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Subject: SPACE Digest V11 #536

SPACE Digest                                     Volume 11 : Issue 536

Today's Topics:
                Saturn Rockets
              Re: Equations and numbers?
           Aim For The Moon - model rocket contest
           Re: NSS protests Chinese launch pricing
              Re: Saturn Rockets
           NASDA launch slated [Forwarded]

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: 17 Jun 90 18:32:35 GMT
From: fernwood!portal!cup.portal.com![e-mail]
Subject: Saturn Rockets

I know that there were Saturn I,Saturn IB, and Saturn V rockets used during
the Apollo days but were there any other Saturn rockets ever designed or
built (A Saturn II for example)?
 If so, what were the specs on those rockets?
  [e-mail]

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

Date: 18 Jun 90 02:35:28 GMT
From: munnari.oz.au!uniwa!vax6![e-mail]
Subject: Re: Equations and numbers?

In article <[e-mail]>, [e-mail] (Andrew Salamon) writes:
> Hello all,
>
>    Someone once (or more, I dunno) posted a list of numbers that are
> usefull for space calculations (orbit radii, planetary masses etc).
> Could that kind soul please repost it and/or mail it to me?  What I am
> looking for right now is the amount of sunlight falling (?) on a unit
> area at both Earth orbit and Mars orbit, or better yet a way to
> calculate them.
>
> Many thanks.

It depends what you mean by "sunlight".  The terminology goes something like

Quantity        Definition        Units

Energy              Q            Joules (J)
Flux              dQ/dt            Watts (W)
Irradiance          dQ/(dt.dA)        W per square meter (W.m-2)
Monochromatic irradiance  dQ/(dt.dA.dl)        W.m-2 per micron (W.m-2.um-1)
Radiance          dQ/(dt.dA.dl.du)    W.m-2.um-1 per steradian
                        (W.m-2.um-1.sr-1)

Now I think you probably mean Irradiance at the earth's surface.  In this
case you consider the flux at the surface of the sun, spread out over a
spherical shell with the radius of the earth's orbit.  So,

Irradiance (normal to sun-earth axis) = Flux at sun surface
                                        --------------------------------
                                        4 . pi . (Sun-Earth distance)**2

Flux at sun surface       = 3.92e+26  Watts
Sun-earth distance (mean) = 1.496e+11 meters
Sun-Mars distance  (mean) = 2.279e+11 meters
(Source: Halliday, D. and R. Resnick (1978): Physics, Third edition.)

Therefore irradiance normal to sun-earth axis at mean sun-earth distance is
around 1393.8 W.m-2, and at mean sun-Mars distance is 600.6 W.m-2.

You should note that this a fairly rough calculation.  However it does apply
to any planet for which you know the planet-sun distance.  I believe that the
best value for the solar irradiance at the earth is around 1372 W.m-2 as
measured by the Earth Radiation Budget Experiment (ERBE) in polar orbit
(someone might want to correct me on that).

You can get more sophisticated by accounting for the the ellipticity of the
planets orbit about the sun, the albedo (reflectance) of the planets surface,
and the average irradiance over its whole surface area.

Some good references for this stuff are
Iqbal, M., 1983: An Introduction to Solar Radiation.  Academic Press, NY.
Liou, K.N., 1980: An Introduction to Atmospheric Radiation.  Academic Press, NY.

Anyway, hope that answers your question.

Cheers,
Liam.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Liam E. Gumley, Department of Applied Physics, Curtin University of Technology.
                          Perth, Western Australia.
                  Internet: [e-mail]
             Bitnet: [e-mail]
            UUCP  : uunet!munnari.oz!cc.curtin.edu.au!LIAM_GUMLEY

        "You're wrong Jana, your're wrong." - Sir Joh Bjelke-Petersen.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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

Date: 17 Jun 90 21:55:15 GMT
From: sam.cs.cmu.edu![e-mail]  (Vincent Cate)
Subject: Aim For The Moon - model rocket contest


1992 marks the 500 year anniversary of Columbus' trip to America.  It
would be fun to commemorate this with an "Aim for the moon" model rocket
contest.  The goal of the contest could be to get a small transmitter near
the moon as cheaply as possible (cost could be measured as total
newton-seconds of thrust for all stages).  The only restrictions would be
that only off the shelf "model rocket motors" could be used and that the
standard transmitter must be in the payload.  I think this limits people
to using "N" or smaller rockets.

It seems that using a small rocket to send a small transmitter to the
moon would be very possible.  It would take a rocket with a number of
stages starting with the larger size motors; however, I think you could do
it without going so far as making a 10 stage rocket that starts with
multiple "N"s.  To save you some arithmetic, let me point out that an "N"
has about 8,000 times the newton-seconds of an "A" motor.  The Isp on larger
"model" rocket motors is about the same as that used on "real" rockets.
This means that, for each stage, the delta-Vs should be comparable to that
of large rockets with a comparable fraction of total weight as fuel -
except for air resistance. :-)   If you only want to lift a very small
payload it should be possible to do it with a reasonably small rocket.

Such an event would probably be well covered by the media.  This would be
good for rocket enthusiast in general and model rocket companies in
particular.  It could be a world wide contest.  Companies could probably
be convinced to donate prize money or sponsor a rocket.

There could be prizes (first, second, ...) in a number of different
categories.  One might be the "cheapest" rockets to get within 100,000
miles of the moon and go beyond the orbit of the moon.  Another might be
for the rockets that come the closest to the center of the side of the
moon facing us (crash landings ok).  Another might be for the shortest
trip time.  Another might be for the cheapest to escape the Earth's
gravitational field.

The rockets would be on the expensive side for model rockets (not for
space in general) so whole clubs would probably work together on one
entry to the contest.  My guess is that a rocket could be built for under
$5,000 in parts.  Once there is a formal contest, kids could get sponsors
and donations.  Many clubs would be able to raise that kind of money for
such a fun project.  The radio could be made to transmit the names of the
sponsors, designers, and builders.

If lots of us recommend the idea to clubs and rocket manufacturers this
might happen.  Please pass the idea on.

Such a contest would dramatically demonstrate the contrast between 1492
and 1992.  Back then many people thought the world was flat, today kids
all around the world can send rockets to the moon!!!!!!!!

    -- Vince


PS   I think the solar sail race to Mars is so neat that it would be fun
     to other things kind of like it.  Since entering this contest is
     relatively cheap, it could let many people get involved.

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

Date: 17 Jun 90 22:23:43 GMT
From: usc!zaphod.mps.ohio-state.edu!rpi!uupsi!uhasun![e-mail]  (Jon Bloom)
Subject: Re: NSS protests Chinese launch pricing

In article <[e-mail]>, [e-mail] writes:
>
>     I read in a recent Clarinet article (by UPI science writer William
> Harwood) that NSS has protested (to the US govt.)  unfair pricing of
> Chinese Long March launch services, via a letter from executive
> director Lori Garver.  The primary complaint appears to be unfair
> pricing and competition with US launch providers.
>
>     I'm not throughly familiar with the issue, but I find it rather
> disturbing (albeit not surprising) that NSS has taken an egregiously
> anti-free-trade position such as this without any notice to, let alone
> consultation with, the members.  As far as I'm concerned, Douglas and
> the rest can damned well figure out how to price launchers cheaply if

How are the commercial firms supposed to compete with an entity that
is willing to lose money indefinitely?  Free trade is simply not what
the Chinese are promoting.  But that's irrelevant...

> they want a market.  Note that I despise the Chinese govt.; that's not
> the point.

I can't comment on the relative responsiveness of NSS and L-5, since
I don't belong to NSS and didn't belong to L-5.  But frankly, I consider
the behavior of the Chinese government to be a bigger issue that the
behavior of the NSS leadership.  In fact, the NSS should take the
position that other countries should not do business with the Chinese
while their current human rights abuses continue.  Even single-issue
interest groups have a moral duty to protect basic human rights,
their single-issue interest notwithstanding.

Jon

--
Jon Bloom, KE3Z                              | American Radio Relay League
Internet: [e-mail]         |
Snail:    225 Main St., Newington, CT 06111  | "I have no opinions."

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

Date: 18 Jun 90 01:09:08 GMT
From: mailrus!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Saturn Rockets

In article <[e-mail]> [e-mail] writes:
>I know that there were Saturn I,Saturn IB, and Saturn V rockets used during
>the Apollo days but were there any other Saturn rockets ever designed or
>built (A Saturn II for example)?

I wrote the following a while ago when there was an attempt underway to
set up a real frequently-asked-questions list for sci.space, and the
matter had come up several times...

Q.  Why were there Saturn 1, 1B, and 5, but nothing in between?

A.  (Henry Spencer)  The general name "Saturn" was applied to a large
    number of booster designs, most of which never flew.  They had
    internal names like "Saturn A-3", although even those got confused
    at times -- there were at least three different concepts called
    "Saturn C-3" at various times.  The three designs that actually
    reached full-scale development were the Saturn C-1, C-1B, and C-5.
    The final versions were officially named Saturn I, IB, and V.
    (There is no such thing as a "Saturn 5"; it's "Saturn C-5" or
    "Saturn V".)

Q.  Okay, what were the missing ones?

A.  (Henry Spencer)  The original Saturn development effort was aimed
    just at the first stage, and many different combinations of upper
    stages were considered.  Most of those looked vaguely similar
    to the C-1 and aren't very interesting in hindsight.  The C-2
    came close to actual development; it was a C-1 with more upper
    stages and was considered as a launcher for Dyna-Soar.

    The C-3 (ignoring some earlier designs with that number) was
    the Saturn V's little brother, with three F-1s in the first stage.
    The C-4 had four F-1s, and existed only briefly; somebody noticed
    that adding a fifth engine in the center was easy, and considerably
    increased performance, which gave the C-5.  C-3 and C-5 fought it
    out to be the lunar booster; C-3 looked cheaper and easier to do
    but the possible range of missions was limited by its smaller
    payload, so it lost.

    There was a C-8 that resembled some of the smaller "Nova" designs,
    with eight F-1s.  Its major use was the direct-flight lunar mission
    (no rendezvous or separate LM) and it died when that concept died.

Q.  What was the difference between Saturn I and IB?

A.  (Henry Spencer)  The Saturn I was the original Saturn first stage with
    a small liquid-hydrogen upper stage.  Apart from some test
    flights, it launched the Pegasus micrometeorite-measurement
    satellites.  There were plans to use it for early Apollo flights.
    Basically, the IB took over its major missions.  In hindsight,
    the I was a dead end that probably shouldn't have been pursued.

    The Saturn IB had a stretched version of the original first stage
    and souped up engines, plus a large liquid-hydrogen second stage
    identical to the Saturn V third stage.  It was used for Apollo
    tests, Apollo 7, the Skylab crews, and Apollo-Soyuz.
--
As a user I'll take speed over|     Henry Spencer at U of Toronto Zoology
features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry [e-mail]

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

Date: 17 Jun 90 22:43:44 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASDA launch slated [Forwarded]

[Forwarded for Yoshiro Yamada. -PEY]

NASDA will launch BS-3A satellite on August 24 from Tanegashima Space Center.

Yoshiro Yamada
Astronomy Section, Yokohama Science Center
[e-mail]

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

End of SPACE Digest V11 #536
*******************