Large scale colonization ship

RobertDyck · 2023-02-13 07:24:16

kbd512: Wow! Complete lack of understanding of what I'm trying to do here. This is not about power for a facility on the ground, it's about primary thrust for a large ship. I already posted about open cycle gas core nuclear thermal rocket. The catch with that is it requires a large quantity of bomb-grade nuclear material. All reactors are configures such that a nuclear explosion is simply not possible, but using bomb grade material is understandable regulatory obstacles. Fusion power has the potential for greater energy output per unit mass of fuel, but more importantly deuterium is non-radioactive so safe to handle, and it's not regulated.

Yes, double-deuterium fusion requires more energy to initiate fusion, and produces less energy. D-T has the lowest ignition temperature, and highest energy output. Problem is tritium doesn't occur in nature, and has a short half-life. It's radioactive, but beta radiation can be easily contained with a sheet of paper, or a sheet of plastic. Helium-3 does occur in nature, but is extremely rare. Helium-3 is non-radioactive, so safe to handle. But it's rarity makes it not practical. The only practical source of tritium and helium-3 are result of double-deuterium fusion reactions. A double-deuterium reaction will produce tritium and a neutron half the time. The other half of reactions will produce helium-3 and a proton. D-3He reaction will produce 4He and a proton with even higher energy. A high energy proton can be contained with the same magnetic field that contains the plasma for fusion, so energy of the proton can be recovered the same time. And this means no harmful particle radiation from the reactor. Neutron radiation is damaging to metal parts, however a rocket engine does not operate continuously 24/7 for years on end.

Using a double-deuterium reaction as the means to produce either T or 3He will result in producing both. Trying to contain T and leave it sit for 12.33 years waiting for half to decay to 3He is not practical on a space ship. So using both D-T and D-3He reactions for the primary reaction chamber is simply a matter of efficiently using products from the pre-burner. The "pre-burner" is the reactor with double-deuterium reaction. Yes, this will mean the "pre-burner" will produce relatively moderate energy neutron radiation, while the primary reaction chamber will produce high energy neutron radiation. You will not want to be anywhere near the engine while it is operating, or after it has operated.

kbd512 · 2023-02-13 09:38:01

RobertDyck,

Sustaining a fusion reaction long enough to produce net electrical power output seems to be a stumbling block for fusion. I'm sure your scheme is more efficient than a single-step D-D fusion reactor, but thus far nobody has been able to continuously fuse any kind of materials to generate net electric power output. The devices various companies or research projects have come up with tend to be very large and heavy by fission reactor standards, because greater reaction chamber volume improves the net gain from fusion. That was my point.

You can generate a large amount of thrust from any type of fusion reaction, regardless of how inefficient it is, assuming you're willing to immediately / deliberately vent the fusion products out of a rocket nozzle, then you no longer have to figure out how to sustain that fusion reaction for extended periods of time. Most of the heat and radioactive waste is carried away as a result. This seems like a win-win if the primary reason for using fusion to begin with is to generate the thrust your ship requires without enormous multiples of the mass of the ship itself in terms of chemical propellants. Your scheme would be the "next step" after first proving that fusion power can propel a large ship.

RobertDyck · 2023-02-13 12:45:06

kbd512,
That's the big deal. Helion is a reactor that does produce a net electrical output. So it's not something I have to invent, instead I modify their work to produce thrust instead of electrical output. Their design uses a series of pulses. Click image for their website.

YouTube: interview with CEO of Helion Energy, uploaded to YouTube 4 weeks ago:

YouTube: interview with the same CEO, but this one uploaded a month ago:

SpaceNut · 2023-02-13 19:29:51

We now have 4 different means to push the large ship to mars and back now with it still being about mass to orbit that is killing this first large ship not only for the build but to propel it to mars.

It sort of looks like a heat engine.

kbd512 · 2023-02-13 20:23:28

RobertDyck,

Does Helion have a working prototype that produces more energy than it consumes, in order to sustain fusion?

By "working prototype", I mean an actual fusion reactor that's operated for, say 24 hours nonstop, rather than a computer model of one.

Even if you don't have to invent a working fusion reactor, someone certainly does.

RobertDyck · 2023-02-14 08:38:54

kbd512,
Yes. Watch the second YouTube video on my last post above.

kbd512 · 2023-02-15 00:42:15

RobertDyck,

I watched the entire YouTube video. Nowhere in the video did they claim to be producing net electrical output. I even watched a second video on what they're up to. If they had a working fusion reactor, then a lot of people would be willing to pay them a lot of money for a copy of it. I'm completely unopposed to the idea of using fusion for power and propulsion, and welcome it with open arms, but someone has to build an actual working prototype that can sustain fusion for at least 24 hours, and preferably two or more years. If the device can function continuously for two years or longer, then it's reliable enough to send to Mars.

As soon as we do have a working reactor, it's time to start building giant steel spaceships to go to Mars. We're going to need one for the colony as well, and preferably 5 or 10 of them, if Starship flights are as cheap as Elon Musk thinks they'll be.

Calliban · 2023-02-16 12:53:29

A new potential propulsion system for the large ship.

Inert reaction mass vaporised by fibre lasers. We now have fibre lasers with conversion efficiency 30-50%.
https://www.xometry.com/resources/sheet/fiber-laser/

One potential solar-electric propulsion system would involve injecting solid material (Phobos regolith?) into a reaction chamber and heating it to several thousand centigrade using a pulsed fibre laser. At these temperatures, any solid material will be dissociate, producing a superheated gas that will generate propulsion. The specific impulse will be a function of the temperatures that the reaction mass achieves when impacted by the laser. Other methods of heating are possible as well. We could use magnetic fields to heat material into plasma, provided that small quantities of metal were mixed with the reaction mass. It should be possible to achieve specific impulse rivalling chemical rockets, although thrust levels will be lower. The plus side it that any trash material can be used as propellant, such as dirt harvested from Martian moons.

Last edited by Calliban (2023-02-16 12:57:01)

SpaceNut · 2023-02-19 20:37:18

Here is another method for New Nuclear Fission Concept Could Power Future Rockets in Space

tahanson43206 · 2023-04-19 07:32:15

For RobertDyck re Unreal Engine

One of the possibilities discussed during the active phase of Large Ship discussion was the possibility of creating a 3D Animation of the concept. Last night's meeting of the local Linux Group included a deep dive into ChatGPT, as a courtesy since I've been bogged down recently. One of their sensible suggestions was to take a look at the documentation provided by openai.com.

In the documentation, I ran across a section showing adaptations folks have created, and this one showed up. I don't know anything about it, but it ** may ** configure ChatGPT to help with Unreal Engine.

Unreal Engine
OpenAI-Api-Unreal by KellanM

If I were pursuing this possibility, I might ask ChatGPT if it knows anything about the capabilities of this library, or how it might be used.

As it is, I am focused on the (probably unachievable) goal of configuring ChatGPT to serve as Teaching Assistant for GW's classes.

(th)

Calliban · 2023-04-19 10:38:24

My recent thinking around the development of a natural uranium reactor for Mars surface, lead me to wonder if something similar could be used for large ship propulsion. The moderator would be heavy water contained in a tank. The fuel would be natural uranium carbide pellets, embedded within graphite spheres within graphite tubes, running through the moderator tank. Hydrogen would be the propellant and coolant. Hydrogen is a neutronic poison in natural U fuelled reactors. So the reactor would function is pulsed mode. Fission would heat the fuel, a burst of hydrogen would be released cooling the fuel but also, dampening the fission reaction as it passes through the core.

This would be a relatively low thrust rocket engine and the use of natural U imposes a minimum critical size and relatively low power-weight. But this is something we can build on Mars without the need to enrich uranium.

RobertDyck · 2023-04-19 14:10:34

PDF: Canadian Power Reactor Fuel

2 FUEL DESIGN
The Pickering bundle shown in Figure 1 is typical of the fuel designers' response to the objectives. It is a bundle of 28 closely packed elements, each containing high-density natural U02 in a thin (0.4 mm) Zircaloy sheath (ref. para. 6.2). Plates welded to the end of the elements hold them together; spacers brazed to the sheaths keep the desired separations. The bundle is approximately 50 cm long and 10 cm in diameter.
The Pickering fuel bundle is 92 wt% U02; the 8 wt% Zircaloy is made up of the sheaths, end-caps, structural end-plates, and spacers. The structural material accounts for only 0.7% of the thermal neutron cross section of the bundles, to give a fuel assembly that is highly efficient in its use of neutrons. There are only seven different types of components in the 76,000 bundles produced to date for the 2,160 MW(e) gross Pickering Generating Station. Replacement Pickering fuel is identical to the original charge except for the addition of (para 7.6.2).

tahanson43206 · 2023-05-20 06:23:24

For RobertDyck re Resumption of work on Large Ship....

Last fall, kbd512 and you were working on Large Ship, and that work came to a halt due to the intervention of the Mars Convention and other factors.

A key discovery at the time of the beginning of the hiatus was that the transition from conceptual design to Real Universe design will be difficult even with great financial resources to draw upon. Since those resources are not available, progress will depend upon availability of powerful tools offered for free.

You have already demonstrated ability to master Blender, and you could (if I can persuade you to do so) animate your model. I have provided an example of what that looks like, in one of the posts in this topic.

However, you had investigated Unreal Engine, and that is another possible pathway for continuing development.

Presentation of your ideas in a compelling and easy-to-understand way would be helpful, if you were to decide to ask for funding.

In my work with ChatGPT, I have been pursuing the idea that ChatGPT might be able to function as an assistant for a project such as yours. I have not asked ChatGPT if it knows either Blender or Unreal Engine, but it might.

One complication is that the free version (3.5) is being crippled by OpenAI in order to drive customers to the paid version (4.0). If you can afford $20 per month, then (from what I understand) you ** should ** be able to ask ChatGPT to access Internet resources.

To get an idea of what interaction with ChatGPT might be like, I have provided as many transcripts as Apache will allow. My current project is Dr. Johnson's course on Basic Orbital Mechanics. Preliminary results of testing are encouraging. ChatGPT appears to be both able and willing to discuss a sentence at a time from GW's course material.

(th)

tahanson43206 · 2023-05-20 07:09:13

The link to the Google Docs file below leads to a transcript about Blender and Unreal Engine.

It appears that ChatGPT(3.5) has some familiarity with both tools.

https://docs.google.com/document/d/1H3w … sp=sharing

(th)

RobertDyck · 2023-05-20 12:08:28

I guess it's time for me to look at this. I have worked as a computer field service technician since September 2017. Registered with 3 services, but total income was below the poverty line. I can afford this because my house is paid for. But my primary employer has only sent me on 2 tasks, 1 hour each, in the last 13 weeks. And nothing in the last 8 weeks. I sent a couple emails, but no reply. I tried to call but no answer. I sent text messages, but no reply. Finally tried to call the administration phone line, but straight to voice mail and no response. Just not talking to me is not professional.

I've been seeing a woman for over a year now. She's not perfect, but we match on many things. She likes to go out to restaurants a lot. But I really can't afford that. My income is so puny that I'm really living on credit. My mother passed away a couple years ago, so I have a little inheritance, but don't want to squander that. Don't know what to do.

tahanson43206 · 2023-05-20 13:21:56

For RobertDyck re #1315

I experience ChatGPT in several different ways, depending upon what I am trying to do. As a programming assistant, it seems to be excellent, and this is the hobbled version. The paid version (apparently) is much more powerful. As a helper to organize thoughts, it has a pleasing "personality" which is willing to work with the client wherever they are, and I find that it often comes up with suggestions that are ones I would not have thought of, along with some that are not useful

Another suggestion I have is a remote operations company. They appear to be succeeding in the market place, by providing machine operators remotely. I vaguely recall you might have commented upon earlier demonstrations of this activity (mining in Australia or Canada come to mind) but ** this ** is an Uber service for remote workers. If you are willing to drive a forklift, that would (apparently) be a place to start. There are (apparently) other opportunities, such as remote truck operation. I can (and will if asked) provide a link to the company. I managed to get on their mailing list, so it wouldn't take much time to find them in my email archive.

(th)

tahanson43206 · 2023-05-20 13:25:35

For RobertDyck re ChatGPT as an income support agent ...

The Internet news has been reporting recently on folks who hold down multiple remote jobs, and use the (paid) version of ChatGPT to do most of the work. This is a temporary situation, because eventually employers will expect workers to use ChatGPT and to be more productive, but the opening exists now.

Since ** this ** is the Large Ship topic, please consider moving the conversation about employment using ChatGPT to another topic which would be a better fit.

(th)

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