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Aerospace Autonomous satilite

  1. Feb 14, 2004 #1
    <first post>
    Would it be possible to program an autonomous satilite? (collecting its own Fuel and power from the sun?)
    It is possible to collect hydrogen from solar winds
    It is possible to charge hydrogen ions like a battery (static charge, using a van-dagraph generator)
    Salilites have solar cells
    Ion drives can use hydrogen as a fuel

    Would it also be possible to program said satilite to use behaviours (find light, find fuel, avoid colision) and a simple state machine (states triggered by formula (1-fuelintank) * (1-powerleft) > 0.5)
    It would need some way of finding hydrogen (look for spectoral lines?)
    And some way to ovoid obsticals (Radar or lidar?)
    Shielding would be a must (something that would be charged by the solar winds- like sheets of aluminium foil with paper?)
    Perhaps magnitising outer layers of shielding will deflect solar winds?

    </first post>
    That was my first post, it wasn't too bad; was it :smile:
    de Nice codre
  2. jcsd
  3. Feb 15, 2004 #2


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    Greetings !

    The particle density of the solar wind is too low.
    I once considered scooping up particles off the top of the
    atmosphere in various ways for a LEO settelite, but
    even there the particle density is too low for this
    to be practical and hydrogen is quite innefficient
    as an ion thruster propellant due to its low mass.

    Of course, if you weren't limmited in terms of power,
    then all that wouldn't matter for propulsion purposes,
    but then, you'd probably not require such "desparate"
    measures as collecting particles in space. :wink:

    Live long and prosper.
  4. Feb 15, 2004 #3
    Perhaps, if this is a communications satilite (and uses the behaviour system) it would 'Find' the van-allen radiation belts (there full of charged plasma).
    For the shielding, does that look like a capacitor to you also?
    (just found that, i thought of using it to stop magnetic fields-ferros and non-ferros layers), would it generate its own magnetic field? (that would capture solar wind-theres a project which dows it p2?2)

    Do you think the ionic battery idea is worthwhile;
    it would use a container of ionic hydrogen (plasma) and charge it by adding electrons from the hull using a van-da-graph generator, that would generate a charge difference between the (insulated) containment vessel and the ship, you could then use that (via step-down transformer?) to power the ships systems.
    (if not it goes in the junk-pile, with my self-reconfiguring transformer)
  5. Feb 15, 2004 #4


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    hmmm... I'm no expert in this stuff and beyond that -
    I didn't quite understand your idea in full, I think.
    However, the, ussualy negative, charge on the hull
    is insignificant, and if you attempt to increase it
    it could have some unfortunate effects for your
    settelite's systems. So, there's hardly any energy gained,
    unless you're, heaven forbid , in a solar flare or something.

    Just building up the negative potential with the inside and discharging won't work either - you need to get rid of the
    electrons in the first place and then all you get is a single discharge and you have to repeat the cycle - there's no
    energy gain.

    You could use the photoelectric effect on a capacitor
    exposed to sunlight to create a voltage - but that's
    what solar panels do - nothing new there. :wink: You can
    also heat something with sunlight - and use a
    thermal generator, mechanical or pietzoelectric. That
    can work for lower wavelenghts that are useless for
    photoelectricity, but such systems are ussualy too massive
    and ineffective.

    Next you have decaying radio isotopes and beyond that -
    nuclear reactors. Diesel could work too - but a land-rover
    engine on a settelite is a bit too costly.

    Live long and prosper.
  6. Feb 15, 2004 #5
    Uhmm a Vandergraph generator needs an electric motor to make it run, you know, something to turn the belt inside of it, so where's the power for that coming from?
  7. Feb 15, 2004 #6
    The vandagraph generator (and hydrogen tank) is used as a Battery you charge the hydrogen tank from the electrons from the outer layer of the shielded hull (it has layers like a capaciter, ferros and insulating non-ferros layers) you can then discharge the tank back into one on the other layers (the next ferrous layer down), or the outer layer.

    The electical discharge is used to power the engine (my other post in this forum, a vasimr/ion propultion drive), the final stage requires a High powered pulse of electricity to run the coil gun bit.

    Perhaps a lidar (for finding hydrogen and avoiding other elements) would be needed perhaps something like;
    if hydrogenlines > 0 then
    mx = (hydrogenlines) / (totalfeldlines)
    mx = 0
    end if

    If you don't understand anything, can you tell me what?
    I have a slight problem with expressing my ideas
  8. Feb 16, 2004 #7
    Well, O.K. Try *here* First...."Van de Graaff"
  9. Feb 16, 2004 #8
    A Van de Graff generator is used to create very large voltages, and could be used to power an ion engine. Where are you getting the energy to run the Van de Graff, because as said above a motor runs the belt used in the generator.
  10. Feb 16, 2004 #9
    1. The power to run the van-da-graph generator comes from the SOLAR CELLS
    2. I am using the hydrogen tank as a Battery, i charge it up using the van-da-graph generator, which moves electrons into the hydrogen. i connect the negitive lead to the hydrogen tank, the tank is conductive and is sealed by an insulating coating.
    3.I use the power (voltage differential) to power the propultion systems.
    4.Can people please read and understand my posts, i have already explained this in EVERY ONE of my posts; do you get annoyed if you have to repeat the same thing again and again and again and again.
  11. Feb 17, 2004 #10


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    Staff: Mentor

    Solar cells create a specific amount of power and conservation law applies: any time you convert it to another form, you lose some. For that reason, adding a van de graff will only reduce the power of the engine.
    Welcome to the site, but yes, part of the problem was that your first post wasn't very clear. You mentioned solar cells, but didn't say anthing about them. The first part of the post was a series of seemingly unconnected statements/questions.
  12. Feb 17, 2004 #11
  13. Feb 17, 2004 #12
    Thank you russ!....I had wondered why the use/mention of the generator...and that is what I had thought/known too.
  14. Feb 19, 2004 #13
    What do you think about the idea?
    (FSM meets satilite?)
  15. May 27, 2004 #14
    Maybe As A Missle Defence Shield Sort Of Thing?
  16. May 27, 2004 #15


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    Hmm... So where do wa stand now ? I'm not sure.
    Do you wan'na use a van-de-graff to create a high
    voltage ? Well, if high voltage is 1 KV like what you need
    for an ion thruster, for example, than I suppose that
    this could work somehow. The external electrode will
    always stay close to neutral due to the plasma outside,
    the internal electrode could be charged to a negative
    voltage and the return loop would be your electrical circuit.
    I don't know what top effeciency this system can
    reach, but I don't suppose it's very high - kinetic energy
    of you belt converted into friction/heat to release and capture
    electrons. Plus, it may be directly applicable to some systems,
    I don'no, but for an ion thruster you'll have to convert
    the energy 'cause a negative and ground potential are no good
    for it, so you loose further in efficiency.

    That's how I see it. But I think we also need an expert opinion here.

    Live long and prosper.
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