Generation vs Colony vs Cryo

Thinksmarkedly wrote:

penny wrote:There is no grass aboard ship.

Of course there is. There should be large parks and green areas too. And I'm talking even the real kind, not astroturf that probably does exist in even greater quantities and may be enough for people.

I certainly agree that there could be grass and parks aboard ship. I considered the possibility then vetoed it. Grass needs watering. We must not take for granted everything that needs or requires water. Off the top of my head...

1. Drinking.
2. Bathing. (Recyclable)
3. Cooking.
4. Swimming. (Recyclable)
5. Tools need water. Drills, etc. (Some not readily recyclable as it is now tainted with hydrocarbons which require an advanced filtration system.
6. The various labs need water. (Non recyclable)
7. Grass.
8. Trees. Although I doubt there would be trees though. Root systems are a bitch to deal with. Dwarf trees like bonsais are possible but require water. An argument can be made that they give oxygen back and remove carbon dioxide. But, other systems take care of that, and water is as precious as gold aboard ship.

9. Radiation shielding. (Non recyclable)

10. Instruments and engines.
11. Livestock.
12. Recreation.

Beware double post

ThinksMarkedly wrote:

Brigade XO wrote:Calvin's Hope was found but it was parked at the planet's L5 point after being stripped. I suspect that there were components that were large (or too radioactively hot like the fusion reactor) to be taken planetside and rather than leave the ship in what ultimately be a degrading orbit, they "stored" it at the L5.

We have no idea how long it took to -in an organized way- land everybody and strip the ship then park it. .

In the Refuge System, Calvin's Hope was already running on fumes of whatever was limiting its ability to keep its population alive. This was a compounded problem from the initial problem in the Calvin System, so I am not factoring in the discussion of what a good colony ship and good colonisation effort should be. We must accept that there was a limiting factor that couldn't or wasn't be mitigated in the Calvin System in the first place, leading to the second trip that was "all or nothing" with no reserves.

Colony ships are going to be designed to be stripped. You will have things like prefabricated smelters, sawmills, printing press, etc, etc.

saber964 wrote:Colony ships are going to be designed to be stripped. You will have things like prefabricated smelters, sawmills, printing press, etc, etc.

Sure, but you can use them to make more of themselves too.

penny wrote:I certainly agree that there could be grass and parks aboard ship. I considered the possibility then vetoed it. Grass needs watering. We must not take for granted everything that needs or requires water. Off the top of my head...

1. Drinking.
2. Bathing. (Recyclable)
3. Cooking.
4. Swimming. (Recyclable)
5. Tools need water. Drills, etc. (Some not readily recyclable as it is now tainted with hydrocarbons which require an advanced filtration system.
6. The various labs need water. (Non recyclable)
7. Grass.
8. Trees. Although I doubt there would be trees though. Root systems are a bitch to deal with. Dwarf trees like bonsais are possible but require water. An argument can be made that they give oxygen back and remove carbon dioxide. But, other systems take care of that, and water is as precious as gold aboard ship.

9. Radiation shielding. (Non recyclable)

10. Instruments and engines.
11. Livestock.
12. Recreation.

Beware double post

Everything in that list should be recyclable. It's just a matter of effort and energy expenditure.

Aboard a ship, you only really lose it when it gets outgassed into space. That's one reason why you have your radiation shield in the form of water, not hydrogen. And because you have water as radiation shield, you have so much of it that water isn't actually very limited at all. The subsoil of your cylinder world is a massive water tank, underneath which the external armour.

We've also been told those ships have Bussard scoops that can collect interstellar hydrogen, so you will have a surplus of hydrogen too. Therefore, if anything were to be limited, it would need to be oxygen, because you can just use some of that hydrogen you collect in a fuel cell, which produces electricity and water.

Let's make some calculations: starting with spin gravity. We want 1 Earth gravity and we want a slow spin so no one gets nauseous with the Coriolis, so 1 rpm. That puts your cylinder's inner radius at ~894 meters. Let's say the ship is 2.5 km long (so it's about 1.25x longer than wider). I don't know how thick the radiation shield must be, but let's say it's 10 m, extending from 900 to 910 m. That's 142 trillion litres of water (37.5 trillion US gallons), massing 142 thousand tonnes.

Likewise, the inner surface at the 894 m radius is 14 million square meters (14 km²). If you give each person (man, woman, child, baby, elderly, etc.) a whopping 300 square meters of living space, that's enough for 46823 people. Or, inverse, a population density of 3333 per square km or 8633 per sq. mile. That's much less than any city on Earth (excepting small, rural towns). Of course, no city on Earth is self-sufficient and must be responsible for its own agriculture. We could compare that density to some small countries. Malta has a density of 1649 per sq. km, the Maldives 1728.

Those 142 million litres of water would give an average of 3321 L / person / day of water over a 400 year journey (or 877 US gallons). This must include all activities, including food production, life support, industry, and maintenance. That number is roughly equivalent to what the US consumes today (usgs.gov says "322 Bgal/day" in 2015 which is 1000 US gallons per person per day), and would require no recycling.

saber964 wrote:Colony ships are going to be designed to be stripped. You will have things like prefabricated smelters, sawmills, printing press, etc, etc.

ThinksMarkedly wrote:Sure, but you can use them to make more of themselves too.

RFC has said current manufacturing is similar to a high definition 3D printer that can use many different materials to make things as various as a fusion reactor or a high density molecular circuit block. So assuming that the colony ships had something similar; then yes, they could build event bigger 3D printers to turn out the pieces for a duplicate colony ship.

So either they had the technology to do what you want, but did not use it; or they did not have that technology.

saber964 wrote:Colony ships are going to be designed to be stripped. You will have things like prefabricated smelters, sawmills, printing press, etc, etc.

Absolutely! You are hitting the nail on the proverbial head! Recycling is the overarching mentality of generation ships. It has to be to survive.

'Waste not. Want not.'

That is why I said that any settlers who want to leave and not adhere to the plan are selfish. That would be like a construction crew boarding a huge rig and deciding to drive across country to build a city. Then the driver of the rig deciding to take off with the tools!

"Oh, but he left us with some tools." Yeah? But you know what he didn't leave us with? A fucking Phillips head screw driver and some duct tape! Nobody ever has a Phillips head when they need one. Your personal Philips head may vary.

tlb wrote:

ThinksMarkedly wrote:Sure, but you can use them to make more of themselves too.

RFC has said current manufacturing is similar to a high definition 3D printer that can use many different materials to make things as various as a fusion reactor or a high density molecular circuit block. So assuming that the colony ships had something similar; then yes, they could build event bigger 3D printers to turn out the pieces for a duplicate colony ship.

So either they had the technology to do what you want, but did not use it; or they did not have that technology.

The same mistake is being made. The average person simply does not stop to think about how things work in the real world. They cannot see beyond what is written on paper.

3D printers are not magic bullets. A 3D printer needs building blocks. The building blocks of a 3D printer are the materials. The materials have to be mined for. Either on planet or in space. For sake of simplicity, let's say that the materials of an HV 3D printer are akin to the ink of present day inkjet printers. Have you ever known an inkjet printer to be worth a damn without any ink? And the ink is specialized for high tech models. They use ink from a "cartridge." This cartridge has to be ordered from a specialty store. Or in our case, made from specific materials that have to be mined. Either in space or on the planet. A generation ship is ever moving. It is impossible to mine for everything while literally on the fly. The ship has to come to a full stop to mine for some materials. And if you fail to pack enough of that material initially, then the overall plan begins to go off the rails. It is impossible to plan for the unseen, the [un]experienced, the unexpected, the unanticipated and the unleashed. And when we run out of ink, we can't make any more Philip heads. And the damn ship didn't leave us one. We could jury rig a solution in a pinch. But we don't have any duct tape. The duct tape is in the tool box too. Right beside the Philips head.

Generation ships are well thought out and designed ships. Everything is recycled if can be. Think of a generation ship as essentially being built from many "Transformers/Autobots" that are designed to fit together to become a part of the whole. And to disassemble to become many different bots. Each bot is a cog in the wheel and it has a specific function. A machine with a missing or broken cog is useless. You might not be able to make a new cog because a critical component is missing.

A generation ship is not only a well thought out ship. But its mission parameters are also well thought out. If either letter of the law is broken when A>B>C>D then the whole thing falls apart.*

Also consider that practice makes perfect. It is difficult to pack for a trip when you do not know what the weather is like where you are going. Or how many pairs of gloves and jackets, etc., might be needed. Pioneers always bear the brunt of the risks for the sake of mankind.

"Uh oh!"

"What now?"

"The idiots left us with all metric tools."

"And?"

"The printers are assembled and put together with SI nuts and bolts, and and... oh my."



* > is to be read as depends on.

tlb wrote:RFC has said current manufacturing is similar to a high definition 3D printer that can use many different materials to make things as various as a fusion reactor or a high density molecular circuit block. So assuming that the colony ships had something similar; then yes, they could build event bigger 3D printers to turn out the pieces for a duplicate colony ship.

So either they had the technology to do what you want, but did not use it; or they did not have that technology.

That is the current "now" in the story line, that was not what would have been available when Calvin's Hope set out more than a thousand years earlier. Yes, they did have at least one shuttle mentioned that was able to go down to the original target planet and come back so we would guess that they probably had several and the stock of stairs etc to keep them running. But....the they were also able to park the remains of the stripped ship out at the L5 point so they probably did the stripping in planetary orbit and towed it out for storage. The real problem was the volcano wiping out not only a lot of the people and imported agriculture, but much of the technology base they landed with including (it would seem) anything that could be used for high end manufacturing to repair what survived. That would also seem it include any written or recorded tech information etc that would have been lost while they struggled to just survive.

tlb wrote:RFC has said current manufacturing is similar to a high definition 3D printer that can use many different materials to make things as various as a fusion reactor or a high density molecular circuit block. So assuming that the colony ships had something similar; then yes, they could build event bigger 3D printers to turn out the pieces for a duplicate colony ship.

So either they had the technology to do what you want, but did not use it; or they did not have that technology.

Brigade XO wrote:That is the current "now" in the story line, that was not what would have been available when Calvin's Hope set out more than a thousand years earlier. Yes, they did have at least one shuttle mentioned that was able to go down to the original target planet and come back so we would guess that they probably had several and the stock of stairs etc to keep them running. But....the they were also able to park the remains of the stripped ship out at the L5 point so they probably did the stripping in planetary orbit and towed it out for storage. The real problem was the volcano wiping out not only a lot of the people and imported agriculture, but much of the technology base they landed with including (it would seem) anything that could be used for high end manufacturing to repair what survived. That would also seem it include any written or recorded tech information etc that would have been lost while they struggled to just survive.

As we both said, that is "current" manufacturing and we are not sure what was available at the time of the launch of the colony ship.

However there is one part of what ThinksMarkedly is saying with which I am in agreement: at the time of launch we know that asteroid mining was viable in the Solar System and so there is every reason why it should be be implemented at every new colony with an asteroid belt. It is cleaner and in some sense easier than tearing up the new planet. It enables and requires that a space presence be maintained. An orbital facility can serve as an emergency backup of knowledge and technology, and even people to some extent, in case of a natural disaster.

tlb wrote:

tlb wrote:RFC has said current manufacturing is similar to a high definition 3D printer that can use many different materials to make things as various as a fusion reactor or a high density molecular circuit block. So assuming that the colony ships had something similar; then yes, they could build event bigger 3D printers to turn out the pieces for a duplicate colony ship.

So either they had the technology to do what you want, but did not use it; or they did not have that technology.

Brigade XO wrote:That is the current "now" in the story line, that was not what would have been available when Calvin's Hope set out more than a thousand years earlier. Yes, they did have at least one shuttle mentioned that was able to go down to the original target planet and come back so we would guess that they probably had several and the stock of stairs etc to keep them running. But....the they were also able to park the remains of the stripped ship out at the L5 point so they probably did the stripping in planetary orbit and towed it out for storage. The real problem was the volcano wiping out not only a lot of the people and imported agriculture, but much of the technology base they landed with including (it would seem) anything that could be used for high end manufacturing to repair what survived. That would also seem it include any written or recorded tech information etc that would have been lost while they struggled to just survive.

As we both said, that is "current" manufacturing and we are not sure what was available at the time of the launch of the colony ship.

However there is one part of what ThinksMarkedly is saying with which I am in agreement: at the time of launch we know that asteroid mining was viable in the Solar System and so there is every reason why it should be be implemented at every new colony with an asteroid belt. It is cleaner and in some sense easier than tearing up the new planet. It enables and requires that a space presence be maintained. An orbital facility can serve as an emergency backup of knowledge and technology, and even people to some extent, in case of a natural disaster.

I am pleased that Brigade_XO suggested that 3D printing is the current technology. I forgot to. But even if 3D printing was available to generation ships, the technology does not operate on pixie dust. So yes, I agree that asteroid mining is critical for a colony and I agree that it is much better than tearing up a planet.

But I do not agree that colonizing the planet should be put on hold after arriving. And if the planet is being settled, I do not agree with mining for water in space for the colonists when a ready source of clean, naturally filtered fresh water is available on the planet. Mining for water in space for the space population, yes, but not for the population groundside.

A space base or space station makes sense to have and maintain as well. Some advanced medicines or materials might need to be manufactured in space. Or might can only be manufactured in space, and or done so efficiently. And building space faring ships would certainly be necessary. No ships. No mining. So a space station should definitely be necessary.

ThinksMarkedly wrote:

penny wrote:I certainly agree that there could be grass and parks aboard ship. I considered the possibility then vetoed it. Grass needs watering. We must not take for granted everything that needs or requires water. Off the top of my head...

1. Drinking.
2. Bathing. (Recyclable)
3. Cooking.
4. Swimming. (Recyclable)
5. Tools need water. Drills, etc. (Some not readily recyclable as it is now tainted with hydrocarbons which require an advanced filtration system.
6. The various labs need water. (Non recyclable)
7. Grass.
8. Trees. Although I doubt there would be trees though. Root systems are a bitch to deal with. Dwarf trees like bonsais are possible but require water. An argument can be made that they give oxygen back and remove carbon dioxide. But, other systems take care of that, and water is as precious as gold aboard ship.

9. Radiation shielding. (Non recyclable)

10. Instruments and engines.
11. Livestock.
12. Recreation.

Beware double post

Everything in that list should be recyclable. It's just a matter of effort and energy expenditure.

For the most part, I agree. However, recycling water is never going to be a 100 % efficient process. If a gallon of water is consumed, we will not get a gallon of water back in urine. The body needs some of the water for itself. The body will lose some in cooling itself off, sweat. We shed tears, etc.

The same with cooking. Foods absorb water while cooking. Plants need water for photosynthesis. 100 % will not be reclaimed.

I don't think it makes sense to recycle water that is utilized for tools and manufacturing because that water becomes contaminated with hydrocarbons and a host of other pollutants which require advanced filtration systems. But let me clarify that statement. I agree that even that water can be recycled. But not for consumption. It should be recycled for further use in manufacturing.

The water for radiation shielding cannot be recycled for drinking as it already has a critical use.

Thinksmarkedly wrote:Aboard a ship, you only really lose it when it gets outgassed into space. That's one reason why you have your radiation shield in the form of water, not hydrogen. And because you have water as radiation shield, you have so much of it that water isn't actually very limited at all. The subsoil of your cylinder world is a massive water tank, underneath which the external armour.

We've also been told those ships have Bussard scoops that can collect interstellar hydrogen, so you will have a surplus of hydrogen too. Therefore, if anything were to be limited, it would need to be oxygen, because you can just use some of that hydrogen you collect in a fuel cell, which produces electricity and water.

I certainly agree. Generation ships should be able to produce water, I am just not sure at what rate of production. There are science fiction stories that deal with this utilizing current technology. The Mars Trilogy comes to mind.

Thinksmarkedly wrote:Let's make some calculations: starting with spin gravity. We want 1 Earth gravity and we want a slow spin so no one gets nauseous with the Coriolis, so 1 rpm. That puts your cylinder's inner radius at ~894 meters. Let's say the ship is 2.5 km long (so it's about 1.25x longer than wider). I don't know how thick the radiation shield must be, but let's say it's 10 m, extending from 900 to 910 m. That's 142 trillion litres of water (37.5 trillion US gallons), massing 142 thousand tonnes.

Likewise, the inner surface at the 894 m radius is 14 million square meters (14 km²). If you give each person (man, woman, child, baby, elderly, etc.) a whopping 300 square meters of living space, that's enough for 46823 people. Or, inverse, a population density of 3333 per square km or 8633 per sq. mile. That's much less than any city on Earth (excepting small, rural towns). Of course, no city on Earth is self-sufficient and must be responsible for its own agriculture. We could compare that density to some small countries. Malta has a density of 1649 per sq. km, the Maldives 1728.

Those 142 million litres of water would give an average of 3321 L / person / day of water over a 400 year journey (or 877 US gallons). This must include all activities, including food production, life support, industry, and maintenance. That number is roughly equivalent to what the US consumes today (usgs.gov says "322 Bgal/day" in 2015 which is 1000 US gallons per person per day), and would require no recycling.

Thinksmarkedly, this is an incredible analysis. I am in awe. And I appreciate the effort. Your effort is so appreciated that I hesitate to say... but. So I won't. "However," instead?

However, employing the analogy of a computer, the available user storage space is missing the amount of "storage space" that is always used "by the operating system."

I am a civil engineer and there are all kinds of studies which analyze the available land mass of a city that is or must be allocated for use by the city. For example ...

Parking Lots are Opportunities for Growth: In the core city centers of urbanized areas with over 500 thousand people, the median percentage of land dedicated solely to parking was 26%.

Then there are government buildings. Transportation. Parks. Police. Recreation. Schools. Etc.

The design of a city is also important. There are several different designs and variations of those designs that are as important to the quality of life as an open or closed floor plan is to a home. The point being that a huge percentage of a city's available land mass is consumed by the city and not available for living. Essentially, we call it zoning. Zoning is very important for safety and for growth.

Transportation is definitely going to be important aboard ship. Is there any public mode of transportation? If not, then technically there are going to be small cities by population if you are limited to meeting new people by walking. Bus system? Trolley system? Tubes? Chutes?