Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v12_5/v12_549.txt

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Subject: SPACE Digest V12 #549

SPACE Digest                                     Volume 12 : Issue 549

Today's Topics:
             Re: orbiting bodies
Re: LLNL Astronaut Delivery (was Re: You Can't Expect a Space Station)
             New Shuttle Engines
                RadioM1/Rudak2

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Date: 8 Nov 90 05:33:19 GMT
From: swrinde!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!tellab5!balr!clrcom![e-mail]  (Bob Martin)
Organization: Clear Communications, Inc.
Subject: Re: orbiting bodies
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In article <[e-mail]> [e-mail] (Jonathan A Bishop) writes:
>[e-mail] (Pete Ritter) writes:
>
>Now, my question:
>Are the forces that synchronized the Moon's rotation and revolution the same
>forces that have nearly done so with Venus relative to the Sun?
>Does this phenomena only happen in a narrow band?

The Moon's rotation is locked to its orbital period by the tidal forces
exerted upon it by the Earth.  These tidal forces deform the moon
so that it bulges directly towards (and dirctly away) from the Earth.
If the moon were rotating at a different rate from the orbital period
these bulges would rotate too.  Since the bulge has mass, and would
rotate out of the line connecting the center of the Earth with the
Center of the moon there would be a very slight tug exerted  on the
Lunar bulge by the Earth which would tend to change the Moon's
rotational velocity to be closer to the rate at which it revolves.

This same effect is slowing down the rotation of the Earth and
driving the Moon into higher and higher orbits.  Very slowly of
course.

Venus must also experience tidal forces with the Sun and perhaps
the it is the Sun's tides which have given Venus such a slow
rotational period.  But the story is more complex.  Venus' rotational
period is 243 Earth-days which is _longer_ than its 255 day period of
revolution.  Thus Venus' rotation is retrograde.  There is
circumstatial evidence indicating that Venus is tidaly locked with
the _Earth_.  I turns out that when both planets are on the same side
of the sun, Venus presents approximately the same face towards the
Earth.  So it is possible that the Earth's meager (at that distance)
gravity is in some way responsible for the small Retrograde rotation
of Venus.

Another interesting result of tidal effects is the vulcanism of
IO.  IO is the innermost moon of Jupiter, which would certainly be
tidally locked to the planet if it were not for the influence of the
nearby moons of Ganymede and Europa.  These moons tug on IO and
force it to continue rotating even against Jupiter's tremendous
tides.  This means that the tidal bulge of IO is continually dragged
around causing IO to be alternately stretched and pulled.  This causes
frictional heating which has melted the interior of the moon and causes
it to spew forth its innards in copious volcanic flows.

--
+-Robert C. Martin-----+---------------------------------------------+
| [e-mail]    | My opinions are mine.  They aren't anybody  |
| uunet!clrcom!rmartin | elses.  And thats the way I want to keep it.|
+----------------------+---------------------------------------------+

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Date: 10 Nov 90 18:51:40 GMT
From: sumax!polari![e-mail]  (Charles Radley)
Organization: Seattle Online Public Unix [phone]
Subject: Re: LLNL Astronaut Delivery (was Re: You Can't Expect a Space Station)
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Why not tell the aboriginies and the greens about this:-

Most launch sites are wildlife sanctuaries.

For example, Kennedy Space Center, Cape Canaveral Air Force Station,
and Vandenburg Air Force Base, all of which I know well first hand.

KSC is crawling with alligators, manatess, and birds of infinite
variety.  When working at KSC for Galileo preps there was a Shuttle
launch, and I watched the tourists line up in their thousands on the
causeway.  Little did they know, a couple of hundred metres behind
them was a waterway where I used to see a pair of alligators have
their morning swim on my daily commute.

(They have crocodiles in Queensland don't they ?)

   In all those locations the wildlife is protected from the
development going on outside.   Those launch sites all border on
prime real estate, which property develpers are overbuilding as fast
as they can.

Queensland is rather more remote, but with a booming tourist
industry, is slowly becoming more developed, and a launch site there
would protect the local ecology. Launch sites, for safety reasons,
tend to prefer large open space where rockets can explode and stages
can drop, and propellant can leak, without hurting people or property.

At Vandenburg a week ago I saw a heard of wild deer next to the
flight line, and a single Roe deer in the middle of the industrial
area.  There is also a small pride of mountain lions in a canyon
behind the Atlas pads on the south base.

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

Date: 11 Nov 90 08:48:10 GMT
From: sdd.hp.com!think.com!mintaka!ogicse!milton![e-mail]  (Brett Vansteenwyk)
Subject: New Shuttle Engines

Not long ago it was noted that the first of Endeavour's engines had arrived
at KSC.  Some mention was made that these engines were "new and improved".
I was hoping that more would be said to elaborate on this, but I will go
ahead and pound out a few questions...

[1].Are these new engines useable in the older shuttles?  It would seem
important considering the considerable swapping of engines and their parts
that seems to go on in the refurbishment process.

[2].Are these engines part of a more "mature" system?  In other words, has
there been a batch of changes made to the manufacture/design of these "new"
engines that will improve their servicability and ease of refurbishment?

[3].(Slight rehash from [2]).  While the SSME's have not been a particular
saftety problem (in hindsight, at least relative to the SRB's), their turn-
around launch to launch has been a nightmare for costs--so much of each
engine needs to be rebuilt.  This seems to stem from the fact that this
design pushed the envelope for efficiency and thrust to weight ratio.
This engine has been in use for almost 10 years, and it would seem
that it could be classified as a "mature" system by now--a learning curve
with subsequent reduction in refurbishment costs as well as a more reliable
engine.  Is there evidence to indicate that this has happened?  If not so
far, will these new engines allow hope for that to happen in the future?

[4].Whenever I see any discussion about new launcher development, I never,
or almost never see any suggestion to using the SSME's, nor do I see any
indication of an engine derived from SSME technology.  The tendency is
to discuss systems originating 25 or even 30 years back.  I am assuming
that the SSME was the most recent major engine development.  Has all the
time and talent spent to make the SSME work been wasted on what is now
considered an evolutionary dead-end?  While it may seem disconcerting,
it seems where the evidence is pointing.

[5].If not the evolutionary dead-end as postulated in [4], could there be
an SSME derivative for an expendable launcher, or a restartable version
for purposes similar to the Saturn 3rd stage system?  (All in all, is
it meaningful to think of derivatives of this technology since this is
the newest technology by far?)

    Just some random thoughts.
        --Brett Van Steenwyk

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

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Date: 11 Nov 90 21:53:19 GMT
From: eru!hagbard!sunic!news.funet.fi!funic!santra!hila.hut.fi![e-mail]  (Kaj Wiik)
Organization: Helsinki University of Technology, FINLAND
Subject: RadioM1/Rudak2
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SB AMSAT @ ALL < RK3KP $03B004RK3KP
RadioM1/Rudak2
R:901103/0935z @RK3KP  [NORD><LINK MOSCOW, TheBox 1.6 OP: RA3APR]

de RK3KP @ RK3KP




                      RADIO-M1/RUDAK-2
                      ================

        The joint work of AMSAT-U and AMSAT-DL for creating the
        set of equipment for the satellite RADIO-M1/RUDAK-2 is
        completed.

        The idea of the cooperation between two groops in the
        USSR and Germany appeared in the spring 1989. The discussion
        about what and how it is necessary to do lasted till the meeting
        of the representatives of two groops in Surrey in July 1989 when
        the mutual preliminary agreement about the cooperation was
        signed.

        The final version of the agreement about the cooperation
        was signed in the autumn 1989, when the work over the project
        was being done.
        According to the mutual agreement the group ORBITA AMSAT-U
        develops and makes the linear transponder, command radio link,
        telemetry system, power supply system and decides all the
        questions with the official organisations about the placing of
        the equipment and launching.
        The RUDAK group of AMSAT-DL developes and makes the digital
        part so called RUDAK-2. This part includes a digipeater and a
        mailbox (protocol AX-25).It also provides other possibilitys
        for the experiments on the  transmitting  of the information
        using modern digital methods.  It also contains input and
        output RF circuits.
        The complete set for ground command station is developed
        by Amsat-U-Orbita and Amsat-U-Sputnik groups.Rudak group
        brings special  digital part for it.
        During the launch and orbital test period ground command
        station will be situated in Molodechno at UC1CWA and in
        Moscow at RK3KP. The ground command station for Rudak-2
        only will be situated near Munchen-DK1YQ and near
        Hannover-DB2OS.


        The final agreement was signed:
        from the side of AMSAT-U-ORBITA  the technical director of
        the project "RADIO-M1" - V.Chepyzhenko  - RC2CA;
        from the side of AMSAT-DL - the president of it K.Meinzer -
        DJ4ZC.
        The coordinators of the project are P.Guelzow - DB2OS and
        L.Labutin - UA3CR



                 SPECIFICATIONS OF THE RADIO-M1/RUDAK-2
                 ______________________________________


          Mission
          -------

        Piggy-back onboard the USSR geological research
        satellite.


          Launch and Orbit
          ----------------

     1. Launch (scheduled)
        Time:         Late of 1990, day is not fixed.
        Launch site:  North Cosmodrom Plesetsk

     2. Orbit (planned)
        slightly elliptical polar orbit
        appogee:      1000 km
        Inclination:  83 degrees
        Period:       105 minutes


          Satellite specifications
          ------------------------

     1. Dimension and shape
        Cylinder of hight about 4   meters
                     diameter   1.8 meters

     2. System configuration
        Professional geological research equipment, telemetry
        system, command link equipment, transponders and power
        supply, thermal control.
        Amateur linear and digital transponders, telemetry
        system, command link equipment, power supply.

     3. Attitude control
        Satellite attitude will be maintained by the earth's
        gravity field by a rod 9 meters length pointing away
        from the earth.

     4. Planned service life: 3 years


          Radio-M1/Rudak-2 System specifications
          --------------------------------------

     1. System configuration
        Two sets of the equipment will be installed aboard the satellite:
        Linear transponder #1 mode B and RUDAK-2 with subsystems
        Linear transponder #2 mode B with subsystems
        The first set is concidered to be the main. The second one is
        reserve. It can be taken into operation in the case of
        failure of the first one.

     2. Commands

        Equiped with real-time program command function

     3. Beacons and telemetry #1 set
        CW telemetry 8 channels         145.822 MHz   0.2 Watts
        Digital telemetry 30 channels   145.952 MHz   0.4 Watts
                                        1100 bps,BPSK/FM, deviation 2kHz
        Digital telemetry Rudak-2       145.983 MHz   3.0 Watts
                                        BPSK 1200 bps AX.25 (like FO-20)

     4. Beacons and telemetry #2 set
        CW telemetry 8 channels         145.948 MHz   0.2 Watts
        Digital telemetry 30 channels   145.838 MHz   0.4 Watts
                                        1100 bps,BPSK/FM, deviation 2kHz
        Digital telemetry 30 channels   145.800 MHz   2.0 Watts
                                        1100 bps BPSK/FM, deviation 2kHz

     5. Transponders #1 set

    (1) Linear transponder: inversely heterodined translator
        Uplink passband             435.102 to 435.022 MHz
        Downlink passband           145.852 to 145.932 MHz
        Transmitter output max      10 Watts
        Bandwith  (3db)             80 kHz
        Uplink EIRP required about  100 Watts

    (2) Digital transponder Rudak-2: digipeater and store&forward
        packet communication (AX.25), telecommunications experiment
        with   digital  signal  processing  up  to  nearly  20 kHz,
        1 MByte RAM disc, four separate uplink channels.

        Uplink frequencies: RX-1  435.016 MHz 1200bps,FSK,NRZIC/Biphase-M
                            RX-2  435.155 MHz (AFC) 2400 bps,BPSK, Biphase-S
                            RX-3a 435.193 MHz (AFC) 4800 bps,RSM
                            RX-3b 435.193 MHz (AFC) 9600 bps,RSM
                            RX-4  435.041 MHz (digital AFC) RX for RTX-DSP

        Downlink frequency:       145.983 MHz     3 Watts

        The downlink can be switched to the following operating modes:
        Mode 1: 1200 bps, BPSK, NRZI,(NRZ-S) (like FO-20)
        Mode 2:  400 bps, BPSK, Biphase-S (Oscar-13 beacon)
        Mode 3: 2400 bps, BPSK, Biphase-S
        Mode 4: 4800 bps, RSM, NRZIC (Biphase-M) (like 4800 bps uplink)
        Mode 5: 9600 bps, RSM, NRZI (NRZ-S) +Scrambler (like 9600 bps uplink)
        Mode 6: CW keying (only for special events)
        Mode 7: FSK (F1 or F2B),e.g. RTTY, SSTV, FAX, etc.(for special events)
        Mode 8: FM modulated by D/A signals from DSP-RISC processor (speech)


     6. Transponder #2 set

        Linear transponder: inversely geterodined translator
        Uplink passband             435.123 to 435.043 MHz
        Downlink frequencys         145.866 to 145.946 MHz
        Transmitter output max      10 Watt max.
        Bandwith  (3db)             80 kHz
        Uplink EIRP required about  100 Watts

     7. Antennas

    (1) 435 MHz receiving antenna (shared by analog and digital modes):
        Helix  +3 db max RHCP.

    (2) 145 MHz transmitting antenna:
        Half wave dipol

     8. Power supply

        From main power supply system up to 100 Watts
        Set #1 consumption  47 Watts
        Set #2 consumption  40 Watts

     9. Weight

        Set #1 approx.  28 kg
        Set #2 approx.  22 kg

    10. Size:  480x400x300 mm^3 each set.

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

 03.11.90      __ ends____                  de UA3CR
/EX

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

End of SPACE Digest V12 #549
*******************