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#176 2020-08-17 21:45:22

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

tahanson43206 wrote:

Edit#1: for RobertDyle ... the image in the original post did not come up for me when I tried it today.

Used Facebook to host the image. Looks like Facebook deleted the image. Local ISPs no longer include a personal website. Looking for another place to host images.

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#177 2020-08-18 06:24:44

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #176

imgur.com is recommended by a number of forum contributors.  An account is free, and so far (tapping wood) the service seems to be reliable.

After you upload an image, you right or left click on it (I cannot seem to remember which) and a menu of generated URL's appears ... choose the one for BBcode.

And thanks for making the effort.  I am looking forward to refreshing my memory of your design.

(th)

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#178 2020-08-18 11:47:14

RobertDyck
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Re: Large scale colonization ship

Ok, uploaded to imgur

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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#179 2020-08-18 12:09:54

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #158

Bravo!  Looks good!  I'd forgotten the docking detail, so appreciate the reminder!

SearchTerm:SketchLargeShip

http://newmars.com/forums/viewtopic.php … 78#p171278

(th)

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#180 2020-08-18 12:45:44

RobertDyck
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Re: Large scale colonization ship

Floor plan of economy cabins. This is a floor plan, you're looking down at the floor.
YsL6tmX.jpg

Floor plan of premium and luxury cabins. Two luxury cabins on the ship, one on each side of the corridor. Luxury cabins can be subdivided by portable walls into 4 premium cabins. Or 8 cabins 2.4m x 8m. Or 4 cabins 2.4m x 8m and 2 cabins 4.8m x 8m. Or 3 cabins 2.4m wide, one 4.8m wide, and one 7.2m wide, etc. Depending on customer demand.
ZkRL1k1.jpg

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#181 2020-08-18 13:27:36

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #180

It is neat seeing your vision developing here!

Your diagram shows the Sun in a direction that seems (to my eye at least) inconsistent with the "floor" of the rotating habitat.

As I understood your concept, the edge of the habitat would be kept edge-on to the Sun, so the residents would experience the full force of Solar radiation only when the habitat has rotated around to the Sun side.

If that is the case, the "floor" would presumably be perpendicular to the Sun.

With out changing the diagram, it might be possible to add text that shows where the "floor" is.

(th)

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#182 2020-08-18 13:47:30

RobertDyck
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Re: Large scale colonization ship

No. Aft end of the ship toward the Sun. Hub is shaded by engine and propellant tank. Side wall is 2.4 metres high while floor is 19 metres wide, so this minimizes area that requires radiation shielding.

:Edit: Floor is outside surface of the ring. Centrifugal force is always directed away from the centre of rotation, so the floor of the habitat ring is the outside surface of that ring. "Up" is toward the centre of the hub.

This ship accelerates with the ring face forward. Once on course for Mars, the ship is oriented with the main engine toward the Sun. That means aft cabins always have sunlight streaming through their window 24/7. The Window has an electronic thing that can turn opaque. Important to make the cabin dark for sleep. The window is also a transparent TV, so making the window opaque is important for picture quality. Would the window turn completely opaque? Would curtains be necessary for complete darkness? Forward cabins would face stars.

Last edited by RobertDyck (2020-08-18 17:51:36)

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#183 2020-08-18 18:01:59

RobertDyck
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Re: Large scale colonization ship

In the initial post, I described "single" cabins. Exactly the same size as economy cabins, but instead of bunks, there's one queen-size bed. And it's a Murphy bed. For inside cabins the hinge would be the head of the bed, as a standard Murphy bed. Outside cabins have a window, so the hinge would be along one side of the bed, folding against a side wall so the window isn't covered. A cabin could be flexible: furniture configured as either economy or single. Some cabins dedicated as single could have the shower and toilet on opposite sides of the door, as shown in the picture in the initial post.

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#184 2020-08-18 19:20:49

tahanson43206
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Re: Large scale colonization ship

For RobertDyck Re recent posts ...

Thanks for the clarification.

You can add a few words to the sketch post, to indicate that the rotation is at 90 degrees to the Sun direction.

Another tiny detail that would help understanding is to indicate that the viewer is looking down on the floor.

I discovered that I was mentally rotating the image.  A couple words to help with orientation would help future viewers.

(th)

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#185 2020-08-26 09:59:28

tahanson43206
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Re: Large scale colonization ship

For RobertDyck after return from your latest adventure in the North country ...

I added the dimensions in your sketch and found you've started with a habitat width/thickness of 19 meters of interior space.  Rounding up for wall thickness, I'd imagine you are thinking of (about) 20 meters thickness for the habitat.

Could you / would you be willing to allocate space in one of your posts in this topic to specifications for various parameters?

I am unable to remember if you specified the simulated gravity level you were aiming for, but conversation elsewhere in the forum has pointed out the advantage of Mars level gravity, which means that the diameter of the habitat can be much less than is needed for a full 1 Earth g at 4 RPM.

I came up with 22 meters radius for a tad over Mars gravity, which would imply a diameter of (on the order of) 44 meters.

Is that what you had in mind?

(th)

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#186 2020-08-27 05:55:23

RobertDyck
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Re: Large scale colonization ship

Initial post:

RobertDyck wrote:

Mars acceleration for the ship, so 38.0% that of Earth gravity. Radius 37.76 metres from centre of rotation to surface of the floor, 3 RPM. One deck. Circumference 237.25 metres. Ring width 19 metres. This allows 2 isles for cabins, corridors 1.5 metres wide, outside cabins have a window, inside cabins do not. Standard cabin size 4x2.4 metres.
...
Premium cabin would be twice as long and twice as wide for 4 times floor area.

A ship this size could have 162 "economy" cabins with average 5 persons each, 90 "single" cabins with two persons each, 4 premium cabins with 2 persons each, and 1 luxury suite that's 4 times the size of premium. That would carry 1,000 passengers and crew.

That leaves 66.85 metres of circumference for food storage, life support, and facilities such as kitchen or dining room. That's 28.177% of floor area. Centre of rotation would have a zero-G hub with padded walls where passengers could enjoy themselves. Docking port at the zero-G hub. A portion of the fabric heat shield over the hub would move out of the way to during flight to provide a view of where they're going. A parasol would move in place for aerocapture. Aft of zero-G hub would be zero-G storage. Aft of that propellant tank and engines.

Beds would require a back-rest so passengers don't slide off the end of the bed. During acceleration thrust would be toward the window for cabins on one side of the isle, toward the door for the other. During aerocapture thrust would be reverse. Ring rotation would never stop.

A later post on page 1:

::Edit:: I said the ship could carry 1,000 passengers and crew. If the captain takes one "single" cabin with no roommate, that reduces total complement by one. If each Premium cabin and Luxury suite has 2 people per hide-a-bed, that adds 2 per cabin. And I said average of 5 people per economy cabin, but maximum is 6. That makes maximum 1,171 people.

Post #44

In the initial post, I calculated 66.85 metres of circumference for everything other than cabins, with ring width 19 metres. That provides 1,270.15 square metres =  13,671.78 square feet. Rule of thumb for restaurant seating is 18-20 square feet for fine dining, 15-18 sq.ft. for full service restaurant, 12-15 sq.ft. for commercial cafeteria, 10-11 sq.ft. for school lunch room, fast food or banquet room. I said 162 economy class cabins with 6 bunks, and 90 cabins with a queen-size bed. Captain would have a "single" cabin to him/herself, so full accommodation would be 1,151 not including premium and luxury cabins. Dining facilities could be sized for 1/3 at a time. No separate common room, instead use the dining room for games and other "common" facilities when meals aren't served. This could be broken up, say 2 large rooms with lunch room space to seat 100 at a time per room. Four themed diners for 50 people each. And for premium/luxury passengers, a fine dining restaurant that can accommodate 20 people. If seating is 10 sq.ft. per person, 15 sq.ft. for fine dining, that's 4,300 square feet.

Post #50

Found a reference to commercial kitchen design. It says 5 square feet per seat in the dining room. I said above a total of 420 seats, so 2,100 square feet of kitchen? That leaves 7,274 square feet for laundry, gym, medical, bridge.

Post #62

Cruise ships today have 20,000 square feet for a ship that carries 2,695 passengers. Our ship carries 1,000 passengers. Providing 4,000 square feet for gym means half the number of square feet per passenger. Enough?

Found a reference for hotel laundry here. It says 500-700 sq.ft. for 120-key hotel. Our ship has 257 cabins, but "economy" cabins have 6 "small single" beds rather than a queen, so double laundry for them? So our 581 "keys" for the purpose of laundry: ... assume a design based on RV washing machines that use the same drum from washing and drying. ... mount the machines with zero rear clearance...stacked 2 high... 403 square feet?

Cruise ship rule of thumb is one infirmary bed per thousand passengers. This ship will have 1,000 passengers so 1 medical bed? Let's say 2. ... 260 square feet?

Ship's bridge. ... 200 square feet?

We're left with 2,411 square feet. That has to include corridors. Cabin corridors are already accounted for, but not the rest. Do we put food storage in zero-G, or some storage in the ring? There's life support with oxygen generator, water processor, Sabatier reactor. Does this leave us with room for a lounge/bar/club?

Post #81

What if we increased rotation rate for Earth gravity instead of Mars gravity? Instead of 3 RPM, that would require 4.8665 RPM. For the very same ship. It would have to be strengthened to withstand the forces of 1G instead of 38%, but same size.

Not posted before: Crew. Based on a 1903 passenger ship, but adapted for modern technology. Result for this ship:
Captain, 6 deck officers
Petty Officer, 4 sailors (janitor, cargo rigging & handling)
Chief steward, 1 steward for luxury cabin, 12 table waiters, 8 bedroom stewards (housekeeping), 12 cooks, 2 baristas.
Chief engineer, 8 engineering staff (electrician, plumber, etc)
Purser, Doctor & nurse
Total: 60
captain & doctor get single cabin. Junior officer cabin: deck officers, petty officer, chief steward, chief engineer, chef.
2 singles, 5 junior officer cabins, 8 economy cabins.
There's enough space left in the ship for crew cabins to be separate from passenger cabins.

Most food would be stored. However, we could have hydroponic greenhouses on the roof of the ring for fresh vegetables & salad. I still argue for soil greenhouse on Mars. Why process Mars soil to produce hydroponic solution? Let the plants extract nutrients from soil themselves. However, space and mass on a ship is at a premium; so hydroponics on the ship. And if you do that, you could add observation rooms with all transparent ceiling and walls; only the floor opaque. For durability and mass, greenhouse and observation windows made of ALON (aluminum oxynitride).

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#187 2020-08-27 07:15:16

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #186

Thanks!  SearchTerm:SpecificationsLargeShip

http://newmars.com/forums/viewtopic.php … 56#p171556

***
Radius of habitat: 37.76 meters ... rounding up to 38 gives Diameter of 76  and Circumference of 238.76

Rotation rate: 3 RPM (nice!)  Simulated gravity: V^2/R

That gives acceleration of 3.75 meters / second^2, which is slightly above Mars average at the surface.

Thickness of the disk is given as 19 meters.

No dimensions of the propulsion unit are given but the SpaceX Starship is said to be 9 meters in diameter and 50 meters long.

A preliminary drawing with a propulsion unit of that size would be a starting point for further development.

***

Do you have a word or phrase for your design?

It is the only one of three currently in discussion in the forum that rotates the entire vehicle.

It looks somewhat like a mushroom, but I'm not sure that is the term you'd want to use in advertising literature.

The same would hold for toad stool, I suppose.

I visited a web site dedicated to listing, showing and naming various kids of hammers.  None of the examples has a round head.

But even "hammer" is less than ideal for a name.

Edit#1: Harley Davidson made a motor its customers called "Panhead" due to the design of the valve covers.

https://en.wikipedia.org/wiki/Harley-Da … ead_engine

Those engines were twins, and the RobertDyck design only has one "head", but the name might work.

It is "remotely" possible Harley Davidson might be amused by an invitation to support development of the design. 

The nature of the enterprise (transport to and from Mars) is in line with the over all heritage of the company, which has a rugged travel related aspect that might connect reasonably well.  The simplicity of the design might appeal to them

Harley Davidson Panhead Transport.  Has a nice ring to it.  I only owned one Harley, but it was my first large bike, and I remember it fondly.

(th)

Last edited by tahanson43206 (2020-08-27 10:53:58)

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#188 2020-08-27 11:15:03

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

Radius of habitat: 37.76 meters ... rounding up to 38 gives Diameter of 76  and Circumference of 238.76

Rotation rate: 3 RPM (nice!)  Simulated gravity: V^2/R

That gives acceleration of 3.75 meters / second^2, which is slightly above Mars average at the surface.

When you use 37.76 metres radius and exactly 3 RPM, that works out to 38.00% gravity. That's precisely Mars surface gravity. In terms of acceleration, it's 3.72676 m/s². Since radius is given to 4 significant digits, that would have to be rounded to 3.727 m/s². Mars surface gravity is 3.72076 m/s² (Wikipedia). That's 37.9412 G.

I had used a calculator to get radius. Would you rather I recalculate for 37.6992 metres radius? At 3 RPM that works out to the precise surface acceleration of Mars. To 6 significant digits. That would make circumference 236.871 metres.

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#189 2020-08-27 11:40:20

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #188

For purposes of generating a model, I rounded the diameter to 76, and set the thickness to 19 since that is an even number.

The model is finished (showing habitat and a sample propulsion unit) and I'm hoping it passes muster with Shapeways so it can be viewed.

I'm calling the model "Panhead" as a temporary tag.

FYI ... I'm using the Google provided figure of 3.711 m/s^2 as the reference Mars gravity.  The actual simulated gravity generated by the vehicle can (presumably) be fine tuned by the Captain to achieve the optimum performance of the system for the given set of passengers.

***
In your long post (which I printed in large font), you referred to the "roof" of the habitat.  If the floor is the outside perimeter, I'm unsure of what you might be thinking about when you use the term "roof".

(th)

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#190 2020-08-27 12:18:46

RobertDyck
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Re: Large scale colonization ship

I said 162 economy cabins plus 90 single cabins, but many cabins could be configured as either economy or single simply by changing furniture. With 4 cabins across the ring that's 63 cabins along the circumference. At 2.4 metres wide from centre of wall to centre of wall, that's 151.2 metres of circumference. Premium/luxury cabins are 19.2 metres of circumference. Using the slightly smaller size, that leaves 66.471 metres circumference for everything else.

Economy and single cabins take a small portion of the bathroom/washroom space for life support. Premium/luxury cabins could have a section of wall protrude slightly into the corridor to enclose life support; their corridor is 3m wide. That includes dehumidifier, regenerable activated charcoal filter for smells, regenerable CO2 filter, urine processor, water processor, and oxygen generator. Toilet would vacuum desiccate feces. Sized for occupants of one cabin. Central life support would further filter water. Using bags of in-vitro chloroplasts for oxygen generation, byproduct is starch. Several pipes/hoses would extend from cabins to central life support: grey water, potable water, concentrated urine, powdered feces, starch.

Crew quarters: captain and doctor each get a single cabin. Junior officers are 2 per cabin, same size as single/economy cabin. Rest of the crew get economy, 6 per cabin. That's 15 crew cabins, 2.4m x 4m = 9.6 m² each.

Remaining floor area: 66.471 x 19 = 1,262.949 square metres
Subtract crew cabins: 1,262.949 - (15 x 9.6) = 1118.949 m² = 12,044.266797 square feet.
Dining: 4,300 square feet
Kitchen: 2,100 square feet
Gym: 4,000 sq.ft
Laundry: 403 sq.ft
Infirmary: 260 sq.ft
Bridge: 200 sq.ft

That leaves 781.266797 square feet for corridors, central life support, workshop (janitorial/engineering), storage, and lounge/bar/club. Pantry (food storage) would be in the kitchen for ready storage; long duration storage in zero-G hub.

Preparing chloroplast bags involves growing pea plants to 14 days from germination, cutting up leaves, crushing and centrifuge to isolate chloroplasts. This could be done in the greenhouse on the ring roof.

If ring ceiling is 2.4 metres high and ceiling/hull thickness is 30cm (11.81 inches), then radius to roof floor surface is 37.3992 metres. That's 37.639 G acceleration. Note: greenhouse floor doesn't require micrometeoroid or thermal protection, greenhouse windows would do that.

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#191 2020-08-27 12:29:05

RobertDyck
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Re: Large scale colonization ship

Hmm. Using 38.00% G acceleration, Mars gravity from earlier sources, that works out to 37.76m radius. That makes circumference 0.3820 metres more. Not a lot, but adds 7.2583 square metres =  78.128 square feet. Is that significant?

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#192 2020-08-27 12:43:38

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re offer of model for viewing

The link below goes to a view that allows for 3D rotation of the model...

https://www.shapeways.com/product/8GL77 … 1&li=shops

625x465_32481206_17190774_1598551067.jpg


The rotation rate can be adjusted at run time.  The width of the habitat, and the circumference, and all measurements that derive from them, are fixed.

I have tried to simplify things a tiny bit, by rounding up (slightly).  The simulated gravity will be slightly greater at 3 RPM.

Once you've set your specifications in stone, the downstream designers can fill out details of room size, furniture and countless other details that make up your working vessel.

(th)

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#193 2020-08-27 12:49:32

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

For purposes of generating a model, I rounded the diameter to 76, and set the thickness to 19 since that is an even number.

You would have to add hull thickness. And remember I said life support will have various pipes/hoses running under the floor. These would have to be accessible by floor tiles that can be lifted for maintenance/repairs. Alternatively, they could run through the ceiling. That would mean ceiling panels that can be opened. Hmm, a covered trackway for these lines just under the ceiling against one wall? Point is pressure hull has thickness, plus thermal insulation, plus interior decorative flooring/wall/ceiling. My precise measurement is surface of the floor; your model has to add floor/hull thickness.

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#194 2020-08-27 13:12:20

RobertDyck
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Re: Large scale colonization ship

A few years ago I read of a new shower developed by a design student in the UK. It recycles water for the shower. Dirty water down the drain goes through a cyclone separator, similar to a cyclone vacuum cleaner but for water. The idea is dirty water and soap is removed and goes down the drain. Clean water is separated so back to the shower head. This recycles 70% of the water that goes down the shower drain. This not only saves water, but that water is already warm, so it reduces energy required for water heating. Brilliant idea! Only catch is don't piss in the shower, since the cyclone water separator can't remove piss. If you piss in the shower, your own piss will come back out the shower head. Intended for Earth, but I think it would be great for our Mars ship. First level of processing; dirty water would be directed to the water processing assembly (WPA) for further processing.

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#195 2020-08-27 13:17:52

tahanson43206
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Re: Large scale colonization ship

I'm very much a novice with Fusion 360, and am not sure how far I might be able to push it.

It's main value is to give you something to show to potential funders.

The model on display now passed the first test, which is a big one from my perspective.  Shapeways is willing to put up with the model!

From here it can be adjusted and replaced until it breaks.  In addition, the text that goes with it can be adjusted.

Depending on how capable your computing equipment is (that varies for each of us), you might be able to venture into the arena of 3D Modeling.  Fusion 360 is pretty much at the top of the line for free design packages.  However, there are numerous capable free offerings that can generate useful views.

I had to buy a new video graphics card to run Fusion 360, but the base machine appears to be acceptable for the most part.  It has 8 Gb of Ram and 4 processors running 64 bits.  Fusion 360 still complains from time to time.  The hard drive is flash memory.  That helps significantly.  The package barely runs on a standard hard drive.

Looking ahead, it should be possible to generate a model without walls, so the interior is visible.  That would stretch my capabilities significantly.  Potentially we might interest a forum reader to pitch in at some point.

If you visit Thingiverse.com you'll be able to get a sense of what's possible.  You can bring a link from there to the forum, to show what you'd like to try.

Edit#1: In going back to your original sketch, I realized I'd missed an important detail ... your sketch shows spokes from the central propulsion unit, so now your reference to the "roof" makes sense.

Before I change the current model, do you want to stay with the spokes, or do you want to go with the full disk?

The full disk adds mass, but it also adds storage space.  On the other hand, everything you add to the mass of the disk has to be accounted for in spin balance.

(th)

Last edited by tahanson43206 (2020-08-27 13:21:37)

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#196 2020-08-27 16:42:24

RobertDyck
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Re: Large scale colonization ship

It's definitely a ring, not a disk. Ceiling 2.4 metres high, plus hull thickness for ceiling and floor.

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#197 2020-08-27 17:16:40

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #196

Thanks for the clarification and for the height detail

Are those spokes cylindrical or some other cross-section?  Cylinders could be made from Starship bodies, but at 9 meters diameter they may be larger than you have in mind.

Questions: What is the shape of the spokes?

And... What are the dimensions of the propulsion unit ...ls a Starship body about right ??? too small ???

(th)

Last edited by tahanson43206 (2020-08-28 04:45:33)

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#198 2020-08-27 19:03:46

RobertDyck
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Re: Large scale colonization ship

Wikipedia: Harmony (ISS module)

It is composed of a cylindrical, 5.1 cm (2 in) thick 2219-T851 aluminium alloy pressure shell with two endcones and is thermally insulated by a goldised Kapton blanket. It is protected from micrometeoroids by 98 panels, each made from a composite sandwich of stainless steel and 6061-T6 aluminium alloy, and a secondary barrier of Kevlar/resin.

So what's the total thickness including panels?

You could add detail. Roof over cabins that don't have greenhouse on top could be 2D curved arch. No half-cylinder, but slightly curved. This would add strength to the pressure hull. One curve for a row of cabins, another for the corridor, etc. Each wall weight bearing; not in compression, but in tension. That means holding the ceiling down to the floor, against air pressure. But obviously the floor must be flat. Where there's greenhouse on the roof, the ceiling must be flat because that's the greenhouse floor. Well, "flat" means cylinder with axis of rotation as centre. Am I making sense?

Spoke diameter: I have no idea. This is where we need a structural engineer. The spokes must bear thrust during main engine operation, pushing on the mass of the ring. Interior of the spokes must be large enough for an elevator. Sufficient number of passengers for smooth operation when receiving passengers via SpaceX Starship.

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#199 2020-08-28 05:00:00

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #198

It is helpful to see your thought process about transfer of force from the propulsion unit to the massive ring, filled with people and supplies, and rotating at 3 RPM.  It is helpful to see your thought process about how the pressure vessels will be constructed.

In other topics in the forum, GW Johnson (as I recall) has offered suggestions on safe construction of pressure vessels for fuel and oxidizer.  The conditions existing in such pressure vessels would not apply to the habitat hull.  I assume that the practices used by the Russians, US and China for their space stations would be worth noting as you go forward.

Overnight, I thought about the transfer of force to the ring, and the idea of braces came to mind.

In your design, force will only be applied to the rotating ring from one direction.  Due to the need for steering, the force applied to the ring will not be uniform, so the ring needs to be strong enough to withstand twisting effects.

If you go with a torus design, you can store supplies under the floor, similar to an airplane, where luggage and freight are under the cabin floor.

***

The pancake nickname does not apply to the design with spokes, but the tradition of branding cattle in the American west may help.

The revised design looks like the Circle Y brand.

A quick check with Google revealed that the Circle Y brand is now associated with a line of saddles,

***
Edit #1: The torus is a design primitive available in (probably most) 3D Printer design programs.  It's available if you want to use it.

Other primitives are cubes and cylinders. 

Edit #2 (after time away from the keyboard) ...

Both Fusion 360 and Blender (and probably other packages) permit design of a cross section of an object in 2D, followed by extrusion of the outline to 3D.

I am not planning any more 3D design until hearing back from you, but this is a word picture of what is possible (I ** think ** anyway)

1) Sketch rectangle with height of 2.4 and width of 19 <<== human habitat
2) Sketch round shape (circle) around the rectangle (torus to enclose human habitat)
3) Extrude the combined drawing into a torus (I don't know how to do this but am (fairly) sure it can be done
Then...
4) Create the propulsion unit as a cylinder to the diameter and length you specify
Then
5) Sketch a triangle with dimensions to go between the torus and the propulsion unit
6) Extrude the triangle to make a triangular solid << to transfer force from propulsion unit to torus
7) Join copies of the "fin" to the propulsion unit and the torus at three points of the compass (0 - 120 - 240)

The resulting object would come pretty close to matching your original sketch.

It would have the ability (an engineer is needed to confirm of course) to transfer force smoothly and evenly from the propulsion unit to the torus.

Edit #3:  The "spokes" you showed in your sketch would be embedded within the fins described above.  The volume of the fins could be used for storage of solids and fluids to supplement what is stored in the torus (above and below the habitat ring) and in the propulsion unit.

I would find the challenge of creating such a model interesting, and worth investment of a bit of time.

(th)

Last edited by tahanson43206 (2020-08-28 11:26:15)

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#200 2020-08-28 12:24:30

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

Cabin cross-section. This shows the ceiling arched. The reason for the arch is stress from pressure. So interior walls hold arch edges down, like an air mattress. The floor requires more structure to be flat. But remember it's not really flat, it's a cylinder.
pSXgUfv.jpg

This arch design isn't based on any scientific principle. Well, it ensures pressure applies forces in tension instead of shear force, but apex height is arbitrary. The drawing is made in 1:100 scale, so 1cm represents 1m. Corridor is 1.5 metres wide so apex of the arch is 0.3 metres (drawn 3.0mm) above wall top. Cabins are 4 metres so apex of cabin arches are 0.8m (drawn 8.0mm) above wall top.

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