Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_6/V12_610.TXT

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Subject: SPACE Digest V12 #610

SPACE Digest                                     Volume 12 : Issue 610

Today's Topics:
           Re: Apollo LightCraft and Lasers
               Galileo News Conference
              Naive HST question
             Re: A philosophical question
          Re: ELV Support to Space Station (1 of 2)
           Re: living in the cradle forever
              Magellan Update - 11/26/90
           Peter Alway's book: Scale Model Rocketry
              Ulysses Update - 11/27/90
                  HST images
        Re: Translunar/interplanetary shuttle?
          Re: ELV Support to Space Station (1 of 2)
        Re: STS 38 Observation Reports -- red?

Administrivia:

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

Date: 26 Nov 90 17:28:25 GMT
From: news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Apollo LightCraft and Lasers

In article <[e-mail]> [e-mail] (Commander Krugannal) writes:
>     As for Person-Rating the system, the current plan that Leik Myrabo (the
>   professor heading up the project) has, was to use a module based on either
>   the Gemini Capsule, or on the extended 5 person Apollo Capsule. (Yes, I know
>   and I am sure he knows the plans are lost etc...).  But, he firmly believes
>   that the lifting capability is within the realm of possibility.

Oh, it's within the realm of *possibility*.  The trouble is, it's not within
the realm of practicality for a first-generation system.

To launch a human with proper protection, you need a minimum of a few
hundred kilograms by the looks of it.  This is unfortunate, because the
laser power required scales directly with launch mass.  RPI's older
"Mercury lightcraft" proposal, for a one-man capsule, specified use of
a one-gigawatt laser.  That is the right order of magnitude for a
several-hundred-kg capsule, even if you get tricky.

1GW is one Ghodawful enormous laser, far beyond anything yet built.

1GW beam-pointing optics are even farther beyond current technology.

Since lasers are inefficient, you will need several gigawatts of power.
Your local power company simply won't sell you that much.  They don't
have that kind of capacity lying around, especially when you want it in
bursts of a few minutes at random times.  You will have to build your
own power plant, and it will be among the world's biggest.

All of this adds up to a fair number of billions of dollars, and a decade
or more of time, even if nothing goes badly wrong.  This is too costly,
pushes the state of the art in too many directions, and is economically
viable only at traffic volumes vastly higher than today's.  Nobody is
going to fund it.

The most important development in laser propulsion in the last ten years
or so has been the realization that a useful system does not *have* to be
an enormous megaproject of this type.  A system which can launch hundreds
of tons a year -- a volume within the range of current demand -- to orbit,
at costs of perhaps as low as tens of dollars per kilogram (compared to
thousands per kg from current rockets) can be built with an order of
magnitude less money and an order of magnitude fewer technical challenges.
It can't launch men, but that's about the only thing it can't launch.
--
"I'm not sure it's possible            | Henry Spencer at U of Toronto Zoology
to explain how X works."               |  [e-mail]   utzoo!henry

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

Date: 26 Nov 90 23:16:04 GMT
From: usc!elroy.jpl.nasa.gov!forsight!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo News Conference


                 GALILEO NEWS CONFERENCE

     A news conference is scheduled at the Jet Propulsion
Laboratory, Pasadena, Calif., on Thursday, November 29 at 1:00 p.m.
EST to discuss recently returned data from the Galileo
spacecraft's Venus flyby last February.  Present spacecraft and
mission status will be described and plans for the Earth gravity-
assist flyby December 8 and associated scientific observations will
be outlined.

     Participants include Project Manager William J. O'Neil,
Project Scientist Torrance V. Johnson and key members of the
Galileo science team.

     The conference will be aired on NASA Select television,
Satcom F2R, Transponder 13, 72 degrees West longitude, with two-
way question and answer capability.

      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 28 Nov 90 19:04:12 GMT
From: isl1.ri.cmu.edu![e-mail]  (Robert Frederking)
Subject: Naive HST question

Something occurred to me recently, and even though it seems like a
fairly obvious idea, I thought I'd mention it in case no one has looked
into it.  It seems to me that it should be possible to use the HST in a
fashion similar to VLA radiotelescopes, to create an artificial
aperture the diameter of the Hubble's orbit.  If this were possible, it
would greatly increase the limiting resolution of the HST, probably
allowing optical detection of any planets around nearby stars, for
instance.

Naively, it seems like you could sum up image data for some part of an
orbit, say 1/N, and use the N observations per orbit as N elements of
an image that formed a ring around the Earth (since the Earth is
moving, I guess it would actually be a piece of a spiral).  I can
imagine that this would have all kinds of implementation questions, but
I was wondering whether there's some fundamental reason it wouldn't
work.  (Especially since I don't know much about the details of the
radiotelescope version.)  Do all the observations have to be made at
the same time?  Does the much shorter wavelength of light require
impossible positioning accuracy?  Etc.  If HST can't do it, would it be
possible in space in principle, say with N smaller orbiting telescopes?

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

Date: 22 Nov 90 13:16:51 GMT
From: hpda!hpcuha!aspen!hpcc05!col!hpldola!hp-lsd!oldcolo![e-mail]  (Keith Hamburger)
Subject: Re: A philosophical question

Alan Carroll says that the psuedo-Libertarian in him makes him opposed to
government spending on any project.  Well, being the Libertarian that I
am I am opposed to much the same.  I had a NASA official tell me on CIS
once that exploration and development are the same thing.  I contend that
they are much different and that as NASA applies funding, research and
propoganda are mutually exclusive.  Private, for profit ventures are
virtually guaranteed to be designed for the use and benefit of large
segments of the population, NASA ventures invariably appear to appeal to
small groups of people and intentionally exclude most of the world's
population.  I feel that the only reason for long term development of
space is to allow humanity to expand their environment.  This can never
be accomplished by the type of fail-safe high-dollar no-return (etc.
etc.) projects promoted by NASA.

The Earth is the cradle of mankind, but man cannot live in the cradle
forever.              Robert Heinlein

Keith L. Hamburger
State Chair, Colorado Libertarian Party
Vice President, Pikes Peak L5 chapter of the national space society
Secretary, Hummingbird Launch Systems
(etc.etc.etc.)
----I am my employer therefore all views expressed are my own.----
[e-mail]                   [phone](voice)
627 Skyline Ave.          Colorado Springs, CO  80905

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

Date: 29 Nov 90 14:39:50 GMT
From: sumax!amc-gw!thebes!polari![e-mail]  (Charles Radley)
Subject: Re: ELV Support to Space Station (1 of 2)


 From: [e-mail] Organization: The Internet Date: 16
Nov 90 15:43:00 GMT Subject: Re: LLNL Inflatable Stations
+Charles Radley mentions that he feels firing thrusters on
+a rotating station would not +be possible for stationkeeping.
+Isn't this exactly  what Galileo is doing? I was under the
+impression that it fired numerous thrusters whenever one was
+pointing in the right direction.
- Different siutations.   Space station in Low
Earth Orbit has an orbital period of 90 minutes and an orbital
plane which is constantly changing due to precession, but the
station's spin axis is fixed.  Even using Galileo type thruster
pulsing, the station spin axis would have to be slewed a large
angle every few weeks for a burn.   Galileo, on the other hand, is
on a cruise trajectory orbiting the Sun in a fixed plane, so much
smaller angule of slew is required for each burn, and the burns
are less frequent.
+    Overall impression: Mir (the only current successful space
+station)
-
You mean the only permanently manned
station, right ?  Otherwise you forgot Skylab.
+I think LLNL's design is at least a good start, but needs
+some fleshing out in terms of + launchers (hey, SSX is a
+fairly cheap thing to try, lets at least look  at it),
+equipment, and maybe some examination of the rotating-
+nonrotating design.
-
  I agree.   Once it is "fleshed
out" its dollar per pound cost to weight ratio will be about the
same as Freedom.
w
q

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

Date: 30 Nov 90 00:32:50 GMT
From: csus.edu!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: living in the cradle forever

In article <[e-mail]> [e-mail] writes:
>Heinlein did not say '...one cannot live in the cradle forever'. I
>think Konstantin Tsiolkovsky said it...

It is usually attributed to Tsiolkovsky.  However, at one point I tried
to dig up a specific citation for it, and couldn't find one.  I suspect
that this may have been a re-interpretation, or at least a rather free
translation, of one or two things that he *did* say, less poetically and
at greater length.
--
"The average pointer, statistically,    |Henry Spencer at U of Toronto Zoology
points somewhere in X." -Hugh Redelmeier| [e-mail]   utzoo!henry

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

Date: 26 Nov 90 20:04:15 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 11/26/90


                        MAGELLAN STATUS REPORT
                          November 26, 1990

     The Magellan spacecraft is performing nominally as it nears the
completion of orbit #906.  This is the 15th mapping orbit since mapping was
resumed on Saturday morning, after the on-board computer put the spacecraft
into a safe mode Friday evening at about 7:00 PM PST.

     The on-board computer detected errors in an uplink command sequence and
halted the stored mapping sequence.  This safe mode kept the High Gain Antenna
pointed to Earth, so communications were not lost.  Spacecraft controllers
worked through the night to correct the command errors and re-configure the
spacecraft for mapping.

     High rate playback of the radar data for orbit 887 was started shortly
after 8:00 AM Saturday morning, and radar mapping resumed with orbit 892 at
10:22 AM PST.  Thus, the incident resulted in the loss of 4 orbits of radar
image data.  Even with this loss, we have received on Earth 97.2% of the radar
image data since mapping was started on September 15.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 27 Nov 90 16:04:08 GMT
From: att!cbnewse!cbnewsd![e-mail]  (R. M. Jungclas)
Subject: Peter Alway's book: Scale Model Rocketry

As reviewed by Bob Kaplow:

        Peter Alway's book "Scale Model Rocketry" is now available. Mine
        arrived in the mail earlier this week. To get your own copy, send
        $19.95 + $2.50 s/h ($22.45 total) to:

                Peter Alway
                2830 Pittsfield
                Ann Arbor, MI 48104

        The book includes information on collecting scale data,
        construction of scale models, and several handy tables.
        Appendicies include plans for 3 sport scale models, a 1:9.22 D
        Region Tomahawk (BT50), a 1/40 V-2 (BT60), and a 1/9.16 Aerobee
        150A (BT55/60).

        I've only begun to study the book, but it certainly will be a
        valuable data source for many modellers. Most vehicles include
        several paragraphs of text describing the missions flown by the
        rocket, various specs including "NAR" engine classification, along
        with a dimensioned drawing, color layouts & paint pattern, and a
        black & white photograph.

        The vehicles include are the Aerobee 150A, Aerobee 300, Aerobee
        Hi, Arcas, Asp, Astrobee 1500, Astrobee D, Atlas Centaur,
        Atlas-Agena, Atlas-Score, Baby WAC, D-Region Tomahawk, Deacon
        Rockoon, Delta B, Delta E, Gemini-Titan II, Iris, Javelin, Juno 1,
        Juno 2, Little Joe 1, Little Joe 2, Mercury-Atlas,
        Mercury-Redstone, Nike-Apache, Nike-Asp, Nike-Cajun, Nike-Deacon,
        Nike-Tomahawk, RAM B, Saturn 1 Block 1, Saturn 1 Block 2, Saturn
        1B, Saturn 5, Scout, Standard Aerobee, Terrapin, Thor-Able, Titan
        III C, Titan III E, Trailblazer 1, V-2, Vanguard, Viking Model 1,
        Viking Model 2, and Wac Corporal.

        I hope that this goes over well enough for Peter to consider a
        "Volume 2". [Unpaid endorsement, #include disclaimers]


R. Michael Jungclas                    UUCP:      att!ihlpb!rjungcla
AT&T Bell Labs - Naperville, IL.       Internet:  [e-mail]

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

Date: 28 Nov 90 18:31:42 GMT
From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Ulysses Update - 11/27/90


                     ULYSSES STATUS REPORT
                        November 27, 1990

     Today Ulysses is about 47 million kilometers (30 million
miles) from Earth, traveling at a heliocentric velocity
of about 131,000 kilometers per hour (81,500 miles per hour).
A relatively quiet week is planned for the Ulysses
mission, with routine housekeeping of science experiments the
main planned activity.

     Ground controllers are continuing to study a wobble in
the spacecraft's rotation that first appeared on November 4 after
the deployment of Ulysses's 7.5-meter (24.3-foot) axial boom,
used as an antenna for the mission's Unified Radio and Plasma Wave
experiment.

     In order to use X-band radio through Ulysses's High
Gain Antenna, ground controllers believe it is necessary to
reduce the wobble later in the mission.  (X-band radio permits a
faster rate of sending data than the currently used S-band
transmitter.)

     In other activities, a precession maneuver -- a
thruster firing to correct the spacecraft's pointing at Earth --
was performed Monday, November 26.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 26 Nov 90 14:07:17 GMT
From: stsci![e-mail]  (Jay Travisano)
Subject: HST images

There have been a number of requests for Internet access to HST images.
It should be noted that all data from HST is proprietary for up to one
year, property of the scientists who propose the given observations.  In
the current phase of Science Verification, most of these scientists have
been involved in the development of HST and/or its instruments.  Unless
these folks (probably with NASA's approval) have decided to make their
data public prematurely, you are out of luck as far as getting actual
HST images (as opposed to just press-release photos).
--
    Jay Travisano
    Space Telescope Science Institute     Baltimore, Maryland
    [e-mail]
    UUCP:  ...!noao!stsci!jay        SPAN:  scivax::travisano

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

Date: 29 Nov 90 21:48:28 GMT
From: [e-mail]  (Millard Edgerton)
Subject: Re: Translunar/interplanetary shuttle?

If the engines(mains) are not restartable, HOW DO THEY FIRE TO DE-ORBIT?

THINK ABOUT IT!

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

Date: 29 Nov 90 14:55:55 GMT
From: sumax!amc-gw!thebes!polari![e-mail]  (Charles Radley)
Subject: Re: ELV Support to Space Station (1 of 2)


+    I think MMU's would be out of the question. They would weigh too
+    much at the lower levels. Also, MMU's require too much maintenance.
They are also rather expensive.

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

Date: 25 Nov 90 01:20:10 GMT
From: van-bc!ubc-cs!news-server.csri.toronto.edu!utgpu!watserv1!maytag!watstat.waterloo.edu![e-mail]  (Duncan Murdoch)
Subject: Re: STS 38 Observation Reports -- red?

In article <[e-mail]> [e-mail] (John Prentice) writes:
>If the red color of the shuttle was due to the passage of light through
>the atmosphere, as has been suggested by people on the net, then why
>haven't people been seeing this phenomena regularly over the last 30
>years?

But they have, and for much longer than 30 years.  The moon often appears
reddish during a lunar eclipse.

Duncan Murdoch

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

End of SPACE Digest V12 #610
*******************