Eventual Convergence?

Void · 2020-04-24 17:44:26

Zubrin and Mars Direct
Musk, Mars Direct with Starship (Sort of)
Bezos Blue Origin, O'Neil concepts.
NASA LOP-G
Gateway Foundation: https://voyagerstation.com/

Here is a video about it: https://www.bing.com/videos/search?q=Vo … &FORM=VIRE

From the start, I am mostly a Zubrin convert. I think that Mars Direct is the right way to start, perhaps with a bit of practice with the Moon first, if SpaceX pulls off the building of the "Big" Starship. So, don't start pulling your hair.

Musk/SpaceX has a lot on their plate, and are also focused on establishing the Big Starship. I understand.

Dr. Zubrin suggests that a Mini-Starship should also be built that can be launched to orbit from a Falcon 9 or inside of the Big Starship. I agree, but I think not until they get the Big one well up and running.

Bezos wants to make artificial worlds in space. That seems to be at odds for what Musk and Zubrin want, but I think in the long run it will not be.

NASA currently wants the LOP-G, and that annoys quite a lot of people here I know. And really, there are quite a few time I wonder what they are up to. But, if the eventual objective would be to have a rotating station somewhere in the proximity of the Moon, where people can be rehabbed, and where telepresence can be operated on the Moon from, then eventually it would make sense. And on the positive side I believe that SpaceX is going to get some contracts for the currently planed LOP-G, so then that may benefit SpaceX, which could benefit a Mars effort.

So, then the rotating devices from the "Gateway Foundation", Voyager Station, could eventually join all of these together, I think.

And strangely, I think that the dreams of Jeff Bezos could be very likely best served in Martian orbit eventually.

Starship does not need a booster for Mars. And neither might a ship eventually built by Blue Origins.

Materials might be brought up from Mars to build more of the rotating stations, and there are two moons that resemble asteroids to practice on, before going to the asteroid belt.

Mars orbit is a easier place most likely to bring asteroid materials to as well.

So for me this looks very good. You can build many habitats in orbit while working on the situation of Mars, however you could.

Done

Last edited by Void (2020-04-24 18:36:06)

louis · 2020-04-24 19:56:34

Void, you're like Erasmus trying to reconcile the Pope, Luther and a few other egotists!

I think Musk has hit on the right way forward...as he has in other areas - he is the Edison of our age.

Whether you want the best result for Earth-Moon, Earth2Earth, Earth to LEO or Earth to Mars I think the Starship represents the best option - and one of the reasons is that it serves all these purposes, which means - as Musk has correctly identified - you can move to production line rocket-making, which in turn means you can make these rockets very cheaply, if not exactly Model T Ford, you will still get tremendous savings.

I also think Musk has it right that it makes sense to think big in terms of Mars. The problem with Mars is not that it doesn't have the resources but it doesn't have the resources presenting themselves in the way we like on Earth. So you need to shift a lot of infrastructure there to get your foothold on Mars to enable you to effectively exploit those resources.

I think Musk definitely has the right solution now. In the future if we are talking about shipping humans to and from Mars, then it makes sense I think to have orbital stations that can pick up and drop off humans into LEO and LMO before they take the equivalent of a taxi down to the surface. Once Mars has its own resource infrastructure in place (energy, food, water, industry etc) there is no point in taking huge amounts of cargo along with human beings. It's similar to the situation in outlying islands off Scotland and Norway where ships deliver the big amounts of cargo but humans take a light airplane to get off the island and to return to it.

Void wrote:

Zubrin and Mars Direct
Musk, Mars Direct with Starship (Sort of)
Bezos Blue Origin, O'Neil concepts.
NASA LOP-G
Gateway Foundation: https://voyagerstation.com/
Here is a video about it: https://www.bing.com/videos/search?q=Vo … &FORM=VIRE
From the start, I am mostly a Zubrin convert. I think that Mars Direct is the right way to start, perhaps with a bit of practice with the Moon first, if SpaceX pulls off the building of the "Big" Starship. So, don't start pulling your hair.
Musk/SpaceX has a lot on their plate, and are also focused on establishing the Big Starship. I understand.
Dr. Zubrin suggests that a Mini-Starship should also be built that can be launched to orbit from a Falcon 9 or inside of the Big Starship. I agree, but I think not until they get the Big one well up and running.
Bezos wants to make artificial worlds in space. That seems to be at odds for what Musk and Zubrin want, but I think in the long run it will not be.
NASA currently wants the LOP-G, and that annoys quite a lot of people here I know. And really, there are quite a few time I wonder what they are up to. But, if the eventual objective would be to have a rotating station somewhere in the proximity of the Moon, where people can be rehabbed, and where telepresence can be operated on the Moon from, then eventually it would make sense. And on the positive side I believe that SpaceX is going to get some contracts for the currently planed LOP-G, so then that may benefit SpaceX, which could benefit a Mars effort.
So, then the rotating devices from the "Gateway Foundation", Voyager Station, could eventually join all of these together, I think.
And strangely, I think that the dreams of Jeff Bezos could be very likely best served in Martian orbit eventually.
Starship does not need a booster for Mars. And neither might a ship eventually built by Blue Origins.
Materials might be brought up from Mars to build more of the rotating stations, and there are two moons that resemble asteroids to practice on, before going to the asteroid belt.
Mars orbit is a easier place most likely to bring asteroid materials to as well.
So for me this looks very good. You can build many habitats in orbit while working on the situation of Mars, however you could.
Done

Void · 2020-04-24 22:06:27

That is a point of view Louis. Not completely wrong in my opinion.

But you understand that if SpaceX has customers who want to build these Voyager wheels, then they can make profits from it, same as to move people from point to point on Earth. More customers, most likely indicates lower cost for sending things to Mars, most likely. More Starships. If you study, what Elon has proposed, then they will make many Starships per year, and those will be best used for a purpose while they are in the vicinity of Earth. Therefore having customers, is a good thing. And then if SpaceX wants to send a armada of 1000 Starships to Mars every two years, they will have been properly tested, and also of good use before that.

If there is an organization called the Gateway Foundation, and they want to build Synthetic gravity machines, and hope to make those financially lucrative, and they are a customer of entities of SpaceX, why should we object?

This is not team sports. We are not at a stadium cheering for our team. But teamwork is a real potential.

I do believe in Mars direct, especially at the first. Mars has an atmosphere that can be used for aerobraking. That is quite good.

The space wheels, however, could easily be moved from a near lunar construction site to Mars, using electric propulsion, and Ballistic capture.
Nothing wrong with that in my opinion. Then we would have the option of places to go to in the Martian orbit where the g forces can be anything the machine can tolerate. We do not know that Mars will work for the birth of babies. Good chances there will be problems with that. And so what if there are space wheels in the Martian sky that people want to use?

And what about the LOP-G? I anticipate that that effort will eventually be replaces by one or more Voyager type wheels, and from there they can remotely drive robots on the Moon, to procure resources, to make more wheels.

Blue Origins will eventually get into the act also and so will other entities. The secret(s) to some extent are out. Copy Cat versions will happen, I am sure.

------
As it happens, the Mars system, Mars + Phobos + Demos, appear to me to be rather ideal for the Bezos dream. Why knock it?

What if Mars was 3 worlds or more? Why cry about that?

Imagine being a citizen of the Mars system, and being able to take a ride on a Starship without the Heavy booster, and go to a space wheel(s), where things would be different. It should be possible.

------

Now about the Mini Starship proposed by Dr. Zubrin to be launched on Falcon 9's or carried to orbit by a regular Starship.

I understand why Mr. Musk does not want to bother with that at this time. He has so many irons in the fire just now that I cannot imagine him wishing for yet another. But perhaps some day, by SpaceX or by some other entity.

Dr. Zubrin suggested the Mini Starship, because it could be put up into LEO by the Maxi Starship full fueled, and ready to go to Mars. And then when at Mars, it would place much less demand for refueling. He also feels that if you fly a Maxi Starship to Mars, you might as well leave it there because it is valuable living and working space.

But again, I do understand Mr. Musks focus on the Maxi Starship at this time as a "Universal" version, (Although there will absolutely be many versions). They need to get it done and real. Can't afford more diversions at this time. I understand.
----

Now, back to the Voyager wheels.

I can see that it would make a great deal of sense to have some near the Moon. There purpose would be to host humans and AI that would work together to run Avatar robots on the Moon, to extract materials to produce "Dry" wheels. Those would not at that location receive water or Carbon or an atmosphere. They may then travel as by AI to a location to receive those things to complete the habitat.

The first ones will likely go directly to Mars using an electric propulsion and a Ballistic Capture method. There they can be filled with what they need to support human life. The water the atmosphere, etc.

For the humans to populate these, first a starship like vehicle would bring them from the Earth/Moon system and onto the Martian surface. Then they would be brought up to the Voyager type vehicle.

Later the process could be modified to include the asteroids.

The dry wheels could be constructed from Moon materials as before. Then they would be directed to the Asteroid belt to receive the "wet" materials. Then they could move to Mars orbit. And then people would travel from Earth to Mars surface by "Starship", and then go up to a wheel.

People in the wheels could very well have jobs teleoperating devices on the surface of Mars for what ever purpose seems useful.

-----

I do think that the people on this board should be more liberal about accommodating the space dreams of others. It is really a mistake I think to refuse to find a symbiotic relationship with those other dreamers. No offense intended.

Done.

Last edited by Void (2020-04-25 07:44:40)

Void · 2020-04-25 07:46:04

There are any number of possible options for propulsion to move the wheels.
Dr. Zubrin I believe has a magnetic device that can sail on the solar wind.
I think that it may also be possible to do a gravity assist from a fly-by of Earth.
And I think that there can be many ways to fling Oxygen out in order to give propulsion.

Using electric power and Oxygen:
-For instance the ESA, I believe has made a electric rocket that can handle air. Perhaps it can handle Oxygen.
-Then we might try a perversion of "Spin Launch" and toss some form of Oxygen out. Perhaps you could pulse Oxygen gas through it. I actually think I like that one. Not sure how efficient it can be made. However since it is then squirting Oxygen gas these centrifugal thrusters might be rather small, and able to spin at really high speeds.
-For some time I have speculated on some kind of Oxygen Mass Driver. I have a type in mind:
*It would shoot out bullets of Oxygen ice, so you would have to have a bullet making process on board.
*It would have a "Gun Barrel" that the bullets were conducted through.
*Surrounding the "Gun Barrel" you would have solenoids which would sequentially accelerate the bullets.
*Surrounding that would be a liquid Hydrogen containing cylinder.
*So the above would involve superconductors, I should think. I presume that allows for some really strong magnetic effects.
*The Moon is 43% Oxygen, so then you understand why I wish to use an Oxygen Monopropellant.

The bullets would present a temporary collision hazard to other spacecraft, but I anticipate that it would not take long for the sunlight in outer space to convert the Oxygen bullets to gas. Collision hazards gone then.
Oxygen is paramagnetic. I know that the liquid form will stick to a magnet. I presume that the solid form will be paramagnetic, but am not sure. You don't see references to Oxygen ice, so hopefully it will prove true. If not then never mind.

In some of these cases because of the complexity of the machines, it likely will prove necessary to have a small crew aboard the wheel, and therefore life support for them. The wheel will need to spin to at least some amount of synthetic gravitation. Of course we do not yet know how much is enough. Of course the crew would be there to conduct repairs, on the complex machinery.

I mentioned Ballistic Capture to get these things into Martian orbit. Just so the readers can have a look at what that is:
https://en.wikipedia.org/wiki/Ballistic_capture
https://www.scientificamerican.com/arti … the-cheap/
https://www.popularmechanics.com/space/ … c-capture/

One thing that has puzzled me for a while is why SpaceX does not consider using Ballistic Capture for Starship.
You have many more launch timing options. You don't' necessarily have to wait for you every two years launch option using a Hohmann transfer.
I'm not sure it is good for a crewed ship as it takes longer, but for freight, it seems a no brainer.
I believe you have multiple options also for how you get captured to Mars. In some cases you can get captured into a Martian orbit, and I believe that there are other cases where you can get captured into a Martian orbit which will allow you to enter the Martian atmosphere.
I believe that in those cases, instead of screaming in at interplanetary speeds your energy to shed would be somewhat less, reducing the necessary heat shielding requirements.

---
I left out a couple of other options:
https://www.fromspacewithlove.com/vasimr/
And also among magnetic sails are plasma bubble drives. Here you attach a bubble of plasma to your spacecraft and let the solar wind push you. I expect it can be found as a "Type" somewhere in the below article:
https://en.wikipedia.org/wiki/Magnetic_sail

Probably combinations of these methods would be used.

Last edited by Void (2020-04-25 08:25:43)

Void · 2020-04-25 08:45:11

So, then the Martian sky is where some part of the dreams Jeff Bezos dreams would be:
https://en.wikipedia.org/wiki/Gerard_K._O'Neill

And I guess that Dr. Zubrin and Elon Musk will have their dreams on the Martian surface.

I will continue to dream as well.

The wheel arrives to Martian orbit. If there was a crew on board, it would likely be small. They would likely have been breathing pure Oxygen at a lowered pressure. As for their small amount of water on board, they would have been recycling it. As for food, perhaps they would have grown some of it during the trip, but also they might have simply had food on board in storage.

Once in Martian orbit, it would be time to complete the wheel. Get Nitrogen and whatever else you need to complete the wheel, from Mars or an asteroid mining operation.

After that, I anticipate a small amount of farming in the wheel, to some degree to make it more pleasant. But I think bulk farming would be done on the Martian surface or under the Martian surface. It may be that it would be economically reasonable to do that, at least at first. Maybe later when it seems sensible large orbital farms could be established. I don't have the economic calculations, but I think this could be why it makes sense to do this to a large degree around Mars, because Mars has what you need, so you don't have to build as much in orbit, at least at first.

So, if some of these wheels end up in geosynchronous orbit, the inhabitants would be in a position to support what goes on down below.
Communications facilitated with some time lag. Also working with mirrors and power satellites perhaps. Maybe directing robots on the ground.

Mirrors could do various things, maybe some terraforming work, but I think more likely directed at large solar energy farms. If you are going to have solar panels, why not send them extra photons?

As for power satellites, yes there could be rectenna's. But I want to consider trying a different type of receiver.

Ice covered lakes as a matter of fact. I do not believe the ice will absorb the energy, but the liquid water below should. Of course some of you understand that I intend these lakes ice to be protected by various types of coverings, as the Martian environment is unfriendly to exposed ice except perhaps at the poles or under dirt.

Several inputs of vibrations to the lakes could be the above, also waste heat from industrial processes and farming, and intentional heating from ground based solar facilities.

For a fresh water lake, the utility is fairly limited. You can only heat the water at the bottom a few degrees warmer than that at the top.

But if you have salt, (And of course Mars has salts), you could make solar pond like situations.

When such a lake is first made, it will likely start as a toxic environment. Perchlorates, and other poisonous chemicals in it. But eventually that could be cleaned up by various means, and it would be more friendly to living things such as humans.

So, in this current version, you would maintain a more salty layer on the lower portions of the waters, and less salty higher in the water column.

You can look up Antarctic Dry Valley lakes, or solar ponds, to get a better grasp of what I am after.

What I would like to try for is ~Earth Sea water at a relative warmer temperature at the bottom of the Lake(s), and close to fresh water just under the ice.

Depending on the thickness of the ice layer applying pressure to the top of the lake and in accordance with Henry's laws, it just might be possible to have enough dissolved gasses in the lake waters to allow for life. The ice probably has to be pretty thick for that.

https://en.wikipedia.org/wiki/Henry%27s_law

Otherwise you just use the water/ice column for pressurization, and you then need to have special enclosures where you can increase the amount of dissolved gasses. If this is not done, and the ice layer is thin, then the gasses will keep coming out of solution at the top of the water column.

The question of farming under artificial lighting now arises. I know that Dr. Zubrin does not prefer this he and Elon Musk want glass domes. And that is perfectly fine with me. They can do that. But I see where an underwater farm can be a useful load leveling method for an electrical power grid. Plants are used to variations in lighting by seasons, day/night, and weather. So, to a degree we can try to use surplus energy to grow them. That is when you need the energy for something else, you simulate a cloudy day. When you have surplus energy, then it is a sunny day. Load leveling to some degree might be accomplished in this way.

The movement of things like humans or fish in the waters will tend to stir and mix them. So it is required to maintain the stratification against that. One method is to distill water from the salty portion, then you have distilled water which might be used for a purpose, or you might dump that water to the top layer after you extract some of it's heat to the bottom layer, and dump the increased salty water to the bottom layer of the lake.

If green farming were to be done on the bottom of the lake of course you need a light source. Pink light being dominant I think. The nice thing about this is you are mostly using surplus energy, and your waste heat is going into the bottom layers. Having such underwater electrical systems will be a challenge, but offshore windmills conduct electricity under the water, so I suppose it can be achieved. Of course some type of assurance would have to be created to ensure that people don't get electrocuted. Ground Fault Methods I suppose would be helpful.

And if waste heat from farming is not enough then heat can be intentionally collected on the surface with some type of solar device. So, if you can simulate sufficiently the environment where Earth seaweeds can grow, then you can grow seaweeds on the bottoms of these lakes.
Temperature, lighting, dissolved gasses, and saltiness.
https://en.wikipedia.org/wiki/Edible_seaweed
I will note, that if it is desired it would be possible to grow dry land crops in diving bells filled with air in the lake waters. And aquatic animals might be an option, but I am not going to go into those much here.

So we have various inputs of vibrations (Heat) into the lake waters, and on top of the ice is likely to be a Styrofoam layer with a vapor barrier under it and some kind of protective coating on top of it. Under current ambient air pressure on Mars, this is going be rather like a thermos. With all the heat inputs, the lake is probably going to over heat, the ice melt, and of course the water boil off into the Martian atmosphere. So, you have to dump heat. Boo Hoo. Actually hurray! You can choose your method to generate electrical power by dumping heat out of the water and into the Martian skies. It is possible that this can occur 24/7, and even during a massive global dust storm. So, this lake is an energy storage device.

However, I think that during a global dust storm it might be necessary to degrade the environment at the bottom of the lake, so you might stop farming for that time. Mars is practically a giant freezer though, so food should have been stored away for such an event.

I think I will leave it there for now.

Bye.

Last edited by Void (2020-04-25 09:57:45)

Void · 2020-04-28 10:44:13

I am going to put several quotes from Index
» Science, Technology, and Astronomy
» Physics Topics

here, so as to get out of the way of other discussions going on there. I will quote #34, #37, #38, #39, #41, and #42.

Several reasons to do it.

Last edited by Void (2020-04-28 10:57:12)

Void · 2020-04-28 10:45:59

Quote #34 by Void:

Hi GW. Think I should clarify what I was attempting to be up to.
Umm.... There is some evidence that some rubble pile asteroids even though dry will have clays, an so hydrated minerals. So they are as per ice, dry, but supposedly it may be possible to bake water out of the clays.
But for what I was after for the Moon, I was pondering several potential options for propulsion concerning Magnesium and an Oxidizer.
To a degree, I was attempting to combine the power from preheated materials, where that heat can contribute to a propulsive exhaust, but I also intended to have a chemical reaction by way of burning Magnesium with an Oxidizer.
Two methods I am somewhat currently interested in would be using molten Magnesium, ideally as close to the boiling point of Magnesium as is do-able.
1) Molten Magnesium as the fuel. Water steam as the Oxidizer.
2) Molten Magnesium as the fuel. A temperate fluid mix of water and Hydrogen Peroxide as the Oxidizer.
I realize that to do this as in cold propellant engines, some method is required to push these fluids into the combustion chamber(s).
Rocket Labs uses batteries to power that pumping method, else an engine would have to use one of the various schemes similar to engines that have used Hydrogen, or Methane, and Oxygen.
It is a tall order, and I don't expect it to be implemented anytime soon.
But the difference is I want to work with hot a thermally hot fuel, (Liquid Magnesium), and either hot steam, or a temperate fluid as Oxidizer.
In the case of steam a pressure vessel is required, which would be a burden.
As for heating the Magnesium to a liquid, I felt that on the Moon, a deployable surround oven could heat up a Stainless Steel Magnesium tank, heat would be applied until the Magnesium is liquid, then the Oxidizer tank would be filled. The oven retracted.
Then a launch.
Nothing that is currently in use. But it would potentially be both a steam rocket and a chemical rocket at the same time.
VOID
From what I understand the combustion products would be Magnesium Oxide and Hydrogen.
As I recall that Hydrogen is a preferred propellant for Nuclear Fission Rockets, because of it's expansion characteristics, I am attracted to the notion that some of the output exhaust through the nozzle would include hot Hydrogen molecules. And at the same time the Magnesium Oxide molecules would have greater inertia. I hope that the Hydrogen vibrations (Expansion), would work favorable along with the heavier Magnesium Oxide molecules.
So, I hoped for a way to mass produce these machines (The hot fluids rockets), on the Moon, and to have it as a way to get lunar materials into orbit. Those then to be recycled into orbital machinery of some kind(s).

Last edited by Void (2020-04-28 10:48:21)

Void · 2020-04-28 10:47:53

Quote #37 by KBD512:

Void,
H2 is the preferred propellant for NTR's because lighter molecules can be accelerated to higher velocities with a given amount of thermal input power, providing more specific impulse for a given amount of propellant mass. More thrust could be provided with higher mass gas molecules, but specific impulse rapidly falls to chemical rocket levels as the mass of the propellant molecules increases. At that point, you're better off not having to deal with the mass and radiation issues associated with operating the world's most powerful reactor crammed into a space the size of a garbage can and may as well get even higher thrust from ejecting even higher mass molecules produced by chemical reactions while you're at it.
If you're already on the moon and have enough power to refine metals, why not use solar power to heat a monopropellant gas like Oxygen, which you would have in abundance from refining all the metals present in the lunar regolith? Keep the Magnesium to alloy with Aluminum, along with the water, for local uses. Instead, collect the O2 from the metal refinery for use as a propellant in conjunction with beamed power, provided by the many tens of megawatts of power you'd already need to refine useful quantities of metals. The Magnesium-based alloys are favorites for complex but lightweight and high strength parts, especially castings. Aerospace alloys are hard to come by off-Earth, so my take on this is that you keep all of that stuff for fabrication of habitat modules or vehicle / computer / camera chassis. Magnesium Diboride is also a material of interest to NASA and ESA for superconducting GCR shielding. Various Mag-based alloys are also known to be good at suppressing EMI.

Void · 2020-04-28 10:49:55

Quote #38 by Void:

KBD512,
I am entertained. I would like to work with you and others on the topic of "Lunar Mass Lifting". The moderater(s) can decide if this material can be placed into it's own topic.
You seem to believe that we should try to have propulsion as much as is plausible from the materials of greatest magnitude on the Moon. I can agree, and would like to examine what they are. I will put the numbers I have down now. If you see errors, please tell me.
Oxygen 43%
Silicon 20%
Magnesium 19%
Iron 10%
Calcium 3%
Aluminum 3%
Manganese .12%
Titanium .18%
I do have propulsive notions for Oxygen, but so far not a Oxygen steam rocket. You do appear to have such notions, which is OK. Tough to do, I bet, but OK.
I would like to limit the magnitude of the required lifting task, by suggesting the utilization of three machines that will handle part of the load(s).
1) Ring Booster (Uses Hydrogen and Oxygen, or Methane and Oxygen, most likely)
2) Orbital Oxygen Propulsion Methods. (There are several, I will get to the list soon).
3) Centrifuge Pulsing Oxygen Thruster (See "Spin Launch, and imagine timing pulses of Oxygen gas into a rotating thruster so that it exits in the 0-360 degree place where you want it to).
1) The "Ring Booster". This is to assist a canister off of the surface of the Moon. The canister could have it's own propulsion Mode as well, we have already each proposed something for that . The ring booster could wrap around the canister, be attached to it and assist in the lift.
The other use for the ring booster is to bring things down such as Carbon, and substances to make alloys, and to fill other needs.
2) Orbital Oxygen Propulsion Methods: This could include an "Oxygen Mass Driver". In my mind this would be a method to manufacture solid Oxygen bullets, and shoot them out of a mass driver, sequential magnets gun. (It is my belief that these collision hazards will be temporary, as I expect the bullets to evaporate fairly quickly). The ESA has an air breathing ion rocket. Perhaps it can handle Oxygen. No firm information on that. Vasimr Propulsion. Item #3, although intended to be a steering mechanism by me perhaps could be used as a sort of propulsion, perhaps to local navigation at a space station. It might help to heat the Oxygen before it is pulsed into the centrifuge.
*Also possible would be a laser pointed at an Oxygen emitting nozzle. I don't rule it out, but things get pretty complex for that at a distance.
3) Centrifuge Pulsing Oxygen Thruster: The Moon having it's own characteristics distinct from that of Earth or Mars, we can have permission to have a steering mechanism on the nose of our lifted canister. It could spin like a airplane propeller, but pulses of Oxygen Gas, pre-heated or not, could be timed so that the Oxygen exits the centrifuge at some direction 0-360 degrees that is desired, for steering the object. This will save on other consumables, such a burn thrusters or cold gas thrusters.
* I am going to propose a point to point objective for a non-landing device to take a big piece of the burden. For now I am going to porpose a device that uses any of the items of #1, #2, and #3, that turn out to be the best practices.
L1 to Low Lunar Orbit. #1 is marginally accepted as having some use in the transit under some notions.
Low Lunar Orbit, would be perhaps 50 miles/80.4672 km. It just needs to clear the Lunar altitudes with reasonable assurance of not crashing.
The device that does this, will have solar panels. I do not want to land them and lift them repeatedly from the Lunar surface. It may have thrust methods, from item #2, one or more thrust methods. They will probably expel Oxygen in some way or another.
As for the "Canister", it is my preference that it would have some lift method of it's own, and that it would likely be quite large, and that it will be able to bring a quantity of LOX to "L1". It might be assisted in that by the "Ring Booster", and the L1<>Low Lunar Orbit electric propulsion device. The canister itself upon arrival to L1 is also a delivered good. Can then be used to build orbital machines, either as is with slight modification and add on devices, or by having it's materials re-cycled into something else.
So, I am thinking "Big" canisters.
Your method suggesting Oxygen as the propellant would be cleaner. However, the method I suggested using Magnesium, allows for a propulsive chemical reaction.
There is quite a lot of Magnesium on the Moon it seems to me. More than enough for any use desired. (Hopefully my numbers for that are correct).
What do you think?
Done.

Void · 2020-04-28 10:51:45

Quote #39 by Void:

Since I am not getting a response, then I will suggest that I am quite satisfied with two parts of the plan mentioned in the previous post.
But as far as the device to lift off the Moons surface to a mountain clearing orbit, I am thinking exotic methods are quite a way off, if ever.
So, for the "Big Canister(s)", I am willing to substitute something like the Space Shuttle External tank. Either Hydrogen/Oxygen, or Methane/Oxygen. At least one of them get us to relatively firm footing, but they may require that Hydrogen be provided from the polar deposits. I still like the wrap around sort of toroidal booster, and expect it to use the same propellants as the canister would. But the canister will be a one way device.
However parts of it might be two way. You might bring back those parts that could be re-used. Engines, AI, maybe centrifugal Oxygen thrusters.
At this time I am thinking about setting Methane aside, under certain conditions. They are:
1) An extra-Lunar source of water ice. (Asteroids perhaps?)
2) A deep dark hole to drop the ice into at a reasonable speed of impact. (Shadowed Craters)
3) A vehicle that can do that manipulation with the ice cube. (I am hoping that the "Ring Booster" could be escorted to a landing run, by theL1<>Low Lunar Orbit electric propulsion device.)
Since I am cheep, I do not want to pay the full propellant price to deliver water to the Moons surface. So, my hope is that on descent the "Ring Booster" would release the ice cube, and that although the "Ring Booster" would land at one of the favored sites near the lip of a shadowed crater, the ice cube would overshoot and impact inside of the shadowed crater.
Needless to say, the "Ice Cube" needs to be shaded from the sunlight during the entire flight. Don't know what the potentials are for that.
While Hydrogen is not favored for a fuel tank these days for Earth or Mars, after all, part of my objective is to deliver big canisters to L1, with a load of LOX. In that travel, I do not want all of the LOX consumed, so the LOX tank needs to be oversized. I don't very much mind if all or most of the Hydrogen is consumed. But then the "Internal Tank" is large, and that is what I want. There is no air resistance, so the penalty for that is minimized.
My favorite use for those tanks would be to use them to construct synthetic gravity habitats. And I would like quite a few of them to go to Mars orbit.
So, the Moons surface would be converted into a "Shop Floor", where canisters were mass produced along with Hydrogen and Oxygen.
Parts from the canister launches would be recycled back to the Moons surface. The engines, AI, and perhaps centrifugal thrusters.
----
So, as I think of it just a little more, we do not have to fling ice cubes into dark craters, until the existing polar deposits become depleted, and that could be a long way off.
And....I think that if parts such as Engines, AI, and centrifugal thrusters are to be recycled, then they should be mounted permanently on the "Ring Booster". The "Ring Booster" also needs propellant tanks sufficient for it to land itself back on the Moon. But for assent, the canister should be it's supply of Hydrogen and Oxygen.
I think this is getting more closer to real possible.
The hope would be that some time from now either Magnesium using engines will be available, and/or Asteroid water. But for now the above may do.

Void · 2020-04-28 10:53:42

Quote #41 by KDB512

Void,
My only belief about this is that refined metal is very hard to come by, no matter how abundant it may be in the crust of another planet. Obtaining the ore is comparatively easy, but refining that ore into useful metal is very energy-intensive. There's far more O2 than humans can breathe, so the next logical use for the O2 is as a nominal quantity rocket propellant. The power required to refine enough Magnesium to use it and Oxygen, in multi-thousand ton quantities necessitated by a low-Isp rocket fuel, could just as easily be stored to use as part of an electromagnetic launch system (no atmosphere and thus no sonic booms nor atmospheric heating limitations placed upon making laps around an electromagnetic donut to achieve orbital velocity). Electromagnetic launch, when combined with a monopropellant gas providing orbit circularization from a simple cold gas thruster and a battery-powered electrical heating element to superheat the O2 for a few seconds, almost negates the requirement to consume propellant to achieve orbit.
Electricity stored in flywheels is simply far more efficient for converting stored energy into propulsive force and most of the propulsion system remains on the surface of the moon, where humans living in a lunar colony (the only good reason to spend the money required to develop and construct any ISRU-based launch system) can much more easily maintain it (because stationary electric motors and flywheels are far easier and cheaper to maintain than severely life-limited rocket engines). Here on Earth we have severe aerodynamic heating issues to deal with, but in a hard vacuum that primary impediment to implementation disappears. The secondary impediment of contending with massive sound pressure waves is likewise non-existent.
There are so many other uses for high quality aerospace alloys that the power required to fabricate them is much more efficiently utilized as structures rather than as fuels. Magnesium combined with Silicon Carbide nanoparticles produces an alloy that's one of the strongest known metal alloys, by weight, in existence. Furthermore, Magnesium Oxide and Aluminum Oxide are frequently found in high quality ceramics used for eating / drinking utensils or cookware and as crucibles for melting metals. If you can refine and use the precursor materials at all, then you'd most likely be making something of high intrinsic value with it. For whatever reason, I just can't see us repeatedly burning thousands of tons of metals after expending the colossal amount of energy required to separate Magnesium from Oxygen. If you could do that even once, then you have a substantial portion of the fabrication materials required by the electromagnetic launch system. After it's set up, it just keeps paying you back each time you use it.
I'm not against experimenting with using metals from the moon as rocket fuels, but you have to understand that you're going to be locked into a perpetual cycle of trying to meet the energy requirement to produce propellants when you could store the energy required for far less total energy input, presuming the intent is to provide reliable and routine transport.

Void · 2020-04-28 10:56:29

Quote #42 from Void:

That's good information KDB512.
I am going to copy the materials that we recently generated for this subtopic, to another location and continue there. If you object to having your quotes copied as well, I will delete my quotes of your materials. I will get out of the way of (th).
Index
» Science, Technology, and Astronomy
» Eventual Convergence?
Is where I will be on this topic.

Void · 2020-04-28 10:59:16

I am interested in exploring all the options.

However if you look, I am ready to put the Magnesium propulsion on the shelf for now. I have decided to see what can be done with Hydrogen/Oxygen launches from the Moons surface to 50 miles up / 80.4672 km up.

The items I want to deliver to that location are a canister with left over LOX.

Then I want a solar powered spacecraft that can retrieve it and deliver it to L1. As much as is possible I want that spacecraft to use LOX as it's primary propellant. There should be references to the options for this in the quotes I transferred here.

Post #10, which is quote #39 may contain useful information for that.

I would add to those options something that I think relates to a suggestion from KBD512. An Oxygen Steam Propulsion.

Probably much more practical at a small scale, and in most areas of orbit could be powered by a solar concentrating mirror. Likely much of the propulsion unit needs to be ceramic.

Last edited by Void (2020-04-28 11:49:08)

Void · 2020-04-28 11:55:02

Labor forces.

Mars has a few robots, that can make some observations. Manipulation of objects is very limited.

However the Earth has a very large potential labor force of AI assisted people who could manipulate objects on and around the Moon.

So, that could be the bottom of a labor force pyramid. Next up would be things like the LOP-G (Which I know almost everyone here hates).

But in time if the LOP-G is replaced by synthetic gravity machines, then that could be the next section up in the labor pyramid.

And then finally actual humans with robots on the surface of the Moon.

So, if that is done, a very large labor pool to manipulate the Moon and make things.

Last edited by Void (2020-04-28 11:57:15)

Void · 2020-04-28 12:15:10

So, I have the idea that certain sections of the Moon can be converted into industrial "Shop Floors", where things desired can be mass produced. Some of those things could be put into orbit. Specifically components for synthetic gravity machines, is my current greatest interest.

Then there are variables.

I try not to lock down too hard on one particular projection of the future. So many things are in motion all the time, that it is best to be adaptive to what actually comes.

Here is an example for energy: "All I want for Christmas is a 90% efficient solar panel".

Quote:

NovaSolix hopes to use carbon nanotubes to capture a broader portion of the sun’s electromagnetic spectrum, a process they hope will yield a 90% efficient solar cell at a tenth of the cost of modern solar modules.

https://pv-magazine-usa.com/2018/11/23/ … lar-panel/

If they ever do master this, then it bodes well for spacecraft that use large amounts of electric power. Specifically my current interest is in methods to move items from low lower orbit to "L1", but also to move synthetic gravity machines from "L1" to a Mars ballistic capture situation. And of course to navigate the hill sphere of Mars itself.

So, the above is a very wild card. It may or may not become real. If it does, then it changes the balance of power for spacecraft propulsion.

I am going to take a little break and then perhaps plan Bezos for Mars.

Continuing later.....

The above illustrates, that if such a solar panel emerges, then at least two things change. The ability to for instance expel Oxygen as a propellant for travel, becomes more sensible. Also, "Pink Greenhouses" on Mars begins to make more sense.

Per Kimbal Musk: https://www.cnbc.com/2019/11/12/kimbal- … -mars.html

So canister farming on Mars, as you know I want underwater farming on Mars. And I have nothing at all against those who want to make glazed greenhouses on Mars that use filtered sunlight. I wish them all the luck working to make it real.

The Gateway foundation may very well make the Voyager space station in LEO.
https://www.bing.com/videos/search?q=Vo … &FORM=VIRE

And they talk about eventually building orbital "Farmland". But what it previously mentioned about farming on Mars, at least suggests that a look should be done at the possibility that in the Martian Hill Sphere, some food could be provided to orbital assets from farms on Mars.

Starships will land on Mars with people and Stuff. To start with they will be refueled for return to Earth on the surface of Mars.

But Phobos and Demos exist. I am not going to assert that fuel can be made from them. I do not know that at this time. However, I am going to venture that Oxygen, and perhaps building materials can be obtained from them. Starship's Oxygen propellant is the heavy part of the propellant. And also there has been discussion here about methods of space propulsion using Oxygen only as propellant.

So, later on perhaps a Starship would take off from Mars with all of it's fuel, and only the amount of Oxygen to get to Martian orbit. It might also bring up food stuffs from Martian farms. Then if there is a way to extract Oxygen from the Martian moons, they would fill their Oxygen tank(s) in orbit from that source. Then perhaps head back to Earth. It might be noted that dust storms will not inhibit the production of Oxygen from the Martian moons.

So, I think the Hill Sphere of Mars, is the ideal place for the dreams of Jeff Bezos to be first fulfilled. So, there could be a convergence on this of Jeff Bezos, Elon Musk, and Robert Zubrin. But it will take a while.

Done for now.

Last edited by Void (2020-04-28 13:33:24)

Void · 2020-04-29 12:44:36

Responding to tahanson43206, his post #43, from the topic:
"Index
» Science, Technology, and Astronomy
» Physics Topics":

tahanson43206, there are two things that I am not particularly working on.

1) A water steam launch from the Moon.
2) Delivering packages to Mars with a balloon.

I was actually working on a propulsion notion that would have involved hot Magnesium, solid, liquid, and or vapor. In some cases, steam might have been used as an Oxidizer for that fuel. But I have hung up the phone on that one for now, for several reasons.

Some of the things that I have posted are sort of cousins of those things, but they are not the same.

However, since you keep mentioning steam to orbit, I will talk about it a bit both the good, and maybe a gooder way.
At this point the only way I would be a proponent of steam rockets on the Moon is if we could generate a more water rich situation.

The only way I can see to make that real is to crash land ice blocks into the shaded polar craters. Ice blocks that would need to come from somewhere. They would not need to be at a full interplanetary speed. Likely they would be partially slowed down before being sent out for the crash.

This guy, once upon a time proposed making free floating synthetic gravity machines in space, at least partially with Lunar materials.
https://en.wikipedia.org/wiki/Gerard_K._O%27Neill

At this time, my objective is to replace one of his proposals with other means. That proposal was to use a mass driver to shoot bags or regolith to arrive at "L1". It was daring, but I don't think maybe reliable. Plus that means that your raw materials are at "L1", and you would have to process them there.

The Moon has 1/6 g, which may be very good for working to completely or partially process materials. Also, if you extract the parts you want to use in "L1", you can leave the "Slag" behind on the Moon, and so do not have to lift it.

So, I want to build components on the Moon, and get them lifted to "L1".

As it happens, large canisters might be quite useful at "L1". Large canisters could serve as propellant tanks during the trip from the Moons surface to a low lunar orbit. Such propellants could be Water Steam, or chemical fuels that burn into steam. (Hydrogen, and Oxygen).

As I painfully discovered, water steam alone is not enough to reach a low Lunar orbit.

So, as I have proposed, in previous efforts, I propose a wrap around booster stage. This would wrap around the canister, and be plumbed to it for the launch. The wrap around booster would have all the parts you want to recycle back down to the Lunar surface later.

Chemical propellant tanks, Chemical engines, AI, maneuvering thrusters, Steam Nozzles (If appropriate).

So, you can have one of two situations.
1) The canister holds water steam.
2) The canister holds Oxygen and Hydrogen as fuels sufficient for the assent to low Lunar orbit.

* Also it may be desired to have extra Oxygen. That depends if there is a source of Oxygen from Asteroids.

In the case for water steam in the canister, the energy of it's thrust is not enough, but it could be helpful to rise to a low Lunar orbit, but I do believe that the "Ring Booster" will have to lend a lot of assistance to make that orbit, by burning Hydrogen and Oxygen.

To be truthful I don't know why we would want to use steam. Maybe it is better to fill the canister with Hydrogen and Oxygen instead.

Not sure, but leaning in that direction.

After the canister is delivered to low Lunar orbit, another craft which I hope mostly uses Oxygen as it's propellant, comes and gets the canister and takes it to "L1".

The wrap around "Ring Booster". Lands back onto the surface of the Moon to go again.

-----

An alternative would be to have much smaller canisters, fill them with steam, but accelerate them to a high speed with a mass driver, prior to venting steam. This would have several problems, and I don't know if it would have sufficient performance either.

Done.

Last edited by Void (2020-04-29 13:26:06)

tahanson43206 · 2020-04-29 14:21:39

For Void re this interesting new topic ...

Again, best wishes for success as you go forward!

Some years ago, I "met" a gent online who was working on a system for moving people and cargo between the Earth/Moon L1 point and the Moon.

I've forgotten most of the details by now, but what I remember may be of interest to you, and (hopefully) it may inspire you to even greater vision.

The idea was to push off gently from L1 so that as the spacecraft fell toward the Moon, it would accelerate along an elliptical path that would "just" graze the back side of the Moon. At that location, there would be an electromagnetic catch facility which would engage with the spacecraft and absorb energy from the space craft so that it ends up gently docking with a landing port. The stored energy would then be used to accelerate the spacecraft back to L1 using an electromagnetic launcher similar to the one that kbd512 has imagined.

The entire proposal seemed quite elegant to me at the time, and it still does, because of the efficiency of use of energy. There would be losses in the system so some energy would have to be made up with Solar input, but there would be no mass lost or wasted or even consumed.

(th)

Void · 2020-04-29 15:21:08

That is interesting, perhaps the deceleration would need to be on a flat elevated area of the Moon, if any could be found.

New Mars Forums

Announcement

#1 2020-04-24 17:44:26

Eventual Convergence?

#2 2020-04-24 19:56:34

Re: Eventual Convergence?

#3 2020-04-24 22:06:27

Re: Eventual Convergence?

#4 2020-04-25 07:46:04

Re: Eventual Convergence?

#5 2020-04-25 08:45:11

Re: Eventual Convergence?

#6 2020-04-28 10:44:13

Re: Eventual Convergence?

#7 2020-04-28 10:45:59

Re: Eventual Convergence?

#8 2020-04-28 10:47:53

Re: Eventual Convergence?

#9 2020-04-28 10:49:55

Re: Eventual Convergence?

#10 2020-04-28 10:51:45

Re: Eventual Convergence?

#11 2020-04-28 10:53:42

Re: Eventual Convergence?

#12 2020-04-28 10:56:29

Re: Eventual Convergence?

#13 2020-04-28 10:59:16

Re: Eventual Convergence?

#14 2020-04-28 11:55:02

Re: Eventual Convergence?

#15 2020-04-28 12:15:10

Re: Eventual Convergence?

#16 2020-04-29 12:44:36

Re: Eventual Convergence?

#17 2020-04-29 14:21:39

Re: Eventual Convergence?

#18 2020-04-29 15:21:08

Re: Eventual Convergence?

Board footer