Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_4/V12_457.TXT

Internet Message Format | 1991-06-28 | 19KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/wb5zYIi00VcJ4Nok4K>;
          Sun, 14 Oct 1990 01:35:17 -0400 (EDT)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sun, 14 Oct 1990 01:34:35 -0400 (EDT)
Subject: SPACE Digest V12 #457

SPACE Digest                                     Volume 12 : Issue 457

Today's Topics:
        Re: Cost comparison: Apollo/Saturn vs. Shuttle
             Atmospheric nitrogen
        Re: Cost comparison: Apollo/Saturn vs. Shuttle
              Re: Launch cost per pound
            Re: Oct. 5 NASA Headline News
        Re: Man-rated SRBs (was Re: Junk the shuttle?)
              Weather satelites
              Re: Launch cost per pound
               Re: Magellan/Venus Info
          Re: ulysses and galileo questions
           Re: space news from Aug 20 AW&ST
               Re: Magellan/Venus Info
     Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)
           Re: Ulysses Update #2 - 10/11/90

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
             [e-mail]

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

Date: 13 Oct 90 06:36:40 GMT
From: norge.Eng.Sun.COM![e-mail]  (John McKernan)
Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle

In article <[e-mail]> [e-mail] (Karl Stapelfeldt) writes:
>  I do not think we should go back to
>manned missions with crew capsules and throwaway boosters.
>They have no appreciable advantages vs. manned shuttle launches -
>certainly they do not offer any great cost advantage, as I have
>tried to show.
>                                         Karl Stapelfeldt
>                                         [e-mail]

Wrong. You've made your case against a booster that no longer exists,
the Saturn 1B. At this years launch rates the Shuttle costs well over
$1 Billion per launch (the NASA appropriation for shuttle operations is
approximately $4 billion per year, not counting things like fixed
facilities costs for people primarily working for the shuttle
program).  Even in an optimum year, if these ten year old shuttles have
any more optimum years left, shuttle costs are approx $500 million per
launch.

A Titan IV costs $93 million from the factory, and it's the most
expensive booster in the private space industry. The point is we NOW
have a private space trucking industry in place. It's insane to pay a
bloated bureaucracy $4-$5 billion a year to haul cargo up in an
extremely fragile experimental vehical. And if we want to get a few men
up into LEO all we need to do is put a simple capsule on one of our
cheap private boosters. Remember, a capsule is a simple thing, at least
compared to other space hardware. It's just a few retro rockets, O2
bottles, and parachutes.

John L. McKernan.                                                  [e-mail]
Disclaimer: These are my opinions but, shockingly enough, not necessarily Sun's
-------------------------------------------------------------------------------

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

Date: Sat, 13 Oct 90 20:13:14 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Atmospheric nitrogen


>From: Richard Ristow <[e-mail]>
>Subject:      Re: gravity and atmosphere (nitrogen

>>For that matter, we don't know for sure that long-term absence of major
>>quantities of nitrogen doesn't have some obscure harmful effect.

>I suggest that for planetary atmospheres (as opposed to short-term breathing
>and managed biospheres) the absence of nitrogen has a harmful effect that's
>far from obscure:  atmospheric nitrogen is the substrate from which combined
>nitrogen is produced by biological and abiological 'fixing' processes
>(the former mainly an enzyme chain in certain prokaryotes, the latter
>including nitrogen oxydation in lightning strokes).

Good point, but that in itself does not not imply that a full 78% will be
required. For instance, the average American takes in far more sodium than
the recommended minimum, so even a significant reduction would have little
or no negative effect on health.

Building a stable and self-sufficient large complex ecosystem is certainly
a very complex task, and probably beyond our current capabilities.
      John Roberts
      [e-mail]

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

Date: 8 Oct 90 17:03:21 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!peregrine!ccicpg!conexch!stanton!zardoz.cpd.com!dhw68k!ofa123![e-mail]  (David Anderman)
Subject: Re: Cost comparison: Apollo/Saturn vs. Shuttle

There are many, many arguments for using expendible capsules for manned
space flight.

Yes, you could use Apollo CSMs on Titan rockets. You could also put them
on the old Boeing/Hughes Jarvis design, and get an entire Apollo CSM/SM
stack plus some sort of space station module with one launch.

On the other hand, you could simply buy Soyuz capsules and rockets at 10
-15 million $ a pop....


--
David Anderman
Internet: [e-mail]
--------------------------------------------------------------------------

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

Date: 13 Oct 90 23:58:35 GMT
From: van-bc!ubc-cs!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Launch cost per pound

In article <[e-mail]> [e-mail] (David Anderman) writes:
>Actually, it might be cheaper to launch the Soviet rockets from the Cape
>(Canaveral) than Baikonur. Yes, workers here get paid more $, but the
>decrease in Delta V needed to get into orbit from Florida may make up
>the difference.....

Cape York is still better, and there are already plans to launch Soviet
boosters from there.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: Sat, 13 Oct 90 21:13:21 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: Oct. 5 NASA Headline News


>From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)

>This is NASA Headline News for Friday, October 5, 1990

>Based on the incident yesterday with Atlantis, the shuttle team
>conducted an extensive review of the paperwork, photos,
>inventory, equipment and work platforms used in Discovery's aft
>compartment to ensure nothing had been overlooked.  The
>review confirmed that Discovery's aft compartment closeout was
>properly accomplished.

But there was something in there. When Ulysses was pushed out of the bay,
a large object (apparently a disk several meters across) floated out too.
Judging from later events, it was apparently not anything needed by Discovery
or Ulysses. I suppose it could have been a cardboard or plastic spacer used
in shipping. (Did they get any stereo views with the multiple cameras to
triangulate it? A 3-D video camera would have been handy.)

It also appeared that many hundreds of small objects floated out of the bay.
Since nobody seemed interested in them, they were presumably thermal foil
or gum wrappers or some such. :-)
       John Roberts
       [e-mail]

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

Date: 13 Oct 90 03:29:04 GMT
From: clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Man-rated SRBs (was Re: Junk the shuttle?)

In article <[e-mail]> [e-mail] (Mike McManus) writes:
>... What is the problem with SRBs?  Safety?
>Reliability?  How do these issues compare against liquid fueled engines?

One big problem with SRBs is lack of control.  Once they are lit, there
is nothing you can do to throttle them or turn them off until they burn
out.  (Well, you can preprogram some throttling, and thrust termination
is practically difficult but not theoretically impossible, but the
overall picture doesn't change much.)  If one starts acting up, all
you can do is wait and pray.

Another is that you can't test-fire the ones you are going to use for
flight, since they are one-shot.  You just have to examine them in every
way you can possibly think of and hope that there are no major flaws.

Still another is that the combustion chamber is huge, and for current
big solids, is assembled out of multiple pieces.  This creates lots of
opportunities for leaks.

Just about the only things *right* about them are that they have high
thrust for their size, and they are a bit cheaper to develop than
liquids.  Guess what the clincher was for the shuttle?
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 13 Oct 90 10:04:00 GMT
From: wuarchive!zaphod.mps.ohio-state.edu!maverick.ksu.ksu.edu!ux1.cso.uiuc.edu!ux1.cso.uiuc.edu!uxa.cso.uiuc.edu![e-mail]
Subject: Weather satelites


(Quoted from sci.space)
* WEATHER SATELLITES *
======================
Spacecraft   Catalog #    Frequency       Status
==========   =========    =========       ======
NOAA 9         15427       137.620        Active-Afternoon
NOAA 10        16969       137.500        Active-Morning
NOAA 11        19531       137.620        Active-Afternoon
------------------------------------
Is there any more information about these?  Does the information come
across as a bitmapped image every 10 min or so?  Freq in Megahertz, right?
What kind of sensitivity would an antenna need to get info from these,
and how many people would send me plans to build an antenna to PC setup? :-)

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

Date: 8 Oct 90 17:00:23 GMT
From: elroy.jpl.nasa.gov!peregrine!ccicpg!conexch!stanton!zardoz.cpd.com!dhw68k!ofa123![e-mail]  (David Anderman)
Subject: Re: Launch cost per pound

Actually, it might be cheaper to launch the Soviet rockets from the Cape
(Canaveral) than Baikonur. Yes, workers here get paid more $, but the
decrease in Delta V needed to get into orbit from Florida may make up
the difference.....


--
David Anderman
Internet: [e-mail]
--------------------------------------------------------------------------

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

Date: 13 Oct 90 18:11:34 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: Magellan/Venus Info

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>>... Also, there is a universal convention
>>on planets other than Earth that the longitude will be measured in the
>>opposite direction that the planet rotates.  Venus rotates backwards...
>
>Sorry, no, this is not universally agreed on, for a different reason:
>there is a difference of opinion on which is the north pole.  Various
>groups are on opposite sides of the question.  The cartographers say
>that the north pole is the one that's on the same side of the orbital
>plane as solar north.  But many fields-and-particle physicists say
>that the planet rotates counterclockwise by definition, and the north
>pole is the one from which you see it that way.  Usually the two
>definitions agree.  For Venus they don't, but the real debate over it
>was in connection with Uranus, which is tipped slightly over 90 degrees
>from the usual orientation and hence is tilted just enough for the two
>to disagree.  If this has been resolved, I haven't heard about it.
>--

Since Venus axis tilt is nearly straight up and down, its North pole is
assumed to be pointing in the same direction as that of the Earth's, even
though this would mean Venus rotates backwards. I
agree that since Uranus and Pluto are both rotating on their sides at about
90 degrees, determining which side is their North and South poles can
be a problem.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 13 Oct 90 03:53:32 GMT
From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: ulysses and galileo questions

In article <[e-mail]> [e-mail] (Fraering Philip) writes:
>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's insertion stage is a custom-built liquid-fuel engine, the big
brother of its little maneuvering engines, with relatively modest thrust.
Normally that sort of approach is preferred.  Magellan was done on the
cheap, and hence ended up using a commercial solid motor despite the
fierce acceleration and resulting structural and control problems.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 13 Oct 90 23:57:30 GMT
From: swrinde!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: space news from Aug 20 AW&ST

In article <[e-mail]> [e-mail] (Steve Friedl) writes:
>> The Pioneer Venus orbiter tried to photograph [Magellan's] injection
>> burn using its ultraviolet polarimeter, but the rocket plume wasn't
>> bright enough to be visible.
>
>If NASA had decided that photographing this was important, would they
>have been able to arrange the insertion so that Pioneer was close enough
>to *surely* get the picture?  Or are they in such different orbits that
>this was just not possible?

Not impossible, perhaps, but not worth the trouble.  I think the attempt
at photography was just a nice bonus, plus a possible source of information
in the event of catastrophic failure (remembering that the burn was on the
back side of Venus from our viewpoint, so there was no real-time telemetry
from Magellan).  If I had to guess, I'd guess that both the position of the
burn and the position of Pioneer Venus could have been altered to improve
things, but at significant cost:  a less-than-optimal final orbit for
Magellan, and substantial expenditure of scarce fuel for PV.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 13 Oct 90 03:49:12 GMT
From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Magellan/Venus Info

In article <[e-mail]> [e-mail] (Ron Baalke) writes:
>... Also, there is a universal convention
>on planets other than Earth that the longitude will be measured in the
>opposite direction that the planet rotates.  Venus rotates backwards...

Sorry, no, this is not universally agreed on, for a different reason:
there is a difference of opinion on which is the north pole.  Various
groups are on opposite sides of the question.  The cartographers say
that the north pole is the one that's on the same side of the orbital
plane as solar north.  But many fields-and-particle physicists say
that the planet rotates counterclockwise by definition, and the north
pole is the one from which you see it that way.  Usually the two
definitions agree.  For Venus they don't, but the real debate over it
was in connection with Uranus, which is tipped slightly over 90 degrees
from the usual orientation and hence is tilted just enough for the two
to disagree.  If this has been resolved, I haven't heard about it.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 13 Oct 90 03:38:50 GMT
From: 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] (Perry G Ramsey) writes:
>The VLA (Very Large Array) radiotelescope near Socorro, New Mexico
>was pressed into service for Voyager's Neptune pass.

And several others.  A large fraction of the Free World's total radiotelescope
aperture was pointed at Voyager for the Neptune encounter.

>the biggest gap is between Madrid and Canberra.  Maybe they could
>put one is, say, India? ...

Why bother?  In principle two would suffice, if you put them precisely
180 degrees apart and didn't mind working right down on the horizon
just before switchover.  In practice you don't want to work at that
low an angle, and the choice of positions is limited, but three is
quite adequate to give complete coverage for anything not enormously
out of the ecliptic.  If you just want to add more antennas, it is
almost certainly more cost-effective to add them at existing sites and
make use of existing support facilities.

>... I seem to remember that there was  a station in Madagascar
>(45 deg E) for the Apollo flights.

Apollo and earlier flights needed a large station network to give good
coverage while the spacecraft were in *Earth* orbit.  The lunar part
of the mission was not a big problem, but low Earth orbit is a real
pain to cover with ground stations.  It's not an accident that relay
satellites were both the first "real" shuttle payload and the first
post-Challenger payload.
--
"...the i860 is a wonderful source     | Henry Spencer at U of Toronto Zoology
of thesis topics."    --Preston Briggs |  [e-mail]   utzoo!henry

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

Date: 14 Oct 90 01:07:41 GMT
From: zephyr.ens.tek.com!wrgate!mtdoom![e-mail]  (Dan Tilque)
Subject: Re: Ulysses Update #2 - 10/11/90

[e-mail] (Ron Baalke) writes:
>                      ULYSSES MISSION STATUS
>
>     The five-year mission to study the Sun's poles and
          ^^^^^^^^^^^^^^^^^
>interstellar space beyond the poles

And to boldly go where no probe has gone before.

---
Dan Tilque    --    [e-mail]

P.S.  Sorry, I couldn't resist.

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

End of SPACE Digest V12 #457
*******************