The prospects of colonizing Mars

Quote from JedRothwell

11,000 of these rockets would reach Mars every minute, but they would change course the last day to avoid crashing into it

It sounds like there are some tight tolerances for a rain of rockets continually bombarding Mars. I don't think you could have more than a minute fraction do the wrong thing.

Quote from JedRothwell

Once the ice is launched it make take months or years to reach Mars,

Related to this and preceding points — it seems like this plan commits not only the generation making the plans, but their children and grandchildren as well, to large capital costs and important coordinating actions, to prevent a fraction of the rockets from hitting the planet, and to make sure the ice cubes do the right thing. Is it ethical to commit one's grandchildren to a plan they weren't consulted on? There are a few circumstances in which it could be argued that such a forced commitment is reasonable; what is the circumstance underwriting the starting generation's committing its grandchildren to the continued terraforming of Mars?

Quote from Eric Walker

It sounds like there are some tight tolerances for a rain of rockets continually bombarding Mars. I don't think you could have more than a minute fraction do the wrong thing.

Itty-bitty rockets, a couple of liters each. Mostly water propellant. All they have to do is nudge the ice cubes occasionally, and report back to Mars where they are and how things are going. It takes little energy to put a 1 ton space vehicle back on track. The on-board course correction rockets used in today's planetary explorers are very small.

If one of these rockets failed, and crashed into Mars, it would burn up long before it reached the ground, and cause no harm.

I do not know if these rockets would even be necessary. I do not know how accurately the chunks of ice can be launched or whether they would need course corrections.

The worst that can happen to the ice is that several chunks of ice get tangled together. I expect they would go off course from the collision, and miss Mars. They would almost certainly fall into the sun, which is where nearly all falling objects in the solar system go. If they whacked into the earth no one would notice. I assume the engineers would be conservative and pick a size at least 3 times smaller than you can safely whack into Mars or the Earth. (In other words, if they made it 1 ton, 3 tons would be safe.)

If the chunks from different comets whacked together shortly before impacting, I am sure they would shatter. They would be coming in at different angles.

Quote from Eric Walker

Related to this and preceding points — it seems like this plan commits not only the present generation, but their children and grandchildren as well, to large capital costs and important coordinating actions, to prevent a fraction of the rockets from hitting the planet, and to make sure the ice cubes do the right thing.

It would make no difference if a fraction of the rockets hit the planet. Lots of things hit Mars, the Moon, Earth and other planets every day. About 100 tons per day of meteorites hit the earth. Most are small, but an "automobile sized" one hits about once a year. See:

https://www.nasa.gov/mission_p…s/overview/fastfacts.html

If a million ice cubes per year went off course and hit the sun instead, it would have a negligible effect on the cost.

The project would commit the children and grandchildren (the taxpayers!) on Mars, but it would be a far smaller, cheaper and shorter commitment than, say, the U.S. Interstate Highway system, which began in 1956 and has no end in sight. That's 62 years, and although most of the planned construction is finished the maintenance such as replacing bridges and resurfacing roads will last for as long as we use the highways. The cost is far, far greater than the Mars project would be, and the number people killed on the highways exceeds U.S. casualties in all wars combined, whereas I doubt anyone will be killed or even inconvenience by ice falling on Mars. Yet no one complains about the cost of the highway system. (Okay, I complain, but I think we should ramp it up and put all the roads underground.)

Which is why I suggest sending big ones crashing to the surface (or maybe exploding themselves on the way in). 3 tonnes of water is tiny. Why not send 30000 tonnes or more at a time instead?

Quote from Eric Walker

Incidentally, the plot of Horizon Zero Dawn, a PS4 video game, was that self-replicating military robots started to multiply without end as a result of a system failure.

Don't forget the replicators from the Star Gate (Atlantis) series...

Quote from Paradigmnoia

Which is why I suggest sending big ones crashing to the surface (or maybe exploding themselves on the way in). 3 tonnes of water is tiny. Why not send 30000 tonnes or more at a time instead?

If that fails to work, it would be catastrophic. Whereas if a 1-ton chunk fails, it would make no difference and cause no harm. I prefer a system that cannot cause any harm no matter what happens.

Since robots will be doing all the work, the cost would be the same. I prefer thousands of small robots rather than one large one. Imagine the equipment needed on the Oort cloud comet to launch 1 ton of ice per minute (260 gallons) for 10 years. That would be something like a kit containing:

1. A small, general purpose robot to assemble and maintain equipment.
2. A 3 HP pump weighing about 70 kg, 250 gallons/minute.
3. A set of 120 filters to be changed once a month.
4. Something like a gigantic ice tray to hold the water as it freezes.
5. A set of 10 small rockets propelled by water to launch the ice, maybe 100 kg each. I assume it would take 10 minutes to launch and recover the vehicle. Maybe you need 20 including spares?
6. Maybe you need 548 little rockets to follow the ice chunks and make course corrections. I suppose these would be a liter or two of equipment each, plus a lot of water for propellant.
7. A gigantic Mylar balloon inflated with hydrogen that forms a concave lens the size of Washington, DC. Used to melt the ice and power PV electricity (which might be cheaper than cold fusion). It would have to be re-inflated from time to time. It would be very low pressure.
8. Various things such as radar and communications equipment.
9. You could fit all of that into a container, as a kit. A rocket could deliver it a comet and have the robot deploy the equipment, inflate the lens, change the filters, unclog the pipes, do routine maintenance as needed.

I think much of the equipment would last longer than 10 years, so in some cases the rockets might deliver a smaller kit of with something like replacement filters, new launch rockets, a new Mylar lens, etc.

You need a fleet of automated rockets to deliver 1.4 million of these kits per year (kits and replacement part kits). I suppose one rocket could carry and deliver 10 per year, so that's 140,000 rockets. Compare that to the 3.5 million long-haul trucks in use in the U.S. today.

I do not think people would actually want to cover one-third of Mars in water. It would probably be more like 3%. So at the peak of the project you need 14 million of these kits in operation. They last 10 years, which is what an ordinary small-town waterworks pump and filter system lasts, with maintenance. So, you need to manufacture and dispatch 1.4 million kits per year. Compare that to the 2.6 million large, long-haul trucks manufactured per year worldwide. It would be a lot of equipment, but not an unthinkable amount. As I said, it would be manufactured in the solar system where the construction materials and solar energy can be found in abundance, I assume in the asteroid belt, not the Oort cloud. A large automobile plant today produces about 500,000 vehicles, so you need maybe ~5 space-based plants the size of a large automobile assembly plant. They would make the pumps, small launch vehicles, large delivery vehicles, Mylar lens balloons, and so on, using local sources of steel, aluminum, carbon, hydrocarbon, silicon and so on. The factories would be mostly made by self-replicating robots and 3D printers. It would cost millions of dollars to get the ball rolling with several hundred robots and some specialized equipment, but once they reproduced themselves and reproduced a few thousand 3D printers (using other printers), they could build factories and they could replace worn-out fabrication equipment at no cost.

That is not a gigantic undertaking. If Mars had a population of several million people, they could easily afford the taxes to pay for that. As I said, compared to our Interstate Highway System, which is built and maintained by people with fossil fuel energy, it would be a small expense.

Quote from H-G Branzell

This is cherry picking if anything is. What kept Moore's law going for so many years is the invention of the transistor and the ever shrinking size of transistors that can be crammed onto a silicon chip. Today there can be billions of them on a single chip.

First, Moore's law is not the only thing that lowered the cost of computers. I personally helped lower the cost in various ways, and I am not Moore.

Second the rise of robotics and AI and the development of self-driving cars was made possible by Moore's law, but rapid progress in robotics and AI will continue even if Moore's law stalls. AI can be vastly improved with the hardware we now have. The same is true of 3D printers, which will evolve into general purpose machine tools even if computers do not get cheaper. Most of this project will depend on robotics, AI and self-reproducing 3D fabrication machines.

AI hardware is being improved now with TPU chips (neural processors). These have the same component size and speed of conventional CPU chips, but a different design. So they do not require any improvement in Moore's law capacity. The first ones were ~30 times faster for AI applications, I think. Later designs are expected to be millions of times faster, with much lower energy demand, even with no improvement in transistor size or speed. Google, NVIDIA and others are developing these.

A space elevator can be built even if Moore's law stalls. The cost has nothing to do with computing power.

There is every reason to think that Moore's law will continue to operate for the next several hundred years. The data storage density of both RAM and offline storage can be greatly increased with 3-dimensional storage techniques. The ultimate limits of data storage can be seen in DNA storage. Using DNA, we could fit all of the data now stored in all the computers, hard disks and Google data centers in the world in a 70-ml vial. Less than a glass of water. About as much DNA as you have inside of you (estimated at 60 g). That would be many orders of magnitude smaller and less energy intensive that today's data storage. The entire data set could be copied in 10 minutes. * The data reliability, speed of replication of DNA, and energy cost for storage and recovery is orders of magnitude better than any human data-storage method. It has worked well for 4.5 billion years.

(DNA data storage is being developed in various labs worldwide.)

(* Based on D. melanogaster genome replication time, which is about 8 minutes, and assuming that the devices used to copy the data are about the size of the cells in your body. The entire machine would be the size of you.)

Quote from JedRothwell

[Why not send 30000 tonnes or more at a time instead?]

If that fails to work, it would be catastrophic. Whereas if a 1-ton chunk fails, it would make no difference and cause no harm. I prefer a system that cannot cause any harm no matter what happens.

Here is an example from the present day. One average nuclear reactor produces about as much power as 300 10-MW wind turbines, taking into account the average output of a land-based turbine (about 30% of nameplate). I prefer the array of wind turbines because the worst accident that can happen with them causes little harm, whereas the worst nuclear plant accidents such as Three Mile Island and Fukushima were catastrophic. They bankrupted the electric companies and forced 90,000 to abandon their homes, farms and towns.

Wind turbines do have accidents. They catch on fire and sometimes collapse. Like this:

Here's the thing:

That is only one turbine in the array. The others are okay. Damage is limited. The total cost is small compared to a typical nuclear plant problem. The others remain on line. Whereas when anything goes wrong with a nuke, the whole thing is SCRAM'ed. The lost revenue from a SCRAM is tremendous, whereas the lost revenue from one turbine burning up is small.

I do not think a turbine collapse has killed a person, although maintenance people have been killed by falling and electrocution.

Terrorists might attack a nuclear plant and cause a disaster. It is unlikely because the plants are well guarded. I guess they are more likely to attack a gas turbine plant, which has a great deal of explosive fuel and expensive equipment. Whereas I cannot imagine terrorists attacking one turbine in an array, and it would take many people a lot of time to attack several turbines.

Imagine a 30,000 ton shipment of ice approaching Mars. Sometime before it arrives, it has to be broken into small pieces, or a rocket has to slow it down and put it into orbit, so that individual chunks can be landed. Something might go wrong, and the entire chunk might whack into the planet at full speed. It could destroy a whole city. It is conceivable that a terrorist might sabotage the programming in the robots that accompany the shipment, preventing them from breaking up the ice.

Which is why we should whack Mars with monster spacebergs (at full speed) before it gets populated. To heck with slowing them down. They could even just get parked in Mars' orbital path, and let the planet crash into them.

Quote from Paradigmnoia

They could even just get parked in Mars' orbital path, and let the planet crash into them.

If they are in the same orbital path, in the same direction, the planet will never catch up. Right? They have to be moving the other way, which is the same as any intercepting orbit. Why bother to change the orbit from the one that drops from the Oort cloud? You would have send along a rocket to change it, which is a lot extra expense and propellant. (A little bitty rocket to nudge them might be needed, as I said. I wouldn't know, but present day planetary explorers make small course adjustments.)

Since they come from the Oort cloud the path to Mars would head toward the sun if they miss. They would evaporate. So, no big deal.

Quote from Paradigmnoia

Which is why we should whack Mars with monster spacebergs (at full speed) before it gets populated. To heck with slowing them down.

I wasn't planning to slow them down. Not sure where that came from. But as I said, I see no economic or technological advantage to one block of ice of 30,000 tons versus 30,000 chunks of 1 ton each. The latter would be inherently safe so I would go with that.

If these things were being produced with human labor or with machines made by people, there would be a big advantage to big chunks. I get that. Fewer launches. 30,000 times less work. Perhaps you are looking at it from the point of view of the 21st century in which people still do manual labor. Think about how it would be when the robots, all of the work, all materials and machine tools are products of self-replicating technology. Why would anyone care if the robots do 30,000 times more steps than they would otherwise?

Suppose you run a program once a day. It is poorly written (as many programs are today), so it takes an extra 10 seconds to run. You are polishing your glasses or stirring your coffee, so you don't even notice. The computer has done 30 billion operations more than it needed to. Well, so what? Do you care? In the 22nd century, if a bunch of robots in the Oort cloud -- robots that no human has ever set eyes on, or ever will see -- do 30,000 times more work than they would have otherwise, why will anyone care? As long as they get it done. They will cost virtually nothing, just as the extra 30 billion operations cost you nothing.

Quote from Paradigmnoia

Which is why we should whack Mars with monster spacebergs (at full speed) before it gets populated.

The big problem with this is: Who's gunna pay for it?! It is like trying to build the Erie canal before anyone settles in upstate New York. You have to have taxpayers on Mars who are willing to foot the bill. People on earth sure won't want to pay for it.

I hope that taxpayers on earth will be willing to pay for the initial stages of the colonization of Mars. I mean sending a few hundred people, and giving them the tools to survive. Heavy equipment, buildings, food factories, hospital equipment, etc. Give them 5 or 10 years of help. After that, I would say they are on their own. They will have to extract resources and build whatever they need themselves. Anyone who wants to join them should pay his or her own way. I sure would not want to pay for a major infrastructure project such as bringing millions of tons of water from the Oort cloud!

Quote from JedRothwell

Suppose you run a program once a day. It is poorly written (as many programs are today), so it takes an extra 10 seconds to run.

That's an actual example. I do that. I know for a fact the program is poorly written because I wrote it myself. Years ago I thought: "I should optimize this. It is wasting a lot of time." Then I thought, "why bother?" That was me thinking of it as 1970s programmer, when computers were slow & expensive and optimization was important. When you think that it might be a good idea to reduce the Mars project workload by a factor of 30,000, you are looking at it from the perspective of the 21st century. Not as things will be with self-replicating robots and fabrication machines.

Quote from H-G Branzell

Our DNA based life is heavily dependent on our biosphere and is not apt for space travel.

As I mentioned, there are biologists at NASA whose job it is to keep our Mars explorers from contaminating Mars with bacteria from Earth. I read an interview with the woman in charge. She says they have gone to great lengths to do that, but she is pessimistic. She thinks many bacteria probably did survive and are now alive on Mars. She subjected bacteria to the conditions of deep space for long periods, and then the Martian atmosphere. It survived.

Quote from Paradigmnoia

Which is why we should whack Mars with monster spacebergs (at full speed) before it gets populated.

If you are talking about dropping a few million tons of ice in places where towns will be built, I agree. Perhaps there are no readily accessible sources of water on Mars, so this would be cheaper than building pipelines from the north pole. They need some water for agriculture, industry, drinking water etc.

I do not know what would happen to the ice on the ground. Perhaps they would need to cover it with a giant tarp?

That would be fine for water for human use. But if you are talking about filling in an ancient ocean with water, and changing the entire biosphere with terraforming, then I think it needs to be done with methods which can cause no harm. I do not know what the maximum weight of an ice chunk would be. I guessed 1 ton but it might be a lot more than that. It might work better if the ice is honeycombed so that it heats up quickly with wind resistance, and melts quickly. Perhaps it could be made as a giant snowball that falls to pieces as soon as it hits the air. Even if many flakes or small ice cubes survived the heat, they would drift out of the sky and cause no harm. It might be possible to drop a 30,000 ton snowball that is sure to disintegrate into flakes even if it does not all melt. I wouldn't know.

If Mars has high altitude aircraft, or satellites, or a space elevator, that might complicate matters.

The main point I am trying to make here is that the project is not impossibly large, or ambitious. Just looking at the mass of equipment needed, we have far more pumps and filters in our drinking water systems, and we carry far more cargo with our trucks. Granted, trucks cannot carry equipment to the Oort cloud. But, dispatching 383 truckloads of equipment per day from something like a complex of 5 large automobile factories is an industrial project on a scale that we could manage. People 100 years from now will be able to manage it far better and more cheaply. Even today, if it were technically possible, it would not take a large fraction of our GDP. WWII weapons production, Liberty ship production, and warship production was far larger than this.

Quote from H-G Branzell

Part of the answer could be that it is not as easy to make mechanical life as you want us to believe.

Robots today are nearly self replicating. Almost all of the work in manufacturing a robot is done by a robot. Chinese factories that make iPhones and the like will soon be populated with robots and few people. The YKK zipper factory in Georgia that makes a large fraction of U.S. zippers has many robots and a handful of people. Robots are better at assembly than fabrication, but 3D fabrication machines will soon mechanize this. Mining and processing raw materials is also mostly done with robots.

I do not mean that one robot is self-replicating from start to finish, like a person having a baby. I mean that the entire process from mine to finished product is mostly automated and done with machines, and those machines (in turn) are mostly made by other machines. Humans play a smaller and smaller role in the industrial production of physical goods. A century or two from now we will play no role. There will be no manual labor, other than hobbies and perhaps surgery.

Even though today's robots are mostly self-replicating, I would not call them "mechanical life." They are many, many orders of magnitude simpler than even simple forms of life such as bees. I do not see why industrial robots 200 years from now will need much AI. Most of their work will be rote. Probably no harder than manufacturing millions of zippers, which are precision objects with demanding specifications. Today's robots can do that. They could probably mine a comet for water. If the future robots are roughly as intelligent as bees, that will surely be enough. Look at a bees nest and I think you will see that the intelligence capable of building that structure could manage to do the work in a project like bombarding Mars with trillions of tons of water. The drone robots that do the work would need guidance from smarter robots and people, but I doubt they they would be any smarter than bees. Why make them smarter than they need to be?

I guess you could call a mechanical bee that is only capable of constructing a nest "mechanical life" but to me, it barely qualifies. Bees can do way more than that! They have hundreds of behaviors, such as flying, or finding pollen and informing the other bees. The comet-mining robots need only do one task, and it is simpler than finding pollen and communicating the location. Robots will have one dimension of intelligence, where any living creature has many dimensions and many capabilities.

Okay, here is my Plan B!

You make a gigantic bag out of thin photodegradable plastic. Fill a bag with 30,000 tons of ski lift snow, loosely packed. Attach a small course correction rocket to the bag and launch it toward Mars. When the bag approaches Mars, the rocket detaches and goes into orbit. The bag whacks into the atmosphere and bursts. A rain of water, snow and plastic shards fall to the ground. I suppose in the worst case this would do no more harm than a hailstorm. After some years the plastic degrades into harmless carbon dust.

I do not know enough about Mars or rockets to judge, but I suppose this could be made fail-safe. That is to say, 100% certain to burst into harmless hail in the worst case.

If the rocket fails to detach, it falls on Mars, but it is not likely to cause harm. As I mentioned, hundreds of tons of material fall on earth every day, including large objects from time to time. I suppose the rocket would be the size of a suitcase, plus a large container of liquid water propellant, that is kept liquid with a cold fusion heater.

The bag can be very thin and weak because it only needs to keep all of the snow in one snowball during course corrections. Perhaps you could just launch a gigantic snowball without a plastic bag, but I do not see how that could be nudged back to the correct trajectory. The course correction rocket has very low thrust, so it would not break the bag. The initial launch would be done with a large rocket with something like a gigantic basket to hold the bag and keep it from bursting.

Perhaps the bag could hold even more than 30,000 tons. I wouldn't know. The bigger the better, as long as it is fail-safe. The advantages of large packages are: They reduce the number of launches. There would be fewer launch sites (comets with equipment on them). Perhaps you could launch one ever 10 minutes, staggering them to keep them from drifting together. The target, Mars, moves enough in 10 minutes that the trajectories would be different and well separated, I think. That would be 3,000 tons per minute per launch site, a much higher rate than with my previous plan. There would be fewer incoming packages and course correction rockets to keep track of. The rockets would be attached to the ice they monitor, so they would not have to move up and down the train. They would use very little propellant, and if they needed more, they could melt some of the snow in the gigantic bag.

The course correction rockets would send regular reports of their position and conditions, maybe once a week, or immediately if a problem crops up. I assume there would be something like a solar-system wide GPS system so these rockets and all others could measure their positions with minimal electronics.