Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_4/V12_435.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/kb4f:PG00VcJMEuk5H>;
          Wed, 10 Oct 1990 01:33:15 -0400 (EDT)
Message-ID: <[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Wed, 10 Oct 1990 01:32:42 -0400 (EDT)
Subject: SPACE Digest V12 #435

SPACE Digest                                     Volume 12 : Issue 435

Today's Topics:
             space news from Aug 20 AW&ST
       Re: Reusable verses Expendable launch vehicles.
             Space Shuttle Radio
        Re: Private Space investment (1 of 4)
                 Re:
         Re: Motorola Cellular phone Comsats
                 Ore delivery
            Re: Ulysses Update - 10/06/90

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: 9 Oct 90 06:27:10 GMT
From: ubc-cs!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: space news from Aug 20 AW&ST

[Okay, I guess we can take it that the Canadian Post Orifice has definitely
eaten my copy of the Aug 13 issue of AvLeak, so there will be no summary of
it.  Stay tuned to see whether McGraw-Hill manages to foul up the renewal
of my subscription yet again... they've only had my cheque for three months
now...]

Orbital Sciences reports its financial position improving, with revenues
rising steadily and breakeven imminent.

NASDA postpones launch of the BS-3A broadcast satellite at least three
weeks due to a helium leak in ground-support equipment at Tanegashima.

Soviets press for more cooperative programs, citing tight budgets at home.
One project that they are studying themselves is a reusable manned spacecraft
to replace the rather old Soyuz.

First new science results from Hubble:  WF/PC image of star cluster in
the Large Magellanic Cloud shows considerably more detail than best
Earth-based images (pictures included for proof), and the situation
improves still further with computerized image enhancement.  This
cluster was a good target because it is bright; there is little hope
for successful image enhancement of dim objects, and even the bright
ones will need longer exposures than with correct optics.

Magellan enters Venus orbit Aug 10, checkout underway.  [This was before
Magellan acted up.]  Discussion of plans for Magellan after its 243-day
[1 Venus year] primary mission ends.  Objectives for the second and third
"cycles" are fairly well-established:  the second will fill the various
gaps in the first's coverage [caused by, e.g., the Sun getting between
Earth and Venus] and will start mapping of the south polar region (not
covered at all by the first cycle), while the third will fill remaining
gaps, improve south polar coverage, and study the detailed structure of
Venus's gravitational field by transmitting a beacon signal to the Deep
Space Network for precision tracking on some orbits.  There are a number
of ideas for later cycles:

- Remapping interesting areas at a consistent side-look angle, to give
    similar features similar appearance; the initial mapping campaign
    varies the side-look angle continuously due to varying orbital
    altitude during each pass.

- Remapping interesting areas while looking forward or aft along the
    ground track, to give better contrast on linear features that
    are perpendicular to the track.

- Stereo imaging by mapping interesting areas from more than one angle.

- Remapping possibly-active areas to look for changes.

- Rolling the spacecraft around its antenna axis to view the planet at
    different polarization angles.

- Viewing the same area from slightly different orbits to set up a
    "baseline" for interferometry, which might make it possible to
    compare phase shifts in the returned signals and do altitude
    measurement to millimeter resolution.  This might suffice to
    detect tectonic movements.

- Aerobraking [!] to bring Magellan down to a 300km circular orbit,
    giving higher mapping resolution and better gravity measurements.
    This will be a dicey procedure because Magellan was not designed
    for it, and there are also possible thermal problems with the
    lower orbit (since there is a lot of reflected sunlight from
    Venus's clouds).  Aerobraking will not be tried until everything
    else of major interest has been done, meaning the fourth or
    fifth cycle at the earliest.

Magellan is experiencing various minor problems [some of which may have
contributed to the later troubles] but is basically healthy.  The solid
injection motor behaved perfectly, and fuel consumption for attitude
control during the injection burn was lower than expected.  Magellan's
fuel supply should suffice for 10 years or more [well, this will be
revised downward a bit because of some of the gymnastics during the
troubles].  The Pioneer Venus orbiter tried to photograph the injection
burn using its ultraviolet polarimeter, but the rocket plume wasn't
bright enough to be visible.

China launches first Long March 2E, the heavy-lift configuration that
will be used for the Aussats.  Payload was a small Pakistani research
satellite and a "simulated satellite" believed to have been mostly
ballast to simulate an Aussat launch.

Picture of shuttle orbiters passing in the night :-), as Columbia rolls
out the pad past Atlantis, parked outside waiting for Columbia to clear
a VAB bay.  Atlantis suffered minor tile damage due to a hailstorm during
the wait, but it should be possible to re-glaze the affected tiles without
removing them.

Japan's Insitute of Space and Astronautical Science decides to initiate
development of an Atlas-class booster for science payloads.  This will
be a further upgrade of ISAS's current M-3S-2 solid booster, a design
which has already had many incremental updates [and is now somewhere
in between Scout and Atlas in capacity].  First flight 1994, carrying
a spacecraft for VLBI radio astronomy.  Launches will continue to be
from Kagoshima.

ISAS is planning several other astronomy and geophysics missions meanwhile,
and is looking at using the M-5 for Mars/Venus orbiters and a lunar mission
carrying several penetrators.  The long-term plan is to develop a series
of M-5-launched spacecraft, so that each major space-science discipline
will have a mission every five or six years.  [Resemblance of this to the
Solar System Exploration Committee's "Planetary Observer" series, largely
dead at the hands of NASA and Congress, is probably not accidental...  It
looks like the Japanese recognize a good idea when they see one.]  Early
development work for the lunar penetrators is already underway; three of
them would be launched from a lunar orbiter.

The Muses-A mission required some emergency revisions after an unexpected
error in final velocity from the M-3S-2, which put the orbit rather short
of the Moon.  (The error was only about 50 m/s, but that's a lot out there.)
The Hiten mother craft expended a fair bit of its control fuel fixing the
orbit.  A further problem appeared when it became clear that the Hagoromo
lunar-orbiter subsatellite had experienced a transmitter failure before
separation; lunar-orbit injection was confirmed instead by infrared
photography (from two ground sites) of its rocket plume.  Hiten has since
made another lunar flyby, and will make several more before its mission
ends; its primary purpose is to give Japanese engineers practice in such
maneuvers.

Major joint project in Japan (three government agencies and thirteen
companies) is near completion of development on a reusable spacecraft
meant to carry technological experiments up for long stays in low
orbit.  It will be launched by the third H-2, and recovered by a US
shuttle mission six months later, on its first mission.  (There are
doubts being raised about later flights, given the high cost of more
H-2 launches.)  Experiments on the initial flight include various
materials-processing packages, a large-space-structure deployment test,
an infrared astronomical telescope, and a flight test of a magneto-
plasma-dynamic thruster for possible use on future spacecraft.

Several other articles on Japanese aerospace activity, long on detail
and light on interest.
--
Imagine life with OS/360 the standard  | Henry Spencer at U of Toronto Zoology
operating system.  Now think about X.  |  [e-mail]   utzoo!henry

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

Date: 8 Oct 90 17:14:34 GMT
From: swrinde!cs.utexas.edu!sun-barr!newstop!texsun!convex!convex.convex.com![e-mail]  (Edward V. Wright)
Subject: Re: Reusable verses Expendable launch vehicles.

In <[e-mail]> [e-mail] writes:

>In a book written by Eugen Sanger shortly before his death in 1964
>(Space Flight: Countdown for the Future, 1965, McGraw Hill, an English
>translation of the original German edition of 1963) I was greatly surprised
>to read his conclusions about the economics of expendable and reusable
>launch vehicles. In the chapter "What Price Space Flight" Sanger makes a
>cost comparison between a resusable (which he called aeronautic)
>and expendable (which he calls ballistic) launch vehicle.

Um, ballistic and aeronautic do not mean the same thing as reuseable
and nonreuseable.  A ballistic launch vehicle can be reuseable (like
the proposed Phoenix or SSX) or nonreuseable (like Atlas, Delta, Titan,
and Saturn V).  A winged or "aeronautical" vehicle can be reuseable
(like the Shuttle) or expendable (some proposals from the 60's).

In addition, there are two types of winged space vehicles.  Some,
like the Shuttle, do not use their wings to create lift during
ascent.  Because the wings create drag, they are a net loss,
but they do give the vehicle are larger cross-range on reentry.

The other type of vehicle (such as Len Cormier's Windjammer and Space Van
and Germany's Sanger II) actually use their wings to fly into orbit.
This creates a net gain in payload.


What we really need is a true space transportation system built
to meet commercial needs, not a bunch of coverted artillery rockets
like Delta, Atlas, and Titan or a botched technological experiment
like the Shuttle.  As G. Harry Stine says, a true commercial space
transportation system capable of putting payloads into orbit for
< $50 per pound can be built with existing technology and shouldn't
cost more to develop than a commercial airliner.

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

Date: Tue, 9 Oct 90 17:20:56 EDT
From: [e-mail]
Subject: Space Shuttle Radio


Question posed for a friend:  can communications between the Shuttle and
Mission Control be monitored on radio frequecies such as short wave?  If so
, on which frequencies can this be done.

Thanks,
Marco C. Barbarisi              Simulation and Test Branch, Code 4320
[e-mail]       Naval Coastal Systems Center
Phone: [phone]            Panama City, Florida   32407

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

Date: 4 Oct 90 22:45:02 GMT
From: swrinde!zaphod.mps.ohio-state.edu!samsung!olivea!oliveb!felix!dhw68k!ofa123![e-mail]  (Wales Larrison)
Subject: Re: Private Space investment (1 of 4)

Brian, you had made a posting about financing private space
development.

> Suppose one wanted to really do something about space development,
>and not just bemoan the ineptitude of the current players, and
>suppose one could assemble the necessary science/engineering talent
>to put together a technically credible proposal.  How much venture
>capital could one expect to attract for the following?

   First, let's start by discussing venture capital.  There is
available in the U.S. over $4 billion in currently available venture
capital funds.  However, venture capital funding comes with several
different variations and strings attached.
  Venture capitalists want their money back.  They are hard-headed
business folks who invest their money, and try not to gamble it any
more than is absolutely necessary.  As a rule of thumb, they want
about a 20% annual rate of return on their investment, or they are
not interested.  If you come in and want a lot of their money
(typical venture captial startups are in the $1-5 million range),
then they want a big say in your company.
  [Note: there are also a lot of "angels" out there - these are
individuals who are willing to gamble more with their money.  But
they are harder to find].
   Typically, a venture capitalist will put in the first or second
round of financing with the expectation that they will be bought out
or be able to sell out their investment at a large profit.  First
round financing is typically to provide a prototype or initial unit.
Second round financing is what is necessary to put into place the
initial production or startup money.  Typically first round
financing is only about $100,000-$500,000 per venture, and usually
secured against some assets of the venture (they don't call these
guys "vulture capitalists" for nothing).  Second round financing
will typically go up to about $5 million or so and is designed to
show the venture is profitable, given enough investment.
  Then the venture capitalists get into "Mezzanine financing", where
they bring in the real financial deep pockets (pension funds,
insurance companies, banks, large corporations), to get the venture
into large scale production, marketing, and/or distribution.  At
this point tens of millions is not uncommon, but is done at a much
lower risk.  The venture capitalist begins selling out their share
of the company (at a profit of course) to the mezzanine financers.
  Finally, the venture will either provide enough of a cash flow
back to the venture capitalist to pay back the investment, or will
be offered at a "initial public offering" where the shares of
company owned by the venture capitalist are sold to the public.
  [Note: this is highly simplified - and no venture is every
financed or run exactly the same way.]
                                        (cont)



--
Wales Larrison
Internet: [e-mail]
--------------------------------------------------------------------------

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

Date:     Tue,  9 Oct 90 10:08 CST
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject:  Re:
Original_To:  SPACE


On 8 October Sean O'Malley ([e-mail]) wrote:

>I would like to present a deep space communcations
>protocol to my networks class. Does anyone have
>a good reference for such a protocol. I would like
>to cover the error correction and retransmission
>strategy used.

I don't trust this guy.  This is a transparent ruse.  It's clear to me that he
is really an interplanetary phone phreak! He wants to learn the protocols so he
can hack into Voyager and download dirty pictures.

During the first and second stage         Bill Higgins
flights of the vehicle, if a serious      Fermi National Accelerator Laboratory
irretrievable fault should occur and      [e-mail]
the deviation of the flight attitude of   [e-mail]
the vehicle exceeds a predetermined       SPAN/Hepnet: 43011::HIGGINS
value, the attitude self-destruction
system will make the vehicle
self-destroyed.
     --Long March 3 User's Manual
     Ministry of Astronautics, People's Republic of China (1985)

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

Date: 8 Oct 90 12:14:00 GMT
From: sgi!cdp![e-mail]
Subject: Re: Motorola Cellular phone Comsats




Aren't the Motorola sats going to be launched by Pegasus?

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

Date: Tue, 9 Oct 90 10:59 EDT
From: RYAN%CMIMGD <@VB.CC.CMU.EDU:[e-mail]>
Subject: Ore delivery
X-Envelope-To: [e-mail]

From: uceng![e-mail]  (daniel mocsny)
>Here is a question for would-be space miners: if you had a nice
>Ni-Fe asteroid parked in LEO and you wanted to bring down, say,
>500,000 tons of it per year, would you be better off:
>
>1. Quarrying out bits of it and sending them down in reusable
>re-entry vehicles;
>
>2. Fabricating one-shot re-entry vehicles mostly out of asteroid metal
>and loading them with mined ore;
>
>or 3. (My favorite) Blasting out large chunks of ore in the
>correct shape to serve as re-entry vehicles, and dropping them
>down onto a piece of deserted land or shallow water? (Obviously,
>you wouldn't want to be around during "deliveries".)
>
>Also, what would be the likely effect on the space-junk situation
>of hacking up an asteroid in LEO? (Heh heh.)
>
>
>[e-mail]


   Personally I've always liked the idea of foaming (easy in 0-gee) a
reentry aerobody out of steel, filling it with ore (or just foaming it for
delivery en masse), hanging a few rockets on it to put it into the
atmosphere, drop it in an ocean, and coming by later to tow the floating
foam steel body away.

   I've gotta admit, though, that just letting the chunks bang into a
specified piece of deserted real estate would be spectacular, cheap, and
probably quite a tourist attraction - "Look, OJ, here comes the 4:17
shipment, right on schedule!" **kerWHAM** "And the crowd is going WILD!
Beautiful splash pattern! What a delivery!" :->

                                                kwr

Internet: [e-mail]

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

Date: 9 Oct 90 02:59:02 GMT
From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!csri.toronto.edu![e-mail]  (Wayne Hayes)
Subject: Re: Ulysses Update - 10/06/90

In article <[e-mail]> [e-mail]
(Ron Baalke) writes:
>      Key Dates for the Ulysses Mission
>      ---------------------------------
>      02/08/92 - Jupiter Encounter
>      05/30/94 - Beginning of First Solar Pass (South Pole)
>      02/05/95 - Perihelion
>      05/30/95 - Beginning of Second Solar Pass (North Pole)

Am I reading this right?  Three years from Jupiter (aphehelion?) to
perihelion, and only one year from South to North?  How far away from
the Sun is Ulysses staying?  At
this time scale, I estimate Ulysses' semi-major axis at about 3 AU;
I understand that we don't really have to get close to the Sun to get
good readings of things like the magnetic field, it just spoils the
naive picture I had of Ulysses skimming majestically and bravely just
above the Sun's photosphere.  :-)

--
"Dad, what should I be when I grow up?"
"Honest." -- Robert M. Persig, _Zen and the Art of Motorcycle Maintenence_.

Wayne Hayes    INTERNET: [e-mail]    CompuServe: 72401,3525

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

End of SPACE Digest V12 #435
*******************