will be
used in final determinations of the correction maneuver now set for
Monday and Tuesday, Oct. 15 and 16.  Following the course
correction maneuver, Ulysses' nine instruments will be commanded
individually during the subsequent six week period.  JPL reports all
onboard systems are operating normally.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

NASA announced yesterday that preliminary observational data
over the Antarctic indicate the level of stratospheric ozone
depletion matches the level observed in 1987.  The 1987 depletion
was the maximum level of ozone depletion which had been observed
to date.  Observational data come from the NASA Goddard
NIMBUS-7 spacecraft, which has been monitoring stratospheric
ozone since 1979.  The data also show that ozone levels in the
Southern Hemisphere are as low as any which have been previously
measured.  The implications of the hemispheric data are uncertain,
due to variability in ozone levels related to both atmospheric
chemistry and meteorological conditions.


Here's the broadcast schedule for Public Affairs events on NASA
Select TV.  All times are Eastern.  **indicates a live program.

Tuesday, 10/16/90
    12:00 pm    NASA programs, continues through 2:00 pm.
    6:00 pm    NASA programs repeats, through 8:00 pm.

Thursday, 10/18/90
    11:30 am    NASA Update is transmitted.
    12:00 pm    NASA programs, continues through 2:00 pm.
    6:00 pm    NASA programs repeats, through 8:00 pm.



All events and times may change without notice.  This report is
filed daily, Monday through Friday, at 12:00 pm, EDT.  It is a
service of Internal Communications Branch at NASA
Headquarters.  Contact:  CREDMOND on NASAmail or at 202/453-
8425.


NASA Select TV:  Satcom F2R, Transponder 13, C-Band, 72 degrees
West Longitude, Audio 6.8, Frequency 3960 MHz.

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

Date: 12 Oct 90 05:14:48 GMT
From: uc!cs.umn.edu!quest!orbit!pnet51![e-mail]  (S Schaper)
Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle

What are the comparisons between Big Gemini/Int-20 and the shuttle stack?
mass to orbit, cost to orbit per pound, mass of Big Gemini vrs. Shuttle.
(might this have been a better shuttle launch stack?) What was this project,
and where can we read more about it?


UUCP: {amdahl!bungia, uunet!rosevax, chinet, killer}!orbit!pnet51!schaper
The necktie is a device of Mordor
ARPA: crash!orbit!pnet51![e-mail]
INET: [e-mail]

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

Date: 12 Oct 90 15:49:30 GMT
From: mentor.cc.purdue.edu!mace.cc.purdue.edu![e-mail]  (Perry G Ramsey)
Subject: Re: ulysses and galileo questions

In article <[e-mail]>, [e-mail] (k.c.archie) writes:
> Ulysses is going to get to Jupiter in  about 14 months, or so I understand.
> This is because of the multi-stage rocket attached.
> Why couldn't this be used with Galileo? Is it too big?

Galileo is a lot heavier than Ulysses.  Among other things, it carries
an engine to put itself into orbit around Jupiter, something Ulysses
doesn't need.

In a sense, both spacecraft do use a three stage upper
stage, but Galileo needs to save its third stage until it gets to Jupiter.

--
Perry G. Ramsey           Department of Earth and Atmospheric Sciences
[e-mail]   Purdue University, W. Lafayette, IN USA
[e-mail]    We've looked at clouds from ten sides now,
              And we REALLY don't know clouds, at all.

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

Date: 12 Oct 90 16:55:04 GMT
From: mtndew![e-mail]  (Steve Friedl)
Subject: Re: Voyager Update - 10/11/90

>                         Voyager Mission Status
>                            October 11, 1990
>                               Voyager 1
>
>      There was an tracking outage of 4 hours and 55 minutes with
> the 34 meter antenna in Spain on September 29 because of heavy rain.

Is tracking lost because the rain messes up the signal or because the
antenna has to be stowed because of wind and stuff?

     Steve

--
Stephen J. Friedl, KA8CMY / I speak for me only / Tustin, CA / 3B2-kind-of-guy
[phone]  / [e-mail]  / {uunet,attmail}!mtndew!friedl

"No job is too big, no fee is too big" - Gary W. Keefe

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

Date: 12 Oct 90 21:49:23 GMT
From: [e-mail]  (DANIEL KEN)
Subject: Please include me in this news group

VEGA::Koehler.Colorado.edu

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

Date: Fri, 12 Oct 90 14:33:49 PDT
From: [e-mail]
X-Vmsmail-To: UTADNX::UTSPAN::AMES::"[e-mail]"
Subject: Re: Disposal of N-waste into the Sun


It seems a waste of net bandwidth to include all the discussion leading up to
this, so I'll summarize briefly:

First, someone asked why we couldn't dump n-waste into the sun.

Then someone asked why it would be harder to send something to the sun than
away from the sun?

Then Henry Spencer said,
>The direction is unimportant; what matters is the velocity change needed.
>To get something into the Sun, you have to kill *all* of Earth's orbital
>velocity (well, just about), and that's 30 km/s, a horrendous amount for
>chemical rockets.

Then all hell broke loose and one person showed how it takes 4/3 as much
energy to go into the sun as away, then another person showed how it's
really 7/4, both of which answers are way off.

Now, here are the correct answers.

First some useful numbers

    GMs=1.37e20 m^3/s^2    Gravitational constant of Sun
    GMe=3.99e14 m^3/2^2    Gravitational constant of Earth
    AU=1.5e11 m        Astronomical unit (mean Earth-Sun distance)
    Re=6.378e6 m        Radius of Earth

    The speed V of an object in a circular orbit of radius R is given by
V^2=GM/R, where GM is the gravitational constant of the orbited body.  Using
the numbers above we get about 30 km/s for the speed of the Earth in its orbit.
    For a parabola, which is the minimum escaping orbit, the speed at R
is V^2=2*GM/R. This means that escape velocity at any radius is always
the square root of 2 times the circular orbit velocity at that radius.  To
escape from the Sun at the Earth's orbit you have to be going about 42 km/s.
    Energy changes with the square of the velocity.  To escape from the
Sun from the Earth, you have to add 144 MJ/Kg, but to drop into it you have
to add 900 MJ/Kg.
    So it takes over six times as much energy to drop into the Sun from
the Earth as it does to escape, but of course, this is just the energy you're
adding to the payload, and doesn't acccount for energy added to the vehicle
and the fuel during acceleration.  I will leave that accounting as an
exercise for the reader ;-).

_____________
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
                        "I will continue to use my boat." -- George Bush

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

Date: 10 Oct 90 23:28:50 GMT
From: edsews!teemc!fmeed1![e-mail]  (Russ Cage)
Subject: Re: disposal of N-waste into sun

In article <[e-mail]> [e-mail] (Alan Hepburn) writes:
>Picture this:  a supertanker modified slightly so that the nuclear
>waste starts out in the bow tank, being diluted 100:1 with sea water.
>This mix is then pumped to the next tank where it is diluted 100:1 with
>sea water.  And so on till the last tank, which is pumped into the open
>ocean.  You would be unable to detect other than background radiation
>in the resulting water.

BZZZZZZZZZZZZZZZZZZT!  Wrong, on at least two counts.

First, if the background level of the radioisotopes in question is
small enough, they could still be detected even after many dilutions.
I-131, for example, even at 6000 atoms/liter (10^20 dilution factor),
could almost certainly be detected by Cerenkov radiation.

Second, you are assuming that the sea is infinite, that the waste
can be diluted indefinitely.  This is false; eventually, your ship
will start steaming through water it took in earlier.  The radwaste
inventory of the sea accumulates.

Third, you are implicitly assuming that dilution is permanent.
Not so; there are many biological pathways which concentrate
nasties such as heavy metals (which many radionuclides are).
--
Russ Cage    Ford Powertrain Engineering Development Department
Work:  itivax.iti.org!cfctech!fmeed1!cage   (Business only, NO CHATTY MAIL PLS)
Home:  [e-mail]  (Everything else)
I speak for the companies I own, not for the ones I don't.

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

Date: 12 Oct 90 15:50:13 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Andy Clews)
Subject: Re: Ulysses Update - 10/06/90

From article <[e-mail]>, by [e-mail] (Bill Haake):
> :Shome mishtake, shurely? What about when Ulysses was in the orbiter payload
> :bay in orbit around Earth? Or even after deployment as it floated gently
> Not if we weren't at perihelion when it was in orbit! :-)

Thanks to all who corrected my own "shilly mishtake", by email and followup.
I completely forgot about the perihelion factor. *blush*

Andy

--
Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, England
JANET: [e-mail]   BITNET: [e-mail]

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

Date: 12 Oct 90 18:00:26 GMT
From: usc!wuarchive!rex!rouge!pc![e-mail]  (Phil Fraering)
Subject: Re: Nerva rockets...

To the people in sci.physics discussing Nerva: Perhaps sci.space would
be a more appropriate newsgroup.

To people in sci.space: there is an ongoing discussion about Nerva
in sci.physics.

Phil Fraering
[e-mail]

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

End of SPACE Digest V12 #454
*******************