What is the status today of O'Neill's vision today?

Void · 2023-08-11 05:26:58

The reason for the high and low pressure is that the blue represents a glass enclosure. Imagine a glass light bulb with compressed air "Outside" of the bulb. This is in fact what light bulbs are like. Even though the glass is thin, the bulb holds against atmospheric pressure. It is being squeezed and experiences compressive forces. When people typically speak of a "Dome" that is pressurized on its inside, so the glass experiences tensile forces, which is not very good for glass.

This does seem like a waste of glass, but keep in mind that I want a vacuum for synthetic gravity machines to spin in. A "Greater Partial Vacuum". I expect that the right end of the "Egg" points at the sun. The left end has windows which can let sunlight in.

The brown shell of regolith is contained in a Carbon envelope as the originator of the idea suggested for a cylinder. Centrifugal force may do to hold the regolith in place for much of that, but for the end pointing at the sun, bags or dirt may need to be attached to the envelope.

I would hope that this could be improved over a time period. At first though you might start with this:

Inside are two greenhouses and one centrifugal stick or Torus. You may note that the regolith protects both greenhouses and the centrifugal stick or torus. The Mirror methods are not particularly drawn well, but they are to convey notions of options.

The notion is to start our simple and over time add more desired features.

There is some attempt to protect from GCR and also outbursts from the sun.

Here are notions of space stations currently under speculation by real space entities:

utube, Elon Musk Evolution, Elon Musk REVEALS FINAL Design For SpaceX's Space Station

https://www.bing.com/videos/riverview/r … ORM=VRDGAR

https://www.bing.com/videos/riverview/r … 1DCA2A8EA1

So, a Vast Space Centrifugal stick might fly out to a source of regolith with a bag and some thin mirrors, and so then with some other hardware, be a suitable construction camp to be able to build this world up. Frankly my eyes are on Phobos and Deimos as sources of regolith, but certainly asteroids may do as well. But for Phobos and Deimos you have materials you might extract from Mars.

I hope that helps improve the communication of the version I present here.

The regolith bag may only spin enough to make the regolith cling to the bag. The centrifugal stick or torus might give 1/3 g to 1 g depending on needs and/or capability.

In this early version the interior of the bag is not pressurized. In the version with two levels of pressure, the low-pressure areas are to collect gasses leaking from the high-pressure area. The pressures must be low for the centrifugal stick or torus to spin in, or the air friction would be a big problem.

Done

Last edited by Void (2023-08-11 06:04:50)

tahanson43206 · 2023-08-11 08:19:08

For Void re recent posts ...

Thanks for bringing back your illustrations .... it seems to me you are gaining skill as you go along. Very nice!

***

This is NOT intended as anything but a comparison with the science fiction writer who created a vision of rotating habitats in a gigantic balloon in space. Unlike your concept of low pressure where the rotating habitats are found, that writer imagined the air pressure inside the entire habitat to be standard sea level pressure. That vision would have required input of energy to maintain rotation as interaction with air would have consumed energy. However, that design element allowed the science fiction writer to describe air moving at the periphery of the rotating habitats, which added interest to the plot lines.

In any case, supply of energy was NOT a concern, because the writer imagined artificial fusion "suns" that were programmed to shine for half the "day". These were some "ambitious" aliens!

(th)

Calliban · 2023-08-11 14:16:04

What would be the EROI of a solar power satellite?

I decided to perform an energy balance assessment for a solar power satellite. This does not constitute a complete EROI analysis, but it does balance the primary energy needed to lift a satellite into orbit, against the electrical energy returned to the grid.

The mass of an SPS is taken to be 6.5kg/kWe produced at source. Transmission of power to an Earth based rectenna is assumed to be 60% efficient. The satellite will be in sunlight for 95% of time. The assumed lifetime of the satellite is 30 years. On this basis, the number of kWh produced by each kg of satellite mass can be calculated.

Q1 = (1/6.5) x 0.6 x 0.95 x 24 x 365.25 x 30 = 23,061kWh = 83,021MJ

I am going to assume that satellite components are lifted from Earth surface to geostationary orbit, 36,000km above Earth. This is inefficient compared to making the components in space, because lifting mass from Earth surface requires roughly 50x as much energy as lifting ores from the surface of the moon. But space manufacturing would require huge investments in space manufacturing and has not been demonstrated.

Elon Musk’s Starship will likely be part of any heavy lift solution, but there is no data at present on its payload capacity to geostationary orbit. The Falcon Heavy carries some 155.8 tonnes of kerosene and 362.6 tonnes of liquid oxygen in both stages. The vehicle has a payload capacity of 26.7 tonnes to GEO.
https://en.m.wikipedia.org/wiki/Falcon_Heavy

Kerosene has energy density of 43MJ/kg.
https://en.m.wikipedia.org/wiki/Energy_density

It took me a while to track down the energy cost of liquid oxygen. This reference puts the energy cost at 200kWh/tonne, which is 0.72MJ/kg.
https://www.sciencedirect.com/science/a … 2621016462

Using this data, the energy content of the rocket propellant can be calculated:

Q2 = 155,800 x 43 + 362,600 x 0.72 = 6,960,472MJ

The energy cost per kg of payload is:

Q3 = 6,960,472MJ/26,700 = 261MJ/kg

Energy balance = Q1/Q3 = 83,021/261 = 318

This tells us that over the course of a 30 year lifetime, a solar power satellite will return 318 times as much energy as the energy content of the propellant needed to lift it. Presumably, any SPS manufactured in space would enable a much better net energy return, but this would come at the cost of investing in substantial space manufacturing capability.

The energy balance does not constitute an EROI analysis, as a great many energy costs are omitted. The analysis does not take into account the embodied energy of the satellite components, the rocket vehicle itself (assumed reusable) or the rectenna. No attempt has been made to include development costs or based space launch facilities. But the energy balance does demonstrate that the SPS is a potential energy source.

The analysis also tells us something about rockets. A rocket taking off is a dazzling display of fire and smoke and it is easy to assume that the energy involved in lifting materials into orbit must be immense. But the fuel load of the Falcon Heavy at take-off is 155.8 tonnes of kerosene (200,000 litres). This is actually less than the full fuel load of a 747-400 (216,840 litres).
https://executiveflyers.com/how-much-fu … -747-hold/

Rockets appear large partly because they carry all of the oxygen needed to burn their fuel, whereas aeroplanes draw all oxygen from the air. The 747 will burn its fuel load over many hours, whereas a rocket will accelerate into low Earth orbit in 8 – 10 minutes. So the power output of rocket engines is enormous. But the energy consumed putting a person into orbit is comparable to a long distance flight on Earth.

Void · 2023-08-11 14:37:35

I'm sick once more, probably bacteria in the lungs and sinuses? Uncomfortable, but I think the worst is over. But I don't have the liberty to go out that much, so I guess this site can be a bit of my amusement.

I feel that your materials are so valuable that I don't want to vandalize them with too much of a post of my own. I did enjoy the QUOTE:

This is inefficient compared to making the components in space, because lifting mass from Earth surface requires roughly 50x as much energy as lifting ores from the surface of the moon.

That's useful to me.

I don't have a good number for the Neumann Drive. But if Starship and SpaceStations, ect use it LEO<>GEO<>Moon Orbits, then I think the numbers may be more favorable. Or at least we might hope so.

We don't have solid specs for the Neumann Drive as it can use many different solid propellants, and then also needs an electric power resource of unknown dry mass.

Here is the site: https://neumannspace.com/

So, at least for humans and some cargo, it will be: Chemical Propulsion<>LEO<>Neuman Drive<>GEO<>Neuman Drive<>Lunar orbits<>Chemical Propulsions<>Moon Surface.

And we may be getting solid propellants from several sources, Earth, Moon, Maybe Asteroids.

As I have said, my posts following yours might be consider vandalism, as there is a whole lot of fluffy speculation involved. But I feel that it could be much better than using chemical burns for all such propulsions. But I don't know.

Since I am "Off on speculation", I will move my efforts to the terraform section per the previous here lately in this topic.

But thanks for the fine work.

Here is information on the types of propellants that might work with a Neumann Drive: https://neumannspace.com/metal-propella … technetium.

Done.

Last edited by Void (2023-08-11 14:51:31)

Mars_B4_Moon · 2023-11-23 20:51:16

Why you should care about life beyond Earth

https://thespacereview.com/article/4694/1

New Mars Forums

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#126 2023-08-11 05:26:58

Re: What is the status today of O'Neill's vision today?

#127 2023-08-11 08:19:08

Re: What is the status today of O'Neill's vision today?

#128 2023-08-11 14:16:04

Re: What is the status today of O'Neill's vision today?

#129 2023-08-11 14:37:35

Re: What is the status today of O'Neill's vision today?

#130 2023-11-23 20:51:16

Re: What is the status today of O'Neill's vision today?

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