Thursday 20 April 2017

Interstellar Trade is Possible Part III: Threats, Strategy and Evolution

Interstellar trade does not happen in a vacuum.

The colony will be face multiple threats, to be defended against as it evolves into a more and more significant part of human civilization.
Imagine an interstellar seed was built on bio-nanotechnology and propelled by a laser sail, exploiting an existing interplanetary transport network. It brakes at its destination with an onboard dusty plasma fission-fragment rocket and lands on a large comet. 

It takes 10 years to reach Barnard's Star at about 0.55C.

The solar neighbourhood.
Within a year, it builds solar panels, excavates mining sites, embeds thermal ovens and starts running a biological 3D printer. Within two years, it has shot off copies of itself onto the largest asteroids and comets of the system and within three years it is building a large solar-powered laser arrays to propel nuclear pulse units into a propulsion track. Rockets ride the track to deliver payloads of refined precious metals back to our home system.

Is that the end of the story? Will investors get to sit back and just bankroll the operation from the fat profits being made?  


The risks facing an interstellar operation vary from the mundane to the criminal. Some have been covered in Part I: the financial risk of not having enough money to maintain the operation, and the economic risk of not being able to provide products at interesting prices, do have solutions.

Here are some other risks to consider and the consequences they may have:

-Mission failure:
The interstellar operation was never fool-proof. It can fail at any step on the way, from departure (the laser sail burning up) to halfway through the set-up phase (the DNA-encoded information is damaged beyond recovery). 

The obvious solution to increase the robustness and reliability of the seed sent out to the stars. This can be accomplished by installing multiple redundancies, using safer technologies and more robust components. However, there is a limit to how much can be invested in improving the seed before we hit diminishing returns - millions might be required to increase the chance of success from 99% to 99.9%.

Sending a second spaceship to the same destination vastly improves the chances of success. Multiple simultaneous missions could theoretically turn a low chance of success per seed into a near-guaranteed success per operation.

For example, imagine the seed had a 50% probability of reaching the star, targeting a comet, settling in, growing, and becoming an interstellar industry. The other 50% is the chance of failure at any point along the way. 

Sending two missions increases the chance of success to 75%. Three missions to 87.5%. Ten missions to 99.9%!  

There will certainly be a point where investors calculate that it is less costly to send ten cheap seeds than to develop and send one ultra-reliable seed. 

-First come, first served and competition: 

It is said that ideas are a dime a dozen, that it is the execution that counts. Many investors with sufficient funds and access to the required technology will have the idea to mount an interstellar operation, but only those who take the risk and execute the plan will count. 

The practical result will be that either multiple operations will be launched to the same destination, or that multiple operations will try to recreate the success of a pioneering group of investors. This leads to competition and considerations beyond simple feasibility and profitability.

An example of such considerations is the cost of including a program dedicated to teaching the colony to hinder competing growths. It must be weighed against another program that tells the colony to grow faster and organically nudge the competition out of the star system. 

Beyond these complications is the great leveller that is exponential growth. 

A slower growing, less efficient and generally inferior seed can 'win' a star system by simply arriving earlier. It would begin to send copies of itself onto the precious few mega-asteroids of the star system very quickly and basically make sure that competing seeds never find a good foothold in the system. This ties into the concept of resource size divided by growth rate. It is much more efficient to concentrate the colony's efforts on the largest groups of rocks and volatiles possible, as exponential growth can break down hundred million ton asteroids into trillions of extraction sites and have greater output than multiple smaller asteroids of the same mass. 

This makes the largest asteroids the most valuable, and the seeds that reach these first will be able to produce more goods faster and cheaper than later seeds forced to settle for smaller asteroids.


One of the major advantages of interstellar mining is that the separation between the industry and the market is so great that authorities at home cannot impose restrictions such as taxes and ownership rights. 

A Wild space where the sheriff is a dozen lightyears and several decades away. 
Laws and tributes cannot be imposed if they cannot be enforced. Once an interstellar self-replicating colony is large enough to send back signals and be detected, it is far too late for a 'military' colony with the sole intent of destroying the former to be effective. 

It would be like sending out a gnat to eat a whale ten years too late.

The downside of this situation is that nothing would protect the colony from hostile forces. Seeds containing predatory programs would have to be confronted head-on, using only the resources available on-site. The worst part is that countermeasures have to be installed from the start, possibly decades before the attack actually happens, or added through instructions beamed across a time and distance gap of several light-years.

The preferred method of long distance law enforcement.
Attackers have an even easier time in settings where the seeds are launched using short-ranged beamed power. The entire acceleration sequence might only last a few hours and could easily be disguised as an interplanetary spaceship launch. The interstellar operators would only be notified 8 or more years later... if the attack was unsuccessful. If everything goes according to plan, the investors will never know that an attack even too place.  

-Hijacking and ransoming:

Let us consider an interstellar operation from the point of view of an attacker. 

The operation is protected by laws and police in the home system. The seed is uncatchable after it is accelerated to half the speed of light or more. You cannot know if it has successfully bloomed into a colony until nearly a decade later, and you would only bother mounting an attack on a successful colony anyways. 

Attacks can be performed along communications channels or physically. A predators seed operates along the principle of 'if a hacker has physical access, its game over'.
What results is that attacks will be focused on the mature, well developed colonies that probably span an entire star system by the time a predatory seed arrives. 

Just like the gnat and whale situation mentioned for law enforcement, an attacker cannot hope to match the size of an established colony. Theoretically, a predatory seed can take on a cancerous strategy and dedicate itself only to growing as fast possible, in everywhere possible, just to deny as many asteroids and comets as possible from the interstellar operation. But how would the attackers benefit from such a move? Spite?  

No, it is much easier to have the predatory seed take over the established colony than to try and destroy it. 

The main vulnerability of an interstellar colony is that it must maintain a communications link open with the home system. If the predatory seed can replicate the signals the colony is listening to and trick it into accepting its own commands, it would have successful hijacked the colony.

A hijacked colony can be told to self-destruct and make room for the competition. It can be ordered to deliver products the attackers are interested in instead of those most profitable to the operators, or stop delivering anything at all! More subtle moves are also possible: building a second communications array that listens to future commands by the attackers back home, or modifying the colony's reports to make it look like that the preferred metals are no longer available. The operators would naturally focus on extracting a new resource, a move the attackers would be able to anticipate and exploit on the market.

Subtle or overt, hijacking the colony is a risky and effort-intensive task. All the attacker's work could be exposed and rolled back by the next update the colony arrives, and partial hijacking is worse than a complete failure.

A much better attack from a risk/reward perspective is to ransom the colony. Ransoms work by scaring the victim with potential damage to something they care about, or by promising to stop ongoing damage, in return for payment. 

Scaring the victim in this case means revealing to the interstellar operators that an attack is taking place. They cannot know that it will be successful or not - they might only be informed, anonymously, that a predatory seed is on its way. Would they risk the complete take-over of the colony, or pay a small sum into an unmarked bank account now? 

The ongoing damage variant is where a successful hijacking does take place, but all the attackers do is demonstrate their ability to make the colony do what they want. Maybe they have the colony beam back a ransom message, or have the next delivery be filled with useless ice as a warning. The attackers demand money in return for not harming the colony. They can keep this up until the operators come together to launch an anti-predator predatory seed... but so can the attackers.

-Interstellar war:

Continued conflict between predatory an anti-predatory seeds over the control of an industrial colony can be called a war. When these seeds are launched across lightyears to other star systems, then it can properly be called an interstellar war. 

A laser sail can deliver goods... or weapons. 
Interstellar war would mostly be conducted out of sight and out of mind. It takes decades for actual battles to occur, and when they do, they are are detectable only as subversive code spammed over the electromagnetic spectrum in between bouts of weird and self-destructive behaviour from the losers. 

Back home, interstellar war is just a necessary expense to fend off opportunists and pirates. It might only be visible as a few lines on a profit/loss sheet and serves mostly to keep Risk Management types and Electronic Warfare programmers employed. 

Your enemy is necessarily anonymous - exposure means a SWAT team at the door and a thorough sweep of the basement. 

Overall, this makes interstellar war far from exciting. 

-Interplanetary war:

Strangely, it is quite logical for interstellar war to take place before interplanetary conflict arises. 

This is contrary to most portrayals in science fiction. 

Consider this: interstellar operations are private enterprises, involving small sums of money invested over long timescales. It is only when million ton deliveries of platinum and iridium reach the market that such enterprises become 'mainstream'. Bigger and bigger players will consider the investment worthwhile. More money is involved and due to the fantastic multiplier that is unhindered exponential growth, the interstellar economy can quickly become larger than the domestic economy.

This is the difference, for example, between Tesla building solar panels and the Chinese government investing $780 billion in renewable energy. One raises eyebrows and looks good on the stock markets, the other can change the world. 

Imagine, within 30 years of the success of the first interstellar operation, having dozens of star systems delivering billions of tons, regularly, of every type of resource imaginable at dirt-cheap costs. The output only increases over time.

An important activity would be building factories to turn interstellar resources into more valuable products.
Entire industries would become completely dependent on these resources. Nuclear reactors fed on interstellar uranium, wiring made out of interstellar gold and copper, bioreactors running on interstellar amino acids... energy, manufacturing, electronics, food, propulsion...

A mature interstellar economy would enable previously cost-prohibitive endeavours to become cheap. In return, they tap into the revenue streams of countless industries critical to human civilization. Were it not for the need for converting all the cheap resources into useful machines and complicated products inside the home system, this would be a post-scarcity situation.

With such wealth comes jealously and competition. Cheap resources, cheap construction and lots of money combine to make war affordable...

Affordable wars would trivialize conflict. Overt interplanetary war, between governments dependent on taxing rosters of interstellar operators, could become inevitable... an interesting premise to a setting, no doubt.


Considering the threats that an interstellar operation might face, investors might request a strategy that implements the countermeasures at minimal cost. 

These can be simple, such as 'send as many seeds as possible to that star!' or 'preemptively design and send anti-predatory seed s every year'. Others can be complex, such as hiding behaviours in the colony's programming to be triggered by attacks, or adding identification/verification protocols that help trace back an attack to the perpetrators.  

Strategies change over time, either as predicted or in response to developments in the home system. For example, anti-predatory programs must be updated to respond to new versions of predatory seeds. A strategy that was effective during the first few years of the colony's growth might not be effective when it becomes a mature colony under attack on multiple fronts...

As described above, attackers will always have the first move against a colony. The departure of a predatory seed can be hidden, the technology employed kept secret and the operators' response will always be many years too late. Does this mean that any interstellar operation is bound for failure? Not necessarily. 

The interstellar operator's trump card is the ability to move outside of the reach of attackers for decades at a time. If even a tiny portion of the colony's production is dedicated towards producing new interstellar seeds, it will gain the ability to colonize new stars very quickly. Unending numbers of interstellar seeds can be beamed out of the first star into surrounding destinations. 

The strategic decision to start exploiting new star systems as soon as the first system matures closely resembles tactics found in nature. When the survival of a species is at stake, exploring new environments is essential. Trees spread their seeds with the winds, chimp groups splinter and settle new grounds and interstellar seeds are shot into space. 

The buffalo (colony) attracts parasites (hijackers) and the oxpeckers (anti-predators) eat them.
Further natural inspiration cannot hurt. Oxpeckers and buffalo have a symbiotic relationship that helps remove parasites. Mothers share antibodies with the fetus to 'update' their immune system and prepare them for the threats of the outside world. DNA mutates over time to create new defences. These can be applied to interstellar trade and self-replicating colonies...


A truly vast neighbourhood. At 0.75C average expansion rate, we'll have 53 stars supplying Earth within 40-50 years of the first interstellar operation.
Like every other human endeavour, interstellar trade will progress more or less quickly depending on the level of success and interest it garners from the largest investors. 

The first interstellar colony might not target the closest stars, but those with the greatest promise for profit. The choice will be influenced by scientific data available at the time. 

What is certain is that the first product deliveries will be small. The most disruptive effect they'll have will be through speculation, but that does not have a concrete effect on human access to resources. What is also certain is as soon as tons of platinum arrive in orbit, some people will want to steal a slice of the pie.

Natural survival strategies compel the colonies and operators to invest in new star systems as quickly as possible.  

If the second wave of colonies also start beaming seeds to a new set of stars, we'll end up with a rapidly expanding front. It will outpace any attempts at sabotage, hijacking or ransoming as predatory seeds must be sent out of the home system and cannot be updated en-route... but this might change if a 'pirate' star system is available.

Our robot servants could meet alien species long before we even notice them.
So, what will we end up with?

After the first colony is deemed successful, it become easier to expand outwards from that point than to start a new operation from the home system. Once multiple systems come 'online', humanity will be flooded by an endless stream of resources at no extra cost. This revenue stream attracts more and more envious eyes, but the damage they do to the economy can only expand linearly. 

Eventually, law enforcement will find a way to impose rules on the game. Maybe a set of predatory seeds is sent out to all nearby stars, developed using a military budget. Or instead, enforcement is done at our end, with interstellar payload travelling at a good percent of lightspeed deemed an existential threat to humanity and controlled as such. These measures cannot stop the expansion of interstellar trade or prevent access to cheap resources, but they can impose legal, political and social restrictions that mean that the trade cannot be analyzed purely from a mathematical/economic point of view. 


An interstellar operation faces a variety of threats, both internal and external. Some can be solved by simply sending many seeds to the same star system, or arriving faster and growing faster than the competition. Others must be actively defended against, such as predatory seeds carrying instructions to hijack and ransom the output of an established colony.

Enduring conflict across interstellar distances is an interstellar war. As the colonies hop from system to system to escape their attackers, truly interstellar war is the result... but it will be long, boring and unwinnable. However, they can lead to conflict in the home system. 

It is necessary to design interstellar seeds according to predicative and preventative strategies, which evolve in response to new developments.


  1. Another survival strategy could be to create a laser highway using another seed, and ship the EW and RM personel to the new colony.
    This would give them the home field advantage over any attackers external to the colony. The laser highway would also speed trading between the home system and the colony. It could even enable immigration...

    Another thing: A colony could be programmed, or reprogrammed, to send out predator seeds to other systems.

    1. Hi VIPM!

      I doubt that anybody would want to get shipped out to another STAR just to do their office job better :D

      However, you do raise an interesting point: if you have a mature colony readily putting out the resources needed to fuel all of human civilization, then some people might want to divert a tiny fraction of that flow and live in situ.

      They won't agree to being shipped out to sit for the next few decades on a cold, desolate rock without being able to call anyone, so they'd need comfortable habitation to move into and company both at the destination and along the way.

      The 'laser highway' could be implemented as a stream of massive re-focusing mirrors pushed out like laser sails at low velocities. After time, you'd have a line of them stretching out to your destination. They can train a laser on a target across lightyears...

    2. Well, you could have the immigrants do it for you instead of shipping out corporation personnel. You'd grant them some percentage of production capacity in exchange for them administrating and defending the mining colony against attack.

      Of course, there's then the interesting problem of making sure they don't mutiny and take ALL the production'll probably want corporate personnel onsite anyway. Or have dire consequences for breaking contract.

      I'd think having laser stations along the way instead of mirrors would be worth the cost because for redundancy and reaction time...part of the reason the highway works well is it laser brooms away interstellar dust and debris along the route. Coordinating this with a huge laser back home would be rather difficult, even absent hostile action.

    3. Well, if the immigrants rebell, then they would be cut off from the homeworld - not in physical, but in informational sense. The corporation could easily stop the retranslation of modern scientific data, cotemporary designs for productions and cultural information to the colony.

      This would hardly be a blow in short therms, but in long therms the colony would start to fall behind rather quickly. Clearly not the price that colonists would be ready to pay for something insignificant.

      And, of course, it is always possible to send a battlefleet to "pacify" the HUMAN rebels.

    4. @VIPM:
      Well, two things to consider in such a scenario:
      -The new, human colony could never use all of the resources being produced and sent out by the automated colony. Stopping production is a purely destructive move.

      -The colonists cannot hold the production for ransom, as the home system cannot really offer them anything they could want. Money? Where would they spend it? Even better technology? At the time they decide to rebel, they would have the most advanced tech possible. What then?

      On the other hand, the home system can play multiple cards to bring the colonists back under control. They can use radio signals to bring the production back online (the automated colony is unlikely to be 100% under the control of the colonists), or tell it to start producing nuclear bombs to wipe out the human colonists instead.

      Imagine being told that if you rebel, the machines you depend on to survive will start building millions of missiles to kill you on the spot.

      @Алексей Широколава:
      That would be a concern for colonists that intend to return to or compete with the home system. The disadvantage they would have in terms of technology would be terrible for them... but this is unlikely.

      First, the type of person who goes to live in another star doesn't really want to come back. Second, they already have everything they need and most new technology would not benefit their lives - advanced in weapons tech, in super-advanced manufacturing techniques or new medicines. They have no real use for those.

      Second, the home system can always order a battlefleet to be built on the spot, or sent in from the nearest non-rebel star system.

    5. Well, this is basically the reversion of usual problem of interstellar trade; instead of "what could colonies offer to homeworld", the question is "what could homeworld offer to them"?

      The answer is exactly the better technology and designs. Yes, the colonists would probably be able to live with the tech they already have, but it's like "we don't need your electricity and radio, we have steam engines and optical telegraph!" Not productive. And, there is also a question of medical and biological information. How long would colonists survive with only the medicine and crops they initially have? Pests and diseases are capable of adapting, too. Without the ability to design new solution, they would eventually face plague and famine, with no means to deal with it.

    6. This is true up to a certain point. Consider the case of the early American settlers. They moved into a land they could grow food on, using only the equipment on their backs and whatever the pioneers had built.

      They could, with difficulty, keep up with the technological advancements of the well-developed European nations. But if they decided enough was enough, would they be in immediate danger? Would they be sad to lose something they don't have yet (future technology)?

      I doubt anyone today is sad that they don't have the iPhone 10. I doubt North Korea would stand down if we promised it the designs of the next Intel processor, when they arrive.

      My point is, promises of future technology and medicine are not strong enough motivators to stop colonists from rebelling. Its not an immediate threat, something they depend upon or even something that lowers their standard of living.

      Also, there are practical issues with imposing the 'no new technology' punishment on a rebellious colony. The Solar System is not a monolithic group. Some part of them will leak the data intentionally or not. The colonists could promise new scientific data to the national rivals of the country imposing the punishment, allowing the colony to play off nations against each other and come out the winner...

    7. //Consider the case of the early American settlers.//

      I'm afraid, all the similarities are false. The North America have the climatic & environmental conditions not only perfectly suited for human lives, but, actually, even better than european.

      Unless you would found a perfectly P.E. (Parallel Earth) planet, this would hardly be a possibility for interstellar colonization. The average conditions on colonial planet would almost always be much WORSE than on Earth. The colonists would depend of technology MUCH more, than the colonists of North America.

      And in such conditions, they would desperately need the scientific capabilities of homeworld to solve the problems. Simply because they couldn't have enough of their own scientific potential before the colony would reach the sizable size of at several millions. They would be forced to deal with quite a lot of purely biological problems; new virus strains, new crop diseases... If the planet have local biosphere, the problem would be multiplied (not directly, because the local organic would hardly be edible for Earth organic and visa-versa).

      Basically, without medical and biological help from homeworld, the colonists standards of living would drop pretty quickly.

      And, in case of crops - we have all cards in our hands. Basically, how the situation looks like? The homeworld university develop new crops for colonial conditions. Said cultivar would then be send - either as physical package, or as data for local synthesis - to the colony, for local testing. After the series of tests, the data would be retranslated back on homeworld, where the initial "crop design" would be refitted according to the colonial data.

      The thing is, that the colonists have no need to knew exactly HOW this particular crop works. They have the DNA sequense, all right - but they have no clue, what exactly are those gene complexes do, and HOW. This data is secret, and held under strict control on homeworld (after all, it's copyrighted biological design!)

      So, if colonists would chose to rebel... Well, we just shrug and stop the transfer of new plant designs to them. And let the pests and diseases to do the rest (they are highly adaptable!) The colonists could not easily replace our plant designs, because, basically, all their ecosystem is build around them! Even if they have benefactors on Earth, without acess to our - carefully protected! - genetic data, their benefactors could only recommend them "well, start to build a new ecosystem from scratch". Definitely not the thing that colonists would approve.

      And I'm not even started to talk about such possibilities as pre-programmed "off switches" in crops... ;)

    8. Early settlers:
      The 'perfect environmental conditions' in North America would be comparable to the habitats ready-built by the autonomous colony, just waiting for the arrival of human colonists. Massive rotating structures where the best food, luxuries and entertainment is available for free isn't necessarily worse than conditions back in the home system.

      Also, I stated in the initial conditions for humans going on an interstellar trip that they would not attempt it until every problem has been solved and every necessity covered, plus the expectation of a better life on top of that.

      Also, considering that we haen't found any planets that even Earth-*sized* within 16 lightyears means that realistic, near-term colonization is mostly a stay-in-space affair. A completely artificial environment minimizes the uncertainties that comes with growing crops on open land and exposing themselves to unknown diseases.

      Considering these conditions, why would living conditions drop? They (and their machines) control every aspect of their lives and environments. If the machines fail, then by extension the entire interstellar operation is doomed to fail because the autonomous colony that supports the humans relies on the same technology.

      Now, we're deviating far from the purpose of the analogy, which was to point out that we've had situations before where the colonists didn't depend on the homeland, so could afford to rebel without immediate or short-term negative consequences... but this is interesting so let's continue :)

      Crops controlled from the home system is not going to be biologically possible, at least without some serious convoluted mechanisms. Consider Alpha Centauri: 4.2 lightyears. Even if everything goes well, 'updates' cannot be spaced closer than 8.4 years in case something goes wrong. The plants will need to sustain themselves and corrected in-situ for 8 year periods or more. This entails very open genetic documentations and mature genetic tools available to the colonists. I mean, some evil corporation might risk dooming the entire colony to starvation and failure to protect its genetic property, but that's more a fixture of dystopian settings than something we can be certain of happening.

    9. @Алексей Широколава
      Keep in mind that this is a colony that has already established itself in another star system. The mere fact of their survival means that they have established self sufficiency. This means that they have sufficient tech to stand on their own, NOW. Being deprived of new tech is not going to change that.
      You also appear to be assuming that the new colonists are going to be nothing more than a bunch of farmers, with no other skills. Such a scenario is actually rather unlikely in the age of interstellar colonisation. The home system might or might not have themotivation and resources to advance faster than the colony; however, this does not mean that the colony would be incapable of making its own advances, and adapting to its new situation.

  2. My IMHO - you are relying too much on self-replicating simple machines. Basically, with "seeding" scenario we are forced to take into accout the purely biological factors - such as mutations and evolution processes. Basically, we are creating an artifical biosphere - without any real means to control it. And the "colonial war" scenario, abovementioned, only worsened the situation. To deal with all possible factors of such situation, the "colony" must rely pretty much on their own ability to adapt and react - i.e. they would need to have quite adaptable AI. And, because the colony computing capabilities growth are almost unlimited, we would pretty soon have a VERY smart AI, which, while may not be truly self-aware, still could deviate pretty much from original ideas.

    Basically, the problem quickly boil down to the situation "we have artifical biosphere, controlled by the evolving artifical intellect, which is capable to operate interstellar-level energies without ANY possible human control".

    The same "good" idea as "let's wire all our nuclear arsenal to the control of computer, linked to the Internet, so it could analyse the data and decide when to launch". Even the "Death Hand"-type machines - like old Soviet "Perimeter" system - NEVER have the ability to call the attack by themselves, they could only control the authority to launch such attack (i.e. they still need human to physically push the buttons and thus rely the command order). You suggest something even worse; the near-biological system, with the ability to threw relativistic kill vechicles anywhere they want.

    1. ...This guy has the right of it, Matter beam. How ARE we going to prevent runaway AI colonies?

    2. I'm afraid, the only way is to have a human control over them. Which means that we need to colonize the system first, and THEN start to think about "what we could send to Earth"?

      So the situation would probably looks like:

      * The initial "seeding" with the goal to prepare space habitats and vital resources (water, oxygen, carbohydrates, trace elements) for the initial human colonization. If we use laser propulsion, they could probably also build braking laser, but they should NOT have any programming that could lead them to the idea "hey, let's launch something back!"

      * Then the colonization mission arrived, and took the matters in their own hands.

      Hm... we actually could have BOTH stimulus for colonization (to control the machines) and interstellar trade here. The colonists would trade minerals from their systems for the newest scientific & cultural data from Earth.

      Of course, we still have the problem that some colonists somewhere in nearby systems have relativistic weaponry in their hands... but at least against humans the deterrence through threat of mutual destruction work well enough)

    3. @Алексей Широколава:

      Well, you are right, but it was stated in Part 1 that without autonomous colonies of machines, you wouldn't be able to start the whole thing at all! I'm just considering it as a required piece of technology essential to the interstellar trade concept.

      On the subject of colony intelligence: I don't think so. The self-replicating machines do not perform research or self-improvement. They must react and adapt, but that doesn't necessarily require intelligence. Our immune system reacts to diseases and finds solutions to a massive variety of problems, but it is not intelligent.
      What we will find is that the colony will have more calculating capacity, because they can add together more and more computers, but just like today, just adding computers doesn't equal intelligence.

      @VIPM: By hoping that no combination of unrepaired damage, stray cosmic rays, pirate software and unprotected computers produces AI in the first place!

    4. @Алексей Широколава:

      So you intentionally cripple the self-replicating machines so that they cannot do anything until humans arrive?

      That sounds good in theory, and might be the sort of thing governments and militaries will impose through laws and regulations, but its bad from an economic/mathematical point of view. Waiting for humans to arrive adds a decade or more to the maturity time. Instead of platinum and palladium arriving on your doorstep in 15 years, you have to wait 30 years.

      On top of that, it isn't really an option for the first few colonies. You don't have a laser highway set up and no affordable rocket can send an entire human population 'ready to go'.

      So, it is only possible for later colonization attempts. Possibly by the time people realize that hey, this thing is happening and we need to get in on it. But by then, the original autonomous colonies would have matured and pose all of the problems you and VIPM mention... it would make for an interesting SciFi setting.

      The mutual assured destruction is an interesting question: it works today because your victim will fire back at you and kill you in half an hour. Would you still attack if it takes 20+ years to your victim to react? If you're a 60 year old politician, you'd press the button.

    5. Matterbeam, all those assumptions are based on the main assumption that the average human life would have the same lenght as in early XXi century and the global economic would be more or less the same. If the human average lifespan would be increased to, say, 150-200 years, or the lenght of "active" period would be stretched from around 40 to 80+ years, we would have the situation where it is perfectly possible to wait half of a century to gain profit.

      Also, if we have more centrally-controlled economic - like socialists - we, again, could wait much longer until the profit would came. Because we aren't limited by the requirement of short-therm payments, we could perfectly agree to the plan, that would generally benefit next generations, not our (at least not directly)

    6. The implicit statement made in Part 1 is that interstellar trade can happen in the next two centuries. As soon as we have fast interplanetary travel, either through powerful nuclear rockets or a laser transport network, we'll be able to send probes to other stars. Whether the self-replicating seed technology becomes available at the same time is speculation...

      ... but the self-replicating technology is as much of an unknown as life-extending medicine and economy-disrupting social structures. Either or all of them could become a reality in the next decade... or stay unavailable for the next 1000 years. Interstellar operations only really need 15 years to come online, so we'd just need for the right conditions to arise.

      A good metric for discussing these sorts of situations is Technology Readiness Level (

      Lasers are TRL 9. We have them.
      Megawatt space lasers are TRL 6. We'd demonstrated smaller scale lasers in space, we just need to make them bigger.
      A laser transport network is TRL 4. We have all the technologies needed.

      In comparison, self-replicating seeds and human life extension are all TRL 0. We don't even have the all the scientific concepts pinned down, and have yet to even invent them. Massive social change doesn't have a TRL.

      What I'm saying is that TRL 0 technologies have no horizon for discovery and we cannot start saying that they will be ready in X number of years. In this case, I could argue that self-replicating seeds will be available in 200 years, you can say they won't, and neither of us will have solid grounds to argue on...

      What we can do though is imagine the consequences of one or both are available.

      In long life is available before self-replicating seeds, then interstellar trade will take a very long time to happen, because long-life humans won't risk the next 80 years of life by going on a slow interstellar cruise only to work their assess off for decades on the other end.

      If self-replicating technology comes earlier, we'll have both massive industrial, social and economic changes. If we can grow a colony around another star, we can build an entire autonomous industry right here too. We won't have the same massive access to resources as in the interstellar scenario (at first), but we'll have things such as houses growing out of the ground, cars being made in minutes and massive mirrors in orbit solving energy and global warming. Labour disappears, production costs approach zero...

    7. //In comparison, self-replicating seeds and human life extension are all TRL 0. We don't even have the all the scientific concepts pinned down, and have yet to even invent them. Massive social change doesn't have a TRL. //

      Actually no, the human life extension technologies are between TRL 2 and 3. We already have sucsessfull experiments with animals life extension by means of "switching off" several genes. We still don't have the total comprehense - because the mechanism of aginng is VERY complex - but clearly not at TRL 0.

      //Massive social change doesn't have a TRL. //

      Well, USSR existed. And several pretty large-scale projects were sucessfully implemented by plan-based economical models. I see no reason to assume that socialist states could not appear again in near future.

      //In long life is available before self-replicating seeds, then interstellar trade will take a very long time to happen, because long-life humans won't risk the next 80 years of life by going on a slow interstellar cruise only to work their assess off for decades on the other end. //

      Not linked. Actually, the modern models tended to show other results; peoples are more likely to risk, if they thought that they have "reserves".

    8. "Well, USSR existed. And several pretty large-scale projects were sucessfully implemented by plan-based economical models. I see no reason to assume that socialist states could not appear again in near future."
      I believe you misunderstood what MatterBeam said. Apologies if that's not the case.

      When MatterBeam said social change, he was not meaning socialism, but large scale changes in a population's culture and values. This has, until recently, been almost entirely uncontrollable from the top, and the tools we have now to mitigate or encourage such a change are inherently unreliable and prone to mutation.

    9. Ah, seems I really misunderstood. Thank your for clarification!

    10. Matterbeam:
      "because long-life humans won't risk the next 80 years of life by going on a slow interstellar cruise only to work their assess off for decades on the other end."

      None of them? Out of a population of many billions in the solar system I would expect there to be enough people with both the skills & odd attitudes to be crew on an interstellar colonizing expedition. If the advances in biotech that lead to long life also lead to reliable suspended animation, the odd attitudes needed would be less odd & more common, since the colonists can sleep through the boring parts of the trip.

      "If self-replicating technology comes earlier... but we'll have things such as houses growing out of the ground, cars being made in minutes"

      Why would self replicating tech work much faster than the existing self replicators? Growing a house or a car should take about as long as growing a similar mass tree.

    11. Out of the majority of the humans today, few would willingly and consciously 'burn away' their lives for next to no benefit when they are 20 years old. The fraction that would do so is certainly a fringe, and fringes aren't where you'd want to source large numbers of skilled technicians that your billions are riding upon. And even if you did find enough to fill a crew, could you really base an interstellar industry, or even an interstellar civilization, on the tiny fraction of people that are skilled, mentally stable and reliable yet self-harming in a way contrary to human nature?

      I agree that the restrictions will seem tolerable for many more people if the decades-long trip is shortened to manageable lengths or suspended animation is used, and if the machinery is advanced enough to handle a lot of the labour required to set up permanent settlements.

      What I meant about self-replicators was that houses would cost next to nothing to build, so you could sprinkle 'house seeds' on a landfill and it will transform into a row of houses for free, and that all the factory processes which build a car in separate pieces to be assembled quickly at different sites can be replaced by a single multi-purpose self-replicator that while not doing any of the tasks individually faster, still managed to be much faster than conventional manufacturing processes.

  3. Matterbeam, I really doubt that autonomous robotic seeding & colonization may be possible without at least SOME level of AI. Too many unknown factors, too many unpredictable parameters. Without at least some ability to adapt and learn, the whole project could decay pretty soon just because system would not be capable to deal with real, non-simulated situation. Entrophy would came in work.

    The immune system analogy isn't correct. The immune system worked with only limited purposes. The immune system is not forced to basically build a biosphere in unpredictable condition and make it stable. And, immune system could not deal with all problems with just pre-programmed responses.

    Basically, the seeding system is an attempt to make not only stable and self-sustained, but productive biosphere, capable of rationally dealing with output. I'm afraid, such system could not be build only on simple "trigger-response" basics.

    1. To Алексей Широколава
      A sub sentient animal like a cow is an incredibly complex system that grows from a single cell through simple "trigger responses". It has no guiding intelligence yet it is able to grow in to a massive collection of systems that all function to maintain the biosphere of organs and gut bacteria that keep the organism running. All multi-cellular lifeforms are an example of a complex ecosystem that works together with nothing but "trigger responses" to guide it. As for being productive, going back to the cow analogy many of the systems in a cow not only serve to make it "stable and self-sustained" but also "productive and capable of dealing with output" in terms of making milk to meet the demands of her calf. Systems can be both stable and produce a product with no intelligent system guiding them.

    2. @Алексей Широколава, @Planetfall:
      The AI can be stored in cellular DNA, to be deployed to electronic machines once they are available. The electronic machines would have to made out of dumb micromachines. These would be made by even dumber cellular manufacturing. Complex cells would only survive in an environment created by 'blind' bacteria that would warm, hydrate and feed them.

      So, in essence, we can start out with a small set of non-sentient, generally dumb micro-organisms that perform according to behaviour hard-wired artificially into their DNA, and use these to create the conditions and tools for more and more complex 'organisms' to be created.

      Consider the human body.

      A sperm cell and an egg cell have no brain, no instincts and no problem-solving ability at all. Their components simply react to the environment. Together, however, they can create a human being, and that person created all of civilization. Interstellar colonization would require the same process to be created at a smaller scale.

  4. Predator seeds are more or less doomed to fail against established seeds. After all, they presumably use a lasernet to accelerate cargo to the home system. This means they essentially have a web of death rays vaporising anything that doesn't get identified by the friend or foe system as a friendly. After all, if something moves towards you at relativistic systems and doesn't identify as a friendly, it's dangerous. Whether it's a relativistic kinetic kill vehicle or a rival seed is irrelevant.

    1. Again the same problem: we have automatic user corporative (I.e. private) control, that could wreak devastation on unprecedent scale. Moreover, the MAIN FUNCTION of said automatic is exactly to shoot relativistic packages toward Sol system.

      The analogue: we allow EVERYONE to use nuclear devices for industrial purposes (like large-scale digging and geological excavations - nukes are, actually, pretty good in it), by the means of automated missile base in Antarctica, controlled via Internet. How long before something would gone wrong, even not counting the possible malevolent attempts?

    2. @Wouter Debois: Yes, brute force attempts to subvert the production will fail. But if the predatory seed only has to find an empty rock and build a radio dish that beams hacking signals to the colony, then it can use the colony's own laser net to do whatever it wants.

      The predatory will arrive mostly unnoticed. The large laser sail is departed on is discarded, leaving only a nuclear stage a few kg in mass. This is a really tiny object. It will be visible during the braking burn, but I doubt that multi-gigawatt beams can effectively track a tiny target once it is already inside the star system. That required military grade tracking.

      If the predatory seed knowns a lot about the colony, it can perform its burn behind the main laser array, such as behind the system's star or very close to the laser array, so that it has a very large angular velocity.

      After the burn is complete, the predatory drone detaches the nuclear stage and basically becomes invisible. A few weeks to months later, it has grown a solar panel and a radio dish and the game is over.

      It's not fool-proof, and there are ways for the colony to physically defend itself, but the advantage remains to the attacker.

  5. If written well, even a subversion attempt by a non-sentient probe could be an exciting scenario.....

    1. If it is non-sentient, then it could be random errors accumulating beyond the self-correction threshold, leading to abnormal behaviour.

      Like sending relativistic kilo-ton payloads at Earth without proper notification and warning.

    2. True that. Ray Bradbury once did an interesting (and creepy) 'non-sentient protagonist' story involving robots- 'There Will Come Soft Rains'.

      Of course, one could try going all H.P Lovecraft and writing a story (pastiche?) about an small unthinking parasite sent to a colony, corrupting, subverting, then enlisting the machinery for a dark purpose, sent by its hidden masters* beyond the immense void.....

      *humans on earth obvs.

    3. It might be the interstellar equivalent of a prion: a slightly malfunctional version of the seeds we send out to colonize the universe, returning to subvert and corrupt existing colonies.

  6. Sorry I have not been very active lately... I have been rather involved with other projects. For the same reason, I haven't had time to read through everything here, so my apologies if I missed something.

    The military and systemic government does not have to go to the other star system in order to impose its laws. All trade has to come back to this system. That means that all the military/government has to do is intercept any incoming product. Anyone not respecting the law either has their product confiscated, or destroyed. This does not evenstart to address the monetary and physical penalties applied.
    The only way that anyone is going to escape the rule of law would be to live outside of the "arms" of that law. If you assume that the law is strong enough to enforce its rules on systemic trade, it will be strong enough to exert that rule on all trade coming into that system. The only thing it would not be able to interfere with would be the actual (preferably human) colonial activities taking place in the other star system, or enroute.

    1. Product smuggling?

      Corporation A sends the colony goods to another colony of Corporation B, which then sends the goods to home as part of their manifest. B pays A for this, because they can then sell the goods for their own profit.

      There's also the fact that, as above, a laser highway can be established to facilitate trade and immigration. A corporation willing to do this could simply pack up everything and move to the new system, using that colony as it's new HQ and base of operations. It would sell to other colonists there, and also with other inhabited colonies, without ever dealing with the home system again.

    2. Addressing this in reverse order:

      I have no argument against using this method to establish a colony. In fact, I consider that to be the most likely viable scenario. The problem is with trade. This would also cover development within the solar system: it is unlikely that "asteroid mining" (etc) would ever be profitable for Earth-based trade; but it would be essential in continued human exploration and expansion, with the explicit intent of establishing human presence in space as the primary objective itself.

      Smuggling is unlikely. Smuggling tends to be an expensive operation, which sort of defeats the purpose. Yes, technically the operation COULD work, at least for a while. However, sooner or later, someone is going to notice the additional product, and start investigating. An existing in-system source could say that they just increased production... but this is not exactly in their interest, because it would cost more, and it would lower market value. The only viable reason I can think of is if an existing mining operation were "tapped out", and would otherwise be unable to meet demand. In which case, however, the question would be "why smuggle?". It would be simpler to just file an out-system claim.

  7. Don't worry, I'm glad to have you commenting in the first place!
    An important point in Part 1 was that when considering an industry over the long term, fixed costs are negligible and all that matters is a comparison of dynamic costs.

    In an interplanetary vs interstellar scenario, the main difference is that the *expansion* of a mining operation would be basically uncapped, untaxed and unregulated by any laws in other solar systems. If the products are taxed equally upon sale, then it is not a point of comparison. If an interstellar operation can grow to 100x larger and not pay a dime, then it has a decisive advantage over a similar expansion at home - just consider the modern day negotiations between landowners and corporations wanting to exploit their land.

    1. Corporations selling raw material are not going to want a massive inflow of product, as this will greatly reduce demand (as in, how much someone is willing to pay for the amount of product). If you have a massive inflow being provided by another organisation, this is competition. If it is their own product, it is inventory that they will probably have to unload at a lower price. Getting product from another star system does not become an incentive until there is no longer sufficient resource available in-system.
      Result: the existing corporations are going to declare "property rights" over the other star systems. They will then sit on the product until such tie as there is need (not likely within their own lifetimes).

      Again, if you can enforce ownership rights in-system, you can enforce ownership rights on any product coming to the system. If you can extract product at low cost out-system, you can extract it low cost in-system.

    2. There is no strict rule that a massive inflow of products means it will arrive on the markets in an uncontrolled manner. Due to laws protecting corporations from espionage, they might even conceal the fact that they possess reserves of high-value products to prevent a market crash.

      However, I agree, things are never so simple. It is in the interstellar producer's interests to capture markets by contract future supplies to various buyers. If everything goes to plan, the buyers receive the products as they arrive on starships, leaving no glut on the market. However, futures prices would be lower than today's and there would be a race to the bottom between the producer, the existing competition and hesitant buyers. The interstellar producer with his zero-extra-cost means of production can afford to under-cut every existing interplanetary operation and still make a significant profit.

      "Getting product from another star system does not become an incentive until there is no longer sufficient resource available in-system."

      Not at all! As I explained, all that matters is the profit levels. The traditional way to make profits in a limited volume market is to increase your profit *margin*, through increasing prices or lowered production costs. Another way is to break the volume limit, outbid your competition and lock in a portfolio of buyers to your product.

      The corporations cannot enforce property rights on another star system. Sitting on the product just incentivizes the black market. Sitting on huge amounts of product crashes the market in prediction of the day you are going to sell. Your investors will not allow you to squander away potential profits by holding onto products of rapidly declining value.

      "If you can extract product at low cost out-system, you can extract it low cost in-system."

      I must point you again to Part I of this topic. There is a limited number of very large rocky bodies in each solar system. The larger the body, the greater the output from a single self-replicating seed. Smaller bodies cost the same to exploit but produce less and at much slower rates. Therefore, while the largest rocky bodies are still being exploited, they can undercut all other small operations.

      For example, a 100km asteroid can be spread out into a meter-thick disk 25829km wide. The surface area that excavators can 'attack' is roughly 1 billion km^2. A 1km asteroid has one million times less resources and an 'attack' area of 1 million km^2. The smaller asteroid costs the same to exploit, but produces one million times less total resources at a rate one thousand times slower.

      It is therefore important to move into other star systems to exploit these larger bodies once all those in the home system are taken. It is cheaper to send a seed to another star system than to sit around a thousand times less profitable than your competition.

    3. First, I need to correct a miscalculation on your part, regarding 100 km vs 1 km asteroids: the larger asteroid has a surface area of just over 31 400 km^2 (not the 1 billion km^2 you claim; and, no, you can't just spread that mass into a meter-thick disk) available for initial "attack". This is actually 10 000x the surface area of the smaller (not 1000x). That said, that is not how you evaluate the competitive extraction rates.
      You have proposed a "seed" capable of establishing autonymous production capable of sending product to another star system. Accepting such a scenario (which is itself problematic), the size of the asteroid is not the limiting factor. Regardless of the size of the initial asteroids being mined, the production rate of the two seed will start off being exactly the same. The rate of production on the smaller asteroid won't slow down until an entire hemisphere has been covered... but mining also progresses downward, creating new surface area, which means that most of the asteroid will have been processed by this point.
      Yes, once this stage of production on the smaller asteroid has been reached, you will have a (short) term of superior production, at an exponential rate of advantage, being achieved on the larger asteroid. However, this advantage is only short lived. There is no longer the need for the same extraction resources on the smaller asteroid, which means that cultures from the original seed can now progress to other available asteroids (the seeds can send product across light-years... it will be child's play to send cultures a few light-seconds, or even light minutes). Once new territory has been reached, exponential production growth resumes, at a rate just behind that of the larger asteroid.
      There is actually an advantage for the small asteroid seed growths. While the larger asteroid culture remains in a single mass, at a single location, vulnerable to an attack that could potentially kill off the entire seed, the smaller seed culture, having sent out culture "spores" to other asteroids, is no longer vulnerable to a single attack. Even if you kill off the entire host culture, the other cultures will continue to spread. The sooner the seed sends spores to new locations, the more secure the "family" of seeds becomes. Thus, the production rate at the larger asteroid does not greatly outperform that of the smaller asteroid; and the increased security of the smaller asteroid production will increase the competitivity.
      Larger corporations can produce better performance by increasing the number of seeds, but this is a different matter. It has already been proven that small companies can manage to survive in competition with larger companies (unless the larger company takes a huge loss in order to try to undercut the smaller... and this manoeuvre has been successfully blocked by the organisation of co-ops).
      In any case, you are correct that there are extremely few bodies in the 100km+ range. Most large companies will probably opt for claims on 10km - 100km range, of which it is projected that there are tens of thousands (not quite so limited). Co-ops will probably focus more on (the estimated million+) 1km - 10km asteroids, which would be just large enough for reasonable scale production at reasonable costs.


    4. Once again, corporations do not need control over the other star system in order to enforce property rights. All they need to do is to control the activity in-system.
      Given existing polito-economic relationships, the current corporations will have all the required influence to ensure enforcement. Assuming that government has the ability to enforce the laws in-system, it will have the ability to enforce distribution of anything COMING in-system. There are actually many ways to do this.
      government capable of enforcing ownership rights throughout the asteroid belt will have no trouble blockading incoming shipments. They don't have to destroy the shipments themselves... they can just destroy or confiscate any assets put in place to recover those shipments.
      Barring that, any increase of product distribution will likely be very noticible, which means that distributors might be required to prove that the product came form within the system, and where it came from. Any distributor not givingrequired proof will be fined, and have the product confiscated... with procedes made available through various mechanisms to profit the owner companies.
      If smuggling is successful, you can easily counter the out-system profit margin (if any exists, which I will discuss later), through cproduct taxes... with tax exemptions given to owner companies.
      Companies do not exactly "sit on product", usually. Instead, they hold off on production. In fact, sometimes (when governments get involved, in particular), considerable money will be spent for NON-production (in particular, a government, for exaple, will pay farmers to NOT grow a crop, because there is too much of a supply of that crop, and it is devaluing the yield). Investors will allow anything to ensure that they get their profits. Sometimes, this is done by keeping products scarce enough that people are willing to payhigh prices.

      I don't have enough time now, but I expect to address your profitability assumptions shortly.

    5. Okay... getting to the costs.

      You have made a number of assumptions that are rather problematic.
      The first is that you will be able to deploy a "seed" that can replicate on the order of 1/day (IIRC). The second is that this seed will mass less than 1g. I won't contest the notion that you would be able to somehow program the seed to generate all the required components for a self sufficient interplanetary mining industry capable of interstellar delivery (given sufficient size); however, third, that this sedd will be able to retain its code, preventing information losses and transcription errors that would cause the mission to fail.
      Fourth, you assume that there would be only a 50% chance of failure rate over interstellar distances. I address this separately because success reuires all the systems to succeed. Not just the seed.
      Fifth, you are assuming that you can attain 50%c velocities. That is problematic enough with the 1g payload. However, sixth, you also appear to assume that product delivery (at much greater implied masses) would be able to attain similar velocities.
      Seventh, you assume that product deliveries will arrive without interference.
      Most importantly, you assume that the "free" production and delivery will be able to offset the initial costs.

      I have grave doubts about all of these assumptions. I will try to address verything, but I ask for patience, because my time is somewhat limited, and I know I won't be able to post everything in a single message.

    6. "Seed" issues.
      We will assume a natural or artificial bacteriological-type process, probably at a scale of a complete culture rather than a single cell, in order to facilitate encoding. This is because you would not be able to fit all the tools required for material extraction, processing, layout, and assembley for a non-"organic" (molecular) duplicate seed within the original seed. IF possible at all, you will need molecular tools, and that is essentially what bacteriological body components are. As for the multi-cell culture... many tasks will need to be performed and programmed, and this will be easier to integrate into multiple interdependent cells.
      There is an important aspect that there will be a great number of material and energy requirements in order for these cells to do their work... especially the initial work of reproduction. Also, these resources will need to be readily accessible at the appropriate time. It is unlikely that all the required resources will be available within immediate reach of seed culture, regardless of size (except on rare bodies as diverse as the Earth). This means that the culture will have to travel from place to place, and small objects tend not to travel that fast, especially when they have to travel with the burden of stored, collected material that they have to bring along with for use. Not only will our artificial bacterial culture need to be extremophile (just to survive), it would need to be able to acquire and store sufficient energy to move without going dormant for long periods.
      We are most familiar with the molecular processes required for life as we know it. There is not a single such known process that would allow the type of activity of the nature and scope you hope to achieve. Even constructing one from scratch, with what is currently understood about the nature of the vast majority of bodies in space, and physical constraints, you would require either much larger (and therefore more massive) cultures that would be able to extract and store more material; and collect, store, and convert more energy for more rapid displacement; AND/OR, you will need to allow MUCH more time between generations of reprodction.
      Even then, it would be difficult to guard against the loss or corruption of the required code in order to manage development of the culture into something that can create an automated mining infrastructure.

    7. Transport velocity is another problem.
      Quite frankly, it would, of course, by impossible to attain 50%c with any on-board propulsion/power system, with the possible exception of antimatter. Even with antimatter, it is considered unlikely that there will ever be a drive capable of attaining 50%c within the physical constraints of any existing theory of physics. This does not even begin to address the mass that would be required just to contain any antimatter fuel. So let's rule that out as well.
      Instead, you have proposed beamed energy. Any beamed propulsion system requiring on-board propellant runs into the problems above: you simply will not have enough propellant to achieve anywhere close to 50%c. Bussard collection really doesn't help either, as you waste most of the beamed energy trying to generate collection fields large enough to collect the required amount of propellant.
      So... that leaves us with the interstellar sail. Since this was your proposed concept, I will assume you already came to this conclusion.
      The problem here is that, not only do you need sufficient power, but you need a sufficiently tight transmission channel so that you are not just wasting transmitted energy. This brings us back to our discussions of lasers for combat. IIRC, we concluded in those earlier discussions that 100m lenses (you suggested mirrors, but that would be an extremely inefficient configuration) would need to be spaced at considerably less than 1 AU (about 8 light minutes) in order to keep the spot area within the limits of the next lens of equivalent size. You could extend this spacing a little if you have larger lenses, but it is unlikely you would be able to construct lenses large enough to get a spacing better than, perhaps, a few light hours.
      The problem is, you need a network of relays in order to keep the beam sufficiently focused. Now, you move considerable distances as you accelerate. At 1%c, you will be out of range of a relay (assuming a rather unlikely 1 light hour interval) in just over 4 days (100 hrs). Now, at 1g, it takes approximately 150 days to accelerate to 50%c, so you would need enough power to accelerate the seed at 40g in order to complete acceleration within the range of 1 interval. In this scenario, both the emittor and sail would have to be HUGE (many km, at least). That much power is going to be expensive. It will also take a considerable amount of time to build something with that much power at the other end. Time that can't be spent replicating or mining. Also, it might be questionable whether or not the sail could survive trying to reflect that much power.
      Alternatively, if you can only manage the power for, say, 1g acceleration, you would need about 40 or 50 relay stages. These will all be just as huge, but the power output would be more manageable. But now you have to figure out how to keep all of these stages in alignment. The problem becomes much worse if you are limited to 100m or 1km lenses.
      Oh yes, don't forget that each relay will be absorbing some of that beamed power. Not only will you have to bulk up tokeep the relay cool and keep it in position from normal drift, but you need to keep it from moving outword from the force of the beam itself (the momentum of the absorbed component.
      You still need to transmit a lot of power, but at least the power doesn't have to be beamed all at once.

    8. BTW: How are you going to slow the seed down once it gets to its destination?
      I suppose you could launch a mirror ahead of the seed (for best efficiency, launch it from the seed itself), then hope that your calculations of their respective positions are correct. But this would also require sending out at least tens of thousands of huge, heavy relays.
      Don't forget that you have to slow down the incoming loads as well.
      Also, don't forget that the seed will have to have enough resources to find and navigate towards a suitable host asteroid. It is highly unlikely that you original 1g seed will be able to perform this task. You need fairly sizable telescopes, as well as other navigational equipment. You also need propellant and engines (you won't be able to keep the beam focused on target for changes in trajectory at light year distances).

    9. Survivability is a HUGE issue. This is especially true at velocities from 1% to 50%c. Even in interstellar space, you have a few molecules and dust particles in every cubic meter. Particle beams with even less mass can be very distructive at these (relative) velocities. You could try to armour your sail, but that requires even more mass. Don't forget the havoc that a single particle would be able to do if it managed to get through to the seed.
      Also, your sail is going to make an excellent target for offensive lasers. You could target the payload, you could add the energy to the propulsive beam to overload the sail, or you could simply use the energy to push the sail off trajectory.
      For that matter, it wouldn't be difficult to use kinetics to kill the seed. You simply need to have a greater acceleration rate. Not difficult since you are only launching a dumb mass. There is plenty of target area, and you don't even need to kill the seed to kill the mission.
      And, don't forget that you will need to protect incoming shipments. Assuming you can manage to slow down the load, anyone else would be able to as well. You would need considerable physical security to keep a load from being hijacked, and it is a LONG road from another star. Don't forget these security costs.

    10. Read this all, I'll respond appropriately when I can.

      Thanks for taking the time to consider all the points.

    11. 1)

      Thanks for the in-depth comments. There is no rush! :D

      The surface area I wrote was for an asteroid flattened into a 1m thick containing its entire volume, not the volume of a spherical object.

      The configuration stemmed from a conversation with Isaac Kuo on G+ and my own idea on how to best use the sunlight in a near-zero-g environment.

      If we are using sunlight to power the mining operation, surface area per kg extracted must be maximized. Spreading material into a disk costs very little energy. Breaking up a microgravity asteroid costs very little energy - breaking up and spreading out an asteroid before exploiting the surface area per kg ratio for fast extraction is faster than straight-up digging into an asteroid. In the latter case, you are limited by your physical 'mining' rate, if we consider mining to be the complete process of extracting, sorting, melting and smelting the rocks.

      So based on the assumption that mining is much slower than just moving rocks, it makes sense to invest time and effort into spreading out the disk.

      Also, the self-replicating seed in an optimal scenario is limited first and foremost by energy availability. Sunlight collection area in a spherical configuration is limited strictly to one hemisphere's worth. Replication and spread of the individual nano/micro-units is considered so fast as to be a negligible worry.

      A 'spread-out' asteroid can exploit sunlight at a constant rate, proportionate to how much material is being attacked. There are no energy limits, and it will quickly outpace a spherical model.

    12. 2)

      For two asteroids spread out to the same kg/m^2, the mining rate becomes proportional to the surface area. So, whatever the original size of the asteroid, they will take equal time to grind down to zero. Therefore a 10x diameter asteroid will produce 1000x resources just as fast. Considering that the only financial input into the project is the seed’s original cost and the cost of transport, the apportioned cost of mining a 10x larger asteroid is very close to 1000x less than a smaller asteroid. Very hard to compete on the market with that difference in prices.

      Now, you mention that the smaller asteroid-seeking project might overtake the larger asteroid. The problem with this is that you multiply the periods of zero production (breaking down and spreading out the material) and add a costly, complex constraint (building a transport system to hop to the next asteroid).
      Imagine the difference between a 100km asteroid and a 1km asteroid. 1000000x the output for the same initial cost, up to hundreds of millions more for the handful of objects the size of Ceres. There’s only 200-300 of these objects in the solar system and could become the McGuffinite for interstellar trade. Even adding up all the asteroids between 100m and 10km would not balance out this ratio, especially when we add up the transfers between them.
      The control of distributing products inside the system can be enforced, I agree. My critical argument, however, was that the expansion of an extra-solar colony could not be taxed or limited in any way. If we compare our Solar System to a colonized system, a single company could never control much real estate here without decades of expenses, efforts and expansions, while elsewhere it could just set a set to work and not pay a dime until it covers every body in the system. An extrasolar company would expand geometrically, an interplanetary company would face paywalls and legal restrictions every step of the way.
      If the control over the flow of products returning to the home system is leveraged by some administration into control over the expansion of a colony out-system, then every economic pressure that exists will make them lose out to administrations that only tax the profits of their roster of companies. Sure, there can be militaro-juridistical reasoning behind it, but then it would fall outside the scope of a scientific discussion into a less rigorous social one!
      The problem with holding off on production in this scenario is that your ‘stop production’ signal takes 4 years or more to reach the colony, and up to 10 years or more to take effect… holding onto and re-labelling the deliveries is the only option.

    13. 3)
      If we base ourselves on a modified set of cells, then we’re looking at the biomass doubling in hours. 1 gram can contain millions of each set of cells, so the chance of sufficient number of cells surviving intact is pretty high, especially when we factor in radiation protection, genetic repair mechanisms and artificially induced self-selection. The latter can take the form of a gene added to create an enzyme that allows the cell to break down the specific sugar in the ‘seed’ needed to fuel its activity. If the gene is damaged by radiation, the cell dies quickly due to the lack of the enzyme. Multiplying these genes gives the option of adding artificial fail-safes to the seed.
      50% is just a number I used to illustrate the statistics, it has no meaning. Even if all the failures add up to a 10% chance per seed, you can send 7 seeds to inflate the project chance to 52%, or 22 seeds for 90% success.
      The ‘seed’ contains radiation protection that doubles as a food source for the cells. It is assumed that when the cells are released, they will consume the food and shape the braking rocket into a self-sufficient system whether or not they have managed to land on a body with all the necessary resources. If they have landed on a barren rock, they should still be able to use the materials on hand to build a sensitive telescope and hop to a better rock.
      Only a tiny fraction of the cells need to be extremophile. They are the ‘pioneers’ that create a suitable, more hospitable environment for the other strains. This environment can be as simple as a hermetic cavity heated by radioactive decay and with holes for water-dust and an outlet for macro-sized machines.
      The velocity of the seed and other transport issues should have been addressed by Part II. Since the payload is so small, extreme mass ratios become reasonable. If the seed and accompanying structures mass 5 grams, a 1:2000 mass ratio braking rocket will only be 10kg. Stopping from 50%C would require an exhaust velocity of ‘only’ 20000km/s. This is well within the reach of fission sails or dusty plasma rockets.
      The outbound journey is handled by beamed power. It is assumed that the same power levels used for the interplanetary transport of thousand ton+ payload rockets can be focused onto a laser sail. The accelerations are measured in kilogees or higher, which keeps the ‘acceleration track’ well within the reach of interplanetary laser webs. I did the maths – is is actually possible to get this performance using much lower power levels than in proposals such as Forward’s Star Wisp.
      Speaking of tracks, there’s always the option of using pre-seeded tracks of impactors or nuclear pulse units to completely violate any conventional thinking on mass ratios and so on.
      The survivability of the seed at relativistic speeds should be decent, considering how small the payload is. 1 gram at the density of water can be shaped into a sphere 12.4mm wide or a cylinder 2mm wide and 3cm long. If we shaped the payload into a tiny, thin wire barely wider than the cells themselves, it would intercept barely no atoms at all!

    14. Addressing part 1: there are a number of false, or questionable, assumptions here.

      First, I was assuming a surface strip mine approach, rather than a tunneling approach. This means the limiting factor is what you can access from the surface area.
      Now, take into consideration that the act of mining IS breaking up the asteroid (in this case). The act of spreading it out after actually INCREASES the amount of work required, because now you need to break up the material, spread it out, and break it up AGAIN. Then there is the problem that you can not just spread out" cubic km of material into a flat disk, ESPECIALLY not in micro-g. Even though the gravity is negligible, the mass is still going to try to redistribute itself into a sphere (even if this "sphere" is quite imperfect)... that is, the mass is going to settle over time (as you spread it out, it is going to slowly "fall" back in toward the center of mass). There is the second problem that the effort of trying to spread the material out in micro-g is going to cause quite a lot of that material to drift off into space for a while, until it settles again... in a spherical shape.

      Second, I believe you are greatly underestimating the amount of energy required to break up and spread out even a single GT of material (1 km^3 at water density). I don't think we have any actual data yet as to the actual hardness of asteroids, but (even assuming that it is all loose dust) just trying to shovel arround that amount of mass is going to take up a LOT of energy. Keep in mind that 10 km^3 will be 1000 GT of material, and you are talking about doing this with 100+km^3, or 1 million GT.
      So, no, you are not going to want to move the rock until AFTER it is processed.

      Third, replication of the seed is limited by energy, yes. However, you can't replicate without SUITABLE material. Given the complexity of what you want the seed to do, you are going to need several different kinds of material, each in many different configurations.

      To Be Continued...

    15. (CONT)
      Keep in mind that you are going to be replicating the seed with mined material. This means that you can't replicate the seed until the material has been mined. Under your plan, it also means that the initial seed can not be replicated until the asteroid has been broken up and spread out... that is a lot of work for a single seed!
      BTW: again, I believe that your projected, "optimal", replication rate is FAR too unrealistic. The fastest and most prolific replicators are bacterial organisms. These are also the replicators that are the most durable, and that function under the greatest extremes. However, experiments conducted by the ISS have demonstrated that, although many forms of bacterial spores can survive in space for very long durations, most of even the most extremophile bacteria die after a few months of direct exposure to the space environment. NONE will reproduce while exposed to the conditions of space (although they appear to be quite prolific once they are completely immersed in a relatively nutrient-rich environment, such as the interior of the ISS). Your growth rates do not take into account that the environment in space does not allow for all the required compounds to be readily present for bacteriological activity, let alone reproduction.
      It MIGHT be possible to faricate a synthetic seed that does not go dormant right away, and that can store small amounts of required compounds while searching for the remaining vital compounds... but seeds of the size you suggest will move quite slowly (especially as it has to "taste" the environment around it as it goes, in order to recognise when it finds something useful).
      Furthermore, the compounds are only useful if they are in the correct molecular configuration. You might have all the right elements, but be unable to use them because you do not have sufficient compounds on hand to break them down.
      Incidentally, this is another problem with the small size of the seed. It will have limited quantities of the materials required to break down the asteroids, so it will have to produce more as it goes... but this requires a long chain of other compounds. On Earth, most (if not all) of those compounds have already been produced and widely distributed. This is not true in space.

    16. This brings me back to the issues with spreading out the material:

      1)You are assuming that simply breaking up the asteroid takes less energy than mining. Even with strip mining, this is probably correct. However, from the point where you have broken down the asteroid enough to move, it will take the same amount of energy to break it down the rest of the way for mining, whether you move it or not. Spreading it out adds to the energy required.

      2)Actually moving the raw material to spread it out redistributes that material, and mixes it. Much of the heavy metallic material will have been distributed by deposits of material ejected from supernovae. This produces veins of ore, with similar materials deposited in close proximity. For many types of ore retrieval, this configuration can simplify the extraction process. The redistribution from spreading out the material first could therefor add to the difficulty of extraction.

      3)The larger asteroids will have more gravitational attraction. This will compress the asteroidal material more. Granted, the gravity is weak, but it will also have been constantly compressing the material over millions, if not billions, of years. The result is that the material on the larger asteroids will actuallybe more difficult to break up than that of smaller asteroids.
      Keep in mind that "tiny" asteroids (meteoroids) have been compressed enough that the material sometimes survives atmospheric entry. This is not loose packing of dust. It is material compressed to hard rock that will already be very difficult to break up.

      4)Asteroids tumble.
      4A)This means that your spread out mass is going to tumble, unless you exert considerable amounts of force to try to neutralise the tumble. This negates any gain of trying to have a large surface area facing the sun at all times.
      4B)The tumbling is probably going to be relatively rapid, with only a matter of minute between passing from daylight to nighttime and back. It would be easier, and far more efficient, to simply build in an energy capacitor to store enough surplus energy to keep operation going through the nightime minutes.

      5)The seed is a growing structure. You are not going to get eny benefit from flatening out the asteroid until the seed culture has already grown to cover the entire hemisphere. This is not going to happen without a cosiderable amount of mining, just to get material for replication. If you ARE getting sufficient material for replication, you are going to be stripping off layers of surface anyway, so there really is no benefit in spreading it out. The amount of surface area processed will be the same no matter if it is spread out or not; and, while the mining is going on, you have a constant resurfacing to work on, which has the same effect as increasing the overall surface area (again, until you have covered the surface of an entire hemisphere).

    17. Addressing part 2:

      Regardless of the asteroid size, the growth rate for two seeds will be the same (until you have covered the entire surface area of the smaller). Your two seeds will have the same processing rate per seed, and the same processing rate per culture (again, until maximum size has been reached). It is not surface area alone that matters... it is the surface area that is being mined by seeds. The only way to increase the production rate for the larger asteroid is to increase the number of seeds. Even after you have reached maximum coverage for the smaller asteroid, it will take several more generations (10 generations for 1000x, and 20 gen for 1 000 000x) before attaining the kinds of production rates you are talking about.

      It might actually be beneficial NOT to continue the growth rate, as much of the material you extract will be devoted to replication. Instead, it might be better to achieve a stable growth rate, and allow all material mined at that rate to be delivered as product.

      Under my scenario, there is no zero production period for spreading. This is an inefficient task. Instead, the only actual zero production rate will be during relocation.
      Even this is not a true zero production rate, as "spores" will be sent out while mining continues to progress on the original asteroid, at a stable rate. You only have inactivity for specific seed spores.

      Don't forget that the transport system is already part of your seed specifications. The product has to get from the asteroid to the buyer, hich requires transport. It is no problem to use this transport to send a few spores to new locations. The only cost is energy, which is free (this has been YOUR argument for the interstellar mining... remember any tech available for interstellar mining will be available for in-system use).

      To be clear, I have been saying from the beginning that the one viable aspectof this interstellar mining operation was in the establishment of an interstellar colony. I have also advocated this point. Insterstellar colony? YES, definitely. Bringing interstellar product in-system for trade? Not so much.

      The best window for interstellar trade will be establishing a niche for "authentic" foreign products. An example of this MIGHT be food products that have a specific flavour due to the specific environments of the new solar system, and/or acquired from during the process of transport. There is extensive precedent for this kind of trade.

    18. Addressing part 3 (the initial paragraph):

      Again, your projected reproduction rates are problematic. You appear to be basing your rates on those of terrestrial cultures, or perhaps even on experimental results on the ISS, WITHIN the habitat. Things change dramatically once you get outside the contained environment. Once you get into vacuum, the biomass preety much immediately goes dorment. Almost all of the biomass dies, except for the most extremophile spores (not the bacteria itself, but bacteriologic spores). In any case, the growth rate for true biomass in vacuum is zero. Growth rate for biomass without a nutrient-rich medium is zero, regardless of energy availability. Thus, your growth rate for true biomass on an asteroid will be zero.
      You MIGHT be able to make a synthetic biomass that operates on the same scale. However, at best, this will remain active so ong as there is energy, but there would still be zero growth rate without suitable "nutrient" sources. It would take time to collect and store even the most limited amounts of such nutrients, for processing once you have sufficient quantities of ALL the required nutrients. With 1g seeds, progress will be extremely slow. You would be lucky to achieve MONTHLY reproduction rates. Hourly rates would be out of the question.

    19. More on part 3:

      It doesn't matter if you have a single "seed" of mass X, a seed culture with a total mass of X, or a seed culture with nutrient stores/protection with a total combined mass of X. You will have absolutely zero growth beyond mass X until you have extracted sufficient amounts of ALL the required nutrients from mined material. Furthermore, the rate of growth will be strictly limited to the amount of time it takes to collect and consume all of the necessary nutrients for any given reproduction cycle.

      The discussion of how many components of the "seed" are extremophile is irrelevent. The important aspect is that the organism as a whole must be extremophiliac. In any case, this is not particularly problematic.
      The problem is that all known natural cultures, regardless of their ability to survive conditions in space, go dormant once exposed to vacuum (that is, once they are no longer immersed in nutrient, which tends to evaporate in vacuum). Note, however, that I allow for the possibility of synthetic biomass structures that will be able to extract ALL of the required energy for operation from sunlight alone, in a closed cycle system. This alows for the culture to move and mine... but there will still be no replication until sufficient nutrient has been collected.

      I have my doubts that a light sail will survive kilogees of acceleration. In any case, at such rates you run into another problem: keeping the beam on target.

    20. I think I need to clarify a point I made earlier. I don't believe I ever said that production on smaller asteroids would overtake that of the larger, as you appear to imply. Rather, I said that production on the smaller asteroid might be more competitive.

      To be clear, the nature of the competitivity that I am suggesting is in the manner of security. Having a widely dispersed operation is inherently more secure than having one single "mega" operation. This is because the single site operation is vulnerable to accidents or sabotage that can potentially destroy the entire operation. For example, if the mining site were hit by a large asteroid or a large nuclear warhead blast, it could potentially wipe out the entire operation. Likewise, if you have a "worm" infesting operations, it could spread throughout the entire mining culture. Such destruction would stop all production, until delivery of a new seed, from which point growth will have to start over from scratch. However, if you distribute spores to other asteroids fairly early, a single site could be devastated, but the damage would not spread to other sites, so production continues and expands.
      You could probably take measures to (almost) ensure that such events don' happen. However, such measures are inherently expensive. It is the added security cost which will dampen the competitivity of the larger asteroids.

      So, recap: the possible advantage in competitivity is not a result of total yield or production rate, but through the reduced security costs necessary to ensure continued operations in case of mishaps.

    21. I have been thinking some more about your comment that only a fraction of the bacteria need to be extremophiles. At first, I was thinking that only the culture as a whole needs to be extremephile, thinking as you did that the extremophile bacteria could provide protection for the non-extremophiles. However, this is wrong.
      In effect, you actually need a "superextremophile" that is capable of creating a protective barrier against the vacuum of space. Without this, all bacteria, even the most hardy of natural extremophiles, go dormant. This superstrain will allow the culture to remain active.
      The problem is, unless your culture can create cell walls that are meters thick (more importantly, HEAVY, since it is the mass cross section, and not the thickness alone that provides protection against radiation), any non-extromphile bacterium is going to die. Quite simply, there is nothing that your superstrains can build that will can protect against the many forms of radiation passing through space... especially cosmic rays. It is also unlikely that they would be able to provide sufficient isolation to protect non-extremophiles from thermal extremes (notably heat loss).

    22. 1)

      Sorry I've been leaving this off for too long.

      Colony replication:

      Creating a new 'seed' from a central cluster that ejects a copy of itself every few hours is a small task to ask. Think of it as a miniature colonization effort, except this time the interstellar probe is the individual sub-clusters and the solar system is replaced by the asteroid's body.

      The central cluster is built from material originating from the first seed. It melts itself a bubble into the asteroid's surface. Ideally, it lands on ice mixed with dust. The ice is shaped into a solar focusing cone, which becomes a simple 'heat ray' that allows it to dig out the bubble and create a reserve of liquid water. The liquid water is used as 'acid' to dig through volumes the solar rays cannot reach. The water allows the colony to quickly sift through soluble and insoluble minerals, allowing for little clumps of mud to be used as bricks to close off and insulate the bubble.

      Once you have the bubble, a heat ray, a source of water and dust and a small cluster of extremophiles, you can activate the 'soft' cells. These cells live inside the bubble and are never exposed to vacuum- they never need extremophile properties. These are the cells that create tiny shells and chemical cannons to eject sub-clusters to restart the process elsewhere on the asteroid.

      If the seed arrived with fissile materials, it can use radioactive decay heat instead of a heat ray to kick off the colony.

      Now, the question of whether the soft cells can eat water and dust in a warm insulated environment and access to sunlight... ask plants :)

    23. 2)

      Spreading the material:

      As far as I know, most asteroids are a hard core of metal-rich rock, covered in dust embedded in ice. They are barely held together and have a rather porous consistency. The difference between an asteroid and a comet is the portion of ices in the 'mantle' of the asteroid.

      So, digging up chunks of asteroid is as easy as pushing a scoop into the surface and pulling it out like ice cream. Moving the chunk into position might be a bit more complex, but we're talking about deltaVs of about 5m/s for a chunk of material to reach the outer edges of a 25829km diameter disk within 2 months. We can use solar thermal ablation to create jets that propel the chunks outwards, then stop them. After all, we won't be shipping water, so its all useful as propellant. Solar thermal propulsion can provide the first rockets. Breaking down the water into hydrogen/oxygen propellants can become more efficient as the infrastructure is put into place. Solar pressure against a reflective face is enough to hold the chunks in place against the asteroid's microgravity....

      Re-mixing the material is a non-issue. Asteroids are by definition too small to be differentiated, that is, heavier elements to the bottom and lighter on top. You'll find minerals randomly distributed throughout.

      Tumbling masses should not be an issue if you can correct the movements of the individual chunks with solar thermal/chemical 'RCS'. Full control over the chunks' albedo eliminates the primary source of tumbling: uneven solar heating. If the material is tumbling at several RPM, its consistency won't hold it together anyway.

      I couldn't understand your growing structure argument. The benefit of spreading material is to maximize the kW/kg available to the mining operation.

    24. 3)

      I don't think increasing the number of seeds will help very much. The first role of the 'soft cells' is to create electro-mechanical machines with macro-sized roles, then have those construct bulldozers, trawlers, smelting furnaces and drills that do the real work. The whole point of the seed is to get standard mining fare onto an asteroid with minimal initial investment - all it is really saving you is having to ship the macro-sized equipment all at once. The growth of the seeds into the macro-scale structures is exponential. Linear multipliers (more seeds, x2, x3, x4) are dwarfed by single-generation increases in colony size (generation ^2, ^3, ^4). Since the generations are measured in minutes to hours... might as well wait an hour and save on shooting off another seed.

      The transport system being part of the seed specifications isn't really true. You don't have the massive infrastructure or the nuclear fuel you started out with at departure... for example, a laser sail seed won't have gigawatt lasers waiting to shoot off a secondary wave of seeds at the destination. This is especially true for interstellar operations. Inter-asteroid transport will have to rely on much slower but much simpler propulsion, such as chemical or solar thermal.

      I must note that the exponential growth of a colony is incredible even if we start with 1g mass and hourly rates. Within a day, the colony has grown to 2^(24) = 16.7 tons. If the replicating part is a fraction of the whole, even as low as 1%, it still grows to 1.7 tons in two months and over a million tons in four months.

      The laser sail surviving kilogees is actually less severe than the electronics in guided artillery shells (40000g), less than the proposed Star Wisp's acceleration (10000g+) or the ultracentrifuge tests of 436000g ( for the seed payload. After all, the sail is so lightweight that it is only needs to support a few newtons across its surface.

    25. 4)

      Security is a concern, yes, but it is has two caveats:
      -In an interplanetary scenario, the mining operation is as vulnerable as an offshore drilling platform. It can be defended and policed by agents in-system. In an interstellar scenario, this protection does not exist... but it would not prevent the essential 'first step' that validates the entire concept from happening.
      -A good rule of thumb is that if there is a means of attack, a way to defend yourself is not far behind. Breaking this rule leads to far greater problems: if your hacking software can overcome electronic defense reliably, then your global financial system is a much juicier

      I also discussed some of the attack/defense scenarios in this post. Your telecommunications are several times faster than even the most relativistic hacking attempt. Your period of vulnerability is between transmissions and returns, which is lightspeed limited to 4-5 years. Attackers will need to send a physical seed, have it establish on a virgin yet suitable rock, build itself a comms array, locate a target and overwhelm or obfuscate signals from the home system and do its worst until the next update. This can be defended against and does not require starting the colony from scratch.

      The security measures you mention must be more expensive than 10000x production capacity at 1/10000 the price or more.

      The radiation protection of a colony would be the asteroid's entire mass around the initial bubble. Afterwards, there is protection in numbers: it is extremely unlikely that the colony's entire stock of undamaged DNA replicators is wiped out at once, so if we include the 'failsafe' genes, there will always be a spark to reignite the fire, so to say.

    26. A couple quick notes:

      Re 1)
      I really hope you did not mean "melts", but just meant to express that the seed deforms into a bubble. The reason is that NO organism, whether natural or manmade, survives the process of melting, while remaining actively functional afterwards.

      Once again, hourly regeneration might very well be too much to ask, especially in the extremes of space. Another factor to take into consideration is that, even within optimal environments, it is difficult for cultures to maintain exponential growth rates because they quickly reach a size where the culture becomes too big for the subsequent generations to move out of the way. At the point that a given volume is saturated, only the surface area of the culture will continue to reproduce. The internal organisms will either 1) die, 2) go (reproductively) dormant, or 3) start consuming adjacent organisms.

    27. I meant melting the surrounding ice. The pocket of water is what I call a bubble. The cells can be dispersed into the solution of water, nutrients and mud.

      The replication bottleneck is true for 'dumb' replicators that use natural strategies. Artificially assisted cultures can intelligently move nutrients in and toxins out while expanding in a non-spherical manner, such as, projecting themselves into lines into the surrounding rock to maximize the surface area of the interface between culture and environment.

    28. Quick response before I continue:
      First, the problem is with the "nutrients" aspect. Spatial "dust" and "mud" are not the equivalent to those found on Earth. Specific microbes require specific environments. On Earth, you have had millions of years of chemical reactions breaking down the mineral deposits into molecular compounds that microbes can digest. This is not the case in space, where asteroids are largely devoid of such chemical interactions.
      Second, the replication bottleneck is a matter of utilisation of space. Yes, it is possible for nutrients to be transported to the interior microbes, allowing for them to continue function. Unfortunately, reproduction depends upon the sufficient supply of reproductive material, and once you have saturation, this is only available at the periphery. So, yes, technically the inner microbes COULD reproduce, but this is at a decreased rate, at the expense of a similar decreased rate for peripheral microbes. The end result is the same. Reproduction rate is limited to what the peripheral microbes can collect. This is part of the reason that human bodies do not continue to grow throughout life. It is not possible to maintain the level of nourishment for continual reproduction of all cells.

      Next message will be a continuation of my previous response.

    29. (cont.)

      Since I have just pointed out that "dust" in space (composed mostly of very simple chemical compounds that are not easily consumable by most microbes) is not the same thing as dust on Earth (which is largely composed of easily biodegradable dead cells), I will continue on...

      I need to correct one small error on my part. I have discovered that I have been misusing the term "extremophile". While I have been using the term to refer to organisms that can survive various extremes, the term actually refers to those organisms that have adapted to specific extremes (or sets of extremes) in such a way that they actually thrive (grow and reproduce) in such conditions, AND ONLY in such conditions (if you introduce these organisms to more moderate conditions, they die). These extremophiles require very precise sets of conditions.

      That said, since I have not found an adequate term for the organisms I have been describing up to now, and since such a misuse appears to be rather ubiquitus, I will intentionally continue this misuse of the term.

      I still have serious doubts about being able to introduce non-"extremophiles" into the culture. OTOH, it probably does not really matter, since the organisms will most likely have to be bioengineered anyway in order to make them suitable for the task at hand. Making them extremophilic would just be a part of this bioengineering.


    30. (cont.)

      I find your proposed mechanism rather problematic.

      I assume that you intend to use the ice as a lens for your "heat ray". However, natural ice, especially the dirty ice you would find on an asteroid, has rather poor qualities for a lens. The first problem is that the average albedo for ice is slightly above 0.5, or 50%+ reflectivity, while it has roughly the same absorbtion rate of any ice melt that you might be able to produce. Unfortunately, this includes the near 100% absorbtion throughout much of the IR wavelength range.
      The result is that your ice lens will tend to melt long before the ice that you actually WANT to melt.

      Another problem with this ice lens, or ANY lens, is that you need to have a good stand-off distance in order to have room to focus the solar energy. I do not see how you intend to provide for this stand off distance.
      Even assuming you provide room for the solar energy to be focused, you run into another problem: except for the high absorbtion levels of IR radiation, ice and liquid water both have very low absorbtion rates (about 5% of the energy, at best). This means that the energy will pass right through the focal point, without heating anything up much at all. You might have slightly better luck if you heat something other than water.

      This brings up the next problem: I am not certain you have taken into account the conductivity and radiation of the heat. Whether you focus the sunlight or not, the total flux of energy is going to be exactly the same. You might be able to heat up a small point, but the conductivity of all the mass around it (and the fact that increased relative temperature, compared to the surrounding environment, tends to increase the efficiency of that conduction) means that you will not likely be able to heat any specific point more than a few degrees, and almost certainly not enough to traverse the melting point of water).

    31. Jumping ahead to item 4:

      Once again, there is no need to attack the mining site. Although such an attack would be possible, if carefully considered, it would never be practical. I have been working under the assumption that the mining site will not be interfered with (any security concerns at site would be the result of local conditions, not interference from "home"). Under this assumption, I have also been arguing that using this approach for the establishment of an independent colony would be reasonable, and probably the best application.
      If someone wanted to deter such operations, there is actually a fairly sizable window while the transport is still in system. But even then, such an effort would not be particularly practical.
      Instead, the security I have been refering to is for ensuring the receipt of delivery to the intended parties in-system. There is a relatively small window of space that all incoming product must pass through, for successful interstellar delivery (for any given star system). There is a LOT of space to traverse between the star system and our system. Effective destruction of incoming product (causing product to be scattered into unusably small densities, in the context of collection) is rather trivial. Alternately, there is a great wealth of oportunity for someone to hijack the incoming delivery of product... all you have to do is get to the product first. Failing that, all you need to do to ensure failure is to prevent the intended assets from achieving rendezvous with the shiment... destroying the asset is an option, but probably would not be necessary. Hijacking the asset is also an option.
      There are, of course, means of defense. However, such means can be costly, and any given means can be overcome (with greater cost to the opposing party). The question becomes how much protection is practical and/or affordable, especially in contextof the risks.

      BTW: I was not refering to softaware hijacking.

      As for protection being the asteroid's mass: this is only true if you are at the center of the asteroid. On an asteroid, you would need to clear out about 2m of debth if you want to protect against cosmic radiation (assuming continual operation over a term of decades).

    32. First part of reply to point 3:

      My point was that, in terms of comparing productivity between two operation sites, actual size of the asteroid has absolutely ZERO effect upon processing rate, until operations have achieved maximum rate at the smaller site. Asteroid area is not the defining factor. Processing COVERAGE area (the amount of area being actively processed) is the limiter of production rate, and this will be identical for the two sites until the full surface area of one side has been covered. Thus, to achieve the actual processing rate advantageyou describe, you need to multiply the number of seeds (which increases the amount of area being processed at any given time). 5x the number of seeds provides a processing rate advantage of 5x. However, this defeats the purpose of having the reproducing seeds. 5x processing rate advantage comes at 5x times the cost.

      So, I am not disagreeing with you. There is no real advantage in starting out with more seeds. HOWEVER, nor is there any advantage in having the extra surface area, except that processing can continue for a longer term before having to move on.


    33. (cont.)

      The means of interasteroid transport will necessarily be exactly the means for transporting product. If your interstellar culture has the means to ship product home, then it (and in-system counterparts on both large and small asteroids) has exactly the same means for sending seeds to other asteroids. The only difference is that the inter-asteroid transfers will take much less time, and the seeds will take much less energy to ship than high-mass product.
      You will also want to develope this capability early on, because you will want to be able to ship product as soon as it has been mined, and possibly processed.

      Yes, exponential growth is quite impressive... to the extent that it can be maintained. The problem is with maintaining growth rate (again, hourly growth is problematic, given that asteroidal material is typically not in a "digestible" form), and that there are geometric, physical, limitations to how far exponential growth can be maintained. That said, this geometric limitation can be somewhat offset by being able to shoot off spores at sufficient distances. However, this has the adverse effect of inhibiting subsequent cooperation between "cells".

      Re the laser sail: I would point out that the solar wisp is a theoretical project, and its actual resistence to acceleration is untested. That said, I have no doubt that it would be possible to build, but the question is how heavy a survivable sail would actually be.
      Keeping the laser on-target is more of a problem. As is adjusting the focus of the laser so that the energy can be spread over the entire sail, rather than burning through the sail at initial close ranges. That, and being able to maintain energy for the acceleration of the mass of the seed, AND the required protective envelope, AND the mass of the sail.

    34. I don't have much time, so I will only make a few comments re point 2:

      We actually have very little information concerning the internal structure of asteroids. We know that they at least have hard cores because of what remains of asteroids that have reached the surface. We know something of the chemical composition and surface structure through imaging analyses.
      Actually, the theoretical model of asteroids as loosely packed piles of rubble has been challenged by results of the NEAR landing. Although neither NEAR nor Hayabusa (the only probes to make physical contact with asteroids) were equiped to analyse the subsurface structure, NEAR was able to determine that the many (over one million) giant boulders on Eros were not loose piles of rubble, but were structurally consolidated into a single mass. IIRC, Hayabusa itself was only able to acquire about 60 or 70 small grains... much less than even the 1g per sample cannister (and only one cannistr functioned properly) the probe was designed to collect. This suggests that it will be rather more difficult mining the material than you suggest.

    35. (CONT)

      Regarding water not being shipped: water is probably the single MOST valuable resource that will be mined from asteroids. It is ABSOLUTELY vital for living organisms in space. It is NOT something you are going to want to waste for spreading out material unnecessarily.
      Nor would you likely have enough water to achieve your projected spreading through solar ablation. Even if you separate the water and burn it, with an overly optimistic velocity of 5km/s, you would need a water mass composition of 1/1000. This is well over 4x the water mass composition of the Earth. So, no... you would need to rethink that idea.

    36. Out of curiosity, have you actually tried running the numbers for solar pressure?

    37. The issue with seed growth is that it is not the available sunlit area that determines processing rate, but the amount of area in contact with the culture doin the processing. It does no good having several thousand times the available area if you don't have several thousand times the area of seed processing it, and this area is determined by the growth rate of the seeds... which is exactly the same for both scenarios.
      Also, keep in mind that the seeds won't grow beyond initial total probe mass without nourishment, and you won't have nourishment until you mine it from the asteroid. This means that you only have the initial seed (fully fed) trying to perform all the work of spreading the material out for mining.
      OTOH, there is absolutely no reason to spread out the asteroid mass, because once your culture consumes and mines the initial surface layer, it opens up a new surface layer to be processed.

    38. I think you misunderstood. I was not refering to gravitational differentiation (settling). I was refering to deposition (successive layers of ejecta from various sources settling on the asteroids) and agglomeration (material being collected and redistributed from successive collisions, over the timeframe of billions of years). Asteroids are not homogenous. Settling would actually simplify the mining process considerably. Material is randomly distributed, but sometimes in packets.

    39. I'll get back to you eventually.

  8. Two points:

    Interstellar war seems to actually be far simpler than described upthread. A pod, seed or whatever is essentially an RKKV due to its immense velocity. A hostile power would not even bother with the expensive machinery and software inside, simply send the empty shell (maybe filled with moon dust or concrete) at the target system at a large fraction of "c". Aiming for the target sun should cause spectacular flares and solar disruptions, and if the RKKV has enough guidance to hit planets or active asteroids (i.e. ones with current operations generating enough thermal energy to be noticeable) then even better.

    The other point is that keeping colonists or even AI's happy and productive while contributing to the economy of the Solar Empire would seem to be more of a cultural thing rather than something enforced by economics or laws and regulations. If deeply seated cultural "norms" are imposed on everyone and everything which leaves (and these norms are observed on Earth as well), then the people and AI's will tend to act in ways which reinforce the prevailing culture and allow economic, social and other exchanges to take place.

    Consider that the Egyptian civilization lasted for thousands of years changing at a glacial pace (even when exposed to dozens of other cultures across the centuries). Religious or other ritualistic mechanisms could be used to ensure that people and machines remain "in sync" over the decades and centuries that interstellar colonization and trade would need.

    Another example of how cultural norms could be used is to consider the story of the Odyssey. Odysseys, despite being stranded on multiple polities across the ancient world, can always count on cultural norms like gift giving whenever he arrives. (The episode of the Cyclops is telling because it is entirely contrary to the norms of receiving guests by giving them gifts, hospitality and shelter). Once again, so long as these mechanisms are common to all and last, they will ensure that the people and machines are working in a generally harmonious manner.

  9. Hi Matter beam, I was reading through your article on Interstellar transportation systems but was kind of surprised because I didn't seeing any mention of mass drivers. Mass drivers are great because you you can slow the payload down on the other end with another mass driver and get most of the energy back. That way the interstellar colonies are providing two imports, matter and power (in the form of their payloads' kinetic energy). In the book "The Millennial Project: Colonizing the Galaxy in Eight Easy Steps" by Marshall T. Savage he outlines how a medium sized asteroid of a few billion tons can provide enough material to build a mass driver 100 AU long, enough to accelerate a payload to 99% C. A much more modest system could be used for the more near term speeds of 50-70% C.

    1. Hi Anonymous! (Try to find a name).

      Mass drivers that work at relativistic velocities for braking payloads measured in the tons are mega-engineering projects. They would resemble a space elevator or a space colony in size, but made out of expensive and energy-hungry components.

      A mass driver 100AU long, as proposed by Savage, would require our civilization to move a few steps up the Kardashev scale! A 50%C mass driver would only be about ten times smaller.

      While the benefits of a massive mass driver are clear, and the project technically possible despite its scale, it is completely outside the scope of the 'Interstellar Trade is Possible' post's objective of showing how little energy and infrastructure we'd really need. You'd have to start very small to prove the usefulness of the trade and finance yourself in the meantime before mega-projects such as the proposed mass driver are able to be considered!

    2. Ah I see, thanks for clearing that up so fast.

    3. I would like to know how you are thinking of using a mass driver to slow don the payload at the receiving end. That is not quite how mass drivers function.
      The only way I can think of to get such a system to work would be the equivalent of hooking up an EM catapult to an aircraft restraint mechanism. However, given the distances and energies involved (and other variables), this would STILL be the equivalent of trying to thread a needle with a boulder spewed from a volcano.

    4. A electric engine in reverse is a generator that slows down the wheel. Similarly, a mass driver in reverse is an electromagnetic brake that extracts the payload's momentum as energy.

      Threading the needle would be hard, but you would have years to correct the payload's trajectory, and magnetic funnels tens of kilometres wide can be created to handle the final stretch.

      If interstellar trade is regular and voluminous enough for mass drivers to be used, then we can easily thrown around terawatts of power to put into electromagnetic fields.

    5. Especially since you would get most of those terawatts back.

    6. @Planetfall: might be a bit difficult in practice. You can put out terawatts of power to accelerate the payloads, but you need to stop much faster than that. The mass drivers are shorter than you 'laser runways'. Also, storing energy is much harder than generating it. A single terajoule requires thousands of tons of maximum strength carbon nanotube flywheels to be stored.

      A 50%c thousand ton payload contains about 90 zettajoules of kinetic energy. Storing all that in 190MJ/kg flywheels (the maximum physically possible) still requires about 474000 million tons. Less extreme flywheels would need much more...

    7. A few problems with the mass driver idea:
      It is difficult enough to operate a mass driver of sufficient size and energy sufficient enough to produce solar escape velocity delta-v, unless (perhaps) you are already on the far outskirts of that system. You can build such systems as a single mass. However, you run into problems when building systems with a big enough "eye" to cover the disersion over multiple-l.y. distances. You are talking about building physical coils tens of km in diameter. I would suggest that this would have to be MUCH larger, but let's accept your assessment for the moment. To be clear, you need a repelling force to slow down the load; thus, you have to catch the load in the middle, otherwise, you will be pushing the load away from your mass driver stages.
      First problem is the amount of mass required for each stage of operation.
      Second problem is the amount of energy required to maintain the field for each stage.
      Third problem, we don't yet know of anything, that could produce AND survive a sufficiently strong field to cover the required (interior) span. If the field is not strong enough at the center, the field will just nudge the load toward the center, and let the load progress on its merry way without any significant deceleration. Incidentally, this is the most immediate objection to Bussard scoop proposals.
      Now, to decelerate the load (assuming that you can design working coils that overcome the above problems), you will need a MUCH greater system length compared to the coil diameter... as in thousands of km.
      Each coil increases the mass requirement. First problem.
      Second problem is keeping the successive coils in position. They are going to want to follow their own orbits, which means that you are going to have to expend a hell of a lot of energy to keep the system alligned.
      At least there is a little bit of good news: each coil will at least nudge the load toward the center, which means the actual required coil diameters will progressively decrease, so you will essentially have a receiving funnel.

      Note: I spoke about needing to "repulse" the load. Yes, I am aware that once you pass the coil, it will actually start to attract the load, while the next coil begins its repulsion phase. The problem is with the original approach to any given coil. This is why the coils need to be larger than the "eye".
      I point this out mostly for the benefit of other readers who might suggest just creating a long pole to generate the field.