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#226 2020-08-30 19:32:13

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re polymer composites ... Radiation protection is not a concern for cruise ships on Earth, but the properties of such materials have been investigated by NASA, with favorable results.  There are (as I recall) several discussions about the benefits of these materials in the NewMars archive, including a recent refresh by SpaceNut.

The passengers who choose the middle cabin will (presumably) benefit from multiple layers of radiation absorbing materials between themselves and the outside.

(th)

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#227 2020-08-31 17:53:55

tahanson43206
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Re: Large scale colonization ship

For RobertDyck ...

The technique for creating the spokes which are at 120 degrees and 240 degrees seems to have worked.

qKmhaks.png

The spokes were set to 19 wide to match the habitat, and 10 to match the hub

All can changed as needed, of course.

The Sketch feature turned out to offer a way to numerically enter the angle, but I noticed it still preferred the Snap-To values.

On the other hand, the numerically entered lengths seems to hold.

(th)

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#228 2020-09-01 04:55:09

RobertDyck
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Re: Large scale colonization ship

Elevator
5bfb2ee390b6c738a98256c0_Dimensions-Guide-Layout-Elevators-Single-Car-Dimensions.svg
This shows an extra large elevator 1.73m x 2.67m = 4.6191m². The outside dimensions of the shaft are 2.5m x 3.6m = 9m². Width of shaft is 2.5 - 1.73 = 0.77m greater, length is 3.6 - 2.67 = 0.93m greater. Common elevators have a counter weight, which I assume slides in the extra space behind the elevator car. On our ship, the elevator will travel within spokes; gravity will vary from near zero at the hub to full gravity at the ring. So assume the car uses cog wheels to drive up and down the shaft. That means no counterweight. And a round elevator, so the spokes are cylinders. For the same car floor area, a circle has area πR². (That's supposed to be Greek letter Pi.) So reverse calculating for square_root(4.6191m² / π) = 1.21256m (and a bunch more digits). Diameter is 2R = 2.42512m. Add 0.77m to get shaft diameter = 3.19512m. But the shaft isn't just a wall, it's structure supporting the ring during rotation, and during thrust. And there's micrometeoroid protection. Round to 3.25m diameter.

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#229 2020-09-01 07:18:24

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #228

Interesting post on moving people along the spokes.

I noticed your mastery of font selection in Post #228 ...

How did you generate the exponent in meters squared?

And, how did you generate the Greek character Pi ?

Copying text in is a technique that I have seen in the forum in the past, but it looks as though you might have typed it in directly?

Since the maximum gravity you'll be offering is Mars level, would it be possible to simply let passengers hook on to sliding rails on the walls of the spokes, step onto a small platform, and whisk themselves the few meters from the rim to the hub and back?

A "dumb waiter" is a simple example of the kind of "lift" that might be appropriate for this low g environment.

Edit#1 ... passengers and crew moving up or down the spokes will experience the same effect (on a small scale) as would apply to space elevator passengers, if such systems are ever built.  On the way from the hub to the rim, passengers will find themselves pressed to the anti-spin wall of the shaft, because the spacecraft will be accelerating them toward the velocity chosen for the rim. 

On the way from the rim to the hub, the momentum of each passenger will cause a force they will experience as a pull toward a side of the shaft.

My "sense" of the situation is that the forces will separate the passengers moving in opposite directions, but I'm looking forward to seeing animation to show the effect using physics.  Blender was designed to provide a platform to create animated movies, and I am thinking of moving the Circle Y design over to Blender, to see if I can set up a simple rotation gif.  It appears that imgur.com supports simple gif files, so it might be possible to post something in this forum.

(th)

Last edited by tahanson43206 (2020-09-01 08:00:41)

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#230 2020-09-01 07:58:31

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

I noticed your mastery of font selection in Post #228 ...

How did you generate the exponent in meters squared?

And, how did you generate the Greek character Pi ?

Copying text in is a technique that I have seen in the forum in the past, but it looks as though you might have typed it in directly?

If your computer runs Windows 10, open start menu, go down to "W", open the folder titled "Windows Accessories". One of the programs is "Character Map". When that opens, you can click on a specific character, then click the button "Select". The character will appear in the box "Characters to copy". Then click the "Copy" button to put it (or them) on the clip board. Go back to your browser and paste. Several useful characters "°¹²³¢¼½¾±÷". Greek letters are found by scrolling down. The first character is actually the degree symbol. If you click on that, along the bottom you see "U+00B0: Degree Sign", this gives you the unicode. Bottom right you will see "Keystroke: Alt+0176". I use the degree symbol so often that I've memorized it. So just hold the Alt key, and on the numeric keypad type 0176, then release the Alt key.

Character Map is a standard feature of Windows, from Windows 95 to Windows 10. I think it was in Windows 3.0 and 3.1.

:Edit: I use Character Map so often that I put a link in the tiles of my start menu. Made it a small tile. And yes, I've removed all the ads from my tiles.

Last edited by RobertDyck (2020-09-01 08:12:27)

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#231 2020-09-01 08:08:47

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #230

Thanks for the helpful reminder!  Linux offers something similar.  I called up OpenOffice.org Writer and found Special Characters as an option in "Insert"

This may be Epsilon: ψ

Yay!  It worked!

Nice! Thanks!

Learning this environment is an incremental process.  SpaceNut gave/provided the insight to use * in the Search feature, and my search success has improved dramatically.

Your tip will surely be helpful in the future.

(th)

Last edited by tahanson43206 (2020-09-01 08:09:38)

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#232 2020-09-01 13:18:48

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re ship fabrication ...

I went back and studied your floor plan for the rim again ...

It looks to me as though you could prefabricate 19 meter cross sections of the rim, and send them up on a Starship  ...

The economy cabins could go in pairs, for a total width of 4.8 meters, and the premium cabins would fit.

The luxury cabins could be shipped as premium, bolted together and then opened up with ports between sections, for a bit of privacy for family members.

Also in studying the sketch again, I realized you had planned for the "normal" conveniences of a hotel room.  The piping needed to support those facilities would run in a part of the "floor" where girders would reside to support the weight of the cabins and their occupants. 

Some assembly in orbit would be required << grin >>

However, much if not most of the facility could be assembled in factories on the ground and lifted into orbit.

Modern home assembly comes pretty close to matching the idea described, and (recalling from video of passenger ship assembly) something very similar is done in assembly of modern ocean going vessels.

(th)

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#233 2020-09-01 21:00:26

tahanson43206
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Re: Large scale colonization ship

For RobertDyck ... re animation in Fusion 360

Lydia Cline's book has one line about Animation ... she just says its there, and that it is possible to make a movie ..

I pulled up the model of Circle Y and got it to roll a few turns, but I don't know how to make it loop.

I also didn't see a way to make a movie.

Because Blender is designed to make movies (and only makes 3D parts as a sideline) I wrote the Circle Y model out as stl and will experiment with it in Blender tomorrow (if plans hold).

Edit #1 2020/09/02 ... the stl of the Circle Y model imported smoothly into Blender, and it looks good there.

I've forgotten how to make a movie, and will have to re-read the instructions.

(th)

Last edited by tahanson43206 (2020-09-02 20:43:57)

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#234 2020-09-02 23:48:49

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

Also in studying the sketch again, I realized you had planned for the "normal" conveniences of a hotel room.  The piping needed to support those facilities would run in a part of the "floor" where girders would reside to support the weight of the cabins and their occupants.

I said cables and pipes would run through a raceway. Here's a typical cable raceway...
0a4cafb8a16e1dfb0e4316f404e6b3a0.jpg
A bit larger, able to contain all the plumbing as well as cables.
protectoway_op.jpg

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#235 2020-09-03 07:24:38

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re topic and new additions ...

Overnight it came to me that the form factor for a section of the rim segment would be comparable to a mobile home.

I haven't checked the sizes of mobile homes yet, but my recollection is that some reach the size of a pod that would be 19 meters long, 4.8 meters wide, and 2.4 meters deep.

I have been thinking about the life support systems as well.

Those could reside in a pod comprising the floor, so that each section of the rim would be able to serve its own needs for cleaning water and air, and for maintaining temperature and humidity.

The life support pod could be where the actual tensile strength of the rim resides.  The pods would be bolted together after they are launched.

Since there are (something like) 9 meters of diameter of a Starship launch vehicle to work with, you could assemble the living quarters and the life support pod on Earth, and lift them to orbit in a single launch.

As a nice add-on ... a 4 meter by 19 meter solar panel could be added to the mix.  It would fit along side the life support pod during launch, and then swing out to project 90 degrees from the rim to collect sunlight perpendicular to the Sun's rays, since you have specified that during most of the flight to and from Mars, the propulsion section will be pointed toward the Sun.

The advantage of packaging all the life support with the living quarters is (of course) that in the event of an emergency, such as a meteor or orbital debris taking out one pod, the others can button up and take care of their occupants for an extended period while the crew attends to patching.

(th)

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#236 2020-09-03 08:15:04

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re topic

Funding your venture will be challenging, but it is small compared to many projects in the history of Earth cultures.

The condominium model is possible in the case of the Circle Y vessel, because your design lends itself to isolation of 19 meter long pods into 4.8 meter sections that can be operated as stand alone life support systems, in addition to their primary mission of travel lodging.

There are enough extremely wealthy people on Earth to invest in individual pods, and in shares of the propulsion unit and other infrastructure.

The condominium would include manufacture of the pod on Earth, launch to LEO, assembly on orbit, and any incidental costs such as meeting regulatory requirements above and beyond those required for launch, which will (presumably) be handled by the launch provider.

In thinking about existing companies that might be suitable for consideration for manufacture on Earth, Airstream came to mind.  They would have to stretch a bit to meet the more stringent requirements for the space environment, but overall, I think they would find themselves quite comfortable with handling of the living quarters.

The life support pod is another matter, and (I would imagine) a traditional aerospace company might be a better fit.

(th)

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#237 2020-09-03 12:21:29

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

Overnight it came to me that the form factor for a section of the rim segment would be comparable to a mobile home.

I haven't checked the sizes of mobile homes yet, but my recollection is that some reach the size of a pod that would be 19 meters long, 4.8 meters wide, and 2.4 meters deep.
...
Since there are (something like) 9 meters of diameter of a Starship launch vehicle to work with, you could assemble the living quarters and the life support pod on Earth, and lift them to orbit in a single launch.

I envision building the pressure hull first, then fitting out the interior. Cabins would be launched disassembled; think Ikea flatpack. Interior walls stacked flat, etc. Based on the figures you posted, a rectangular fairing could enclose 2 wide by 4 deep, by one long, packed on end. Single cabins (Norwegian Cruise Lines calls them Studio Single), are 4 metres long by 2.4 metres wide. This would allow 4x4x4=64 cabins to be launched at once. Lightweight composite cabins manufactured by Trimline for cruise ships mass 972kg each. Obviously that's without life support. But that's 62,208kg total. Starship will be able to lift 100 metric tonnes to LEO. Oh, wait. That's usually calculated for 185km, but we would want roughly 400km, about where ISS orbits. Space Shuttle could lift 27,000kg to 205km @ 28° inclination, or 16,050kg to 407km @ 51.6° inclination (ISS). So Starship should be able to lift 59,444kg to ISS. If our ship orbits at lower inclination, say 28°, Starship could lift a little more. That works out to the mass of that number of cabins. Huh!

tahanson43206 wrote:

As a nice add-on ... a 4 meter by 19 meter solar panel could be added to the mix.

SpectroLab manufactures solar panels for satellites in space. Their best today has 32.2% conversion sunlight to electricity, beginning of life. They produce 135.3 mW/cm² @ 28°C for 27cm² cell. For a panel, there are gaps between cells. They used to provide power for complete panels, but it's not on their website now. Should we speculate at gallium-indium-nitride, prototype developed in year 2000, estimate was an 8-junction cell should produce 70.2% conversion? Or stick with the best that exists now?

Using what exists now: let's guess 95% surface area of the panel is usable cell. There's 1,000 mW per Watt, and 10,000 cm² per m², so cells produce 1,353 W/m². If a panel is 95% cells, then 1,285.35 W/m². Sunward side of the ship will have windows and mirrors to collect sunlight for chloroplast based oxygen generators. You suggested hanging solar panels hanging down (outward from hub of rotation) from the ring. Ok. 4x19 metre solar panel would produce 4x19x1,285.35 = 97,686.6 Watts. For economy or single cabins, there are 2x4=8 cabins in that space. Is that enough power? Again, oxygen generators use sunlight directly, so don't require power. We have LED lights, but this would have to include air conditioning, fans, water filtration pumps, etc.

Oh, we haven't discussed air conditioning. I guess the dark side of the ship would require radiators. That's the forward side of the ring.

tahanson43206 wrote:

The advantage of packaging all the life support with the living quarters is (of course) that in the event of an emergency, such as a meteor or orbital debris taking out one pod, the others can button up and take care of their occupants for an extended period while the crew attends to patching.

That is intended. I waffle over whether final filtration from grey water to potable water should be central, or with each cabin. But sections of cabins (such as what you proposed) could be sealed to form pressure tight compartments. Just as a ship at sea has water tight compartments to prevent sinking, a space ship has pressure tight compartments to survive a hull puncture.

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#238 2020-09-03 12:23:54

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

Funding your venture will be challenging ... condominium model ... There are enough extremely wealthy people on Earth to invest in individual pods

They're a major market for settlement on Mars. Why would they want to stay on a ship?

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#239 2020-09-03 13:03:00

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #238

The model is the only one I could think of ... the investors would own the asset, which would be bolted to the structure provided by the company.  Passengers would use the asset, and income would flow through the company back to the investor.

There are (of course) other models ... the traditional one is to simply sell shares ... The advantage of packaging a single segment of the rim is ease of assembly (on Earth), ease of assembly on orbit (self-assembly ... locate sockets in adjacent pod and bolt together), and ease of replacement when the time comes.

The investor can see the pod on Earth before launch, and watch the assembly via video.

And ** these ** investors would ** not ** be going to Mars.  They'd be angling for income from those who ** do ** want to go to Mars.

(th)

Last edited by tahanson43206 (2020-09-03 13:03:37)

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#240 2020-09-03 18:10:20

RobertDyck
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Re: Large scale colonization ship

So the investor's name is Quark? Runs the ship's bar?
d819a74d4f3492a165f9b285138b5e9e.jpg

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#241 2020-09-03 18:19:10

SpaceNut
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Re: Large scale colonization ship

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#242 2020-09-04 02:49:36

RobertDyck
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Re: Large scale colonization ship

In areas with standard cabins, every 4th wall between cabins would be a pressure wall. A pressure tight door could close the corridor. Doors would be a one-piece pocket door, like those of Star Trek TOS. Plumbing pipes through the walls would have pressure tight solenoid valves that could seal shut; one set of valves on either side of the pressure wall. So one pressure section consists of 4 cabins along the sunward exterior wall, 4 interior cabins across the corridor, 4 cabins along the forward exterior wall, and 4 interior cabins across the corridor from them. Total 16 cabins per section. If something happens to puncture the pressure hull, an alarm would sound, coloured emergency lights in the affected section would illuminate, and a recorded voice would instruct passengers in that section to evacuate. Take pets and their smartphone with them, but leave other possessions behind. Security cameras would monitor who is still inside. As soon as everyone is out, pressure doors would close. Each pressure door would have a seal around the door where a plastic sheet air lock can be attached. On both sides of the door. Anchors built into the walls a short distance from the door would be used to attach the plastic sheet door section of the plastic sheet airlock. Emergency air locks would be stored in lockers in various parts of the ship. Crew could install these airlocks so a crew member in a spacesuit could enter an airlock, decompress, then open the pressure door to enter the evacuated section. If someone was incapacitated and unable to evacuate, the pressure doors would have to seal with them still inside. Crew would quickly install the airlock, a crew member in spacesuit enter to rescue the passenger inside. The crew member would put the passenger in a rescue ball, seal and pressurize. Then carry the ball with passenger to the airlock and out to the pressurized part of the ship. If someone was exposed to vacuum, they would have to be taken to infirmary.
200px-First_Six_Women_Astronauts_with_Rescue_Ball_-_GPN-2002-000207.jpg
Once everyone is outside the evacuated section, crew would repair the hull puncture. Once repaired, then repair any damage to life support caused by vacuum. Repressurise the section, and everyone can return. If repairs take significant time, one of the dining rooms can be used as emergency housing. Just move tables and chairs aside, people sleep on the floor. Mattress and bedding can be removed from the evacuated section by crew in spacesuits, set on the floor of the dining room as temporary "camping".

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#243 2020-09-04 03:36:16

RobertDyck
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Re: Large scale colonization ship

I suggested processing grey water into potable water would be done in central life support. Rather than a central location, this could be equipment in a pressurized box on the roof. If a greenhouse or observation deck is on the roof, the box would be inside that. The box of equipment would be in a pressure sealed box, so if the greenhouse decompresses, the box of equipment can remain pressurized. The box will be accessible for repair simply by opening a hatch in the box, so repair crew can stand inside the pressurized greenhouse or observation deck to do repairs. If there's no pressurized room on the roof of that section, the box would have to be accessible by hatch in the ceiling of a corridor. Repair crew would have to work on a ladder.

This box would include the compressor for air conditioning. Radiator (instead of condensing coil) on the forward hull of the ship, facing deep space. Evaporator coil in life support for each cabin.
ca41c63c771a764cf4a4edd1975437e7.jpg

Radiator would be similar to radiator on ISS.
iss_sts98_strip.jpg

Water storage would be common for a pressure section. So that means 16 cabins share a water tank. If someone takes a long shower and drains the tank, that affects all cabins in the pressure section. Water tank is a water wall on the sunward side of the ship. All wall that isn't window is covered in a tank 4" deep. A plastic sheet inside this water wall separates the tank it two compartments. The plastic sheet is flexible. As clean potable water is drained for a shower, grey water would accumulate on the other side of the plastic sheet. So total volume of water is constant, but consuming water results in moving water from the clean side to the grey side. Water filtration equipment will clean that grey water, pump it through filters from the grey water side back to the potable water side. Since this means total volume of water in the physical tank will remain constant, so will continue to provide radiation shielding regardless whether it's ready to drink or not. Water pipes will allow transfer of water between sections, but normally water will remain within a section. If someone goes to the toilet in another section, obviously this will require transfer of water between sections. As stated previously, transfer pipe can be sealed by solenoid valve on either side of a pressure wall.

When I was in grade 8 and 9, my parents owned a house in a suburb just outside the city. That suburb used well water. The basement had a small pressure tank. The well was just a pipe driven into the ground to the water table, a pump with electric motor was buried at the head of that pump outside, with an access pipe capped in the back yard. The pump was deep enough that ground would not freeze in winter. A horizontal water pipe extended from the pump to the basement. The tank in the basement had a membrane; water below, air above. Air above the membrane was contained in the steel pressure tank. The system had to be flushed so no air on the water side of the membrane. The tank had a pressure sensor; when pressure below a certain level, it would turn on power to the pump outside. This would draw water from the well, increase pressure to the system. When pressure rose above a set point, power to the pump would turn off. When taking a shower you could feel pressure from water coming out the shower head increase, then decrease, then increase, then decrease. It was a soft oscillation. Water in our ship would have the same. Water tank in the sunward wall would not be pressurized, but plumbing would. The water wall would have air above the water, so water in a particular section could increase or decrease a little. Again, if someone used the toilet in another pressure section, that will deposit moisture there. Each cabin will have a dehumidifier; simply spending time in another section and breathing will result in sweating and exhaling moisture there. Water in the water wall tanks would be separated from air by a plastic membrane, so the tanks could continue to operate in zero-G.

Windows would be made of aluminum oxynitride for micrometeoroid protection. Two panes, with mineral oil filling the gap between panes. Radiation "hot cells" in the 1950s used this system to contain radiation. So water provides radiation shielding for the wall, mineral oil for windows.

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#244 2020-09-04 04:11:54

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re additions to topic ...

SearchTerm:PressureWalls http://newmars.com/forums/viewtopic.php … 03#p171803
SearchTerm:AirConditioning http://newmars.com/forums/viewtopic.php … 04#p171804
SearchTerm:RadiationProtection Water in walls, mineral oil in windows

The space program in several countries to date has done as much assembly on Earth as possible.  Space walks take hours of preparation and meticulous planning, supervision and execution by numerous persons. 

A large ship to be assembled in orbit should NOT require on site activities by human workers at all.  There is no need for such antiquated construction techniques. 

All modules can and should be capable of guiding themselves to their assigned locations in the larger structure, and making the necessary mechanical locks.

(th)

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#245 2020-09-04 09:42:41

RobertDyck
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Re: Large scale colonization ship

tahanson43206 wrote:

The space program in several countries to date has done as much assembly on Earth as possible.  Space walks take hours of preparation and meticulous planning, supervision and execution by numerous persons. 

A large ship to be assembled in orbit should NOT require on site activities by human workers at all.  There is no need for such antiquated construction techniques. 

All modules can and should be capable of guiding themselves to their assigned locations in the larger structure, and making the necessary mechanical locks.

Hard disagree. NASA was working on a device to fabricate truss structures in space. The Shuttle would carry a roll of aluminum, the device would unroll and flatten the aluminum strip in space, and bend into a angle in one rolling operation. This would be done with 3 rolls simultaneously. A cartridge of cut sections would deliver pieces to the mechanism as the rolls were deployed, and weld cross sections at angles. Result is a truss would extrude from the Shuttle cargo bay, fabricated from pieces on site in space. This was intended for US space station Freedom; NASA worked on it under President Regan. However, the Soviet Union collapsed under the watch of President Bill Clinton. At first Clinton wanted to drastically reduce the station to such a small size that NASA felt no useful work could be done. After collapse of the Soviet Union, their station Mir 2 was cancelled. NASA administration approached the Russian space agency and suggested combining their two stations to create an international space station that would be large enough to do useful work. When they approached President Clinton with this idea, he was worried Russian aerospace engineers would be unemployed and seek work developing ICBMs for Iran, Iraq, or some other third world power. So to keep Russian engineers busy, he approved ISS. Construction techniques for ISS were Russian, specifically to keep Russian engineers busy. Russia had developed stations Salyut 1 through Salyut 7, launched by a single Proton rocket. Mir was based on a core module that was an incremental upgrade from Salyut 7. Additional modules were docked automatically to the end of the Mir core module. They were moved to a side port after docking with a robot arm they called a "paw". This was done because Russia didn't have a Shuttle, or any other base for construction workers to work from. Mir 2 was going to be an incremental upgrade from Mir, so same design. ISS module Zvezda is the module constructed to be the core module for Mir 2. NASA calls it the Russian Service Module, but it's a lot more than "service".

NASA didn't have any way to automatically dock station modules when ISS was built. Only Russia could do that. American modules are assembled by Shuttle. The Shuttle docks to the APAS docking port, then uses Shuttle's arm to move a module from its cargo bay to attachment location where it is "berthed". "Common Berthing Mechanism" (CBM) does not have shock absorbers, so the module must be mated very gently. This cannot be done autonomously. Canada provided the arm for Shuttle, and later provided an arm for station. Japan developed a technique where a small unmanned cargo spacecraft can rendezvous with ISS and hover close to the station, close enough that station's arm can grab it. Once grappled it can be slowly and gently brought in to a CBM berthing port. In the last few years, SpaceX developed Dragon to do the same. Another American company developed Cygnus to do the same as well. Bt when station was constructed, that was not an option. Only Russia could autonomously connect modules.

And realize the Russian docking ports are small and not that firm. Russia developed their "paw" because several modules connected end-to-end would be so wobbly that they would likely fall apart. So the Mir core module (and later Zvezda) had a node with multiple docking ports. All modules would dock axially, but once docked could be moved to a side port by their "paw". Soyuz spacecraft would dock to the aft axial docking port. This worked, but number of modules is limited, and certainly doesn't work with artificial gravity. Any sort of acceleration force due to rotation would cause modules to break apart.

CBM has a more firm attachment than either APAS or the Russian docking port. When ISS was built, NASA was interested because they didn't have any sort of docking mechanism that could work with anything as large as a station module. They have developed CBM, but it doesn't have any shock absorber so has the limitation I mentioned. APAS is an incremental upgrade from the docking port developed under the Apollo-Soyuz program to dock an Apollo spacecraft to Soyuz. APAS used the shock absorber and latching mechanism developed by Russia for their modules, but applied to an androgynous docking mechanism based on Apollo-Soyuz. APAS was first used to dock Shuttle to Mir. Later used to dock Shuttle to ISS. CBM has multiple screws that very firmly hold the two sides in place. But still don't expect that to work for something as large as this large Mars ship. Especially not with acceleration due to rotation.

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#246 2020-09-04 13:18:13

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #245

First, thanks for a review of the history of assembly on orbit.  I am familiar with some of the procedures and organizations you cited, but don't recall seeing a concise summary such as you have provided.  I'll give myself time to try to absorb the details, and the implications.

Meanwhile, should you decide to have humans assemble hundreds of thousands of small components of a very large structure, you will single handedly help SpaceNut with his ever renewing plea for ways to address poverty in America!

(That is, come to think of it, if you decide to employ Americans).  There is no reason I can think of why you should, unless one or more of Quark's friends decide to insist upon it, which seems counter intuitive, since Americans are not currently thought of as the low cost provider.

However, whichever way you decide to go, you'll need to decide early, because the flow of design (all aspects of the system) are determined by critical decisions made early in the process.

Your decision (for example) to place the lives of 1000 passengers and crew at enormous risk by trying to fly through the thin atmosphere of Mars will flow through to the selection of Captain and Navigator who are willing to take that risk, and to the insurance companies who will be covering those passengers, as well as the (probably different) insurers who will be covering the assets owned by Quark and his friends.

I'd like to see you succeed with this initiative.  You're definitely young enough to be able to pull it off, and you keep showing signs of having the heft needed for the role of Chief Architect, but no one has attempted what you are attempting, so my feeling is that anyone who becomes aware of your efforts should feel free to assist in whatever way is available to them.

There is an excellent chance that at least one of Quark's friends is keeping an occasional (and ** very ** skeptical) eye on your progress.

(th)

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#247 2020-09-04 14:23:13

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

I've gotten several hints that someone at SpaceX reads this forum. And at least one occasion when a contractor for NASA told me the NASA administrator himself objected to something I posted here. I deleted it. So that confirms we do get attention.

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#248 2020-09-04 14:35:11

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

Latest mining technology is remote mining. That means vehicles operated below ground, with operator on the surface in a shack. They even connected control systems over the internet so workers in an office building in downtown Toronto could operate mining equipment down the mine in Sudbury Ontario. The nickel mining company Inco was developing a fully autonomous loader that didn't even need a driver; a computer would operate it. It's safe because other mining vehicles are operated from the surface, or over the internet, so no humans present. Then a Brazil mining company bought them out. 1f622.png Too many Canadian companies bought out by foreign owners. The American aluminum company Alcoa tried a hostile take-over of the Canadian aluminum company Alcan. To prevent that, management sold to the Australian company Rio Tinto. I know, that's the name of a river in Spain, so how can it be the name of an Australian company? I'm sure there's a story there, but doesn't matter; Alcan is no longer Canadian owned.

The point is remote technology. If we can do all that in 2005, we should be able to build a construction robot for space. Operate remotely, where the operator is safe. Fully automate as much as possible.

Once the pressure hull is finished, the ship can be spun for gravity. Then cabin interiors can be assembled by human workers. Inside, with gravity and air, in shirtsleeve conditions. If construction work requires a flexible hose to bring in air for workers, then do it. I've seen construction sites in this city that have a duct that looks like a dryer duct to bring in fresh air for workers. They have to breathe when the building air system isn't completed yet. In space, they have to breathe when life support hasn't been installed yet.

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#249 2020-09-04 17:35:25

tahanson43206
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Registered: 2018-04-27
Posts: 10,327

Re: Large scale colonization ship

For RobertDyck re #248

Nice follow up!  I'm happy with the teleoperation option.

***
The only reason I can think of that you are holding to a risky procedure to slow down at Mars is to save money.

There can't be any other reason to put 1000 lives at such risk.

The cost of using fuel to slow down at Mars must seem overwhelming.

No doubt you can find customers willing to save a few monetary units in return for putting their lives in the hands of the Navigator you hire.

(th)

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#250 2020-09-05 12:26:37

RobertDyck
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From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,250
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Re: Large scale colonization ship

I find your fear of aerocapture to be unreasonable. Never forget, NASA only tried it once: Mars Climate Orbiter. They made a US measure to metric conversion error. The problem isn't the technology, it's using inconsistent units. At the time a NASA website listed ISS altitude in miles. But the number was too low, as if the station was about to deorbit. When I checked the Canadian Space Agency website, it listed ISS altitude in kilometres, at the correct altitude. These did not agree. Why? Took me a while to realize the number on NASA's website was not the n miles, even though that's what it said. The number was nautical miles. So this is what they probably did with Mars Climate Orbiter. Since then NASA has ordered everything in metric. The problem is solved, but coward bureaucrats in NASA don't want to try again.

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