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#1 2019-07-16 10:55:45

tahanson43206
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Registered: 2018-04-27
Posts: 1,635

New Mars Topic Proposals

One of the many beneficial features of the New Mars forum is the quality of the administration.

SpaceNut (in particular) has been working to encourage discussion of topics, and to try to keep discussions on topic.

It was discovered in 2019 that no mechanism existed to discuss the introduction of new topics.

This topic is created in Meta New Mars to provide a place for introduction of new topics that might be of interest to members.

Any topic would be eligible for introduction here, but if a new topic is found to be of interest, then it needs to be created in the appropriate place in the forum structure.

(th)

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#2 2019-07-16 11:13:39

JoshNH4H
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Posts: 2,526
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Re: New Mars Topic Proposals

Hey tahanson,

Should you or any other member want to create a new topic, you can simply go to the appropriate subforum and click on the "Post a New Topic" button on the upper right of the page.


-Josh

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#3 2019-07-16 12:04:56

tahanson43206
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Registered: 2018-04-27
Posts: 1,635

Re: New Mars Topic Proposals

For JoshNH4H re #2 ...

Thanks for your reply Josh!  What I am addressing is a problem that came up when I tried to discuss two potential new topics with Void.  SpaceNut quite correctly pointed out that the new discussion was off topic of the topic in play.  My reason for posting in void's topic was to reach him directly, which would not happen otherwise, unless void reads every post, which I cannot guarantee.

However, this new topic ** IS ** a perfect place for me to tell you about my attempts to move forward on two topics you introduced to the forum some time ago.

One was the inflatable tower which (if I recall correctly) was conceived as a way to achieve launch altitudes.  I picked up on the idea for a more modest scale pneumatic lift system that could be deployed on Earth for some of the many lift situations that occur daily, or at Mars where (potentially) it could be set to unload SpaceX landing craft by lifting a platform up to the port near the nose of the vehicle.

I am a certifiable novice 3D printer designer, and have been worrying away at the problem for some time.  I just got a message back from Shapeways, informing me that a model designed by a 20 year veteran designer could not be printed because the walls are too thin.  That makes sense, since the model print request was for a scale model of what would be a full scale 50 meter tall lift device. 

My own model, much cruder in comparison, has been approved for printing, so I'll see it in early August, but my model is only of the top segment, which has a solid surface for passengers or cargo.  The professional model will print if I scale it up so the walls are .7 mm thick, but then the cost is greater than my budget.

***
The other topic you introduced was the idea of collecting iron ions to make a battery with properties not otherwise achievable in the known universe.

You kindly looked at an ion storage system which keeps ions circulating in a cylindrical pattern until they are pulled off for research.  My recollection is that you observed that the ion density achievable with that system was low, and certainly lower than your vision called for.

I've been thinking about that ever since, and reported elsewhere in the forum that a recent issue of Analog magazine included a fact article by John Cramer, about a dispute involving properties of the proton.  I've forgotten the details of the argument at this point, but what i remember is that Einstein's General Theory came into play in the resolution.  Apparently, relativity is at work inside the proton, where three quarks are bouncing around at such a rate that they achieve a collective mass 1900 times that of an electron.

That was from memory. Google says:

Proton is 1837 times heavier than an electron.

But to your (proposed) storage system .... I imagined that a spherical metal container in a bath of liquid helium would be able to hold iron ions, but the mechanism for admitting ions into the sphere without releasing ones already there is beyond me.

One benefit of the liquid helium bath is that thermal agitation of the captured ions would be significantly reduced, so that the internal pressure on the metal wall of the sphere would be primarily electrostatic.

On the outside of the helium would (presumably) be a metal enclosure at ground potential, or ship potential if mounted in a vessel, so the electrostatic force across the helium would comprise the stored potential energy of the system.

***
Finally ... in my post to void, I asked about the possible use of anti-matter as part of a radiation shield (ignoring the impracticality for the sake of learning).

Thanks again for picking up on this new topic.

Also ... the models of the work-in-progress pneumatic lift are available for viewing in my shop at Shapeways, if you (or anyone) is interested.

(th)

Last edited by tahanson43206 (2019-07-16 12:07:27)

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#4 2019-07-16 16:47:00

SpaceNut
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Posts: 17,382

Re: New Mars Topic Proposals

The folder and topics have gotten quite blurred over the years but to make any topic constructive its got to have some sort of outcome for all that we do to talk about it and how it impacts man going anywhere beyond LEO.

Here is what I would do with this item

spherical metal container in a bath of liquid helium would be able to hold iron ions

This is clear to me that its a science technology for initial folder for where it needs to go and after that if we do not have any discusion about use of Helium or of capturing Iron Ions then I would creat a new topic with a good lead of what the topic might have for a quest of knowledge or of how we might look to apply this new find.

Another thing is not to create simular topics which really are just a rehash of what might already been there just domant waiting for technology to catch up to what we believe from science to be true.

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#5 2019-07-16 16:54:06

JoshNH4H
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Re: New Mars Topic Proposals

Normally what I'd do is create the new topic and link to it in the other thread.

As far as 3D printing and inflatable structures: I happen to have 3 years' experience in 3D Printing, including some direct experience with the people at Shapeways' NYC facility.  They're good, smart people but the wait times are a little long.  Anyway if you've got anything you might want help with specifically with regards to 3D printing let me know.

You'll find that it actually doesn't matter what you do on the outside of a sphere if you're trying to contain particles inside, because the internal electric field will always be zero.


-Josh

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#6 2019-07-16 17:08:33

SpaceNut
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Re: New Mars Topic Proposals

Lets see if this makes sense for where  this was posted in topic "Heat on aerobreak"

Void post #42 snipet

http://newmars.com/forums/viewtopic.php … 88#p158588

Well, this seems promising, as it could indicate yet another method to get better solar cell efficiency for items proposed in the previous post.

https://phys.org/news/2019-07-carbon-na … nnels.html
Quote:

Carbon nanotube device channels heat into light
by Rice University

A scanning electron microscope image shows submicron-scale cavities patterned into films of aligned carbon nanotubes developed at Rice University. The cavities trap thermal photons and narrow their bandwidth, turning them into light that can then be recycled as electricity.

Connection of article is extreme heat that CNT can take and do an upshift of energy to produce light or energy.

A heat shield is for pica combination are made of carbon and tubes of carbon have simular characteristics to filament and batting in the end game for a heat shield.

The fact that entry into an atmosphere is very short so any system using this would be short lived under 7 minutes but using them in the other article of the past from void on high temperature solar panels and for use in Heliostats would seem to be a better fit for placing and continuing with this.

Now embedded CNT's in a solar panel would add capability as to strength under temperature ect...

So again high temperature solar could also be its own topic with in the science technology area.

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#7 2019-07-16 21:56:33

tahanson43206
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Re: New Mars Topic Proposals

For JoshNH4H ... quoting all of post because it is short ...

JoshNH4H wrote:

Normally what I'd do is create the new topic and link to it in the other thread.

As far as 3D printing and inflatable structures: I happen to have 3 years' experience in 3D Printing, including some direct experience with the people at Shapeways' NYC facility.  They're good, smart people but the wait times are a little long.  Anyway if you've got anything you might want help with specifically with regards to 3D printing let me know.

You'll find that it actually doesn't matter what you do on the outside of a sphere if you're trying to contain particles inside, because the internal electric field will always be zero.

If there is interest in dynamic radiation protection I am sure someone will create a topic for it. 

I am delighted to learn that you have experience with 3D printing, and specifically with Shapeways!  I'd made the decision several years ago to NOT invest in printer hardware, and instead to focus on software to drive the hardware.  I'm a member of a local maker group whose members tend toward hardware projects.

Shapeways was one of the few organizations available for remote printing orders at the time, and I have been pleased with their performance, as well as impressed with their constant innovation.  No doubt other service companies are similar in quality and performance.

The role I'd appreciate your playing, if you are willing, is "project sponsor".  In this case we have a project under way to design a scale model of a pneumatic lift tower, inspired by your launch tower idea from late last year.  I would very much like to see more than one person inspired to design and actualize models based upon the idea.

I'm not sure what you meant with your comment about zero charge, but I'm sure the problem is a failure on my part to communicate properly.

A capacitor can be made of metal foil separated by dielectric, so that two strips of foil are brought out to connection points.

If one foil strip is held to ground, and electrons are pulled from the other (using a battery for example), then an electrostatic force will come into being between the strips.  The force will exist in the dielectric (as I understand the physics of the situation).

Your message from last year, about storing electrical power using ions (such as iron stripped of all electrons) inspired me to think about how such ions could be stored.  A possible solution is a sphere in which the ions would be stored, separated from another sphere by a bath of liquid helium.

The outer shell would be connected to the Earth (a traditional "ground") or to the body of a space craft.

Ions lacking electrons would be admitted to the interior of the inside sphere, and the electrical charge would be distributed over the interior sphere at near to the speed of light.  The helium would then "contain" (I'm not sure what word is best) the electrical force between the inner sphere and the outer one.

As more ions are admitted to the inner sphere, at some point the helium dielectric would break down.

It would be interesting to know how far that process could be carried before breakdown occurs.

Obviously this is a thought experiment, because (as far as I know) there is no way to admit ions into the interior of the sphere.

Still, the accumulation of ions might become significant.

Variables at play are the size of the spheres. 

As a detail, the inner sphere would be evacuated, so that only the admitted ions are present.

(th)

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#8 2019-07-18 17:21:56

JoshNH4H
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From: Pullman, WA
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Re: New Mars Topic Proposals

The key point is that the energy in this case is *not* stored through capacitance (IE charge storage) as we normally think of it.  It's stored in the ionization energy of the elements.  The key point here is that the second ionization energy is larger than the first, the third larger than the second, etc., and so while first and second ionization energies are on the order of a chemical reaction, the more stripped a nucleus becomes the closer the energies become to nuclear-scale energies*.

The key point here is that there exists a tremendous potential energy between a normal neutral atom and a stripped atom when they are next to each other regardless of the local macroelectric field or potential.  This means that these stripped nuclei cannot be allowed to get within arcing distance of any normal matter if they are to continue existing.  This is why your suggestion to embed them in a capacitor cannot work, because they will steal electrons from the matter from which the capacitor is made.

*Is it possible to induce a beta decay by stripping an atom of its electrons? I do not know; perhaps it is.


-Josh

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#9 2019-07-18 18:03:35

kbd512
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Re: New Mars Topic Proposals

tahanson43206,

I haven't really been following, but are you talking about the instance of beta decay of Rhenium-187, stripped of all electrons, to Osmium?

If so, then you should know that that's a special case and the energies involved are none too spectacular.  I'm not sure what you'd do with it.

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#10 2019-07-19 12:37:33

tahanson43206
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Posts: 1,635

Re: New Mars Topic Proposals

For kbd512 re #9 ...

Thanks for your interest in this discussion ... it started with a post by JoshNH4H entitled "Ion Neutralization Propulsion"

Thanks  to SpaceNut for finding that topic in his post of the 17th, in another topic.

As you will see, JoshNH4H was talking about a family of ions which exist without electrons. 

The best example I can offer from memory is Galactic Cosmic Rays, which (as I recall) are often found to be (or observed to be) iron atoms which have been stripped of electrons in whatever process causes them to head out into space at a significant fraction of the speed of light.

In the article, JoshNH4H laid out the potential energy storage capability of a system which could harness such ions.

I had proposed a storage system consisting of a metal sphere surrounded by a bath of liquid helium, surrounded by another metal sphere.

So far I've not succeeded in persuading JoshNH4H to buy into the concept, but I'm hoping it will grow on him << grin >>

A problem which I have admitted is an unknown at this time, is how iron atoms without electrons could be brought inside the inner sphere.

Setting that aside, I would like to suggest that if one WERE to be admitted into the inside sphere, it would immediately collect electrons from other atoms comprising the sphere, until equilibrium is achieved.  At that point, the inner sphere would have a net deficit of electrons with respect to the outer sphere, which would be connected to the Earth or other source of electrons.

The electric force existing over/through the helium layer would exactly equal the force of the electrons missing from the iron atom when it was admitted to the inner sphere.

(th)

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#11 2019-07-19 17:02:09

SpaceNut
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Re: New Mars Topic Proposals

I can think of a few more atoms that are sent out from the suns forces which are ionic and some what stable.

Hydrogen stripped of the electron is a photon or a proton, Duetrium and tritium, Helium 3 all come to mind. Which leads to how the ecat works which is via ionic transmutation of the materials as they create heat from the decay which is given a shove to get going for the reaction.

The solar sail is one plate of a capacitor collection of the ion energy but its missing the second plate to allow for a difference of charge occurr.

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#12 2019-07-21 10:24:35

tahanson43206
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Registered: 2018-04-27
Posts: 1,635

Re: New Mars Topic Proposals

For SpaceNut .... Working from Louis' topic about flexible PV on Mars ...

I would like to introduce a new question, in hopes someone will find it interesting to consider ...

ouch!!!

Sandblasting winds shift Mars' landscape

"In our study area, sand-moving wind occurs almost daily" throughout much of the year, "Winds on Mars can be strong and can reach hurricane speed (more than 120 kilometres per hour or 75 miles per hour),"

Understanding the characteristics of Mars' winds would allow scientists to make predictions about the rate of erosion of the landscape and about the martian climate, which is heavily influenced by dust in the atmosphere.

Since sand storms are a problem on Mars, and since sand storms on Mars appear to serve no purpose other than artistic expression, I am posing the question...

If the entire surface of Mars were covered in a tarp, and the Sun continued radiating as it is doing now, what would happen?

Next ...

If selected portions of the surface of Mars were covered with solar panels, is there a point at which the phenomenon of sand storms would diminish, so that major disturbances no longer occur?

(th)

Last edited by tahanson43206 (2019-07-21 10:24:59)

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#13 2019-07-21 13:36:54

SpaceNut
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Posts: 17,382

Re: New Mars Topic Proposals

Sort of like when I did my roof a decade ago.. even though the tarp was blue in color it still allowed for the heat to build up under it and so did the pressure of air under it. That said a tarp that has low lose through it will allow for a build up of heat and gasses under it during the days temperature rise. Of course if the gas is allowed to flow around the globe under a tarp then evenualy that cooling during the night for it will be less over time as more gas is trapped under it. Of course moisture will increase and the likelyhood of methane being the gas is very probable.

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#14 2019-07-22 12:14:40

JoshNH4H
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From: Pullman, WA
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Posts: 2,526
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Re: New Mars Topic Proposals

Hey kbd512,

This is how I described the idea in the thread referenced by tahanson:

I wrote:

What I've come up with is the idea of trying to take advantage of ionization energies.  Basically, you heat up a gas until it's a plasma, use electric and magnetic fields to capture and store pure positive ions (H+, i.e. a proton, is the most basic example), and then when you're ready reintroduce electrons and use the energy produced to heat up some propellant and fuel your rocket.  Incidentally the simplest way to introduce electrons is probably to let your positive ions steal them from normal matter. Have a look at the following table with selected nuclei (All units: eV/amu):

EGEfiWz.png

(Data from CRC by way of this wiki article)

The upshot of this table is that the energies available from ion neutralization meet or exceed what you need to get substantially higher Isps.

The problem here is storage: This energy is released when an electron from the environment interacts with the positively charged ion.  Any contact with normal matter will cause a loss of containment, and given that there will be a substantial store of positive ions you'll also have problems with electric arcing.

I don't really know how to go about storing these ions, especially not how to go about storing them in a reasonably dense and stable manner.  Does anyone have any ideas?  What do you all think about the idea more generally?

I do know that it has substantial promise: Iron, if stripped of all its electrons, would be able to store 619 eV/amu, which works out to almost 60 GJ/kg.  If used directly as a fuel, with no propellant, you could theoretically achieve exhaust velocities as high as 350 km/s (35,000 s), or 0.1% of the speed of light.  This is the kind of fuel that could take a rocket from Earth to Mars in under a week (I'm thinking a 1 m/s^2 brachistochrone)

I do think it's a good idea, but the storage challenges are substantial and possibly insurmountable.  A rocket with a payload of 10 tonnes, 10 tonnes of structure, and an exhaust velocity of 9 km/s (mass ratio of 3) would require the storage of 35 kg of stripped Iron, having a charge of 1.4 billion coulombs, literally billions of times more than we can store and under particularly challenging conditions (no interaction whatsoever with any normal matter).  Note that Iron under these conditions is not a solid; Electrons hold solids together and without them you'll have a plasma.


-Josh

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#15 2019-07-22 20:52:38

SpaceNut
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Re: New Mars Topic Proposals

RF energy transmission:

SpaceNut wrote:

I was thinking about this solar powered mass on the nasa helicopter.

Another could be an RF power transmission scheme for the craft to get power from in order to go the distance on a fixed path.

tahanson43206 wrote:

You can find it by entering the search string shown below, without spaces:

S e a r c h T e r m :  and  : D e s i g n C O 2 P i z z a D r o n e

Author: tahanson432

***
The suggestion of a supply of power to the drone is interesting as well, although I was imagining that battery power on board the vehicle would be sufficient for a round trip time of one hour.  Can you expand a bit on your idea of RF power supply for the vehicle, and how you would use it.

The helicopter would pickup the power from a platform via the legs much like the pad for charging a cellphone. This would remove mass for gaining a higher level of altitude and flight time as well. The platform pad would have solar panels and batteries to charge while the helo is in use. Once it re-lands on the pad it would begin recharging for rapid reuse.
Another part to this is the platform pads could be designed for the unit to bring to other locations and with modular build stay within the lift capacity of the helo. String the recharge stations to gain further and further distance of exploration around the base.

SpaceNut wrote:

I was in a local walmart and spied the q wireless cell phone charging plate. What shocked me was how much energy went in versus what could be recieved for charging. The particular unit required 5 Volt at 2 amps (10w) and what it would create for the cell phones charging was 5 Volt but at 1 amp only 5 W .

tahanson43206 wrote:

For SpaceNut .... re #70

Off Topic << grin >> ... Please consider moving this to the new topics topic I created.

That said, your post inspired me to investigate a bit, and I read a number of customer reviews of products that looked similar to the one you described.

Summing up ... there are a few rave reviews, but the majority of customer reviews were on the complaint or unhappy side of the ledger.

With regard to your specific observation ... I'm not an engineer but I've hung around with them, and (in this case), specifically electrical engineers in RF specialties.  My (somewhat) educated guess is that the system has to post voltage significantly to generate an RF signal that can propagate to the phone.

What is surprising is that the engineers of THIS product were (apparently) able to achieve 50% efficiency.  That is amazing!

Thanks for your interesting post!

(th)

SpaceNut wrote:

The device needing to charge needs 2 Amps, when its near dead of power in the battery and that is why the 1 Amp does not work out so well. Converting DC to AC for RF signal and then back to DC is why there is so much loss that plus an AC signal is a 50% duty cycle sine or square wave shaped wave of energy that is transmitted. The larger the gap between the charging pad and the device means less energy will be transferred.

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#16 2019-07-22 21:05:56

kbd512
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Re: New Mars Topic Proposals

Josh,

Well, you might want to look at Lockheed-Martin's fusion reactor design.  At least theoretically, it should be possible to achieve a beta over 1 with this configuration.

Compact Fusion Reactor Overview, Status And Development Plan - CFR

The plasma density achievable was the entire reason that LM went with that particular configuration.  So far as I know, that's the only real way to drastically reduce the size / weight / cost of fusion reactors.  The Troyon limit basically precludes Tokamaks from achieving plasma densities that would make fusion reactors appealing technology to a power utility company.  I'm not sure why you'd actually have to confine multiple kilograms of plasma for any substantial length of time, provided you could dump in enough microwave energy from an external source to fully ionize an input gas.  Separation of the power supply from the powered vehicle seems to be at the heart of many of the more feasible advanced propulsion concepts.  Basically, we'd start with a high-beta fusion reactor core that we intentionally allow plasma to leak out of at a controlled rate.  The plasma produced should be compatible with existing electric thruster technology.  This is just VASIMR on steroids.  We should look at Argon and Hydrogen as candidate propellants.

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#17 2019-07-23 08:24:35

JoshNH4H
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Re: New Mars Topic Proposals

Hey kbd512,

While I have confidence that we will eventually be able to build a fusion reactor that produces enough excess power to be useful, I am really skeptical that we will have a fusion reactor dense enough for a ground launch rocket any time in the next hundred years.  It's a problem of sheer power density.  To build a rocket engine with a T/W of 50 and an exhaust velocity of 10 km/s, you need a mass flow rate through the engine of .05 kg/s of propellant per kg of engine mass.  At 10 km/s, each kilogram of propellant will have 50 MJ of kinetic energy, figure 65 MJ/kg of thermal energy with a high efficiency engine.  Your engine therefore needs to produce about 3.25 MW/kg of useful thermal output.

In NTR engines, you "cheat" a little because you're not really flying a nuclear reactor, just a nuclear reactor core which by itself is fundamentally stationary metal.  A fission engine is not like that: In order to continue operating, you need the core (which is itself a highly complex set of containment technologies) and a way to generate energy from the core in order to keep the reaction going.  Then you're also talking about a set of powerful magnetic fields to focus and direct plasma out the engine--it'll be heavy. 

That's why, if fission is out for safety reasons and fusion is out for power-to-weight reasons (and for not-yet-existing-despite-billions-of-dollars-of-research reasons), I wanted to look into something else.  Unfortunately, my stripped-ion battery seems substantially harder in some ways than fusion, but presuming you could store an adequate amount of stripped ions the power-to-weight limit would not be a problem.

If, as I suspect, it's possible to induce radioactive decay by stripping an atom you might be able to drastically reduce the amount of atoms required and thus make this possible.

Last edited by JoshNH4H (2019-07-23 08:27:19)


-Josh

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#18 2019-07-23 09:36:14

tahanson43206
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Re: New Mars Topic Proposals

For JoshNH4H re #14 ...

JoshNH4H wrote:

Hey kbd512,

<snip>
  Note that Iron under these conditions is not a solid; Electrons hold solids together and without them you'll have a plasma.

Thanks for this particular gem in a bed of diamonds!

You have a global audience (albeit mostly spammers) so the kernel of insight packaged in the quote above has the potential to inspire for years to come, just as your original idea inspired me.

I have not had the opportunity to think along those lines before, and I really appreciate your taking the time to add it to the post to kbd512.

In the scenario I presented, a metal sphere would reside within a liquid helium bath.

In that scenario, I was (incorrectly) imagining that when completely ionized iron atoms are admitted to the interior of the sphere, they would collect electrons from the metal wall of the sphere until all forces are equalized, while at the same time, the helium would be immune to disturbance.

I ** think ** I have a better mental picture now, but am hoping you will tweak it as needed, both for my sake, but also for the future readers who can be expected to find the discussion interesting.

What I am imagining now is that as electron free iron atoms are admitted to the interior of the (evacuated) sphere, they will collect electrons from the sphere as described above, but at some point, the number of electrons available in and inside the sphere will fail to meet demand, and (I presume) catastrophic failure will occur.

In addition, I am imagining that (at some point) electrons will be stolen from the helium atoms which are bouncing up against the wall of the metal sphere, albeit slowly, since this is (after all) liquid helium.

A feature of this scenario is that it ** should ** yield a curve showing the amount of energy which can be collected before the system breaks down.

(th)

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#19 2019-07-23 12:42:17

JoshNH4H
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Re: New Mars Topic Proposals

Hey th,

I think you're still missing the main point here.

Ignore the electrical charge of a stripped iron nucleus for a second and consider it just as a reactive chemical.

If you're building a rocket fueled by Hydrazine/Nitric Acid, you will not permit the two to make contact with each other prior to firing because they will immediately release their energy (this is called a "hypergolic" fuel combination).  This will damage your equipment and possibly cause fatalities (very bad--this is in fact what happened in the 2007 Virgin Galactic Explosion iirc, which killed 3 people) but also renders your hydrazine and nitric acid useless as propellants (they have reacted with each other to form Nitrogen and Water).

You could think of a stripped nucleus as an extremely reactive chemical that is hypergolic with any chemical containing any electrons.  The problem doesn't have to do with charge per se.  The problem is that as soon as these nuclei make contact with normal matter they will react and their utility as an energy store will be done.


-Josh

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#20 2019-07-23 17:26:54

kbd512
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Re: New Mars Topic Proposals

Josh,

I'm not talking about achieving fusion, just using the magnetic chamber to ionize and compress a plasma to use as a propellant for an in-space propulsion system.  The fusion reactor core is just generating / compressing / very briefly storing plasma, rather functioning as a fusion reactor.  It's there to contain the plasma just long enough to achieve the density desired and to direct it out of an electromagnetic nozzle.  In orbit, fantastic thrust-to-weight and power-to-weight requirements need not be met, especially if most of the power is provided by an external source- such as a constellation of microwave power satellites at Earth and Mars.  The technology is interesting from the standpoint of providing greater thrust to quickly inject into transfer orbits to other planets.  Thereafter, a lower-powered cruise propulsion system takes over, meaning a normal VASIMR.  That's just another way of saying onboard solar panels generate a lesser amount of power to produce continuous thrust from non-compressed plasma.  We may not make it to Mars in two weeks, but we can still drastically lower the propellant requirements while achieving higher thrust with higher-Isp Argon / Oxygen / Nitrogen / Hydrogen (whatever convenient gas happens to be available from the upper atmosphere of the target planet).  Iodine would obviously be a very dense storable propellant as well.

It's just a distributed VASIMR that uses high pressure plasma for departure thrust and normal plasma for cruise propulsion.  Most of the juice comes from power satellites that are just orbiting the local planetary body.  Besides, a week transit to Mars means hitting a grain of sand is like running over a stick of dynamite in your car- not generally recommended.

I'm interested in overall efficiency of propellant and power consumption, therefore total solution mass and power required to deliver a ton of whatever to orbit or to another planet, rather than trying to come up with a silver bullet solution to all of our propulsion problems.  I think electromagnetic launch and microwave power stations are the best combination of technologies to achieve orbit, if efficiency in both power and propellant consumption are under consideration.  Such a system could provide a lot of the velocity increment required on the ground, with the remainder provided by the microwave power system.  This concept involves a circular electromagnetic acceleration track, a high power microwave station to transfer power to a heat exchanger onboard a spacecraft about the size of a fighter jet, and perhaps another microwave power station on the other side of the world for orbit circularization.  Since all of the infrastructure except a small cargo delivery vehicle is on the ground, it should be easier to maintain and permit dramatic increases in flight rates.

The individual payloads will be used to construct much larger vehicles, primarily from woven CNT's and CNT composites.  Since MIT came up with a way to fabricate composites without autoclaves using electrified CNT fabrics, we should be able to do the same in orbit.  I'm challenging the notion that everything can or should be prefabricated on the ground.  If nothing else, rocket payload shrouds drastically limit the sizes and shapes of payloads that can be delivered to orbit.

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#21 2019-07-24 07:50:24

tahanson43206
Member
Registered: 2018-04-27
Posts: 1,635

Re: New Mars Topic Proposals

For JoshNH4H ...

JoshNH4H wrote:

Hey th,

I think you're still missing the main point here.

Ignore the electrical charge of a stripped iron nucleus for a second and consider it just as a reactive chemical.
<snip>
You could think of a stripped nucleus as an extremely reactive chemical that is hypergolic with any chemical containing any electrons.  The problem doesn't have to do with charge per se.  The problem is that as soon as these nuclei make contact with normal matter they will react and their utility as an energy store will be done.

Thank you for the experience of being stunned.  You've awakened my awareness to two concepts ... one is [void] caliber! ... a non-material wall

However, the one I find most promising is the fourth state of matter, and specifically, COLD plasma, which I have not had occasion to think about before.

As I understand radiation flows in deep space, there are significant quantities of deionized atoms moving at great speed in every direction, at all times.

All that matter is a potential resource, although at present, at the level of knowledge humans can marshal, it is mostly a liability.

However, what intrigues me most about the concept of cold plasma is its potential for use as a tool.

The first application I thought of was cleaning ... disinfecting, for example. 

However, beyond that, I thought of cutting or shaping (of asteroid material, for example).

If you were to create a new topic devoted to Cold Plasma Applications in Space, I would be an enthusiastic supporter.

Edit .... Google came up with more citations than I was expecting:

About 157,000,000 results (0.57 seconds)

Some disambiguation is required ... I'll start with the Cold Plasma treatment for Faces.  That may well be a useful product, but it is not what I think your vision of a completely deionized iron atom (or any other) is capable of achieving.

Edit #2: A thin stream of deionized iron atoms would ? could serve as a precision cutting or welding tool in a vacuum.

This would be far more precise than a soldering iron, for example, and perhaps better suited for work at the nanometer scale.

The iron atom would become part of the structure receiving the attention. 

Photons from the site of the operation would ? could be detected by sensors bound to the tool, to guide the controller, much as bright light from an Earthly arcwelder helps to guide the artisan operating the equipment.

(th)

Last edited by tahanson43206 (2019-07-24 12:40:18)

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#22 2019-07-28 18:01:11

tahanson43206
Member
Registered: 2018-04-27
Posts: 1,635

Re: New Mars Topic Proposals

For JoshNH4H ....

Your original proposal, to use a store of nuclei stripped of electrons as a source of energy for propulsion, may yet come to pass, if new discoveries in physics reveal a way to construct a non-material wall.  I find the concept intriguing, and will be on the watch for any hint of work along that line.

However, your message quoted below was helpful (to me at least) in removing the underbrush I had mentally entangled with your idea.

After a period of reflection, I've decided the capabilities of an electron free nucleus, moving slowly with respect to a material surface, might have interesting behavior if allowed to move into contact with it.

By way of illustration, if such a nucleus (iron for example) were brought into contact with a copper surface, I would expect the iron to weld securely to the copper atoms it encounters.  What I'm not clear on is whether the energy set into motion as electrons are gathered up by the needy iron nucleus would lead to movement of atoms away from the site. 

A nucleus travelling through space at near light speeds and colliding with the nuclei of atoms it encounters is NOT what I am talking about.

Instead, I am following the path you allowed me to see, of purely electron shell exchanges.

It is possible research has been done along these lines, but my preliminary searches have proven unhelpful.

I'd be interested in any suggestions you (or any member) might have for focus.

Where I'm headed with this is a possible improvement in the density of digital data storage.  There is an existing market amounting to billions of dollars for data backup systems.  However, to the best of my knowledge, NONE of the existing electronic systems have lifetimes of more than a few years.  Paper and stone are known to have substantial lifetimes, but they do not lend themselves to rapid data retrieval.

Atoms, on the other hand, are reported to have substantial lifetimes.  For that reason, I am imagining that an iron atom, embedded in a copper (or other metal) substrate, could hold a bit value for a substantial period of time.  While this would be Write-Once-Read-Many storage, there is a substantial market for that capability.

Data Backup and Recovery Market Size, Share, Report, Analysis ...
https://www.reuters.com/brandfeatures/v … e?id=33545

Apr 18, 2018 - According to Stratistics MRC, the Global Data backup and Recovery Market is accounted for $6.98 billion in 2017 and is expected to reach ... Dell Inc., Commvault Systems, NetApp, Inc., Unitrends Inc., IBM, Oracle Corporation, ...

JoshNH4H wrote:

Hey th,

I think you're still missing the main point here.

Ignore the electrical charge of a stripped iron nucleus for a second and consider it just as a reactive chemical.
<snip>
You could think of a stripped nucleus as an extremely reactive chemical that is hypergolic with any chemical containing any electrons.  The problem doesn't have to do with charge per se.  The problem is that as soon as these nuclei make contact with normal matter they will react and their utility as an energy store will be done.

(th)

Last edited by tahanson43206 (2019-07-28 18:03:57)

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#23 2019-10-31 11:00:41

tahanson43206
Member
Registered: 2018-04-27
Posts: 1,635

Re: New Mars Topic Proposals

The purpose of this post is to introduce a possible new topic.

A secondary purpose is to restore the ID of JoshNH4H to visibility. 

JoshNH4H wrote:

Hey tahanson,

Should you or any other member want to create a new topic, you can simply go to the appropriate subforum and click on the "Post a New Topic" button on the upper right of the page.

The potential new topic I'd like to toss out is a method of capturing momentum from vessels approaching Mars, in order to facilitate their docking with Phobos.

I am of the opinion that as soon as they are able, Mars settlers will want to impose restrictions on access to the planet from unknown visitors with unknown intentions and with unknown liabilities such as physical ailments such as communicable disease, agricultural ailments, computer malware and a myriad of other potential factors.

What I am about to describe is (to the best of my knowledge) completely acceptable to known physics, and simultaneously nearly impossible to engineer.

Never-the-less, by introducing this concept for intercepting incoming objects and delivering them gently and safely to Phobos, I hope to stimulate one or more of the fertile minds who read forum posts.

The scenario I have in mind is composed of two elements fitted with the appropriate equipment.

The incoming vessel needs to be fitted with an electromagnetic device, able to draw energy from a moving cable such as a woven wire cable, along with electronic control systems able to manage the flow of energy captured from the cable.  The capture device will perform two functions.  It will deliver force to the incoming vessel that will enable it to slow down with respect to Phobos at a rate that is low enough to avoid excessive heating.  It will also deliver electrical energy into storage on the vessel while simultaneously radiating energy that is developed above the capacity of the storage subsystem.

The outbound vessel will, in this scenario, receive momentum opposite to the incoming vessel and sufficient to bring the two vessels to a stop after a period of time.  The outbound vessel will tow a cable which is to be drawn into the capture port of the incoming vessel.

As the incoming vessel slows, in approach to Phobos, the outbound vessel will slow as well, so that at the conclusion of the exercise, both vessels will be at rest with respect to Phobos.  At that point, the incoming vessel will enter quarantine, and the outbound vessel will be drawn back to Phobos by coiling the cable if that is appropriate, or simple by pulling the cable behind Phobos in its orbit, to await the next inbound vessel.

Again, I understand this system would be impossible to implement with known engineering.  The objective here is twofold.

1) I would appreciate analysis of the physics, so I can be reassured I haven't missed something
2) It would be interesting to see what ideas might flow from this post, to achieve the same objective.

(th)

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#24 2019-11-03 12:04:31

tahanson43206
Member
Registered: 2018-04-27
Posts: 1,635

Re: New Mars Topic Proposals

Continuing from Post #23

The momentum transfer concept outlined in #23 could have another important benefit, if appropriately adopted.

Phobos is scheduled to fall onto Mars because it is losing momentum to tidal forces:

http://www.astronoo.com/en/articles/pho … press.html

Because Phobos orbits Mars in 7:39, faster than Mars rotates on itself (24H36), the tidal forces are decreasing its orbital radius in a slow but steady pace of a few cm per year.
Since its orbit is below synchronous altitude in 20 to 40 million years, it is possible that Phobos crashes or crashes on the Martian surface.

While some might argue that there is plenty of time to worry about that, I like to address problems when I become aware of them, on the theory that welding a crack immediately after it starts is a better strategy than waiting until it cannot be repaired.

The momentum of incoming space craft (and objects) can be transferred to Phobos to raise its orbit, if care is taken in planning arrivals.

A tractor beam (ala Star Trek imagination) would be ideal for this purpose, but in the absence of one of those, a simple cable can be used to gently slow incoming vessels or objects with respect to Phobos.

The process would be similar to landing a large fish at sea.  Generally, or at least often, the mass of a fish caught by a line is far greater than the tensile strength of the line, or the physical strength of the angler, for that matter.  The technique used is to apply modest resistance to the line while the fish moves away, and to reel the line in when the fish is moving toward the angler.

(th)

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