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Subject: SPACE Digest V13 #306

SPACE Digest                                     Volume 13 : Issue 306

Today's Topics:
    SOLAR TERRESTRIAL BULLETIN - WARNING UPDATE - 21 MARCH
             Re: Linear launchers
              Ulysses Update - 03/21/91
              Re: More cost/lb. follies
                Re: "Follies"
               Galileo asteroid imaging
         Re: railguns and electro-magnetic launchers
        Question about Phobos mission results
      One Small Step for a Space Activist... Vol 2 No 3

Administrivia:

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

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

Date: Thu, 21 Mar 91 01:01:28 MST
From: [e-mail] (CARY OLER)
Subject: SOLAR TERRESTRIAL BULLETIN - WARNING UPDATE - 21 MARCH
X-St-Vmsmail-To: st%"[e-mail]"

                /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\

                        SOLAR TERRESTRIAL BULLETIN

                              21 March, 1991

                    Solar Terrestrial Warning Updates
                         Solar Information Update

                /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\


UPDATED WARNING INFORMATION

     The potential for major flaring has declined with the continuing decay
of Region 6545.  Major flaring is still possible, but will probably
originate from Region 6555.  The warnings have been updated as follows:


Cancelled Warnings:

   - POTENTIAL PROTON FLARE WARNING
   - POTENTIAL PCA ACTIVITY WARNING

Warnings still in effect:

   - POTENTIAL SOLAR MAJOR FLARE WARNING
   - POTENTIAL SATELLITE PROTON EVENT WARNING

These warnings will continue to be updated as necessary.


SOLAR INFORMATION UPDATE

     Region 6545 (S08W57) does not appear to be capable of producing any
further major flaring.  It has decayed to the point where major flares are
unlikely from this region.  It currently consists of 27 spots encompassed in
an FAI type optical configuration.  The region has decayed to a beta magnetic
configuration.  Although major flaring is not likely from this region,
continued low-level M-class flaring is possible.

     The most threatening region currently visible is Region 6555 (S24E41),
which has now been analyzed in greater detail.  This region is very large
(6,810 million square kilometers in area) and encompasses 64 visible spots
in an FKI optical configuration.  It has a magnetic beta configuration at
the present time.  Development into a more threatening magnetic structure
is certainly possible.  The region has an east-west inversion line.  Some
shear is present in this group.  This, combined with the complexity of the
system as a whole, could be enough to spawn an isolated major flare.  This
region could easily evolve into a major flaring source.  At the present
time, numerous M-class flares have been observed from this region.  It is
currently a fairly active region, but is not yet a major threat.

     An impressive surge was seen on the west limb today.  The region most
likely responsible is Region 6538, which is beyond the west limb now.  The
surge was bright and was observed between 03:40 UT and 05:12 UT on 20
March.  The event was associated with an M1.9 x-ray burst at 03:33 UT and
was also responsible for a moderate intensity Type II sweep which drifted
from 110 MHz to 22 MHz.  The surge was ejected out to a distance of about
0.3 solar radii.


**  End of Bulletin  **

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

Date: 21 Mar 91 21:02:37 GMT
From: agate!bionet!uwm.edu!linac!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Linear launchers

In article <[e-mail]> [e-mail] (John Roberts) writes:
>>Actually, a more fundamental problem is that anything launched to less
>>than escape velocity from Earth's surface ends up in an orbit that
>>intersects the surface.  It needs at least a *bit* of apogee kick anyway.
>
>Is there any hope of getting a deflection from the atmosphere (i.e.
>aerobraking) over the course of one or two passes, of sufficient magnitude
>to circularize the orbit to a point at which use of thrusters could be put off
>for several more orbits?

Not really.  The simple rule of thumb for such things is that when you
change your orbit, the new orbit always passes through the point where
you made the change.  So aerobraking and such inevitably result in an
orbit which intersects the atmosphere.  There are tricks you can play,
but nothing terribly promising for this case.

>If not of sufficient magnitude for that, perhaps aerodynamic maneuvering could
>be used to adjust the planes of the orbits so that projectiles launched at
>different times of day could be brought together.

This definitely sounds plausible, although I'd have to do numbers to see
how well it would work.
--
"[Some people] positively *wish* to     | Henry Spencer @ U of Toronto Zoology
believe ill of the modern world."-R.Peto|  [e-mail]  utzoo!henry

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

Date: 22 Mar 91 01:47:21 GMT
From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Ulysses Update - 03/21/91


                         ULYSSES STATUS REPORT
                           March 21, 1991

     The following orbital data was taken on the Ulysses spacecraft as of
9 AM (PST), March 19, 1991:

        Distance from Earth               185,654,657 miles (298,782,209 km)
        Distance from Jupiter             268,960,240 miles (432,849,549 km)
        Velocity relative to the Sun           56,058 mph        (90,216 kph)
        Velocity relative to the Earth         94,197 mph       (151,596 kph)

     Tape recorder operations based on recovering data acquired during the 16
hours out of view periods are continuing on a routinely scheduled basis.
Experiment reconfigurations have been carried out as required.  An average of
97.5% data recovery was achieved during the past week.

     An Earth pointing maneuver was performed on March 13.  A very small
nutation was observed which damped out after about 24 hours.  A close watch is
being kept for the possible return of nutation.  Procedures are available to
control it should it occur.  However, the period of maximum forcing has now
passed and it is considered unlikely to return during this period of the
mission.  The next period of solar forcing will occur when the spacecraft is in
the region of the South Solar Pole in 1994.

     A slew maneuver will be carried out on March 21.  Routine data gathering
operations will continue together with experiment reconfigurations as required.

     On March 18, a failure occurred just prior to the start of the pass at the
34 meter site at Madrid making it impossible to move the antenna.  The station
reacted promptly to make available a downlink only antenna and then to replace
the failed unit on the 34 meter antenna.  The antenna was restored and the only
serious impact to the pass was a delay in commanding the spacecraft.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab |
  ___| | | | |__) |/  | | |___   M/S 301-355        | Change is constant.
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 |
 |_____|/  |_|/       |_____|/                      |

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

Date: 20 Mar 91 15:56:07 GMT
From: skipper![e-mail]  (Mary Shafer)
Subject: Re: More cost/lb. follies

In article <[e-mail]> [e-mail] (Bob Pendleton) writes:

[An extremely cogent discussion of rocket technology]

                   Yours in Murphy

                           Bob P.

Just wanted to remind everyone that Murphy was working with rockets
when he formulated his now-well-known law.  Of course, they were
used to drive the sleds down the flat track here at Edwards, but
they were rockets.

I've always found it reasuring that Capt. Murphy was here at Edwards,
working in aerospace testing.  Things haven't changed much.
--
Mary Shafer  [e-mail]  ames!skipper.dfrf.nasa.gov!shafer
           NASA Ames Dryden Flight Research Facility, Edwards, CA
                     Of course I don't speak for NASA
 "A MiG at your six is better than no MiG at all"--Unknown US fighter pilot

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

Date: 20 Mar 91 20:50:46 GMT
From: argosy![e-mail]  (Kevin S. Van Horn)
Subject: Re: "Follies"

In article <[e-mail]> [e-mail] (Perry G Ramsey) writes:

Allen W. Sherzer writes:

>> A comparison with past efforts is interesting. According to (I think) G.
>> Harry Stein, both the Plymouth Rock and Salt Lake City colonies where
>> started with 50 middle to upper middle class famlies selling everything
>> they owned to pay for the voyage.

In the case of Salt Lake City, it was considerably more than 50 families who
undertook the trek -- it was an entire city (Nauvoo, Illinois) of many
thousands, although the advance group was probably on the order of 50 families.

Perry G. Ramsey replies:

>The obvious differences are that both Massachusetts and northern Utah
>support human life quite readily.  Food, water, building materials,
>etc. are all readily and cheaply available.

This is an overstatement in the case of Salt Lake City.  Jim Bridger, an
explorer who knew the area well, told the Mormons that they were going to
their deaths, and was so confident that the land was too arid and barren to
be cultivated that he offered to pay $1000 for the first ear of corn grown in
the Salt Lake valley.  Only the building of canals and the extensive use of
irrigation made the area capable of supporting a significant population.

------------------------------------------------------------------------------
Kevin S. Van Horn | The means determine the ends.
[e-mail]  |

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

Date: 20 Mar 91 17:15:24 GMT
From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax.uwo.ca![e-mail]
Subject: Galileo asteroid imaging

The question about Galileo imaging of asteroid 951 Gaspra prompts this
reply:

In November 1990 I spoke to Joe Veverka at Cornell about this - he is
planning the observation sequences. The range is about 1000 km (not miles)
but is not known very precisely because of uncertainty over the asteroid
ephemeris (especially its range from Earth). Lightcurves suggest about
a 9 hour period if I recall correctly (see a recent ICARUS paper), so
about 4.5 hours before closest approach the view is of the side which will
not be seen close up, assuming a low latitude approach (and we know very
little about the axis orientation). Those images will resolve few features
but will give an idea of shape. At closest approach the asteroid should
overflow a single frame, as Miranda did at Uranus, so a mosaic will be needed
for full coverage. The problem is with the image motion compensation - the
rate depends on the exact flyby distance and there seems little chance it will
be well known in time. The strategy will be to take as many redundant frames
as possible with different image motion compensation rates, in order to get
at least a few frames with very little smear. At least, that was the plan in
November. The lightcurve variations suggest a complex shape, and the images
may be quite dramatic.

Phil Stooke,
Department of Geography,
University of Western Ontario,
London, Ontario, Canada N6A 5C2

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

Date: 21 Mar 91 21:11:02 GMT
From: agate!bionet!uwm.edu!caen!news.cs.indiana.edu!ariel.unm.edu!triton.unm.edu![e-mail]  (John Prentice)
Subject: Re: railguns and electro-magnetic launchers

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>
>Can we see some more precise numbers?  Chemical guns routinely hit
>*ten thousand* Gs and more.  None of the EM-launcher proposals I've seen
>have gone higher than that.
>

As I said originally, I don't know what EM launchers are supposed to
do.  My experience is with military railgun systems where the accelerations
can be stupendous.  Someone else just posted a note saying 1500 g's.

John

--
John K. Prentice    [e-mail] (Internet)
Dept. of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
Computational Physics Group, Amparo Corporation, Albuquerque, NM, USA

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

Date: 21 Mar 91 19:59:38 GMT
From: usc!wuarchive!rex!rouge!pc.usl.edu![e-mail]  (Phil Fraering)
Subject: Question about Phobos mission results

I have a question about some of the results of the Phobos mission to
Mars. Does anyone know if there have been any follow-up papers of any
sort to those published in Nature in 1989? I am specifically looking
for any follow-ups to the plasma-physics and magnetometer experiments,
with special attention to:

1. The transport of oxygen ions out of the martian ionosphere. I
believe the authors of the paper (I just gave my copy to one of the
professors here) had written that the equivalent of all of the oxygen
(free and bound) in the martian atmosphere is 'carried off' (to use a
probrably grossly inaccurate and nontechnical term) every 100 million
years. For the purposes of comparison, Mars had running water on its
surface roughly during the period of the late heavy bombardment,
3.8 billion years ago.

2. A possible gas torus of some sort at the orbit of Phobos.

Phil Fraering
[e-mail]

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

Date: Wed, 20 Mar 91 10:14:37 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: One Small Step for a Space Activist... Vol 2 No 3


                  One Small Step for a Space Activist...
                                      by
                            Allen Sherzer & Tim Kyger

Last month we wrote about a heavy lift vehicle McDonnell Douglas proposed to
SDIO. Another alternative was proposed by Martin Marrietta based on their
Titan launcher and was called the Zenith Star Launch System (ZSLS).

Martin used their Titan IV as a baseline. Instead of clustering Titans as in
the Heavy Lift Delta, Martin decided to make the Titan IV bigger. The core
diameter of the Titan IV was stretched to 225 inches (from 120 inches), which
was the largest size tank dome they could build. This gave room for going from
two to five liquid fuel engines and from two to five Titan solid strap-on
boosters.

The second stage was stretched from 120 inches to 200 inches in diameter and
the engine was replaced with a higher thrust alternative with a new higher
expansion ratio nozzle. This stage ends flush with the payload fairing which
is an off the shelf Titan IV fairing with a collar on the bottom.

Like the Heavy Lift Delta, maximum use is made of off-the-shelf components. The
engines (solid and liquid) are the same as used on existing Titans. In
addition, the avionics suite exist today. All in all, 86% of the ZSLS dry
weight is made up of existing components.

In its initial version the ZSLS can put 118,000 pounds into LEO. Later,
with higher thrust strap-on boosters (in the works today), that weight
will go up to 150,000 pounds.

How much does this beast cost? we have two estimates on that; each made under
different assumptions. The Office of Technology Assessment (OTA) provided one
estimate in a document called "Launch Options for the Future". In it they
assumed that development would be funded under the usual rules used by the
government when they develop similar hardware. They estimate the development
cost at about $1.2B.

The second estimate comes from SDIO and Martin Marrietta. Just as with the
Heavy Lift Delta, ZSLS could be built for about $500M and future launches
can be had for below $250M (some sources say launch cost will drop to $150M
per launch in quantity). This is far cheaper than the Shuttle per launch yet
two to three times the payload.

Why the difference? OTA assumed the development would be managed like
any other government project: lots of oversight and risk assumed by the
Government. This adds cost both from the extra paperwork involved and the
fact that the contractor has no incentive for the program to be efficient.
SDIO assumed they were just buying a service at a fixed price. They would pay
a fixed price for one launch. The contractor owned the vehicle and was liable
for any extra costs. This gave the contractor the incentive to hold down
costs and save money.

Would you like to see one of these cheaper alternatives built? A lot of
people inside and outside Congress would like to fund this instead of the
ALS/NLV/ALDS alternative. However, it will be an uphill fight and your help
is needed. Read the article on Heavy Lift Delta and ZSLS in the September 1990
'Aerospace America' and then meet with your representatives and ask them for
their support.

                               Legislative Roundup

                               The Great Exploration
The federal FY '92 budget has in it $30 million for Department of Energy civil
space efforts: $7 million for nuclear propulsion, $6 million for space based
nuclear power generation, and $17 million for Concepts and Technologies. Some
of the Concepts and Technologies money will go toward the
development of Great Exploration hardware (inflatable modules, prototype mining
equipment, and other systems). If they meet with success this sum could be
augmented later with Internal Research and Development funds which could
double the size of the effort.

Getting this through will be very hard. The Appropriations committees will be
very reluctant to fund civil space with DoE funds despite the fact that DoE is
a member of the Space Council. The showdown won't be for a few months but
grassroots help is needed to show support.

Things to do:
1. MEET with your Representative and Senators. Ask them to write a letter to
Rep. Bevil (D-AL) and Senator Johnston (D-LA) supporting this new program.

2. If you talk with your Senator about DoE efforts in civil space don't give
th impression that this effort will hurt NASA. NASA's support in the Senate is
very strong. In fact, when supporters of commercial space legislation last
year told senators that the legislation would get NASA out of the launch
business it made it a lot harder to get the bill passed. Instead tell them
that the Great Exploration will help leverage NASA's efforts (which it will)
and that this effort is in line with the Augustine recommendations.

                             Omnibus Space Act
The Omnibus Space act from last year should be re-introduced around the time
you read this. It has been delayed because they received a lot of good feedback
from activists and they want to include some of the comments (again, we CAN
have an effect if we try). Some changes include:

1. The private sector will be able to put advertisements on the sides of US
   launch vehicles (just like the Soviets).
2. Bonds issued to raise money for spaceports will be treated just like regular
   municipal bonds for tax purposes. In other words, spaceport bonds will be
   treated just like today's airport and sea port bonds.

Allen Sherzer: [phone] (W) [phone] (H) [e-mail] (net)
Tim Kyger: [phone] (W) [phone] (H) [phone] (voice mail)

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

End of SPACE Digest V13 #306
*******************