You are not logged in.
On the basis of the previous post and the counsel of Calliban, and with the knowledge that it is likely that Mars can be a place to construct orbital structures that could be deployed to the solar system, it becomes apparent that we may want to style terraforming to best support that activity in the orbits of Mars until alternate methods appear.
So, a Mars with an average air pressure of 11.5 millibars, may be suitable for that, if you don't need to use Mass Drivers to deliver cargo to orbit. Actually, the mountain peaks may still allow the use of Mass Drivers.
So, in my opinion Mars becomes a resource, more than a notion to make a paradise on its surface. If you want a paradise and can afford it, build it in orbit.
As the reach of humans and their machines extends further into the solar system then the means to further terraform Mars may appear, and the need to use Mars for resources to orbit may go away and be replaced by other sources of such things.
Done
Last edited by Void (2024-02-06 11:10:56)
End
Offline
I now have this for you:
Electrical wiring will be a problem, especially underwater.
So, the cone having a stainless-steel inner cone can hold the differential pressure allowing the apex to be near the ice. And only piping will bring cold fluid down to the turbine/generator. And in this case light is generated for plants.
Where the stainless-steel gives tensile strength, the hard brick gives some compressive strength. The Regolith overlay helps to weigh the cone down.
We already know that we can grow lots of Algae, yeast, and mushrooms using Oxygen and Acetate. We hope that a method to grow vascular plants can be developed that would also use Oxygen and Acetate but may also use some light. This may allow the growing of terrestrial crops that humans currently like.
The sources of Hot Water at the bottom of the lake can be solar electric, both panels and solar thermal, also nuclear, also space based transmitted power.
It might be notable that it may be true that the colder the surface gets on the condenser, the more power that can be generated, provided you have a working fluid that is suitable.
Done
Last edited by Void (2024-02-06 21:33:30)
End
Offline
Per the previous post where light is projected to an air enclosure, it is a curious matter that waste heat can be dumped back into the lake, so using lighted gardens is not as energy expensive as would normally be true.
Done
End
Offline
I have somewhat revised this drawing:
So, this is not what we normally think of on Earth. On Mars though we can think of regolith, ice, water, salt as construction materials of significant value.
Even on the Equator of Mars this should work. Particularly if the lakes have vertical solar panel/radiators on them. They should shade the surface of the structure likely preventing the surface from getting warmer than freezing even in the day. And the nights are very cold.
So, any ice body on Mars may have great value and be worth exhuming from burial on Mars, this one for instance: http://newmars.com/forums/viewtopic.php … 89#p218989
I recall that in order to thaw Mars to Earth similar conditions you would need 2 Bars of N2/O2 mix on the planet or 1 Bar of CO2 on the planet. We are nowhere near that. If somehow, we were able to bring the pressure up to 1/3 Bar O2 or 2/3 Bar N2/O2, the planet would still be very cold. So, then we need to make cold our best friend to give us warmth.
Just now what seems to be in reasonable reach is an average pressure of 5.5 to 11 millibars, mainly of CO2. That is going to be a cold planet, even at the equator.
Pause.............
What we should want just now would be a Mars where we can extract materials to orbit, particularly Hydrogen. Later, we might with almost magical levels of technology, we may get to 2/3 Bar of N2/O2. That will be very much later though.
The Mars that could be developed in the next few centuries will remain low pressure I think but may have a network of ice tubes and warm bottomed lakes, all over it. And it would then be a giant power plant and would be very productive farm wise.
And I am very excited at the notion that the orbits of Mars could be where an enormous amount of habitat and energy harvesting machinery can be built.
Done
Last edited by Void (2024-02-07 07:53:39)
End
Offline
This seems worth adding: https://www.msn.com/en-us/news/world/pr … 73bb&ei=11
Quote:
Project Iceworm and the labyrinth of tunnels dubbed 'the safest place on Earth'
Story by Sarah Hooper •
3h
Done
Last edited by Void (2024-02-07 08:00:39)
End
Offline
I would like to mention other worlds where these technologies might be adapted to.
For the surface methods, using water and ice, Mercury at the poles might work, and Titan seems like a good bet.
Mercury has the promise of huge amounts of energy, and Titan has a very useful atmosphere.
Mercury has thick ice sheets in some of its polar craters. https://www.astronomy.com/science/explo … peratures/ Quote:
Hot and Icy
It’s estimated that Mercury has been accumulating ice for approximately 50 million years. This ice is up to 164 feet (50 meters) thick in some areas.
Other worlds may apply.
As for orbital habitats that might be manufactured in Mars orbit, those could be shipped to various worlds, including Venus.
So, all terrestrials are of interest, and our Moon because of proximity to Earth, and then Titan.
Done
Last edited by Void (2024-02-07 09:01:25)
End
Offline
This is a thing I have mentioned before, basically a way to use water, and perhaps ice as a window:
While it may apply to a lake on the surface of a world, I also very much like it for water filled spin habitats in orbit.
If our window were a sort of glass, then it would only need to hold about 24 or more millibars of differential pressure. The spin gravity working on the water column would provide the rest of the pressure for an open bottomed water filled enclosure.
Transparent bubbles/domes can have improved pressurization by being air filled, or by having pressure imposed hydraulically.
The radiation problems and thermal problems are likely to be well addressed with these.
In the event of an air leak in a bubble, it is likely that the deflation process will be slow enough for escape downwards to pressurization by water column.
So, this might apply to Mars orbits if you can procure Hydrogen to make water, and also use Oxygen from Phobos and Deimos.
Once you get out to Ceres or beyond more or less, then you have plenty of water for this.
In some cases, access to the shell that is the tank for the water, is relatively easy as it is not covered with regolith/soil.
If you want pressurized and air-filled park like habitats, then you can do that also.
All of these will need radiators to get rid of heat if light is conducted through the windows. That can then be a source of electricity if done in the proper way for it. If the radiator system breaks down then you need to be able to stop shining light into the windows. It would also be wise to have a method to evacuate to another facility in that case as well.
Done
Last edited by Void (2024-02-07 09:38:22)
End
Offline
Titan would be a more appealing destination if it could be warmed up a bit. As it is, the moon has a thick atmosphere with a temperature of -160°C. That makes Antarctica look like a tropical paradise! Even with thick clothing, it would be difficult to spend any time in that environment without a heated suit. Frost bite in hands and feet would be a severe problem.
One thing that Mercury has in its favour is an almost non-existant axial tilt. It has no seasons. Whilst the equator gets fried during the day, higher and lower lattitudes won't be so bad. This explains how the planet has managed to retain volatiles within its crust.
The two things that really go against Mercury as a destination are its proximity to the sun and lack of atmosphere. The first issue is a delta-v problem. When you get closer to the sun, you aren't just getting hotter. You are going deep into the strongest gravitational field in the solar system. Short of realising an Epstein Drive, it will be very difficult and expensive to enter orbit around Mercury with conventional propulsion. It is the most difficult planet to visit for this reason. Landing will be difficult too. It has substantial gravity - 37% of Earth. But there is no atmosphere at all, so all of the braking must be propulsive. Once you are there, you have the problem of refuelling your ship on a world where the only volatiles are in the cold polar regions or buried in the crust. So Mercury will be a tough nut to crack so far as human exploration is concerned. A high-thrust, high-ISP propulsion system would be needed.
Last edited by Calliban (2024-02-07 09:46:07)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
Your post is very appreciated Calliban.
My view of Titan is that very, very large domes, in part made of ice, can hold warm air. And as you may have seen reasonably warm tunnels can be dug into the ice to allow connections between domes.
As for Mercury, it does have water at the poles, and lots of graphite on the surface. https://www.theverge.com/2016/3/7/11174 … nce%20says. Quote:
Patches of a carbon-rich material called graphite — the same stuff that’s in a pencil — cover Mercury’s surface, tinting it dark gray. These patches are thought to come from an ancient carbon crust that's been hiding underneath Mercury's surface, a study published in Nature Geoscience says.
And so, lots of plastics and hydrocarbons can be made, but I am guessing not much Nitrogen.
I would think to build cities in the polar shadows and have power lines that bring electricity in from around the planet. Venus could be a source of Nitrogen, and Mercury could supply what it has to Venus.
But I think Mars is by far a gem. I anticipate that at Mars habitats filled with water can be made and sent to worlds like Venus and Mercury.
But yes, Mercury is a tough nut.
Titan though has all the volatiles you might want, and with mirrors you could light up an enormous amount or orbital habitats filled with them.
I am very much interested in aquiculture in space, particularly in orbital habitats around all the terrestrials and for Jupiter and Saturn orbits.
It seems that in the far past Europeans used to consume seaweed as food.
https://www.msn.com/en-us/health/nutrit … r-AA1invJw Quote:
A nutrient-rich food that once largely disappeared from Western diets was a staple of early Europeans, study finds
Story by By Katie Hunt, CNN •
3mo
So, in my post 1632, I discuss orbital habitat methods that might suit seaweed. With proper mirror methods, these could work for orbits from Mercury to Saturn, at least. If you have a tank full of water and can bring sunlight into it you have a potential seaweed farm and power plant, and very good protection from the space environment.
As far as Mercury goes, if you could boost mass from it using Mass Drivers and/or Skyhooks, then the lack of atmosphere is a good thing.
So, most people of Mercury would not live on the planet. By then robots could do most of the labor. (Or have killed us off).
I see Mars however as being a place to manufacture power plants and habitats that can be sold for a profit and delivered to places like Venus. With robots and solar energy, and if possible nuclear energy, I think that would be in reach.
These devices might migrate between the planets getting water, and Nitrogen and other desired things. It will not matter if it takes years for them to transfer from one planet to another.
Done
Last edited by Void (2024-02-07 11:39:04)
End
Offline
I feel a desire to note the downside of water filled habitats.
-They will need partitions/baffles to keep the water from all pooling on one side and so then busting out of whatever bearings it would have.
-If they freeze solid, they will likely rupture.
-The water may be corrosive on Metal, but then wet soil might also be very corrosive.
-Some advantages might be that they don't need as much Nitrogen as an air-filled habitat.
-They may be very protective for radiation concerns.
-As the inside of the containment wall may be exposed and not covered with dirt, leaks might more easily be detected and patched.
-The windows may only need to hold a differential pressure of perhaps 3% of a bar of pressure against the vacuum of space.
I think that the build cycle of such things is to make a shell, perhaps from materials of a stony asteroid and to then add Nitrogen from somewhere and also water and some Carbon.
All of those can come from Mars/Phobos/Deimos at first.
Callisto may have everything needed, I am not sure.
Titan has all the Nitrogen and Hydrogen and Carbon needed, so machines sent there could be filled up.
Done
Last edited by Void (2024-02-07 20:08:20)
End
Offline
If what I am thinking of can be economical, then the first instances can be in the Mars/Phobos/Deimos system where the spectrum of materials is favorable.
The needs are met from products from:
1) Stony Materials.
2) Non-Nitrogen Organics.
3) Nitrogen.
I think that covers the bulk of what is needed.
Places where this balance seems somewhat possible are:
A) Mars/Phobos/Deimos.
B) The Asteroid Belt.
C) Maybe Callisto, if it has Ammonia/and other Nitrogen compounds.
D) Technically the Earth/Moon qualifies, but the lifting of vast amounts of Hydrogen and Nitrogen from Earth may have undesired consequences.
E) The Saturn system may be very good, provided that Phoebe and maybe some other moons may have accessible stony materials.
'A' has the best solar energy conditions, but lifting Hydrogen and Nitrogen from Mars will be a fair task, and there is limited Nitrogen.
Worlds with specialization are Mercury with abundant rocky materials, and Venus with abundant Nitrogen.
I favor the solar wind and gravity assists to move bulk materials. It works best to send materials away from the sun.
Unlike photon solar sailing, the force of the solar sail is more consistent even as you travel further out, as the size of the magnetic field can expand as the force of the solar wind diminishes. But of course, if it works from solar energy, the solar energy falls off as you travel outward.
In the early days, it would be nice to have a method to move constructed machines from Mars/Phobos/Deimos inward to Venus to collect Nitrogen.
But eventually it may be that Mercury could be where the large part of machinery would be built, in the orbit of Mercury, provided that Mass Drivers and Skyhooks would work.
Then the Machines would travel to Venus to get lots of Nitrogen, and maybe just a pinch of water. The pinch of water would allow them to have a very low-key type of simple agriculture, perhaps.
As for sending things to Venus from the outwards of the solar system, I know that some types of solar sailing may work, but perhaps reaction mass processes and gravity assists could be of value.
Mercury is a very hard nut to crack, so alternatives for stony materials are our Moon, the Stony Asteroids, and it is thought Centaurs may be a mix of rocky and volatile materials. And of course Mars/Phobos/Deimos.
While Callisto may have some of it, and we think that Phoebe may be a captured Centaur.
Titan, if it does not have cryo-life, could be a very good source of Nitrogen and Carbon, and of course Saturn has lots of icy moons for water. I really don't think the attenuated light at Saturn is a showstopper. Mirrors could concentrate the ~1% sunlight to useful values.
There is a lot of "Space" out there for such very large mirrors.
And then there are the Lagrange Points all over the place. Saturn has an L4 and L5, and I expect that Titan has an L4 and L5.
It seems to me that a device manufactured more inward in the solar system that then filled up on volatiles at say Titan, then might ravel to a Lagrange point to bask in the sunlight.
Isaac Arthur has a nice video I have linked to before which discusses Lagrange Points: https://www.bing.com/videos/riverview/r … ORM=VRDGAR
I used to be paranoid about volatile leakage from space habitats, but I think that the Solar Moth can take care of that. Again Isaac Arthur: https://www.bing.com/videos/riverview/r … &FORM=VIRE
I now visualize the solar system as like the Earth's atmosphere. Condensation occurs very far out. So much of what leaks may condense there. Passing stars or the galaxy itself perturb comets so that they come in closer to the sun. So, basically catching those comets and redirecting them is like diverting a river to irrigate farm fields. I did not used to this it was going to be practical, but now, I think it eventually will be.
I was interested in "Comets that approach Mercury": https://www.bing.com/search?q=Comets+th … AA&pc=U531
So, that would be interesting. Mercury has a small magnetic field. If you smacked it with a comet, I am guessing that a lot of the materials might end up in its shadowed craters.
A dangerous game that would need to be played well, but if you could intercept comets using Jupiter, Saturn, Uranus, and Neptune to do gravity assisted orbital modifications, then as the comets got inward you could fine tune the path to smack Mercury. Only for some comets.
And a very dangerous game. A mistake could kill Earth or Mars.
But civilization would have been distributed across the solar system by then. Perhaps it would be too dangerous a game though. Maybe better to simply take the comet apart and put the volatiles into containers, and use the solar wind to make a more circular orbit, perhaps one that is not quite on the orbital plane as Earth and Mars.
Done
Done.
Last edited by Void (2024-02-08 11:53:45)
End
Offline
This could be very useful on Mars: http://newmars.com/forums/viewtopic.php … 09#p219109
Quote
Void
Member
Registered: 2011-12-29
Posts: 6,754
It has occurred to me that you could embed plastic tubing into such a structure to make a heat exchanger.Plastic tubing with cladding of miner wool or beta cloth, and organic matter included, growing mycelium to bind this together.
I also want to hang vertical solar panels on these. (Some people have a pathology about solar panels, but I don't).If we want to deal with solar thermal the similar can be done with tubing embedded in mirrors. Then of course one face has to be given a shiny surface, probably of metal.
Then you can use these things for at least a dual purpose.
One of the games I want to play is to tap into the deep cold of the Martian night. If you have a thermal reservoir of some kind of stored heat, or maybe even geothermal heat, or nuclear heat, you then can tap into the deep cold that Mars can present in the nighttime or winters.
But also, the heat exchanger will allow you to play trick of other types.
You might shine heliostat mirrors at a solar panel to increase the output. But if you overheat the panels, you then reduce the efficiency, and shorten the life span of the solar panels, but if you have built in cooling, then you can pull down the level of heating and save the extracted heat. You could involve a heat pump process as well, as while the solar panel is warm, in the sunshine the panel is providing electricity at the same time.
This could work very well with ice covered hypersaline lake energy storage on Mars.
Done
Oh dear, I skipped over why I started a post in the first place. I think that hot slag from some industrial process such as metal work, could be turned into a mineral wool, for the above concepts.
Done
I think that also something like chicken wire or screening could be added.
If you could grow this sort of thing in a lava tube, you might line it with something that may have good tensile strength. How to make that environment good enough for mushrooms first though is a problem.
And I wonder if air filled enclosures within water would be a possibility.
Done.
Last edited by Void (2024-02-08 13:34:39)
End
Offline
In a natural lake like Lake Vanda, I sort of understand the salt levels.
https://en.wikipedia.org/wiki/Lake_Vanda
The bottom waters might be extremely salty and warm, and the upper water near the ice may be perhaps 2 times as salty as the sea and rather cold.
The upper water has a lot of Oxygen the bottom waters are anoxic.
So, using acetate, and Oxygen it should be possible to grow algae, yeast, and maybe types of bacteria.
So, then plenty of organic matter to grow mushrooms on. But you could also feed the Mushrooms Acetate as well.
Of course they need some Oxygen.
Well, that is interesting if it is true! https://totalgardener.com/mushrooms-req … 0to%20grow.
Quote:
Mushrooms do not need oxygen to grow. Mushrooms do ‘breathe’ and exchange gases directly with the atmosphere, but not oxygen.
I don't entirely trust that yet; I will research it more later.
Done
Last edited by Void (2024-02-08 14:11:29)
End
Offline
I have been looking into this: https://newmars.com/forums/viewtopic.ph … 54#p219154
Quote:
Index» Life support systems» Wood and Wood Simulants in Space
It could be useful in structures like this: https://newmars.com/forums/viewtopic.ph … 32#p219032
Quote:
I wanted to develop this a bit further and point out a few things that are potential for it:
Probably best in the air or in the interface of air and ice. Structural and insulating perhaps.
I feel that a lot of this type of structure may be possible, perhaps at a reasonable cost.
Done
Last edited by Void (2024-02-10 10:42:35)
End
Offline
This information about vertical panels could be of some value on Mars: https://newmars.com/forums/viewtopic.ph … 30#p219230
Quote:
This is a nice set of information on solar panels: https://www.youtube.com/watch?v=5AVO1IyfA9M
Quote:Vertical Bifacial Solar Panel Performance Results Part 1
Projects With Everyday Dave
47.2K subscribers
The information in part could relate to methods for Mars.
Vertical panels on Mars could be pretty good, at least in places.
This post discusses the creation method for such devices as might be useful to mound solar panels on https://newmars.com/forums/viewtopic.ph … 55#p219155 (Post #1639, the previous post).
On Mars an advantage will exist in that the force of the wind is comparatively light.
Because of this I am tempted to think of active positioning vertical solar panels, that might be of a single face.
For Mars at least you could rotate them almost 360 degrees and still have electrical and fluid umbilical devices. So, you would have a vertical axis. Also, it might be considered to have a horizontal axis. So, this device could be sun following bot for the Equator and Polar areas of Mars. I will think that actuators like those for the Optimus robot might be adapted. The back side of the solar panels could be thermally insulated so that the solar panels will heat up. But if fluid carrying tubing is between the solar panels and the insulation then on Mers these may work both as electric and thermal solar panels.
I anticipate the use of both heat pumps and also on occasion turbines to be involved with this.
In this method, the ground of the solar farm could be well shaded. If it had a Hypersaline Lake under it, then the heat form the heat pumps could be pushed into it's bottom waters when the sun would shine. Otherwise, to get power the solar panels would work as heat exchangers so that heat from the lake rejected to the sky would turn a turbine to push a generator.
Done
Last edited by Void (2024-02-12 14:37:52)
End
Offline
I am interested in considering the value of solar trackers on Mars: https://en.wikipedia.org/wiki/Solar_tracker
Quote:
A solar tracker is a device that orients a payload toward the Sun. Payloads are usually solar panels, parabolic troughs, Fresnel reflectors, lenses, or the mirrors of a heliostat.
I have read some articles this morning, and it appears that a tracker that has two axis, may likely cost about twice as much as a stationary solar panel, I think for the initial cost.
Most worlds that we might put solar panels on have a lesser gravitation. For Mars. it is about .38 g. For the Moon it is about .17 g. Mercury would be about .38 g, even the large asteroids would be a very small g force.
Of these only Mars has an atmosphere of consequence. It does not do much of a push for winds, but the atmosphere does distribute dust.
This is a very nice article: https://www.solarreviews.com/blog/are-s … investment Quote:
What is a solar tracker and is it worth the investment?
By Catherine Lane
|
Updated 11/01/2023
Quote:
. Manual solar trackers
Manual trackers require someone to physically adjust the panels at different times throughout the day to follow the sun. This isn’t always practical, as you need someone to constantly monitor the sun and change the position of the solar panel system.2. Passive solar trackers
Passive trackers contain a liquid with a low boiling point that will evaporate when exposed to solar radiation. When the liquid evaporates, the tilt system becomes imbalanced. This imbalance causes the panels to tilt towards the direction of the sun’s rays.3. Active solar trackers
Active trackers rely on motors or hydraulic cylinders to change position. The motors in active trackers will move the PV panels so they are facing the sun. While this is more convenient than manual trackers, the moving parts within the motors could easily break. This could lead to higher maintenance costs over the lifetime of the system.From there, solar trackers can be categorized even further based on which direction they move. A solar tracker can be either:
Single-axis solar tracker
Dual axis solar tracker
So, that helps. Two things I have considered is if Humanoid Robot could operate a number of "Manual solar trackers".
So, if it could walk around resetting solar panels with dual axis and no motors, that might be somewhat effective. Such robots might also be desired for cleaning the panels.
As for motors on a tracking system I might think about wind up motors. A robot could "Recharge" them, (Wind them up), with a rotary motor of some kind. Probably the horizontal axis could work OK with that, although adjustments that compensate for the Hight of the sun in the sky over seasons might be desired.
One thing that could be of value would be to have the panels face down during the dark hours. This might reduce accumulation of dust.
Another sort of fun idea would be for these solar panels to be quadrupeds, with four legs at least. The Boston Dynamics "Dog" is such: https://bostondynamics.com/products/spot/
Image Quote:
But on alien planets these machines would move maddingly slow. Much slower than a sloth.
And it appears that such a device would not need pivot bearings if it had legs like spot:
Anyway, that is at least a little stimulation of the imagination. I am supposing that the device would have solar panels on its back. That however may present cleaning problems.
Anyway, it seems to me that animated solar panels could be considered for low gravity worlds. Earth of course is not low gravity and has very destructive weather at times. However animated solar panels might posture to avoid blocking wind, and perhaps also to a tolerance of hail. On Mars at high latitudes in the winter, these things might be stored in tunnels in the ice, or they may tilt themselves to a vertical position to perhaps tolerate CO2 frost accumulations.
Although these things might be able to walk around, I would expect that they would be hooked up to utility lines, such as for electricity and also perhaps thermal collection.
These devices, capable of intercepting the output of the sun, then can also shade the ground. So, then extensive installations of "Herds" of these things, could alter a local microclimate.
If we could imagine this particular notion as being like dogs on a leash, then the "Dogs" can collect solar energy when it is available, and also be used as radiators when Mars presents nighttime and seasonal cold.
The working fluids may be a challenge though, I am not sure which could be useful.
Ice being found buried all over Mars in large amounts, I think the idea of building Hypersaline ice-covered reservoirs is valid. These machines poised on top of the ice can push energy into the lake bottoms when the sun is "Up", and can serve as radiators otherwise.
The belly of these devices could be strongly insulated so that the solar panels will accumulate heat. We would not want to do that on Earth, but Mars is colder by a lot.
A fluid heat exchanger method between the belly insulation and solar panels, could be rigged to a heat pump system to extract the heat. The heat pump would operate only when the solar panels were activated by sunlight.
I have suggested that we might use the robotic solar panels as radiators. But I will confess that that may be more complex than we may want.
I think that there is another way to tap into the cold of Mars using the ice layer of the Hypersaline Lake. These robots could not only posture to affect the solar albedo, but at night could posture to allow heat to most effectively flow out of the ice. In the daytime the robots may shade the ice from sunlight but at night they may posture to assist the departure of infrared photons from the ice.
This then would drive the ice to thicken. That thickened ice then can be used as a resource. A low differential temperature system could generate electricity, using the warm/hot water at the bottom of the lake and the cold water under the ice. Then it can tap into the phase change of the ice, to get more of the cold side. But your process control has to make sure that too much ice is not melted.
I think I will stop for a while.
Done
The solar pond again: https://en.wikipedia.org/wiki/Solar_pond
Quote:
Efficiency
The energy obtained is in the form of low-grade heat of 70 to 80 °C compared to an assumed 20 °C ambient temperature. According to the second law of thermodynamics (see Carnot-cycle), the maximum theoretical efficiency of a cycle that uses heat from a high temperature reservoir at 80 °C and has a lower temperature of 20 °C is 1−(273+20)/(273+80)=17%. By comparison, a power plant's heat engine delivering high-grade heat at 800 °C would have a maximum theoretical limit of 73% for converting heat into useful work (and thus would be forced to divest as little as 27% in waste heat to the cold temperature reservoir at 20 °C). The low efficiency of solar ponds is usually justified with the argument that the 'collector', being just a plastic-lined pond, might potentially result in a large-scale system that is of lower overall levelised energy cost than a solar concentrating system.
Now, I believe I have just stumbled into something very good: https://en.wikipedia.org/wiki/Paraffin_wax
Quote:
Properties
Paraffin wax is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 46 and 68 °C (115 and 154 °F),[7] and a density of around 900 kg/m3.[8] It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents but burns readily.[9] Its heat of combustion is 42 MJ/kg.[10]
So, now we could phase change the hot side, if we had containers of Parafin in the bottom of the Hypersaline lake.
The temperature needed may well be attainable.
So, then we would have both cold and hot side phase changes for energy storage.
This heat pump appears to be quite capable of melting the Parafin wax: https://ammonia21.com/norwegian-researc … heat-pump/
Quote:
Researchers from Sintef Energy Research in Norway, the Norwegian University of Science & Technology (NTNU), and industrial partner ToCircle, have developed a new high-temperature water-based heat pump suitable for many industrial processes, and capable of producing temperatures of up to 180°C (356°F).
The solar pond again: https://en.wikipedia.org/wiki/Solar_pond
Quote:
Examples
The largest operating solar pond for electricity generation was the Beit HaArava pond built in Israel and operated up until 1988. It had an area of 210,000 m² and gave an electrical output of 5 MW.[3]India was the first Asian country to have established a solar pond in Bhuj, in Gujarat. The project was sanctioned under the National Solar Pond Programme by the Ministry of Non-Conventional Energy Sources in 1987 and completed in 1993 after a sustained collaborative effort by TERI, the Gujarat Energy Development Agency, and the GDDC (Gujarat Dairy Development Corporation Ltd). The solar pond successfully demonstrated the expediency of the technology by supplying 80,000 litres of hot water daily to the plant. It is designed to supply about 22,000,000 kWh[citation needed] of thermal energy annually . The Energy and Resources Institute provided all technical inputs and took up the complete execution of research, development, and demonstration. TERI operated and maintained this facility until 1996 before handing it over to the GDDC. The solar pond functioned effortlessly till the year 2000 when severe financial losses crippled GDDC. Subsequently, the Bhuj earthquake left the Kutch Dairy non-functional.[4]
The 0.8-acre (3,200 m2) solar pond powering 20% of Bruce Foods Corporation's operations in El Paso, Texas is the second largest in the U.S. It is also the first ever salt-gradient solar pond in the U.S.[5]
So, actually it looks rather good, maybe we could store hot paraffin wax in containments in our bodies of water on Earth.
Done
Another look at this would not hurt: https://newmars.com/forums/viewtopic.ph … 55#p219055
Done
Last edited by Void (2024-02-13 15:20:57)
End
Offline
If Paraffin Wax is good for one thing I think maybe it should be investigated what other uses it could have.
This was pretty useful: https://web.stanford.edu/~cantwell/NASA … 20NASA.pdf
Candles as emergency lighting on Mars? Quote:
HANCOCK COUNTY, Miss. – NASA Stennis Space Center (SSC)
recently tested a rocket motor powered by fuel most people have in
their homes: paraffin, the waxy material used in common candles.
In the past, paraffin was thought to be too weak and unstable to use
as rocket fuel, but a research team at Stanford University in Palo Alto,
Calif., found it to be twice as strong as conventional solid propellants.
It also burns at a higher combustion rate, is safer, cheaper and very
friendly to the environment, producing water vapor and carbon
dioxide.
designe
And a rocket propulsion method as well.
It might compliment storing Perchlorate for Oxygen as well.
This rocket apparently is designed for Mars: https://www.intechopen.com/chapters/76789
This is more interesting than I thought.
Well, it seems to me that if you are going to manufacture Paraffin Wax for one purpose, it may help to have other uses for it as well. This one includes metal fuels embedded in Paraffin and then two types of Oxidizer, Quote:
Propulsion system uses CO2/N2O mixture as the oxidizer.
So, Aluminum and Magnesium added to the wax, the wax then being a binder.
Done
Paraffin of course is also good for radiation protection, I believe.
Done
Last edited by Void (2024-02-13 13:38:22)
End
Offline
Highly electropositive metals like calcium and sodium, are soluble in ammonia.
https://en.m.wikipedia.org/wiki/Ammonia#Solvent
Calcium is abundant in lunar highland regolith and rocks.
The resulting solution should be hypergolic in contact with liquid oxygen.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
Your post Calliban may have been for Venus? But yes the same method might be good for Mars as well.
I am going to try once again to mate the idea of thermal storage in vaults in the Oceans, with intermittent energy sources. It will be more possible to sustain it here and less likely to be overwritten with more traditional ideas.
I have suggested Paraffin Wax reservoirs for Mars, to store intermittent energy, from the sun. That might be suitable on Earth as well.
But for wind farms it may also be suitable. If it can be made to be economically profitable, then we will have found a new market for our Hydrocarbons that does not as much add Carbon to the atmosphere. It may also make it economical to extract Carbon from the atmosphere, to make Paraffin Wax.
This may help with visualizing such an immersed Paraffin Wax Tank: https://newmars.com/forums/viewtopic.ph … 65#p219065
Ignore the fact that I previous described a tank filled with air, the cone shape is what I care about in this post.
A quote from post #1641:
This heat pump appears to be quite capable of melting the Parafin wax: https://ammonia21.com/norwegian-researc … heat-pump/
Quote:Researchers from Sintef Energy Research in Norway, the Norwegian University of Science & Technology (NTNU), and industrial partner ToCircle, have developed a new high-temperature water-based heat pump suitable for many industrial processes, and capable of producing temperatures of up to 180°C (356°F).
So, an example could be the North Sea wind farms. On peak wind electric you may charge such a Paraffin Wax reservoir on the cheap as you have an almost ideal source of heat to draw on the ocean water. Thiis then creates a load at the wind harvesting site, so that you do not have to waste the peak energy available, and do not have to transmit it to land through cables. It could even be that at times a land grid would send power though the cables in reverse to charge up these Paraffin Wax reservoirs. This could be true if a land grid had lots of solar energy.
Such thermal reservoirs might work with wave and tidal energy.
Now, if other locations would make Liquid Air, then you may react Liquid air with the heat from the Paraffin Reservoirs.
This then may provide an export commodity that could get a profit for entities elsewhere in the ocean or shores of the ocean. Super Tankers filled with liquid air.
So, by creating an increased value for Paraffin Wax, and the supporting devices for this liquid air battery, we may create incentive to sequester Hydrocarbons in such thermal vaults in large bodies of water.
If the Paraffin Wax becomes valuable enough, then it may be incentive for some places to make it out of Carbon in the air and Hydrogen from water. Or from various sources such as Natural Gas, Oil, or Coal.
This then might provide a livelihood for entities that get their paychecks from the petrochemical industry.
If a hot Paraffin Wax reservoir were light enough to float, the answer would be to add some rocks or bricks into it.
About heat pumps: https://en.wikipedia.org/wiki/Heat_pump
Temperature of the North Sea: https://www.seatemperature.org/north-sea
Image Quote:
Green Colors are about 5 to 11 degrees C. (41 to 52 degrees F).
Here is a blurb about heat pumps, I think it says efficiency might be 200% to 400%, forgive me if I am wrong, I am in need of more understanding for heat pumps: https://www.technologyreview.com/2023/0 … eat-pumps/
So, i think that it is pretty good that using scrap wind power you could pull heat out of the ocean and then use that energy to drive a liquid air battery process.
Done
The big picture here is that you may make it more valuable to manufacture Paraffin Wax, than to burn Hydrocarbons.
This may get the fossil fuel industry on board with green energy. (I almost puke when I say green energy).
I know the truth about the people who tout green they are simply anti-industrial, and think that the verbal and violent have a right to own everybody else as their slaves/peasants/sharecroppers/surfs. That is why I don't like them. But if we can be clever enough soon enough, we can dodge captivity, and the corruption of the gene pool.
Done
Last edited by Void (2024-02-14 08:08:26)
End
Offline
Void, that is an interesting idea. What you are describing is an offshore thermal energy storage system, using sea water as a heat source and heat sink. One of the advantages this provides is that sea water temperatures do not vary as much as air temperature throughout the year. So your heat pump source has a relatively stable temperature and your generator has a stable heat sink temperature. You can deal with minor temperature fluctuations by varying pumping rates across your heat exchangers.
The paraffin wax storage tank could be conical, or spherical or cylindrical. It doesn't matter hugely. A sphere is most stable from a structural integrity and thermal insulation viewpoint. A cylinder or cone can be covered in dredged gravel or mud to provide ballast against bouyancy. Another advantage that your idea has is its ability to scale. It is possible to build trully huge tank structures on a slipway on shore, launch them into the sea and then float them to where you want them. On land, the difficulty in transporting structural components makes this trickier to do at the same scale. To sink them in place, you flood ballast tanks removing just enough bouyancy to allow them to sink. In this case, we would probably just flood the entire tank. Once it is on the bottom, we would ballast it with gravel, pump the water out of it and fill it with molten wax.
You don't necessarily need to put this tank in deep water for your idea to work. It could relatively close to shore. So long as it has access to sea water across the tidal range. This raises another possibility. If we put the tank near shore and close to a coastal town or city, it could supply direct heat for district heating through a piped water main. But we would need to built a heat distribution network first.
The tank itself can be made from reinforced concrete. This is usually much cheaper than a steel structure and will resist corrosion and wave action much better. There are a number of different ways you could build it. The low thermal conductivity of concrete and thickness of the walls, will help with heat retention. The inside of the tank can be textured to limit heat distribution by convection. As wax freezes to the walls, it wouid form a layer that insulates tge wax in the middle. In the event of spillage, environmental impact is minimal. Paraffin wax freezes solid at sea temperature and will wash up as solid lumps onshore. Nothing will ingest it and you can clean it up gradually without worrying about threat to wildlife.
So far as I know, paraffin wax is thermally stable in anaerobic conditions at temperatures <100°C. So the wax shoukd be indefinitely reusable.
Last edited by Calliban (2024-02-14 08:33:14)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline
Thank you for your valuable inputs Calliban.
The method could work in some lakes as well.
A typical winter lake at may have slightly warm water in its bottom even in winter.
Particularly large reservoirs on rivers might host such things. If one has hydroelectric already, and you add thermal storage, then it may be more possible to accommodate wind and solar power inputs.
I am thinking of dams on the Colorado and Missouri rivers in particular.
As you have pointed out the toxicity of the process being relatively low, other lakes such as the great lakes could host these as well. In that region relatively cold winter air may make the production of liquid or compressed air easier. But still the lake water would hold some heat even in the winter for heat pumps to pull heat out of. Obviously other parts of the world could do similar.
Done
Last edited by Void (2024-02-14 09:22:04)
End
Offline
I want to explore the interaction with Mars crossing asteroids or grazers with the Martian effort.
Phobos and Deimos for any purpose can be the initial source of similar materials. Eventually then more materials could be brought in perhaps using ballistic capture methods, and/or aerocapture. (Aerocapture will be very hard).
I think that this article is somewhat optimistic about ice in the moons. But I hope it is correct about Carbon rich rock: https://science.nasa.gov/mars/moons/facts/
It is not essential that Carbon exist on the Martian moons but it would be convenient.
Many Mars crossing asteroids may have some water, even if they are stony but may also lack stuffiest Carbon or Nitrogen.
Although Ceres and other asteroids further out could supply those Mar also could. Focusing on Mars as the source could make sense at least at first, as we intend to address Mars as an object of strong interest anyway.
List of Mars crossing asteroids again: https://en.wikipedia.org/wiki/List_of_M … or_planets
Some stony asteroids may have some water on them:
Itokawa: https://www.sciencenews.org/article/wat … 20Advances.
Itokawa: https://en.wikipedia.org/wiki/25143_Itokawa
https://www.space.com/water-detected-as … ers%20said.
7 Iris: https://en.wikipedia.org/wiki/7_Iris
20 Massalia: https://en.wikipedia.org/wiki/20_Massalia
So, it sort of looks like at least some stony asteroids will have some water.
Like Itokawa, Eros has an interesting orbit. We have no proof of water on it but it seems a real possibility to me.
Eros: https://en.wikipedia.org/wiki/433_Eros
Perhaps Eros is quite dry, I have found little evidence for water, but it has a useful orbit and is of a significant size.
So, it may be needing donations from elsewhere, perhaps Mars/Photos/Deimos.
In thinking about Venus, I came to notions about Wood and Urea, and I suppose water ice. Those can be solid materials that may keep fairly well in cold containments and at lower pressures. Things like Ammonia might need greater protection, but I don't rule is out.
So, I reveal my intentions. Venus could be a very good donor of such materials, but it will be a much harder planet to access than Mars, so I think starting with Mars would be a good way to build up the utilization of asteroids that could be assistive in accessing Venus eventually.
It is true that the more outer asteroid belt may provide the substances, but with Mars you get a twofer. we want Mars and it has what stony asteroids may need.
Urea: https://en.wikipedia.org/wiki/Urea
Quote:
CO(NH2)2
So, it appears to be what you would want on a stony asteroid for materials hard to come by.
Wood: https://en.wikipedia.org/wiki/Wood
Chemistry Quote:
The chemical composition of wood varies from species to species, but is approximately 50% carbon, 42% oxygen, 6% hydrogen, 1% nitrogen, and 1% other elements (mainly calcium, potassium, sodium, magnesium, iron, and manganese) by weight.[31] Wood also contains sulfur, chlorine, silicon, phosphorus, and other elements in small quantity.
So, not that efficient for it has a considerable amount of Oxygen which you could get at the asteroid even if it is stony. But wood is structural,
Other substances that might keep in long term transport to a stony asteroid would be Carbon and plastics.
Cycling spaceships might be derived from some of these asteroids that could link to Mars or Earth else Mars and Earth.
Another substance desired from Mars could be Fluoride. I am definitely on thin ice when I try to be secure in knowledge on this.
https://en.wikipedia.org/wiki/Fluoride
Quote:
Occurrence
Fluorite crystals
Fluorine is estimated to be the 13th-most abundant element in Earth's crust and is widely dispersed in nature, entirely in the form of fluorides. The vast majority is held in mineral deposits, the most commercially important of which is fluorite (CaF2).[4] Natural weathering of some kinds of rocks,[5][6] as well as human activities, releases fluorides into the biosphere through what is sometimes called the fluorine cycle.In water
Fluoride is naturally present in groundwater, fresh and saltwater sources, as well as in rainwater, particularly in urban areas.[7] Seawater fluoride levels are usually in the range of 0.86 to 1.4 mg/L, and average 1.1 mg/L[8] (milligrams per litre). For comparison, chloride concentration in seawater is about 19 g/L. The low concentration of fluoride reflects the insolubility of the alkaline earth fluorides, e.g., CaF2.Concentrations in fresh water vary more significantly. Surface water such as rivers or lakes generally contains between 0.01 and 0.3 mg/L.[9] Groundwater (well water) concentrations vary even more, depending on the presence of local fluoride-containing minerals. For example, natural levels of under 0.05 mg/L have been detected in parts of Canada but up to 8 mg/L in parts of China; in general levels rarely exceed 10 mg/litre[10]
In parts of Asia the groundwater can contain dangerously high levels of fluoride, leading to serious health problems.[11]
Worldwide, 50 million people receive water from water supplies that naturally have close to the "optimal level".[12]
In other locations the level of fluoride is very low, sometimes leading to fluoridation of public water supplies to bring the level to around 0.7–1.2 ppm.
Mining can increase local fluoride levels[13]
Fluoride can be present in rain, with its concentration increasing significantly upon exposure to volcanic activity[14] or atmospheric pollution derived from burning fossil fuels or other sorts of industry,[15][16] particularly aluminium smelters.[17]In plants
All vegetation contains some fluoride, which is absorbed from soil and water.[10] Some plants concentrate fluoride from their environment more than others. All tea leaves contain fluoride; however, mature leaves contain as much as 10 to 20 times the fluoride levels of young leaves from the same plant.[18][19][20]
In reality it may prove easier to get it from Earth at least at first.
My obsession with it is that plastics including it are very durable and would be useful on Mars and Venus.
I think that plastics having Chlorine are pretty good but not as good as those containing Fluorine.
Calliban sort of set me back about cloud cities on Venus, so I am taking a more humble path. I am more thinking that you could have machinery in the clouds, for the extraction of Hydrogen from H2SO4, and to also create Urea to export to orbit. But in this slightly more humble notion I have it that people would like in habitats in orbit and would not normally enter the atmosphere of Venus.
Caliban's opinions probably have merit, so I have reduced the level of ambition. But I still see Venus as a vast reservoir of organic chemicals wanted in space for Humans and their machines.
I think that the stony asteroids can help produce that result for Venus, but to bootstrap that, we might want to start at Mars/Phobos/Deimos.
I also believe that using Ballistic Capture, and sailing on the solar wind, it would be possible to extract materials from Mars crossing and grazing asteroids and to get those materials into Mars oribit.
So, eventually the two worlds Venus and Mars could host a very large amount of orbital habitation space.
Done
Last edited by Void (2024-02-17 11:30:59)
End
Offline
Before trying to embed floating machines into the atmosphere of Venus, maybe less aggressive methods could be tried more or less in orbit.
The Europeans have experimented on this: https://en.wikipedia.org/wiki/Atmospher … propulsion
Quote:
Impact on Atmosphere-Breathing Ion Engines
The generalization of Child's Law has implications for the design and efficiency of atmosphere-breathing ion engines. By accounting for the high-velocity ambient gas that enters the ionization chamber in low Earth orbit, the modified law allows for more accurate theoretical modeling. Once the ambient gas is ionized in the chamber, it is electromagnetically accelerated out of the exhaust, contributing to the propulsion of the spacecraft.ESA's RAM-EP, designed and developed by SITAEL in Italy, was first tested in laboratory in May 2017.[11][12][13]
The Institute of Space Systems at the University of Stuttgart is developing the intake and the thruster, the latter is the RF helicon-based Plasma Thruster (IPT) [14],[15] which has been ignited for the first time in March 2020, see IRS Uni Stuttgart Press Release. Such a device has the main advantage of no components in direct contact with the plasma, this minimizes the performance degradation over time due to erosion from aggressive propellants, such as atomic oxygen in VLEO, and does not require a neutralizer. Intake and thruster are developed within the DISCOVERER EU H2020 Project.
Intakes have been designed in multiple studies, and are based on free molecular flow condition and on gas-surface interaction models: based on specular reflections properties of the intake materials, high efficiencies can theoretically be achieved by using telescope-like designs. With fully diffuse reflection properties, efficiencies are generally lower, but with a trapping mechanism the pressure distribution in front of the thruster can be enhanced as well.[16]
Busek Co. Inc. in the U.S. patented their concept of an Air Breathing Hall Effect Thruster (ABHET) in 2004,[17] and with funding from the NASA Institute for Advanced Concepts, started in 2011 a feasibility study that would be applied to Mars (Mars-ABHET or MABHET), where the system would breath and ionize atmospheric carbon dioxide.[18] The MABHET concept is based on the same general principles as JAXA's Air Breathing Ion Engine (ABIE) or ESA's RAM-EP.[19]
It seems that the USA has an air breathing Hall Effect Thruster.
I am more interested in the intakes than the thruster.
I would like to have a short tether that could tow it through the upper atmosphere of Venus. The motor would actually be a magnetic field at the upper end of the tether.
Some method to condense atmosphere would be desired, temperature and perhaps Adsorption used.
A magnetic field might also possibly be used to concentrate gasses into the intake, but I don't really feel sure about that at this time.
https://en.wikipedia.org/wiki/Atmosphere_of_Venus
Image Quote:
Quote:
Venus interacts with the solar wind. Components of the induced magnetosphere are shown.
Quote:
Due to the lack of the intrinsic magnetic field on Venus, the solar wind penetrates relatively deep into the planetary exosphere and causes substantial atmosphere loss.[49] The loss happens mainly via the magnetotail. Currently the main ion types being lost are O+, H+ and He+. The ratio of hydrogen to oxygen losses is around 2 (i.e. almost stoichiometric for water) indicating the ongoing loss of water.[48]
It is likely much harder to gather Carbon and Nitrogen that high up.
I probably have things to learn here.
Well, this suggests why Venus has so much Nitrogen in its atmosphere: https://dash.harvard.edu/bitstream/hand … 20nitrogen.
Most of the ions lost from Venus are said to be O+, H+ and He+ That is mass and it could be useful if it could be collected. I don't know if it can. A magnetic heat shield may be able to accumulate ionized gasses, but not neutral gasses as I understand it.
https://www.universetoday.com/46474/the … -magnetic/
This video may include mention of collection of ionized gasses in a magnetic field. I will want to review it later to make sure. For now, I think I will hang up the phone for a while: https://www.bing.com/videos/riverview/r … &FORM=VIRE
Done
Last edited by Void (2024-02-17 17:35:44)
End
Offline
If Venus has no life on it and if it is decided to utilize/alter Venus, then some interesting options may well exist.
If you could airbrake asteroid materials into the orbit of Venus, then you could use them like an inverse Dyson Swarm to mask sunlight from the atmosphere of Venus.
On the other hand, if you used heating you could swell up the atmosphere of Venus. Heating could be something like microwaves, if those could penetrate deeply into the atmosphere. A major asteroid impact could also swell the atmosphere of Venus. Some historical terraform plans do suggest using an asteroid to swell the atmosphere so much that it will fly off of the planet. I consider that the be a very wasteful notion. You would lose all that Carbon and Nitrogen and the Oxygen as well to the universe, and there is some Hydrogen that would be lost.
So, I am very much in favor of collecting materials from Venus that are relatively hard to some by in low g force places in the inner solar system.
Possible collection methods would be to collect in orbit what can be ingested into machines. Or cloud machines that can collect things like Ammonia or Urea produced from H2SO4 and N2, and launched to orbit.
Tethers may be able to join the orbital and cloud collection processes.
Solar wind sailing and perhaps photon sailing devices may be able to acquire orbit momentum from the solar wind, and that momentum could be used to lift materials from the atmosphere of the planet.
It may not be impossible to mine the surface crust of Venus and also lift that material to the clouds or orbits, but it seems like it would be very hard. My hope would so far be that a substance in the atmosphere could be chilled to a condensate, and a ship containing it would drop down to the surface of Venus and collect regolith to bring up. The hope would be that the chilled condensate vaporizing would then keep the machine cool enough to survive, and also provide motive force for the machine to climb to the clouds with its "Ore". Perhaps that could be possible someday. But asteroid materials air braked into the hill sphere of Venus, would likely be easier, and this might remove collision hazards that might harm an inhabited location in the solar system.
If platforms in the clouds were possible, I think that appropriate robots might inhabit them mostly, to manipulate matter.
Such platforms might be an island, or size up to a continent, or a ring that floats in the clouds and surrounds Venus in the clouds.
Eventually a shell that floated might be possible. Such a shell would not be required to be without portals for atmosphere to pass though.
In such a floating shell, the air passing up or down though the portals though convection could run turbines.
But a closed shell might allow all toxic gasses to be put under the shell and a N2/O2 partial pressure atmosphere to be place above the shell.
The shell could have many decks.
But I confess, atmospheric floating machines even in the simplest form approach Clark Tech. I am sure that beyond attempts to collect Ammonia and Urea to send to orbit, more than that is not likely to be in human reach any time soon.
Done
Last edited by Void (2024-02-18 08:40:40)
End
Offline
Another option for atmospheric mining could be a ram scoop satellite in an elliptical orbit about the planet. The perogee of the satellite would pass through the ionosphere, allowing gas to be compressed and captured. The apogee would be much higher, several thousand km above the surface. For most of its orbit, the probe would use solar electricity to chill a mass of nitrogen and CO2 beneath their freezing point. As it passes through upper atmosphere, this accumulated cold energy is used to chill the intake gases. With each orbit, it would accumulate more liquefied gases. A plasma engine of some kind would accelerate the satellite before and after passing through the upper atmosphere, replacing the energy lost by transiting the atmosphere.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
Offline