Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_4/V13_475.TXT

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Subject: SPACE Digest V13 #475

SPACE Digest                                     Volume 13 : Issue 475

Today's Topics:
               Galileo Solution
       Re: Why does every SAR have another resolution?
          Re: Energia (was Re: Saturn V blueprints)
               Re: Saturn V and the ALS
           Re: Launch Scrubs due to Weather
        Re: Alexander Abian wants to blow up the moon?
             Re: Saturn V vs. ALS
             Re: Galileo Solution
     Re: slight problems with HLV's in general, Saturn or not...
       Re: Shuttle Reliability (was: Re: Saturn V and the ALS)

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
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Date: 27 Apr 91 20:51:15 GMT
From: usc!cs.utexas.edu!uwm.edu!ux1.cso.uiuc.edu!pequod.cso.uiuc.edu![e-mail]  (Andrew Higgins)
Subject: Galileo Solution

CNN reported this morning that JPL is recommending launching a
communications satellite to Jupiter to act as a relay for the
malfunctioned Galileo spacecraft.  A brillant solution, IMHO.
--
    Andrew J. Higgins
    [e-mail]

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

Date: 27 Apr 91 12:05:43 GMT
From: nitrex![e-mail]  ( Dr. Robin Lake )
Subject: Re: Why does every SAR have another resolution?

In article <[e-mail]> [e-mail] (Daniel Fischer) writes:
|>From NASA NEWS RELEASE 91-34 of February 27, 1991 on the RADARSAT spacecraft:
|>> The satellite's synthetic aperture radar (SAR) will be ... scanning the
|>> Earth in swaths varying from 50 to 500 km. The SAR will produce high-resolu=
|>> tion (10 to 100 meters pixel size) images of the Earth's surface...
|>
|>Now we all know that the Magellan in its orbit around Venus produces swaths
|>some 25km wide, with a resolution of approx. 120 meters. Why can the resolution
|>of RADARSAT's SAR be so much better, about a factor of 10? This can't be due
|>to a lower orbit alone, I presume. Also, why can RADARSAT have many more
|>pixels across the swath's width (according to this article 5000) compared to
|>Magellan (200)? Does that depend on their antennas or on the data processing?
|>
|>Furthermore, there are rumors that the Lacrosse satellite's SAR can resolve
|>features down to 1 meter in size (how official is that?).


As I recall from last year's excellent short course at UCLA:

    The along-path resolution of SAR depends (in part) upon velocity
of the craft.  Lateral resolution depends upon bandwidth of the pulse.
(Sorry, my notes are at the office!)

    NASA/JPL have several excellent publications which include details
on SAR satellite resolutions.

Rob Lake
[e-mail]

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

Date: 27 Apr 91 00:28:02 GMT
From: hub.ucsb.edu!ucsbuxa![e-mail]  (Charles Frank Radley)
Subject: Re: Energia (was Re: Saturn V blueprints)

In article <[e-mail]> [e-mail] (Robert McGwier) writes:

 No, my original post was correct as written, read it again.
The launches you refer to are not paid for by the US government.
They are private commercial luaunches paid for by o private
companies.
  The US Government does not purchase foreign launch vehicles,
and never has.
   There are no signs this policy will change in the forseeable
future.

>From article <[e-mail]>, by [e-mail] (Charles Frank Radley):
>>
>>
>> Federal law prohibits The Us Government ( including NASA )
>> from purchasing launches on foreign launch vehicles.


>You are incorrect.  There will be US built satellites launched on Long March's
>sometime in the near future and there are now DOZENS of launches on
>Arianes.  I have PERSONALLY built satellites in the US that were launched
>on Ariane.

>How's about checking your facts before making false flat statements.

>Bob

>--
>____________________________________________________________________________
>    My opinions are my own no matter    |    Robert W. McGwier, N4HY
>    who I work for! ;-)            |    CCR, AMSAT, etc.
>----------------------------------------------------------------------------

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

Date: 28 Apr 91 02:04:03 GMT
From: mnemosyne.cs.du.edu!isis![e-mail]  (Glenn A. Serre)
Subject: Re: Saturn V and the ALS

In article <[e-mail]> [e-mail] (/dev/null) writes:

[Brent says F-1s need to be improved, Henry says they work fine]

   The engines do NOT work fine if they help contribute to $1500+/lb to
   orbit (optimistic estimate).  I suggested lowering the amount of fuel
   NOT because kerosene is expensive (it's not), but to open up
   more VOLUME and LIFT for payload, thus dropping costs!

Lowering the "amount of fuel" (I assume you mean raising Isp) will not
neccessarily reduce costs.  To raise Isp in an F-1, one would:
1) Raise the chamber pressure (the F-1 operates at low altitude, so there's
a limit as to how much a larger nozzle would raise Isp.
2) Raise the chamber temperature.
3) Use more powerful turbines (more RPM's, larger blades, whatever).
4) Because of 1) redesign the engine structure to accomodate higher loads.
5) Because of 2) redesign the cooling system, deal with the problem of "coking"
(sp?) in the RP-1 which is used as coolant (Thanks, Henry, for telling me what
that effect is called.)
6) Because of 3) increase the tolerances on the turbine assemblies, use higher
strength materials, whatever.
etc. etc.

The point is, making something "better" doesn't mean making it cheaper.
If you think that the main goal of ALS is to make launches cheaper, then why
isn't ALS going to at least experiment with BDBs?

   the payload SIZE is wonderful (though it could be better :) ),
    its COST is terrible.  We need to get

But MUCH better than what we have now.

   cost per pound down below $1000/lb (preferably $200/lb).

You mean like the Shuttle (another advanced lanch system)?

   You missed my whole point.  The Saturn V is too expensive as it iS!
   We neeD launcher that gives us a large payload AND cost less than $1000/lb or
   there will never be a use for it or any other "heavy launcher!"

It is highly unlikely that this cheap launcher will be ALS (the name itself
is an indication).

Oh, well.  More incoherent ramblings...

--
--Glenn Serre         |Soon-to-be former Payload Integration Engineer for
[e-mail] |Martin Marietta Astronautics Group, Space Launch Systems
                      |Company.
                      |Next job:  Script writer for Cayenne Systems, Inc.

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

Date: 27 Apr 91 16:09:35 GMT
From: usc!samsung!spool.mu.edu!cs.umn.edu!kksys!wd0gol!newave![e-mail]  (John A. Weeks III)
Subject: Re: Launch Scrubs due to Weather

In article <[e-mail]> [e-mail] (Doug Phillipson ) writes:
> Has anyone got some stats concerning what percentage
> of shuttle launches were scrubbed due to weather from KSC?

There's something else the Saturn V did not have to worry about,
based on the Apollo 12 flight 8-).

> Can anyone tell me how much of an advantage it is, in payload pounds,
> to launch from KSC as opposed to say Nevada.  The weather in Southern Nevada
> is such that launches could take place 300 plus days a year.  There is
> lots of open land for launch failures to fall into. The humidity is usually
> below 20 percent and it is not a wildlife refuge (I understand that launches
> are not allowed sometimes when they might disturb the hatching of protected
> birds).

The big disadvantage of KSC is the salt water.  Things corrode like mad
near the ocean.  One of the space magazines recently had pictures of the
Gemanii pad--it is almost rotted away.

Although a drive through Nevada might give you the impression of lots of
open land, there is still not enough empty space to safely launch rockets.
Birds are launched from KSC at angles of up to 57 degrees that I recall.
This would put a large part of the USA under the path of a failure.

Now consider logistics.  Where would the SRB's fall?  Some vehicle
components are shipped by barge--would you dig a canal?  Shuttle launches
require a large quantity of water on the pad--where would you get a large
amount of water in the desert?  Actually, these points assume the current
shuttle design.  I suppose one could argue that, given Nevada as a launch
site, the shuttle design would be different.

At KSC, the shuttle can ride out any storm except a hurricane (I'm unsure
what a hail storm would do).  In Nevada, how would a sand storm affect
the shuttle?  I suspect that a sand storm would seriously contaminate
the shuttle.

-john-

--
=============================================================================
John A. Weeks III               [phone]             [e-mail]
NeWave Communications                       ...uunet!tcnet!wd0gol!newave!john

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

Date: 26 Apr 91 23:37:42 GMT
From: prism![e-mail]  (Matthew DeLuca)
Subject: Re: Alexander Abian wants to blow up the moon?

In article <[e-mail]> [e-mail] (Paul A. Estin) writes:

>    Very late last night (around 4 or 5 AM) I tuned in to CBS's
>"Nightwatch" news program in the middle of a "debate" between Bevan
>French of NASA and some crazy loon at Iowa State University named
>Alexander Abian.
>    My question is basically... who IS this Abian guy and what
>exactly is he trying to say?

While standing in the checkout line last month with my bag of Doritos,
waiting for the cashier to figure out the price on a bar of soap for the
customer in front of me, I had the good luck to spy a copy of the Weekly
World News, with the headline 'SCIENTIST WANTS TO BLOW UP MOON!' in type
large enough to announce the advent of World War III.

Basically, this guy wants to blow up the moon in such a manner as to
have a large chunk drop into the Pacific, thereby knocking the planet
into a 0 degree (as opposed to the current 23.45 degree) axial tilt,
making it springtime forever over a large chunk of the earth and bringing
happiness to all.  How he plans to do this wasn't made clear.

There weren't any sidebars or graphs, though, so I discounted the article
entirely. :-)

--
Matthew DeLuca
Georgia Institute of Technology      "I'd hire the Dorsai, if I knew their
Office of Information Technology      P.O. box."  - Zebadiah Carter,
Internet: [e-mail]    _The Number of the Beast_

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

Date: 27 Apr 91 03:29:48 GMT
From: agate!lightning.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: Saturn V vs. ALS

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Frank Crary) writes:
>>Not at all. If someone thinks a market is possible, they will invest in
>>the infrastructure....
>
>Oh really?  Who?  Especially in the US, where the Next Quarter's Bottom Line
>is God?  People invest because they are *sure* there is a market, not because
>they think there might be one or they think one might develop eventually.
If the US does not invest, then Japan or the EC nations will. They have
been known the invest in projects which did not show a profit for five
or more years.
However US companies CAN make long term investments. Orbital Sciences
Corporation has yet to make a cent on the Pegasus launcher, unless
you count advanced money for launch contracts. Their vehicile will not
start making for-profit launches untill (if I remember correctly) later
this year. It has been in development for over four years. Is this not
a long term investment in space infrastructure by a US company, who
thinks there is a market?

                        Frank Crary
                        UC Berkeley

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

Date: 27 Apr 91 22:35:34 GMT
From: prism![e-mail]  (Matthew DeLuca)
Subject: Re: Galileo Solution

In article <[e-mail]> [e-mail] (Paul Dietz) writes:

>"Brilliant" is not the word that springs to my mind.  "Desperate"
>seems more applicable.  Perhaps I am cynical, but I doubt NASA
>can or will build a new RTG powered comsat from scratch in time
>(do they even have enough Pu-238 on hand?).

Well, the actual Jupiter encounter isn't until 1996; they have five years
(assuming they can't get the antenna opened up correctly) to build a relay
sat and get it out there.  If they make it small enough, they should be
able to get it onto a Titan and on to a two-year route (the same one the
Voyagers and Pioneers took) to Jupiter.  They've got three years...I'm
pretty confident that with the importance of this project, they can whip
something up and get it out there; remember, these guys (at JPL) can do
anything. :-)

>Perhaps a more sensible approach would be to jettison the reentry
>probe, change the second gravity assist and salvage some science by
>abandoning Jupiter and converting to a multiple asteroid flyby
>mission.  It could repeatedly swing by earth and/or mars to be
>directed onto flybys of new asteroids.  With luck, we could get
>pictures of half a dozen or so, with the data from each encounter
>played back over the low gain antenna at the next flyby of earth.

I dunno about this one.  Getting a look at the atmospheric composition
of Jupiter from the 'top' of the atmosphere on down to where the probe
stops transmitting would seem (to me) to be worth a *lot* more than
a few extra asteroid encounters, especially considering that the original
encounters can still be done.  Not to mention, the extra detail (as compared
to Voyager) we can get on the moons of Jupiter is worth a lot, especially
for Io and Europa.  Dropping all this for a few measly asteroids seems to
be a waste.
--
Matthew DeLuca
Georgia Institute of Technology      "I'd hire the Dorsai, if I knew their
Office of Information Technology      P.O. box."  - Zebadiah Carter,
Internet: [e-mail]    _The Number of the Beast_

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

Date: 27 Apr 91 03:15:33 GMT
From: pasteur!agate!lightning.Berkeley.EDU![e-mail]  (Frank Crary)
Subject: Re: slight problems with HLV's in general, Saturn or not...

In article <[e-mail]> [e-mail] (Fraering Philip) writes:
>2. I believe that on-orbit assembly will be much easier than you seem
>to believe.
The Soviet Union (or more correctly the Energia NPO, which operates the
Mir space station) offered to have kosmonauts do work in orbit for
$1,000,000/hour. This was in relation to baby-sitting a Japanese reporter.
They also said they would charge a similar rate for any experiment which
required the kosmonauts time. EVA (spacewalk) time would, they said, cost
more. Such EVA work would be needed to do on-orbit assembly.

The assembly of the international station, Freedom, will require
17 shuttle flights with intensive EVA schedules to assemble from 5 to 20
tonne elements. Assuming 5, 2-man, 5-hour EVAs/flight (a low number) this
would be 850 man-hours of EVA. At the soviet's rates this would cost
850 million dollars.

Soviet cost quotes may or may not be meaningful.

                                      Frank Crary
                      UC Berkeley

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

Date: 26 Apr 91 22:00:27 GMT
From: hela![e-mail]  (Allen W. Sherzer)
Subject: Re: Shuttle Reliability (was: Re: Saturn V and the ALS)

In article <[e-mail]> [e-mail] (Michael V. Kent) writes:

>>There is a good graph of this in the November 12,1990 Avation Week on page
>>27. It shows Shuttle actual flights vs flights on the manifest for the past
>>ten years. The first manifest had the 55th flight happening around the end
>>of 83. Eight and a half years later we have had less than 40 flights. Even
>>manifests made as recently as the Fall of 89 are off by a factor of two.

>Aye, but there is more to the story than that.  These predictions of 50 flights
>a year were with a fleet of 6 oribiters, not 3....

This is not relevant. The manifests I am refering to where made starting
less than a year from the first flight to the end of 89. At that time
NASA knew how many orbiters there would be and all that. For ten years
dispite all the experience to the contrary they where still predicting
twice as many flights as they could deliver. Just look at the graph and
you will see what I mean.

I don't doubt that manifests would be off in the first few years but
for ten years they have had little relation to reality.

>Going back to another AvWeek article, this one in the late '87 / early '88
>era, we will find NASA complaining that they are short 500 personnel to
>work on the Return to Flight.  They predicted that this Congressionally
>mandated hiring freeze would push Return to Flight back 3 to 6 months, and
>that Columbia would probably be delayed until 1989.

Even granting that it wouldn't have made any difference. All it would have
done is add even more cost to what is not the most expensive way to put a
pound in orbit.

>NASA has been addressing the lower flight rate.  They have increased Discovery
>and Atlantis from 25 to 50 man-day flight-capability, and Columbia to 75 man-
>days.  Columbia is about to undergo further modifications to extend that to
>110, with a possible further increase to 200 in the man-tended Space Station
>era.  Endeavour weighs in at 75 man-day capable, with possible increases to
>the 200 man-day level.

Won't be enough. Even if we give the Shuttle all the breaks on assigning
cost they still got to fly 20+ times a year to be priced reasonably. That's
three times the current (inflated) manifest.


   Allen

--
+-----------------------------------------------------------------------------+
|Allen W. Sherzer | If you love something, let it go. If it doesn't come back |
|   [e-mail]   | to you, hunt it down and kill it.                         |
+-----------------------------------------------------------------------------+

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End of SPACE Digest V13 #475
*******************