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  1. Joined
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    07 Aug '20 18:494 edits
    I watched this video about this and I totally agree with the first 4 reasons the commentator says but I actually think the last reason he gave is pretty irrelavant and flawed;

    YouTube

    He explains some of the reasons but I think there are some significant more reasons; So I think there is still at least 5 good reasons even if he got one wrong.
  2. School Hill
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    08 Aug '20 02:09
    @humy said
    I watched this video about this and I totally agree with the first 4 reasons the commentator says but I actually think the last reason he gave is pretty irrelavant and flawed;

    https://www.youtube.com/watch?v=ESQ1bKd7Los

    He explains some of the reasons but I think there are some significant more reasons; So I think there is still at least 5 good reasons even if he got one wrong.
    Good post, in my time here - pure fantasy.👍
  3. Subscribersonhouse
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    09 Aug '20 20:21
    @humy

    So how it might play out: We send folks to Mars and they come back almost dead.
    A moratorium is put on that bit and another 50 years goes by with no Mars trips.
    But in the meantime, propulsion systems like Casimr which cuts the trip time to a month rather than 200 odd days would be a big help for radiation damage.
    Also in the meantime the art of chemistry builds up to the point where the soil issue can be dealt with and maybe some work done on thickening up the atmosphere with directed comet strikes or some such, get more water and O2 and N2 in the atmosphere maybe to the point of human breathability which will help with the cosmic ray issue.
    So work would continue on keeping things dust free inside the habitat, maybe charged air filters or some such scrubbing the air 24/7.
    But even a first trip may solve the problem of whether life exists there in the past or even now microbes and then the study of what does the Mars version of DNA look like? Totally different than Earthy life? Exactly the same? Either way sends science on brand new avenues of research.

    So I think the first trip will be a go no matter what the dangers are and the crew would know that full well.

    Personally, if I was in charge, I would through a couple billion into advanced nuclear propulsion systems to cut the time travel from 200 days to a week or two.

    But it looks like it is going ahead at the snail pace we use now, 200 days and the hell with what happens to the crew.

    I think there is work ongoing regarding light weight radiation shielding which will help and may be ready by launch time.

    Still the other issues raised, low gravity, dust contamination and the like will still be a problem for a long time. Seals will have to get a lot better than during Apollo days for sure.

    And the radiation danger gets a thousand times worse if the spacecraft intercepts a corona blow, that might kill the crew within a week.

    But solar weather is much better understood now and I think we can more or less predict one of those solar storms that would kill.

    Bottom line, bad idea or not, it will go forward. Whether the crew is alive when they get to Mars is another issue.
    I'm sure the ground stations would know pretty much exactly what condition they are in health wise since instrumentation is a very live art right now and will only get more powerful in the future.
  4. Standard memberbunnyknight
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    09 Aug '20 23:02
    @sonhouse said
    @humy

    I think there is work ongoing regarding light weight radiation shielding which will help and may be ready by launch time.

    Still the other issues raised, low gravity, dust contamination and the like will still be a problem for a long time. Seals will have to get a lot better than during Apollo days for sure.

    And the radiation danger gets a thousand times worse if the spacecraft intercepts a corona blow, that might kill the crew within a week.
    Do you think a strong artificial magnetic field could shield the capsule from excess radiation?
  5. Joined
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    10 Aug '20 06:093 edits
    @bunnyknight said
    Do you think a strong artificial magnetic field could shield the capsule from excess radiation?
    No. At least not by much.
    A magnetic field may help defect some, but (and contrary to popular belief) not all, of the solar wind particles but wouldn't deflect X-rays and gamma-rays from distant supernovae explosions and other distant high-energy cosmic events.
    This is because a magnetic field can only significantly deflect charged particles and not electromagnetic radiation.
    But for the people inside the capsule this would be just one of their significant longer-term problems.
  6. Joined
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    10 Aug '20 08:2710 edits
    @bunnyknight

    A more effective albeit not necessarily a more practical way to shield people inside a space capsule would to surround it with thick layer of lead or some other radiation absorbing material. Unfortunately that would also massively increase the payload and thus make the costs of the whole mission even further totally spiral out of control.

    In my opinion the whole idea is a dangerous totally-insane totally-irresponsible total-waste-of-money pointless non-starter and we should stick to only unmanned space missions to Mars at least for the next 100 years by which time our technology might have improved enough to make the whole idea significantly less insane.
  7. Subscribersonhouse
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    10 Aug '20 14:14
    @bunnyknight
    The problem with mag fields is the size issue. The field around Earth is thousands of kilometers wide. The field lines have to be very long to herd radiation into the north and south poles.
    The problem with fields is the radiation is not stopped, just herded. The radiation gets concentrated around the poles. So the field lines don't actually stop anything.
    With that in mind, what would work is a redesign of the spacecraft where it would be shaped like a donut and with that you would aim the north and south poles to the inside of the donut where nothing is there so the field lines would just herd the radiation through the center of the donut.
    That is about the only way you could deal with radiation with field lines.
  8. Standard memberbunnyknight
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    10 Aug '20 15:13
    @sonhouse said
    @bunnyknight
    The problem with mag fields is the size issue. The field around Earth is thousands of kilometers wide. The field lines have to be very long to herd radiation into the north and south poles.
    The problem with fields is the radiation is not stopped, just herded. The radiation gets concentrated around the poles. So the field lines don't actually stop anything.
    Wi ...[text shortened]... the center of the donut.
    That is about the only way you could deal with radiation with field lines.
    The field around Earth may be thick, but it's very weak per given volume, so perhaps we could compensate for that by making it a million times stronger. The deflected radiation could then be guided through a central core of the spacecraft.
    Then there's the ozone layer -- if we could simulate the property of the ozone layer it could offer additional protection.
  9. Subscribersonhouse
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    10 Aug '20 15:181 edit
    @bunnyknight
    I think you still don't get it. Radiation curls around field lines and corkscrews its way to one of the poles. THAT"S ALL IT DOES.
    So whatever radiation is gathered up, it all gets concentrated by the poles.
    So where the poles meet, the radiation all gathers up there and is a LOT stronger there than anywhere else. That is why I said a redesign of the craft is needed where the field lines go through the craft without touching anything.
    It doesn't matter if the field lines are a million times stronger, they just herd the radiation they don't provide a barrier.
    The best it can do is guide the radiation into the poles and there better not be anything in that region so the radiation can be safely shot out the ends or whatever.
    You can't really use the word 'shield' when you talk about magnetic lines of force.
    They only HERD not stop radiation.
    I hypothesized about the shape of such a craft, a donut shape would work so the field lines poles go through an empty space so it could be a large cylinder shape also with the caveat that the width of the empty space would allow for the divergence of the field lines at the end of the cylinder shape, that is, where the lines come together the field lines are wider spaced away from the exact center of the fields. Now there may be ways to add additional field lines to force the incoming field lines to make like a cylinder shape themselves but the simplest shape without the need for augmented field line adjustments is to just make the whole craft shaped like a donut and that way the widening field lines are also in a place where no craft touches.
    Anything that actually touches the field lines will be a delivery spot for the guided radiation so you want to avoid that at all cost for the simple reason that even if no humans are in that space, high energy radiation can weaken and over time destroy just about ANYTHING made by mankind so the simplest way is to keep stuff away from that incoming guided radiation.
    Does that make sense?
  10. Standard memberbunnyknight
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    10 Aug '20 15:43
    @sonhouse said
    @bunnyknight
    I think you still don't get it. Radiation curls around field lines and corkscrews its way to one of the poles. THAT"S ALL IT DOES.
    So whatever radiation is gathered up, it all gets concentrated by the poles.
    So where the poles meet, the radiation all gathers up there and is a LOT stronger there than anywhere else. That is why I said a redesign of the craft is ...[text shortened]... the simplest way is to keep stuff away from that incoming guided radiation.
    Does that make sense?
    That's what I'm saying -- to guide all that radiation into the poles and through a special core at the ship's axis where it can be isolated from sensitive areas, or even ejected from the rear and used for propulsion.
  11. Subscribersonhouse
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    10 Aug '20 16:101 edit
    @bunnyknight
    At least you get the idea mag fields only GUIDE radiation not stop it.
    As far as propulsion goes, not sure if you would gain much because if if that would work it would depend on getting into a powerful radiation field and would last only as long as you were in that radiation field. You get out of it and you would lose any acceleration gained.
    But I am not versed enough in that area to figure out if you could actually get propulsion from such guiding. It might be the radiation just continues along the field lines without making any actual thrust. That would be my guess as to what happens at the ass end of the craft. In the case where the field lines don't encounter any mass I would think the radiation would just keep following the field line and not contribute to thrust.
    Just my guess however.

    My professional field is in semiconductor manufacturing machines and one of those devices I spent near 20 years on was the ion implanter.

    If you can get to a site that shows how they work, the history of that device is the result of two technologies converging on one product, the first being magnetic field steering of ions and we know what happens there, ions and like electrons tend to get curled around field lines, any charged ion does that so you can steer the ion and in this case, a specific AMU number of an ion, its exact isotope number which has an exact mass associated with it.
    So the end result is a bunch of yecchy stuff comes out of the ion generator which you would aim for one you want, say Boron 11 as opposed to boron 10.
    B11 is a more massive ion than B10 but the main difference there is there is naturally occurring 3 to one more B11's than B10's so the resulting ion beam strength is 3 times more intense so it is in our interest to be able to select a particular isotope number.
    So the magnetic steering allows that to be done and what happens is when you adjust the field strength, say it turns out to be 1300 Gauss (which also depends on the incoming velocity of said ions) so B11, being more massive, gets through a small exit slot but B10 being less massive steers into a lower diameter curve which means it bends the most and as a result hits a field stop piece which happens to be graphite which absorbs those ions and thus keeps B10 out of the resultant ion beam.
    Then the B11 beam gets accelerated by electric fields to some new velocity which in ion inplanters is how you control how deep into the substrate the ions penetrate, in most cases, silicon wafers but there are others too.
    So accelerating to say 100,000 volts of acceleration, the ions bury themselves X amount of microns deep under the surface of the silicon wafer or if it is 200,000 volts of acel, it gets buried deeper, not quite double but quite a bit deeper which is an important parameter for building computer chips for instance.
    But the bottom line here is there is a LOT of research already done on the guiding effect of magnetic field lines and any ionized particle gets corkscrewed around the field lines and thus guided by said field lines.
    I just found this piece about using mag fields to protect astronauts:

    https://www.sciencealert.com/scientists-are-developing-a-magnetic-shield-to-protect-astronauts-from-cosmic-radiation
  12. California
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    10 Aug '20 17:041 edit
    The Russians did a long term "mock" space trip in isolation.. And there was one in Hawaii, too. There are still problems to correct before the real Mars trip. The women probably were jealous and wanted to the most popular.
  13. Subscribersonhouse
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    10 Aug '20 18:17
    @ogb
    Hey, didn't you know that only happens with RUSSIAN women!
  14. Joined
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    @sonhouse said
    @bunnyknight
    I think you still don't get it. Radiation curls around field lines and corkscrews its way to one of the poles. THAT"S ALL IT DOES.
    So whatever radiation is gathered up, it all gets concentrated by the poles.
    So where the poles meet, the radiation all gathers up there and is a LOT stronger there than anywhere else. That is why I said a redesign of the craft is ...[text shortened]... the simplest way is to keep stuff away from that incoming guided radiation.
    Does that make sense?
    "I think you still don't get it. Radiation curls around field lines and corkscrews its way to one of the poles. THAT"S ALL IT DOES. So whatever radiation is gathered up, it all gets concentrated by the poles. So where the poles meet, the radiation all gathers up there and is a LOT stronger there than anywhere else."

    I'm curious. You first said one of the poles, then you said both of them as you kept writing. Isn't it both poles?

    Also, would there be a danger living at the magnetic poles on Earth? I have never heard of that being a danger before. I thought the northern lights were harmless. Is that not the case at the northern magnetic pole?
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    22 Aug '20 11:23
    @humy said
    No. At least not by much.
    A magnetic field may help defect some, but (and contrary to popular belief) not all, of the solar wind particles but wouldn't deflect X-rays and gamma-rays from distant supernovae explosions and other distant high-energy cosmic events.
    This is because a magnetic field can only significantly deflect charged particles and not electromagnetic radiation. ...[text shortened]... e people inside the capsule this would be just one of their significant longer-term problems.
    https://www.thenakedscientists.com/articles/questions/how-does-lead-absorb-radiation-x-rays-and-gamma-rays
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