dystopic dystopic

bussard ramjets, cryonic stasis, and exoplanetary colonization

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bussard ramjets, cryonic stasis, and exoplanetary colonization

what will it take?

from GalCiv2 Forums
hello everyone,

i'm a bit of a writer, and i can't help but feel drawn to science fiction. that shouldn't be surprising.

lately i've been reading up a great deal on theoretical physics, exobiological speculation, and all that. i was dismayed at first to learn that the chances of faster-than-light travel being physically possible are slim. it was also pretty discouraging when i sat down and looked at the actual speeds that'd be required to traverse sizable parts of the galaxy in a single conscious lifetime. it was a kick when i was down to learn about how difficult terraforming probably would be. but the more i've been learning, the more i've been excited about telling a different kind of science fiction story.

to draw an analogue to our world, the thing that made both the european colonial age and the modern process of globalization have been technology. it's not that we couldn't go to various places around the world before, it just cost too damn much to make anything worth it. i got my BA in sociology, and these sorts of things interest me.

if FTL travel isn't possible, then more than likely it'll be too damn costly to ever colonize beyond our own solar system as the way it's been envisioned in most of the celebrated scifi universes. But there are examples such as Arthur C. Clarke's Songs of a Distant Earth or Sid Meier's Alpha Centauri where humans colonize to escape destruction on earth.

recently i had the chance to meet both Kim Stanley Robinson and Geoff Ryman. Robinson is a hard scifi writer after my own heart; the Mars Trilogy is a really interesting look at our first attempts to colonize within our own star system. Ryman was actually more interesting to talk to, though. maybe because few people have ever heard of him (i was only there because i work at UCSD where he was being hosted). but i actually got to talk to him. he said he thinks we probably won't ever leave our galactic neighborhood.

i'm interested in writing a hard scifi story (or series) myself. i'm interested from a sociological point of view: what would drive us to colonize space? from a writer's point of view, i want to keep the earth around, so i'm not interested in a flight from disaster. what would societies be like after colonies were established? trade would be difficult, but not impossible. same goes for war.

while i'm certainly interested in contributions along those lines, i'm also interested in learning more about the hard science and engineering behind interstellar travel. i've got a lot of questions i haven't been able to answer through wikipedia and google alone. but i'm not about to list them all here.

it seems like a discussion about real ("real") colonization and space travel could use a place on these boards.

i'll kick it off. i've been reading up on propultion especially, and bussard ramjets seem like the most economically feasible option since they gather their fuel as they go - perhaps especially if it could be hybridized with another form such as antimatter-catalyzed fusion. the wikipedia article on bussard ramjets describe that they'd probably need what is essentially a magnetic funnel or ramscoop to gather interstellar hydrogen as propellant.

The mass of the ion ram scoop must be minimized on an interstellar ramjet. The size of the scoop is large enough that the scoop cannot be solid. This is best accomplished by using an electromagnetic field, or alternatively using an electrostatic field to build the ion ram scoop. Such an ion scoop will use electromagnetic funnels, or electrostatic fields to collect ionized hydrogen gas from space for use as propellant by ramjet propulsion systems (since much of the hydrogen is not ionized, some versions of a scoop propose ionizing the hydrogen, perhaps with a laser, ahead of the ship.) An electric field can electrostatically attract the positive ions, and thus draw them inside a ramjet engine. The electromagnetic funnel would bend the ions into helical spirals around the magnetic field lines to scoop up the ions via the starship's motion through space. Ionized particles moving in spirals produce an energy loss, and hence drag; the scoop must be designed to both minimize the circular motion of the particles and simultaneously maximize the collection. Likewise, if the hydrogen is heated during collection, thermal radiation will represent an energy loss, and hence also drag; so an effective scoop must collect and compress the hydrogen without significant heating.


talk about kick-butt imagery! spirals of heated gas careening towards a ship only to be fused and expelled in a jet plume? sweet.

anyway, i've written enough, and i hope it hasn't put anyone off. some of the the community here has proven to be very well read with regard to these kinds of science, so i thought it'd make a great topic for discussion: all things related to space exploration and colonization with reasonable extrapolations of current technology.

my biggest point of curiostiy was with respect to ramjets, so i'll take the kickoff: could the spiral motion of the inbound gas somehow be harnessed to artficially generate gravity by rotating the ship, instead of producing drag?

any volunteers?

final words: i hope no one minds my double-motive. i won't try to steer any dicussion, though if things quiet down i might pose more general questions to keep it going; i encourage anyone interested to pose your own!
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Reply #226 from GalCiv2 Forums Top
but my inclination is that raw materials will always be cheaper to make or mine locally.


not if we run out of raw materials to mine. such as titanium. as far as i know there is only one source on earth in russia. whom we bought from to build the black bird
Reply #227 from GalCiv2 Forums Top
here is something else to think about.

the ancient greeks had all of the parts to build a steam train.
Sins of a Solar Empire: Rebellion
Reply #228 from GalCiv2 Forums Top
not if we run out of raw materials to mine. such as titanium.


that's my point about fusion: you fuse two hydrogens, you get energy and one helium. you fuse two heliums and you get... crap, what's number 4? beryllium. you could also fuse 1 hydrogen and 1 helium to make a lithium, and i think that's actually the next phase in solar fusion. but in controlled fusion, i'm not sure there would be any limits to what we could combine and make. energy is released in all of the reaction that produce anything as light or ligher than iron, atomic number 26. that includes such notables as titanium, silicon, oxygen, carbon, and yes, even noble argon   

that's why there's so much iron in the universe: it's the last thing a star can fuse to create energy--the only thing keeping it from collapsing upon its own gravity. i'm not sure how cosmologists explain the presence of heavier elements (though now i'm really curious, perhaps tomorrow at work i'll try to find an answer).

but we can still create heavier elements via fusion; it just means we'd have to add energy. so the real question is: does the energy it'll take to fuse what we need cost less than what it'll take to mine on a colony and ship back to earth? as in modern economics, when it's close it really depends on who offers a better deal.
Reply #229 from GalCiv2 Forums Top
i'm not sure how cosmologists explain the presence of heavier elements (though now i'm really curious, perhaps tomorrow at work i'll try to find an answer).


super nova
Reply #230 from GalCiv2 Forums Top
i'm not sure how cosmologists explain the presence of heavier elements (though now i'm really curious, perhaps tomorrow at work i'll try to find an answer).



super nova


Yep, that's it. The heat and pressurized shock waves formed by an exploding star create adequate conditions for heavy elements to form.

Also, note that all reactions don't proceed with 100% predictability. Even in a star, there are fluctuations of temperature and pressure, meaning that for very brief periods there are areas where heavy elements may be formed by a sudden spike in pressure/temperature. This goes for any reaction, not just nuclear. Free radicals, for example, are very rare, yet due to minute fluctuations in chemical conditions, they can be formed in our bodies, and do considerable harm once made (though some free radicals are necessary for certain biochemical reactions).

------------------

The fact that we would be able to fuse any element we wished, and synthesize whatever molecular structures we needed from said elements, is why I said earlier that the only raw resource that would be traded is natural fuels; energy is the only real resource once we reach the "synthesis age".
Reply #231 from GalCiv2 Forums Top
super nova


i thought as much, but i couldn't remember for sure and didn't feel like researching it.

Also, note that all reactions don't proceed with 100% predictability. Even in a star, there are fluctuations of temperature and pressure, meaning that for very brief periods there are areas where heavy elements may be formed by a sudden spike in pressure/temperature.


a very good point, and i hadn't even thought of that. i always assumed that high metal bands in a star's spectrograph meant the metals were present when the star formed, but in this light it also makes sense that higher metal content could form over time in a less-stable star.

Free radicals, for example, are very rare


i'm curious about this. what is 'rare' in this context - 1 per year? 1 per day? considering the multitude of chemical reactions that constantly take place in the body, i could still imagine 'rare' being every second or two.

energy is the only real resource


energy and information, of course.

once we reach the "synthesis age".


nice name! i swear earlier i read a slightly different post where you said you made the name up... i'd suggest 'synthetic age', to remain in keeping with the fashion of naming ages with adjectives when possible: middle, industrial, modern, but 'space age' makes a lot more sense than 'spacious age' or 'spacey age' (which i actually think refers to the 60s  ).
Reply #232 from GalCiv2 Forums Top
If you're seriously interested in this, a good book to read is "The Voices of Heaven," by Frederik Pohl. It covers a lot of social stuff and a lot of colonial stuff, and does it all in a (with our current knowledge) possible manner. And by that I mean we'd have to scale up a great many projects, but it could almost exactly be done now.

Edit: And if you're worried, no, it's not religious; instead, it looks into the social hows and whys of religion (hence the "covers a lot of social stuff").
Reply #233 from GalCiv2 Forums Top
i'm curious about this. what is 'rare' in this context - 1 per year? 1 per day?


The radical its self is considerd "rare" as it will otfen interect very quickly with surrounded molecules and neutralize its self. However, chemicals desinged to form radicals are not rare - Hydrogen Peroxide is one example. Oxygen is the most common radical (due to Ozone and the fact that it is heavily used in our bodies during metabolism), but many other radicals exist especially in biology as defense and cell signalling systems.

Many of our non-neurological toxins (poisons) operate by a process known as lipid peroxidation, in which a radical chain reaction literally eats up the cell membranes' of cells, causing wide spread necrosis and damage.

i could see that kind of information being guarded as a means to create a never-ending source of income. i mean, you send off this valuable thing your colony has discovered/created, and what do you get in return?


What about patents, Licensing? Let some one else on earth take up the cost and complexities of producing it (instant product placement!) and the colony gets the licensing, intellectual property rights, and fees from the contract (X% of profits, or something). The colony could make money a lot sooner that having to build an infastructure for mass commerical production and then shipping to another star system.
For example; Think of some of the larger corporations like Sun or IBM. I don't have anything with IBM stamped on it, but I can guaruntee that my intel and nvidia chips have IBM patented circuts, etc. Bell labs didn't mass produce transistors, they just held the patent for it. There could be a lot of potential, especially if the colony can produce design/think up things that would not be possible or thought of on earth, like new enzymes, or construction material design (there are different formulas for concrete, steel, etc)

Hope that makes sense and it might solve some of out distance problems with FTL out of the picture.
Reply #234 from GalCiv2 Forums Top
i swear earlier i read a slightly different post where you said you made the name up...


You probably did. I did a minor edit of my post sometime after my original. I must have cut that out.

We have been talking about how we could transfer funds electronically between Earth and its colonies, but I think that this is all a moot point. Money today is really more of a "space holder" for future goods one intends to own, essentially it is what we use to operate open-ended trades where one person hasn't yet decided what they want in return for their goods/services, as well as complex trades between multiple parties. But as we said, its value only exists amongst those who recognize it. Transfer of digital funds between worlds makes no sense, because if there are no trades taking place between those worlds, these funds aren't holding the place of anything.

What about patents, Licensing?


Thats what I was trying to get at earlier, when I was talking about "Galactic Imports". Whatever company that had sponsored the colony would have the rights to its intellectual property. Note that the colony itself doesn't really forfeit rights to this information, because there is no way for Galactic Imports to enforce this from Earth. Essentially, Earth's economy would be entirely separate from that of its colonies.
Reply #235 from GalCiv2 Forums Top
a space empire economics as i see it

take for instance

3 colonies in sol.(possibilities of lots more not counting artificial constructions.)

1 colony in alpha (same possibilities of above.)

each colony would have their own economy.
each system would have their own economy.
and then the empire would have its economy.

translate economy to budget.
Reply #236 from GalCiv2 Forums Top
using the above samples there would be few if any systems that couldn't be colonized.

the ones with no habitable planets. can still be colonized using the colony ships by docking them to each other make a base or bases.
Reply #237 from GalCiv2 Forums Top
dammit all to hellena! i had a nice, thoughful post, and the site stalled out.

so, with less care, here goes. millertime, what you said lines up very well with what i've been getting at. the phrase that money is a place-holder was especially articulate.

the issue with any kind of trade is one of enforcement: who's going to enforce trade agreements? when you won't hear back from your trade partners for years or decades, what's to hold them to their side of the deal? how would you know they didn't cop out? and not knowing that, why would you want to hold up your end? and they'd have the same questions, so why would they hold up their end if they can't know you'd hold up your end?

as a dirty liberal i hate to admit it, but: might makes right. enforcement: it's the basis of complex government, and the root of classical ideas of power. there are other kinds (or at least theories of) power. the most notable one that's popular in the social sciences and humanities now concerns the relationship between power and knowledge, especially truth. i'd be hard-pressed to explain Foucault's ideas of power/knowledge succinctly, but i can get to the point here. i think the only kind of power struggles in the future are going be related to struggles to control or access lines of communication. i'm talking struggles between star systems here, not within them. i think systems will tend to form coherent political units because the issues of travel and communication are so much less a problem within a system as opposed to between two or more of them.

material trade will be difficult if not impossible, and maintaining a unified government across separate star systems will be a tenuous venture at best, and probably not stable enough to survive. i'm not even sure the Earth/Sol would want to run colonies in other systems - it'd be a lot of work for no real gain.
Reply #238 from GalCiv2 Forums Top
there are two things that a starting colony won't be able to do.

1 it can not research better engines while traveling.

2 it won't be able to build any combat vessels if needed. yes i have read the arguments against interstellar wars. but there is always a chance.

humans are not going to send a fleet of colony ships out without some sort of protection. ie combat ships. it will and can send out a single ship but not a fleet
Reply #239 from GalCiv2 Forums Top
as for cargo and payment is concerned. the best way to do it would be for the buyer to transmit the payment to the ship that will carry the cargo. the ship computer will be programmed in such a way that if it the payment program is tampered with in anyway before it reaches its distention the payment is erased. otherwise after reaching distention it transmits it back to the colony. yes i know that is still about 60 years. but it seems to be the only way to make sure payment is received and cargo is received
Reply #240 from GalCiv2 Forums Top
humans are not going to send a fleet of colony ships out without some sort of protection.


protection from what? i think if there were aliens next door, we'd have heard them by now (or at least, by then - we're already on the verge of being able to go gas spectrometry to look for organic compounds in the atmospheres of known exoplanets, and if there were funding for it, soon we'd have orbital telescopes with the power to resolve much smaller objects (both in the outter reaches of our own system and in nearby systems). i mean, in terms of arming the colonists, yes it's always better to be prudent, but no matter how big a ship gets, every gram of it will still have to be justified as necessary. i could see it on the enourmous "corporation on a rocket" colony ships i've been talking about, where the entire business itself goes with the colony. if the ship's their headquarters and the bulk of their resources, i think they'd find it very easy to justify defensive measures.

besides, you're the one who keeps saying small ships are the way to go. i don't necessarily think you're wrong, those are just a couple unadressed questions.

the ship computer will be programmed in such a way


i thought about a similar but general idea earlier but didn't bring it up, using programming to safeguard these transactions. i think a much better use, though, would be in the information trade. the colony transmits a self-extracting program that will not parse the content data (the actual message) until it verifies that a bartered amount of data as been sent back to the colony; once it verifies that, it decrypts its own data for its target consumers.

even there it isn't perfect; i firmly believe that with enough time and energy, any digital security scheme can be broken. and i think the prospect itself still fails to really address the issue of enforcement. okay, so the ship's computer can be programmed to ensure payment - what's to stop the military at the destination from simply seizing the cargo? certainly not fear of reprisal. even if the cargo ship is armed, it's one ship against an entire system's military.
Reply #241 from GalCiv2 Forums Top
Well if we are waiting fro a confirmation msg from earth to reach colony and get back wouldn't that be a super long time, plus the time it takes for the "packaged" info to get to earth in the first place?

What if it was done via a satellite or outpost halfway between the colony and earth. Cut response times in half. Info and payemtn would be sent there, confirmations sent from there, and then the info and payment would go on to their final destination.

Bedides I know we talked about singal bosting and not needing it. But we are talkign about packing hug amount of info, digitally into a little wave. Even a little loss or deflection from a magnetic thing (can't think of an example - a solar flare, maybe?) could really mess up the transmission. Might be nice to have sometthing outthere that can descramble it in case.

ps sorry for typing wierd - not drunik, I swear - Sleep medication kicking in - Good night!
Reply #242 from GalCiv2 Forums Top
as for paying for science info

we will have to do it the way we do it now with grants.
Reply #243 from GalCiv2 Forums Top
What if it was done via a satellite or outpost halfway between the colony and earth.


one problem with that is drift. granted, the problem itself would only emerge after incredible durations of time, and could probably be fixed by adding even weak engines to the station. but i think a station wouldn't be massive enough to be affected by the mutual gravity that keeps stars rotating around the center of a galaxy in a relatively predictable way.

Bedides I know we talked about singal bosting and not needing it. But we are talkign about packing hug amount of info, digitally into a little wave. Even a little loss or deflection from a magnetic thing (can't think of an example - a solar flare, maybe?) could really mess up the transmission. Might be nice to have sometthing outthere that can descramble it in case.


well... i'm not sure a midway station would be able to help offset an EM disturbance like that. a quasar or supernova might affect things. however, the solution is simple enough and would probably be a standard part of ensuring data integrity anyway: redundant transmissions.

if a disturbance lasted too long for that, messages could be relayed via a third colony. the only issue i see with midway stations is how to get them there. one of two challenges would occur if you wanted to construct them on site: either hauling enough raw materials there, or how long it'd take to gather enough ISM for fusing the raw materials you need on sight. if it was mobile, the biggest challenge would be justifying the expensive of building powerful engines that wouldn't be used all that often. if the engine itself was dual mode - sometimes a fusion reactor and sometimes a fusion engine, it might be more justifiable.

just some thoughts.

as for paying for science info
we will have to do it the way we do it now with grants.


grants pay for new research to be conducted. i at least have been talking about how to pay for new knowledge - i.e., the results of research that's already taken place. grants might cover that for other researchers, but i was thinking more in terms of applied technology - gene sequences of interesting organic life; molecular configuration information for useful enzymes; skematics for new propultion or radition shielding or whatnot.

and i think info trade (whether it's egalitarian, barter or through some currency system) would also include historical and cultural information. people (at least some people) can be intensely interested in other people, esepcially people with marked differences - so you'd see music, film, writing and other forms of recorded art going back and forth; philosophies, ethnographies, theologies - hell, i could even see blogs and such going back and forth (not in the same exhibitionist way that the internet facilitates, but as archived research data and human records, the same way we've preserved the diary of anne frank).
Reply #244 from GalCiv2 Forums Top
if you want to or need to put up relay stations along the way.

then why not just build a base.


remember my idea was to have the colony ships so that they would move independently of each other but be able to dock together making one base if necessary. as for station keeping rockets you only need thrusters. thrusters can be fueled by anything. thus you ram scoop would work very good in between the stars.
Reply #245 from GalCiv2 Forums Top
if you want to or need to put up relay stations along the way.

then why not just build a base.


i'd actually presumed a station with living staff, i supposed there are tradeoffs in either respect. the only problem i see with a staffed station is... well, ever watch Sealab 2021? it's one of, if not my favorite cartoons, but a lot of people don't really get the show in the same way i do, at least not at first. they often say it makes no sense to them. i point out that, first, it's not a show they can drift out of; because the episodes are only 12 minutes each, 30 seconds of distraction can leave you clueless. but more than that, i explain my sense of the premise, and i do it like this.

what do you think would happen if you were isolated in some remote location for months or years on end with only the same hundred or so people around? everyone would become psychotic, nymphomaniacal, or both. and that's Sealab for you.

while i don't think that makes for very convincing 'hard' sci fi, psychology is such remote isolation would be a difficult task. i suppose if a fair amount of trade, carried out through actual travel between stars, were taking place, it wouldn't be as much an issue. but even if it does sometimes occur, i can't see it being frequent by the measure of even an extended lifespan.

thus you ram scoop would work very good in between the stars.


properly speaking a ramscoop would be a horrible: their ability to draw in propellant is directly related to the ship's forward momentum, so a relatively stationary object wouldn't be able to draw in much propellant at all.

however a slightly modified version could do the trick. using lasers one could ionize hydrogen, and then draw it in using an electrostatic field.

but that doesn't solve everything: there still is the issue of power. i don't think a fusion plant would be ideal for deep interstellar space. if the fusion, like the trust propellant, were based on drawing in interstellar hydrogen, i'm not sure ISM would be dense enough to provide sufficient power via fusion. a station like this might more likely rely on "solar power" mainly. i put solar power in quotation marks because it wouldn't be absorbing primarily visible light, the way we think of solar power now. i imagine rather that the photovoltaic substances would be engineered to primarily absorb the dangerous side of the EM spectrum - UV and above - but at the same time refract the lower- end frequencies into the feed antenna. so if it's possible the radio dishes would double as high-frequency EM photvoltaic cells. it'd provide electricity and reduce the needs for separate radiation shielding.

another issue relates to deceleration and re-acceleration. but i'm going to have to come back to this in a separate reply. it's a complex of issues i want to talk about, but i had to wake up at 5:30 this morning for an early meeting, so i don't have the energy, and i'm not even sure i'd be very coherent. i thought about my above replies earlier today at work, so i'm hoping they at least make some sense (i don't think i can tell anymore; i feel delerious; what ever happened to my ability to pull all-nighters and function without sleep? it got me through college with high honors, and now if i get less than six hours of sleep i'm a useless lump all day).
Reply #246 from GalCiv2 Forums Top
sorry i assumed that the station would be rotating or you could stick the scoop on a boom that could rotate this solving the movement problem.
Reply #247 from GalCiv2 Forums Top
sorry i assumed that the station would be rotating or you could stick the scoop on a boom that could rotate this solving the movement problem.


i don't really think that'd work. the ramscoop on a moving ship works better the faster the ship goes. it starts reaching peak performance when the ship starts getting closer to light speed. also keep in mind, we're not talking a kitchen funnel here. the ramscoop's magnetic diameter would have to be at least hundreds, more likely thousands of kilometers across; it has to be to draw in any significant amount of hydrogen. in what i'd imagined, a ship propelled by a ramjet would have to use stored hydrogen to accelerate initially. when the ship needed to decelerate it could redirect its intake stream to refill the tanks, creating drag and thus slowing the ship down. if that wasn't enough, you could vent the tanks in the opposite direction as a kind of reverse thruster.

i think actually for a station, it'd be easier to generate thrust using a laser. photons have mass, and we can convert them from electricity. there's a link/post somewhere above about a kind of propultion system like that. it wouldn't generate much thrust, but you wouldn't need much thrust just to maintain a "galactico-synchronous orbit", and it'd be extremely more efficient than trying to collect ISM while sitting relatively still.

even though i don't think we'd set up deep space stations for the sole purpose of relaying messages between systems, i do think this is a productive line of discussion for me. surely we'll discover thing we'd like to study up close and personally, and our discusssion so far can pretty much apply to any type of deep space station, not just ones for communication.



anyone noticed our uses of pronouns in this discussion? we, and by we i mean those of us posting, tend to use "we" and "you," but not "they" - as if any of us will actually participate in anything like this. but i suppose that's what stories are for in the first place, and it interests me that in just talking about these things, we (the real we) have already suspended our disbeliefs to a large extent. maybe it's just a convenient speech convention, but it seems very pervasive in this discussion.

just a random observation, no real significance attached to it in my mind.
Reply #248 from GalCiv2 Forums Top
you don't need a lot of fuel for station keeping. it doesnt even have to burn. the thrusters on the shuttle and sats just use air. remember every action has an equal and opposite reaction. and a station between the stars wouldn't even be fighting gravity just motion
Reply #249 from GalCiv2 Forums Top
you don't need a lot of fuel for station keeping


i did consider that, and i hope it doesn't sound like i'm dismissing your ideas out of hand. i think the underlying issue here is that without some hard numbers, we can't really tell what methods would be most efficient; without that, we're just going on intuition.

with the way technology goes, i think different methods would be used at different times, perhaps even in a back and forth pattern, similar to the way different computer hardware and software design methods can oscilate for first place performance.

along those lines, i was actually thiking that at some point i might try to compile a list of more technical engineering questions (and general ideas), and see if i can recruit a member of the engineering faculty on campus for an afternoon of brain picking picking and idea bouncing. if nothing else, maybe s/he could point me to someone else - lockheed martin's integrated systems division is located here in san diego (at least partially; i go by their facility every day to work), and they also just opened (or announced, i'm not actually sure) their 'global vision center' here.
Reply #250 from GalCiv2 Forums Top
i am just saying that if a puff of air can keep you on station in orbit where there are three strong gravity sources. earth, sun, and moon.