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#751 2021-07-07 19:29:22

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Large scale colonization ship

I was hoping that it would be as simple to gain access back into the system for its use and good luck.

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#752 2021-07-08 08:55:21

tahanson43206
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Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

For RobertDyck ... re new public view private update data storage facility for Mars Society / NewMars projects

Please let us know when the new/old data storage location is visible.

***
Following up on Unreal Engine request .... there is a compilation of learning and reference materials a few posts back ... please provide guidance for how best to invest in resources to help you advance the Large Ship.

I would like to point out that GW Johnson's concept for a service facility to be permanently stationed in the immediate vicinity of Hubble is a golden opportunity for you to secure funding for critical elements of the Large Ship.  The service you would be selling is your cabin concept, and the Mars equivalent gravity.

The facility would be in LEO at the Hubble orbit.  It would be rotating so not suitable for work on Hubble, but it ** would ** be perfect for astronauts visiting in a SpaceX capsule to connect to the air lock and perform teleoperations or even space walks as needed.

I would propose a minimum of three cabins in your design, to improve stability, and to provide the model for how to provide for space visitors in the future. One person per cabin is the goal I am hoping to encourage you to sell to your prospective funders.

The Chinese are (apparently) showing the way, so it is acceptable for Western folks to unashamedly copy their example.

(th)

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#753 2021-07-08 11:49:14

kbd512
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Registered: 2015-01-02
Posts: 6,241

Re: Large scale colonization ship

Reply moved to Post #4 of Hubble Space Telescope Replacement, at the request of tahanson43206.

Last edited by kbd512 (2021-07-08 16:14:38)

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#754 2021-07-12 12:58:46

tahanson43206
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Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

For RobertDyck re topic and specifically, readiness for Unreal Engine deployment ...

I had a chance to talk to a Mom with teenage sons today ... she seemed to think they might be interested in computer animation, so I told her about the Large Ship project and free animation software including Unreal Engine and Blender.  Of the two (of course) I only have experience with Blender, so am looking forward to your starting to develop designs and eventually animations using Unreal Engine.  It is ** much ** easier for me to learn a package if I have something to work on.

(th)

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#755 2021-07-15 12:32:15

tahanson43206
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Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

https://www.yahoo.com/finance/news/thal … 19962.html

Aria Alamalhodaei
Thu, July 15, 2021, 12:44 PM
More details are beginning to emerge on Houston-based Axiom Space’s ambitious project to build and operate the world’s first commercial space station.

Thales Alenia Space, a European aerospace manufacturer, will develop the two pressurized modules of the Axiom Space Station. The two elements, which are scheduled to launch in 2024 and 2025, will dock to the International Space Station before eventually detaching and operating as fully independent, commercial station.

The two companies announced the signing of the final contract, valued at €110 million ($130 million), on Thursday. Each module will be able to accommodate four people. Thales will also be designing the micrometeoroid and debris protection system for each module.

The modules are still in their design phase, Thales Alenia said. The company recently completed development of the first module’s four radial bulkheads at its facility in Turin, Italy. The bulkheads, once connected, will form a cylinder. That structure will attach to the common berth mechanisms, parts of the module that will can connect to the ISS, and hatches.

For RobertDyck ... these modules look (to me at least) like candidates for cabins for your Large Ship.

If you could assemble a ring of these as your cabin deck, then you could concentrate on the other decks you'll need to provide the complete system.  The ratio of people to volume looks about right to me.

By the time you are able to persuade funders to build your system, these modules should have some on-orbit experience to lend credibility to the proposition.  Unlike the Bigelow concept (as I understand it anyway) these are modules capable of supporting their passengers in modest comfort for a period of time without resupply.

That would be helpful when Large Ship is performing maneuvers that require all personnel to be in their cabins.

Update next day ....

In thinking about SpaceNut's challenge to try to make distilled fresh water from his groundwater using sunlight, I thought about mirrors.  And in thinking about mirrors, i thought about directing sunlight into underground living quarters on Mars, using ground level windows with a view toward a valley below.

And ** that ** sequence led me to imagine the cabins described above being detached from the Large Ship after arrival in orbit around Mars, and delivered to the ground for permanent "starter" quarters for residents.

The Large Ship could retain enough cabins for the return flight to Earth for the crew, but it's mass would be reduced so the fuel needed to drop down to Earth would be reduced.

SearchTerm:Axiom Space modules suitable for Large Ship cabins and Mars settlement habitat use
SearchTerm:cabins Axiom Space modules
SearchTerm:passenger accommodation on large ship

This topic will advance with regular and not infrequent updates in support of the topic objective.

(th)

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#756 2021-07-23 05:56:00

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 2,232

Re: Large scale colonization ship

I suspect we have discussed fission-fusion hybrid propulsion in the past, but I can't remember where it was.  It is definitely a good candidate for large ship propulsion, as it combines high ISP with relatively high thrust in a way that may obviate the need for aerobraking in a very large ship.  This paper describes a NASA propulsion concept very similar to what I had in mind for an inertial confinement fusion-fission hybrid approach.
https://ntrs.nasa.gov/api/citations/201 … 000723.pdf

The idea is to incorporate small amounts of fissile material into (or in this case around) a lithium-deuteride fuel pellet.  Critical mass is inversely proportional to the square of fissile density.  So with sufficient compression, critical mass can be reduced by several orders of magnitude, maybe even to milligrams.  That increase in density is provided by a z-pinch in this case, which capable of developing gigabars of pressure without the sort of temperature rises that would accompany x-ray ablasion compression in conventional IC concepts.

The key to the functioning of this concept is the close atomic coupling of the fissile and fusion fuels.  The range of fission products in matter is ~1E-3 mm.  Coupling starts long before critical conditions are reached.  A single spontaneous fission releases fission products into fusion fuel.  The fission products, each carry average energy of 80MeV.  Those that escape the fissile material, enter the fusion fuel, leaving a cone of ionised and high energy lithium and deuterium ions in their wake.  A substantial portion of these then undergo fusion, releasing 13MeV neutrons, that lead to more fission in the liner or core.  As fission rate accelerates, the escaping fission products heat surrounding ions to temperatures of 10s to 100s KeV.  These stream into the surrounding compressed lithium deuteride pellet and act as a detonation wave.

The concept greatly reduces the driver energy needed to trigger fusion.  In my previous concept, the fissile fuel was a milligram raisin at the centre of a gram mass fuel pellet.  I chose this arrangement so that fusion fuel would serve as a reflector and because neutron flux will be highest at the centre of a spherical fusing system.  The NASA concept varies only in the fact that fissile material is a thin foil around the outside of the pellet.

This concept could be used as a near term practical Earth based nuclear fusion power supply, as well as a propulsion scheme.  Ideally, fission serves as a trigger, but contributes negligible net energy gain.  That way, fission product release will contribute negligible radioactivity in the exhaust.  As a power supply concept, the limited driving energy lends itself to more compact fusion reactor concepts.  However, the required thickness of the neutron absorbing blankets and the critical mass at achievable compression, suggests a minimal achievable size.

Last edited by Calliban (2021-07-23 06:28:53)


"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."

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#757 2021-07-23 07:18:10

tahanson43206
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Re: Large scale colonization ship

For Calliban re #756

Thank you for this post, which could fit comfortably into several topics.

However, since RobertDyck has his heart set on plowing through the Atmosphere of Mars (see Post #1 and many subsequent reinforcements) I think he would be disappointed if you were to provide a reliable, safe, affordable option to deliver passengers more quickly than he had planned, and without needing to decelerate at Mars using aerobraking.

Please continue developing your thoughts along these lines in whatever topic might seem most welcoming.

In particular, since the quantities of material you are proposing for individual pellets are on the order of one gram, it ** should ** be possible to secure approval from authorities in all our jurisdictions to perform (carefully supervised) experiments.

Can you imagine a test apparatus affordable by an average person that could demonstrate the magnetic pinch effect you've described?

What would a basement/garage experimenter require to achieve fusion of one of these pellets?

I note that a physicist who is working on string theory started out by building a working cyclotron in his parent's basement, and came to the attention of a notable physicist of the day, who encouraged his progress.

This is all reported in numerous television videos, interviews and books by this gent.  I am disappointed but not surprised to have forgotten his name.

Google came to my rescue ... I asked for the name of physicists working on string theory, and among the results were:

The God Equation
Book by Michio Kaku
4.1/5 · Goodreads
94% liked this book
Google users
The God Equation: The Quest for a Theory of Everything is a popular science book by the futurist and physicist Michio Kaku. The book was initially published on April 6, 2021 by Doubleday. The book debuted at number six on The New York Times nonfiction best-seller list for the week ending April 10, 2021. Wikipedia

That's the person I was remembering ...

The point of my post here is to see if an experimental apparatus capable of achieve fusion of a single pellet might be within the reach of a young person of the caliber of Dr. Kaku.

A related question is whether minuscule amounts of fissionable material can be in the possession of citizens of various jurisdictions.  I'll invite contributions from members with posting privileges who might be able to report policy in their locations.

(th)

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#758 2021-07-23 10:18:57

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 2,232

Re: Large scale colonization ship

The topic of hybrid nuclear fission fusion technologies, probably needs a new thread.

Aerobraking, whilst attractive in principle, will be more and more technically difficult as the ship gets bigger.

1) Mass per unit frontal area will increase, necessitating a deeper dip into the Martian atmosphere to achieve the same dV.  Peak pressures and heating get worse and worse as the ship mass per unit frontal area increases.

2) As an aeroshield gets bigger in diameter, it faces problems of pressure and density gradients in the Martian atmosphere.  Air density at the bottom of the shield will be slightly greater than at the top.  This means that the centre of pressure on the shield will shift as it passes through different layers of the atmosphere.  This will exert a net turning force on the ship, as centre of pressure moves away from centre of mass.  A trimming system might help with this problem.  I have no idea how feasible it is or what pumping rates would be needed.  But pressure and density gradients in the Martian atmosphere can be unpredictable.

3) At some point, the hypersonic shock wave may pose a threat to people and structures on the ground.  Again, I have no idea how big a ship would need to be, or how deep it must go into the Martian atmosphere, before that becomes a problem.

4) Some sort of very low density, high altitude drag chute could provide a partial solution to these problems - essentially using exospheric ions for drag.  It might work, but oxygen ions will limit its useful life.

5) A partial solution is to reduce dV requirements on an aerobrake, by approaching Mars on a Hohmann trajectory and using low thrust propulsion to limit velocity gain from entering the gravity well.  The ship would brake into a highly elliptical orbit, almost out to the Mars-Sun L1 and L2 points.  Subsequent passes through the upper atmosphere would gradually reduce apogee, with a circularisation burn performed at some point.

6) As the ship is being victualled and refuelled at Mars, it could take on board sacrificial water, methane or ammonia, which could be excreted through the shield and would limit peak plasma temperatures by dissociation.  One might use recycled gray of even black water for this purpose.

Last edited by Calliban (2021-07-23 10:31:13)


"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."

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#759 2021-07-23 11:03:53

RobertDyck
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Re: Large scale colonization ship

Many people have different ideas. All are valid. I thought developing gas core nuclear thermal rocket for the main TMI engine was a lot, even though this is a concept from the late 1960s. Using pulse microfusion thrusters for manoeuvring is also a lot, even though NASA's Advanced Concepts division published a paper on it. I left open the idea of replacing the propulsion stage with new technology when it becomes available. Remember, one advantage to Mars is it takes less propellant to travel from Earth to Mars than to the Moon. That's because Mars has an atmosphere, the Moon does not. That's true for orbit-to-orbit due to aerobraking, or surface-to-surface due to atmospheric direct entry. The Moon has the great disadvantage of requiring propulsive orbital insertion. Deliberately using propulsion when you don't need to means you sabotage your own mission for ideological reasons.

As Robert Zubrin said, if you had more propulsion available you wouldn't reduce transit time to Mars, instead carry more payload. The reason is a 6-month transit is the only trajectory that gives you free return to Earth. Apollo used a free return trajectory to the Moon, just in case something went wrong. Good thing they did because Apollo 13 had to use it.

One concern is return to Earth. So many satellites have been placed in Earth orbit that aerocapture at Earth may not be possible without hitting something. SpaceX is adding satellites for Starlink.

Basement experiment with nuclear detonation? I thought a large billion dollar corporation would be required to fund research into nuclear propulsion. You expect to do it in a basement or garage?
TV show Young Sheldon: Season 2, Nuclear Power power generation at home is not easy, Sheldon is in trouble
sddefault.jpg

Last edited by RobertDyck (2021-07-23 14:20:30)

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#760 2021-07-23 11:14:16

RobertDyck
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From: Winnipeg, Canada
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Posts: 7,343
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Re: Large scale colonization ship

Calliban wrote:

4) Some sort of very low density, high altitude drag chute could provide a partial solution to these problems - essentially using exospheric ions for drag.  It might work, but oxygen ions will limit its useful life.

My design spins the wheel so it is face-on in front of the ship. That wheel is covered by a fabric heat shield, so the drag surface is the entire face of the wheel. ADEPT uses carbon fibre, which can withstand the most heat of any fibre, but the problem is embrittlement. That embrittlement is a problem for re-use. NASA's Ames Research Center developed thermal blankets for Space Shuttle. The white tiles were replaced by quilts of silica fibre cloth on top, regular fibreglass against the aluminum skin of Shuttle. Batting was more silica fibre. That silica was 99.9% pure, so the same purity as heat shield tiles. But that makes them weak. This quilt was known as AFRSI. Near the end of Shuttle's run, Ames developed Durable Advanced Reusable Surface Insulation (DurAFRSI). Also a quilt, but with Nextel 440 fabric on top and bottom, filled with Saffil batting, covered in Inconel 617 mesh. The quilt was "quilted" by stitching through the mesh, securing the mesh to the fabric quilt. Then regular brazing material was added, and Inconel 617 foil added to the top. That was baked in an oven. The result can withstand more heat than AFRSI, more durable, and the metal foil provides an aerodynamic smooth metal skin. My design would use just Nextel 440 fabric for the aerocapture heat shield. It won't withstand heat of direct entry, but will withstand enough for aerocapture.

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#761 2021-07-23 11:58:48

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,952
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Re: Large scale colonization ship

Most of those silicate-type materials have meltpoints in the 3200-3300 F range,  but more importantly,  a solid phase change temperature in the 2000-2300 F range.  If they reach the phase change temperature,  they crack,  embrittle,  and basically just fall apart at the slightest touch.  There's about a 2-3% volume change (shrinkage) if they reach the phase change point.

I used similar materials long ago to create a fabric-reinforced ceramic composite similar to NASA's shuttle tile.  It was a Cotronics trowel-able pipe insulation paste (I think the product name was 360M),  reinforced with Nextel 312 fire curtain cloth.  I used Cotronics 901 adhesive as a surface sealing coat,  like a paint. 

I believe the way I heat-cured this item is how I achieved low density:  it's a water-based paste from which the steam had to wormhole its way out,  creating the porosity.  As built,  the density was about like that of the higher-density grades of industrial styrofoam.  As a combustor insulator,  it withstood hundreds of heat-up cycles,  about 5 hours burn at ~3500+ F gas temperatures,  and dozens of violent shaking events from rich blowout instabilities.  (Without the fabric reinforcement,  it shattered and ejected the first time I hit the "buzz" of incipient rich blowout.)

The same Nextel 312 fabric I used to create a sort-of out-sized Coleman lantern mantle,  heated by the hot gas from the combustor to a material temperature right at 3000 F.  Most but not all of these were coated with the 901 adhesive "paint".  They were one-shot items,  never reusable.  Extremely fragile and brittle upon cooldown,  but not before.  This gas mantle was an infrared decoy.  It was very non-gray radiatively,  with a color temperature nearer 1200-1500 F.  The mid-band-dominated IR would blister my face 20 feet away,  from a mantle about the size of a coffee cup.

The combustor liner was presented by me at the 2013 Mars Society convention in Boulder,  CO,  as a possible heat shield material for reentry from (only) orbital speeds. 

GW

Last edited by GW Johnson (2021-07-23 12:03:11)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#762 2021-07-26 13:42:17

tahanson43206
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Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

https://www.yahoo.com/finance/news/agri … 17563.html

Growers are now aware that crops can be cultivated indoors and hydroponically anywhere and in any season, with weather conditions playing no effect on the process. Hydroponic farming also has the ultimate potential to provide fresh, local food for areas with extreme droughts and low soil quality.

The article at the link above describes technique that ** should ** work well on the Large Ship, as well as in habitats on Mars.

(th)

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#763 2021-07-26 15:31:08

RobertDyck
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From: Winnipeg, Canada
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Posts: 7,343
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Re: Large scale colonization ship

Northern remote areas in Canada have a problem with high cost for food, and lack of food security. When the rail line to Churchill Manitoba was washed out, for months no train could arrive. And there's no road. There is a sea port, but in winter Hudson's Bay freezes over. That only leaves air. Flying fresh produce is expensive. One company set up a hydroponics operation in a couple steel shipping containers, but they're only growing salad, and fuel for heat is expensive. And they use LED light, so require electricity. What we really need is a greenhouses that can use sunlight for both illumination and heat. There's plenty of soil in northern Canada. Soil agriculture in a greenhouse avoids dependence on hydroponic solutions. One simply way of producing hydroponic solutions is to dissolve fertilizer in water, but that still requires commercial fertilizer. Of course aquaponics is an integrated system that can void commercial fertilizer.

My job as a technician repairing computers for retail postal outlets in northern reservations has allowed me to see what's there. I have suggested greenhouses. However, many communities have problems with theft and vandalism. People at Berens River told me many homes do have a vegetable garden. They're not the most northern, and in 2019 got an all season road. Convincing communities to grow their own food and not vandalize everything is going to be an issue.

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#764 2021-07-26 18:17:36

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Large scale colonization ship

For the large ship its about the windows towards the sun as while its going to let the light in but with that is going to be lots of IR, UV and we will need to filter such as to provide the right quality of energy for the plants to grow in for the large ship.

Mars surface is quite a bit different for the passive greenhouse design in that we will need lots of insulation to keep the cold out and the heat in to maximize the energy we use to its fullest.

A good resource for the levels of sun for natural energy was taking place on the Devon Island location but beyond the natural levels what was the amount beyond that was required is the question for its design?

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#765 2021-07-26 18:46:30

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,343
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Re: Large scale colonization ship

NASA developed a spectrally selective coating for spacecraft windows a long time ago. Mercury capsules didn't have it, and Mercury astronauts developed cataracts later in life. But Apollo had the coating. Blocks UV and controls IR. We don't need to re-invent the wheel, just use the same coating that NASA uses.

On Mars, very little heat is lost to the atmosphere, because the atmosphere is so thin. A Mars greenhouse would also use the spectrally selective coating. Reflecting 20% of shortwave IR (from hot objects like the Sun) and reflecting 40% of longwave IR (warm objects like the floor and walls) will help keep the greenhouse warm. But we can also draw an aluminized Mylar curtain across the ceiling at night, open at dawn. That will prevent radiant heat loss. A small motor with a cable configured like a garage door opener can automate the curtain. The idea of a curtain is from a "Case for Mars" paper, published before founding of the Mars Society. The greatest heat loss on Mars will be to the ground. There's a few ways we could do that.

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#766 2021-07-27 20:01:08

GW Johnson
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From: McGregor, Texas USA
Registered: 2011-12-04
Posts: 4,952
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Re: Large scale colonization ship

The trick is not to put your habitation floor directly on the ground.  It has to be off the ground,  with lots of insulation in the crawlspace,  the way they do it in Antarctica.  Most of Mars is about as cold as South Pole Station.  Some parts even colder.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#767 2021-07-28 07:10:46

tahanson43206
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Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

This is the Large Ship topic, so the floor of the cabins would be exposed to space if there were no subfloor, but I'm pretty sure that RobertDyck is planning to have a layer of equipment and pipes for liquids and gases under the floor which people would trod.

In any case, the thermal environment for a ship in space would be considerably different from Mars. 

RobertDyck has spoken of wanting the axis of rotation of the habitat ring to be aligned with the center of the Sun.  In that case, the exposure of the floor of the habitat would be to the cold of deep space, since the Sun facing wall of the habitat ring would "enjoy" the full benefit of Solar radiation.  I can't recall now whether RobertDyck was planning to install solar panels on the Sun facing wall, but that would make sense.  I ** do ** recall that he is/was planning a layer of water on the Sun facing side of the habitat to help with protection from solar flares.

It will be good to have a permanent storage location for facts about the Large Ship, and happily RoberDyck is hard at work making that happen, as a benefit of his connection to the Mars Society via the Canadian Chapter of the Mars Society.

Bye-and-Bye, we should be hearing about progress on that front.

(th)

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#768 2021-07-28 14:42:35

RobertDyck
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From: Winnipeg, Canada
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Posts: 7,343
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Re: Large scale colonization ship

tahanson43206,
You posted an article about hydroponics, and you mentioned using this on Mars. So yea, we got off-topic, talking about a greenhouse on Mars. GW's comment is relevant.

The Large Ship proposed here is a wheel. The outer ring (lowest deck) is the habitation ring with cabins, dining rooms, etc. Upper deck is observation rooms, and greenhouses. I proposed aquaponics for the ship. That's integrated aquaculture and hydroponics: processed human urine to fertilize crops, and plant waste (stems, leaves, etc) fed to fish. And fish poop also fertilizes crops. Axis of rotation aligned with the Sun, with mirrors to reflect light "down" into greenhouses. Chloroplast bags for oxygen generation, with parabolic mirrors on the sunward side of the ship reflecting light into light pipes that lead to chloroplast bags. The chloroplast bags will be sized to provide all the oxygen that humans need on the ship, but with the greenhouse also producing oxygen, not all of the chloroplast bags need be installed. I visualize photovoltaic panels (solar panels) dangling "down" from the edge of the wheel, generating electricity for the ship.

And yes, the habitation ring will have a water wall, floor to ceiling, for the entire deck. That's one reason to align axis of rotation with the Sun. The water wall will be 2.43 metres (8 feet) high, but the ring will be 19 metres wide. The water wall provides shadow shielding for the deck. During a solar proton event (solar flare or coronal mass ejection) the upper deck will be off-limits. Because the upper deck will not be shielded. The zero-G hub and zero-G cargo hold will also be off-limits. But making the entire habitation ring a giant radiation shelter means passengers don't have to shelter in a closet or other tight space for hours or days. Habitation ring will include cabins, corridors, all dining rooms, all kitchens, bar, medical (sick bay, dispensary, or whatever you call it), Command Information Centre (bridge), and even the gym. If the gym is 2 decks, the upper deck will also be off-limits.

I said solar panels will dangle from the edge. The outer surface of the wheel ("bottom" from perspective of passengers) will be covered with radiators. This means solar panels not only generate electricity, they also shade radiators. The space-ward side of the wheel will also be covered by radiators. In this case "space-ward" means the side away from the Sun.

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#769 2021-07-28 14:47:10

RobertDyck
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From: Winnipeg, Canada
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Re: Large scale colonization ship

Tom, I'm having difficulty with Unreal Engine. The interface is non-intuitive. Looks like I can place simple cubes and spheres, not more complex stuff. A YouTube video tutorial for architects talked about using something else to model furniture, then exporting it to Unreal Engine. I thought this would be a good idea because it's free and you could walk around it. You wanted people to experience what it's like inside, not just look at pictures. Perhaps I chose the wrong tool. Or maybe I just don't have a starting point for learning.

I've heard of Blender. Is that easier to learn? One tutorial for Unreal Engine said it assumes you already know how to use something like Blender.

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#770 2021-07-28 18:03:22

tahanson43206
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Posts: 12,063

Re: Large scale colonization ship

For RobertDyck ... thanks for the update!

I'd be happy to help you (or anyone who might be interested)  to work with Blender.  There is a learning curve, so I recommend a book which I've reported in the forum ... look for blender in posts by tahanson43206.  I'd be happy to have someone(s) working on the program.  I've been on my own (pretty much) for several years, and have reported several projects (again in the archive).

However, I'm ** also ** interested in learning Unreal Engine.  I while back I posted a list of books about Unreal Engine, and one of them I flagged as potentially of interest because it featured a merge of the two. 

Blender is free, so if you system has storage space, it's not too difficult to install it and start it running.

I've run into a (hopefully temporary) budget glitch, so I'm going to have to hold off on the more advanced graphics card you were able to acquire.  My little two Gb card ** may ** be able to run Unreal Engine.  It is able to run Fusion 360 and Blender.

***
Your post asked if Blender is easier to learn than Unreal Engine ... I can't answer the question directly, but I ** can ** report that I found the book (described earlier) helpful, and I took a class on Blender at the local Maker Space.  In addition, I had a chance to spend about an hour with a gent who makes his living doing Blender animation for on screen television quality videos of interiors of office spaces, using furniture designed by his employer.  From this exposure, I understand the power and potential of Blender in the right hands.

What I found in attempting to create 3D printer designs using Blender, is that Fusion 360 is better at some things, but each seems to be able to generate stl files that are accepted (and often mangled) by Slicer programs.

***
PS ... thanks for pointing out that I set the seed for the Mars digression by showing the hydroponics link, and suggested the technology might work for both the Large Ship and on Mars.  I'll try to keep that possibility in mind as we go forward.

(th)

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#771 2021-07-28 18:30:23

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 26,803

Re: Large scale colonization ship

Normally, plant roots grow downward, where it’s easy for them to soak up water and nutrients that make their way into the soil. In space, roots grow in every direction, and water and other essential plant foods float.
In the garden with in the outer shell it will have due to rotation water moving from its standing location moving towards the wall of the shell where the sun will come in. Water holding sponges such as those on the ISS will be needed to make the water stay in the root area of the plants. The sponge is called ”plant pillows” with in the veggie experiments. These pillows are bags of dirt, fertilizer, and nutrients equipped with wicking material that soaks up water.

images?q=tbn:ANd9GcRChocVExt_XO4PiKZSOnQmXA-uYAXCtyooIA&usqp=CAU

Have added to Roberts next post with his content for clarity

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#772 2021-07-29 00:44:29

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,343
Website

Re: Large scale colonization ship

Nope. In artificial gravity, plant roots will grown down. Just like Earth. A six month trip to Mars in zero gravity is a very bad idea. One of the fundamentals of this ship is artificial gravity.

And no, light will not come from the floor. The wheel is not a solid disk, it's a wheel with spokes. Greenhouse on the upper deck of the ring. Greenhouse will have transparent roof and walls, like any other greenhouse. The window material will be Alon to ensure micrometeoroids don't degrade it. And mirror above the roof to reflect sunlight down into the greenhouse. When using centrifugal force for artificial gravity, "down" means inside the ring.

edit repost of Robert's

The engine points toward the Sun during transit to/from Mars. That means the ring is facing away from the Sun, the aft side of the ring faces the Sun. So Axis of rotation is along a line toward the Sun. There are no bearings, the entire ship rotates.
xIcxX8t.jpg

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#773 2021-07-29 07:08:35

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

For RobertDyck re #772

Thank you for helping SpaceNut to visualize the design you have in mind ...

I confess to confusion because (at present) you are limited to words in describing your vision ... "roof" is normally associated with the surface of a living space above the floor.  In the case of the rotating Large Ship, the floor is the surface on the outside of the ring.  That surface would NOT be exposed to sunlight, since you repeatedly stated that you want the axis of rotation of the vessel to be aligned with the center of the Sun.

The surface that ** would ** be exposed to sunlight would be the sun-facing side of the habitat ring.  This surface is where radiation protection against solar flares would be installed.  Solar cells could be mounted (and I assume ** would ** be mounted) outside of the radiation protection section.

If the greenhouse is installed on the roof, then it will receive no sunlight directly.  It would make perfect sense for you to deploy mirrors to deliver sunlight passing through the spokes of the rotating vessel to the greenhouses, but if that is your plan I have missed it.

***
This is a good time to remind you that your quest for storage space on the Mars Society servers is worth continuing, despite whatever obstacles must surely have appeared in your way, or it would have been achieved by now.

Permanent storage space under your control will allow you to publish specifications for the Large Ship as you conceive and revise them, so that constantly recurring questions (such as whether there is gravity present in the Large Ship) can be quickly answered without having to repeat earlier posts, as you have done countless times already.

(th)

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#774 2021-07-29 10:06:16

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,343
Website

Re: Large scale colonization ship

HqwDQJi.jpg
Cross section. Lower deck has cabins, shown are standard cabins. Sunward side has water wall. Outside hull on sunward side has a column of 4 parabolic mirrors, each reflecting sunlight into a light pipe. The light pipes extend under the cabins, one to each cabin. Light pipes shine up through a small window in the floor to illuminate a bag of chloroplasts. This is the oxygen generator, powered by sunlight. Bottom covered by radiators. Space-ward side also covered by radiators. Dangling beneath the sunward wall is photovoltaic panels (solar panels). These provide electricity and shade the radiators.

Greenhouse for growing food. Haven't sized it yet. Some areas have an observation deck or Mars simulation room instead of greenhouse. The greenhouse will use hydroponics to grow fresh vegetables for the salad bar. Not just lettuce but fresh vegetables for a buffet salad bar. The greenhouse will also house aquarium tanks for fish: aquaponics. Spin axis of wheel is oriented with direct line to the Sun so that water wall, parabolic mirrors, and photovoltaic panels are always oriented to the Sun. This means greenhouse will have sunlight coming sideways through one wall. To illuminate greenhouse, a mirror will reflect sunlight down through transparent roof of greenhouse.

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#775 2021-07-29 11:22:35

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 12,063

Re: Large scale colonization ship

For SpaceNut re update by RobertDyck

Please take an extra moment to evaluate the diagram RobertDyck has kindly provided.

I understand you normally fly through the posts because there are so many and your time is so limited.

This one (in my opinion) deserves a bit more than the usual flying visit.

***
For RobertDyck ... I brought up Large Ship tangentially in email correspondence with an astronomer today.  The discussion was about (positive) changes to their web site, but I took the opportunity to mention the forum and specifically your project.  It can't hurt to have a bit of visibility, and your diagram here is quite timely.

(th)

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