I'm sorry, the quote stacks are getting a bit too large for me to have a full overview of this discussion, but where exactly is the disagreement? Space is a profitable market, we do space stuff to profit. Development costs and risks are high, so everyone can't just rush in with their capital, and returns on investment are slow. I don't understand what more there is to discuss on this front - space industry is trying to make a profit, these are multibillion corporations, not a star trek fanclub.
And frankly, I find the rapture stuff pretty insulting. To take the AI example: "What are these university-educated people doing working in a profitable soon-to-be trillion dollar industry at the forefront of technology, with enormously wide applications both future and current? They probably believe that nerd-rapture is real olololol idiots"
If you're imaganing von Brauninan ''Let's put 50 people and Mars and then go home... because flags!'' scenarios or some kind of NASA with 20% of USA's GDP spending trillions on getting a slightly better understanding of how the solar system was formed, then sure, I agree with you. But then, I think it is your view of spaceflight that's suffereing from zeerust, not spaceflight itself.
My understanding is that today, there is an economic incentive for developing spaceflight, based on current technology. Orbital systems for supporting communications, earth observation, etc. are undoubtedly profitable. The eventual costs and profits for a system of tugs and refueling infrastructure based on ISRU can and has been assesed, and the judgement is that the development costs would be very high, but it would be profitable. This system would be used for stationkeeping, orbit changes, ejection burns and maintainance of spacecraft in Earth and lunar space. This is, as I understand it, a very lucrative market that is currently completely untapped. With this system in place, it would be profitable to construct infrastructure for mineral extraction and simple manufacturing in space. Valuable metals would be extracted and colony-dropped on a suitable spot of Earth. Replacement parts for spacecraft would be manufactured, maybe eventually entire spacecraft. The cost of manufacturing something in space using ISRU would be outweighed by the humongous costs of launching something out of Earth's gravity well, and what if you only need to replace a 3D-printed 0.05 kg cog? The final step would be construction of low-cost launch infrastructure like Rotovators, that would usher in an age of Sea-Dragon-style cheap and shoddily (in a mass-conservation sense) built payloads that bring the costs of spaceflight into the realm of aviation.
Feel free to doubt this statement, I don't really have a source right now, I could try to look it up if you are interested.
And commenting on the CoadE lore: While it's true that Earth was rendered uninhabitable and this is part of the explanation for the situation in CoadE, it's worth noting that the civilization already had what I would consider an interplanetary economy, with several Rotovators (meaning many tonnes of payload per day!) active. And I would consider that a plausible or at least possible future.
Uh. The mass of the human, life support system is just unacceptable.
As for dodging, fuel endurance is an issue. If my megameter-per-second frag linear accelerator can accurately hit a dinner plate from say, 100 megameters away, you need to be able to continuously evade until within your own effective range of my ship. It just doesn't seem feasible.
Is it really? A closed cockpit, air recyclers and life support for a week might end up being less than a ton. We don't need the fully recyclable closed life support systems on spacecraft designed to make interplanetary voyages. If the spacecraft's total dr mass is 100 tons, then we've added a 1% mass penalty for a perhaps significant gain in total effectiveness.
The fuel endurance is an issue, but it is relative. You only need to dodge after each shot, which might substantially reduce the amount of time spend thrusting. Rapid approaches also reduce the total time required for dodging. Agreed, it will be easier to do in settings where high-energy propulsion is widely available and compact, such as inertially confined fusion schemes.
If we set the upper limit for acceleration at 10G, then the 'fighter' can approach up to a distance of 200km while being 100% certain to dodge all incoming projectiles. It can approach up to 150km if it dodged by only half its width. The last row (1000km) is calculated from a starting point of 2000km. The total deltaV required for dodging with either option is 2559m/s@100% and 1280m/s@50% up to a closest approach of 200km. If the closing velocity is increased, deltaV requirement is reduced but acceleration remains the same. If the fighter is made smaller, it can approach closer. If the projectile velocity is decreased to 100km/s (a fast coilgun), the closest approach at 10G limit is only 20km. That's practically visual range, at the same distance as above of 200km, the 100% dodging deltaV is 1m/s per shot.
I'm sorry for pulling this offtopic (I seem to be doing this a lot on this forum, sorry if I'm annoying), but this analysis seems to be a bit too simple. The fighter might just be 2 meters wide, but it needs to escape the kill zone of the warhead, which might be a lot larger. How large does a Mm/s fragment need to be to kill the fighter? How large is the warhead? How many shots can be fired before the fighter is in range? All of this affects the optimal spread pattern of the warhead.
Don't forget that you not only need the ability to change your velocity vector rapidly, you need to be able to change your acceleration vector rapidly too. Extremely rapidly, if we're discussing situations where the time to target is less than 1 second. This either means some quick way to change your orientation or powerful translation thrusters. Either way is probably going to be pretty heavy. (oh, and also, it means that it has to be two meters in every dimension, not just a facing direction)
Looking at the dv expenditures in your table, it might be possible that the fighter simply never will get into range if enemy fire forces it to run off in a direction. Unless it is going to turn around and thrust back between shots, which will further increase dv expenditure.
Finally, this dodging can be accomplished by just drunkwalking. The targeting computers are probably going to 'drunk-aim' on various expected future positions anyways, so it's not like a hotshot fighter pilot is going to outsmart the targeting in order to get close. These 'dogfights' would probably just consist of automated drones spraying pellets widely in the general expected position of the enemy while drunkwalking. Oh, and all of this doesn't take into accounts things like sensor data processing time, engine thrust changes not being immediate...
Is armour design for resisting lasers really less complex than kinetic armour if you include different power levels and frequencies? Many designs that I've seen here seems just as complex as antikinetics.
So in the end, I basically don't see how pellet fighters would be possible, assuming high-performance fragcoilguns. And if they would be possible, there is zero reason to not have them be unmanned drones that drunkwalk instead of space fighters. Sorry for not posting about lasers in a laser thread!
You accept the near future solar system ecology as portrayed in Children of a Dead Earth as gospel.
Not everyone does.
It is a great and fun game, and much of the engineering and physics stuff are incredibly rigorous. Beyond that, it is no more "realistic" than the Fallout Universe, no offense meant to Qswitched. It is a work of fiction and the solar system ecology it portrays is strictly fictional.
If there's no people in space, there's not going to be people with guns in space either. I think a well-populated solar system like that in COADE is required for the concept of space infantry to make sense. I'm not sure what you mean with me 'accepting' something, I certainly don't think that it necessarily is the future, but assuming it is a prerequisite for this discussion, IMO.
I don't think that it's too implausible to have a large-scale space economy with many thousands of people operating in space, if we assume a bootstrapping space economy. 2067 might be a bit early but that's hard to predict. What could we have predicted about the population of the american colonies in the year 1550, 50 years earlier? Not saying that our situation now is equivalent to 1500, but I think predicting the scope of a potential interplanetary economy in 2067 runs into the same problems. The question is if enough pieces (such as sourcing materials in space, reducing launch costs, etc.) fall into place to make deep space exploitation a serious business oportunity.
We've already partially conquered Earth Orbit, but a weather satellite on its own doesn't generate much interplanetary trade. That said, start space-based water sourcing and fuel depots, and suddenly stationkeeping services for satellites start to seem like a lucrative opportunity. And if the satellite orbits don't decay, need for maintainance and upgrades is going to increase, since satellites will not be as disposable. Of course, for that to be economical, we might need to have component production in space, and raw material sourcing... and now we have everything necessary to start wondering about the feasibility of orbital shipyards...
I think that this kind of bootstrapping economy is a completely necessary factor. The USA is not going to fund NASA until NASA builds a bunch of cool stuff that makes our world become COADE, and then we can have space adventures. Anything beyond the scope of limited prestige/science expeditions and beyond Earth orbit is going to have to pay for itself. But if it does pay for itself, there's the potential for very explosive growth and a very rapid exploitation of space, and then I think that we can have a serious interplanetary economy in the second half of this century. And if that society is anything like ours, I'm pretty sure that there will be spacelegs running about with guns too.
Everything is debatable, but given something resembling COADE I think it's pretty obvious (with the reasoning above) that it is completely impractical for pirates and only very marginally maybe practical for someone with a large amount of resources, like a nation. I'm really grasping at straws to find some kind of near-future setting where this type of piracy would be even marginally practical. It's just so completely riddled with failure points and sensitive. Space combined with the technology needed for space travel simply lends itself too well for surveillance and control for this to be possible without some serious magitech/plot-tech.
I could maybe imagine some other types of criminality that could work, based in messy environments like the inside of a station (still a lot easier to control than something on Earth), or maybe some really forlorn-hope style stuff where the people doing the crime don't expect to survive but do it for some cause... I do think that space criminality might be a possibility, just not your brand of piracy.
defacto As I said, stealth in space is possible, but really hard.
Well, as I said, it's certainly possible but completely impractical, even more so if you're a pirate. It's like if the only way for the somali pirates to continue doing piracy would be to secretly construct a nuclear attack submarine in their garage. That could be considered possible but I think that there are better criminal opportunities.
I don't want to derail this further but... I deposit cold gas missiles I secretly produced on a body using my cold gas spaceship (must avoid detection) that I produced using non-civilian methods (civilian ships have enough hull emission to be detected) in a secret shipyard that is also undetectable and was also established secretly with materials that can't be traced... finally i extort traders that pass by the dv-envelope of my cold gas missiles... it's not just the missiles that need to be stealthy, it's every step, from the very beginning (even just planning), that needs to be completely watertight, otherwise everything is ruined and you either surrender to the authorities or get nuked by a passing-by patrol ship.
Basically, it feels like the 'stealth in space' problem, but even more problematic since you have less resources. I think I'd rather invest in that trader than extort it. Or maybe use my secret shipyard to build more traders.
Still... to tie it all with infantry in space... even without space piracy, I think there is plenty of reason to assume space criminality, or at least a need for security of some sort. If you have large civilian interplanetary economy. There needs to be some level of force between stern words over the radio and a rain of hydrogen bombs. Police forces, 'coast'-guard, station militia and security forces, maybe even true space marines/espatiers, wielding cool near-future tech. Deterrence would be the main purpose, combat extremely rare, actions like boarding hostile ships in flight practically non-existant, but maybe something that espatiers train, in order to maintain that they have the capability.
I imagine that the people of COADE are a bit better than us at creating survivable ecologies on inhospitable bodies, for the simple reason that the alternative is death. Also, they are more experienced, because once again, the alternative for many years has been death. I think that they were significantly more accustomed to space life than us even pre-apocalypse, since they had a system of skyhooks which would hint at some kind of interplanetary economy. That could mean anything, of course, from some automated mines to full-scale cities on other worlds, even before the apocalypse. I'm not sure if there's some development on this in the lore.
The spaceships might use 2017-technology, but they're not year-2017-spaceships. Similarily, I imagine that the habitats work on principles that could be concieved today, but with many decades of experience and some keystone technological developments that arised out of necessity.
Not that I would be opposed to an overhaul. That would be interesting. I wonder how many managed to flee Earth, given that the solar system population many years later still is below 2 billion. The official population of the more signficant bodies, at least. After the exodus, how many years did it take before the population started growing again?
Holy crap, natural materials can be strong... limpet teeth, 6.5 GPa tensile strength? Can't we just build spaceships out of gigantic limpet teeth? We just need to genemod gigantic space limpets...
I can acess the report, but I'm not sure if I can post it here wihtout being taken by the science police. Is there something specific you're wondering about? I don't think I'm knowledgeable enough to judge how 'legitimate' the report is, but it's worth noting that the tensile strength of some the spiders dropped after being fed nanotubes, in some cases to just a few MPa.
I've been lurking around here for a while, but I decided to make an account for this thread. Here is my entry: Defacto Industries presents... the 10mm Infantry rifle system - VaK2 Automatic Vacuum Carbine. Features: - No modding (but black box power module... more on that further down, also contains diamond) - 50 round magazine system mounted in the rear of the carbine - Accurate fire against 1m^2 sized targets beyond 2km - Capable of punching through most lighter armours - Can empty magazine in 3 seconds if necessary, enabling use as LMG or SMG. - Can fire many magazines in quick succession before barrel becomes dangerously hot - Complete system weighs in at just below 6kg
The black box generator is a 10W hand-crank (a quick google made it seem like that was reasonable) with a weight of 0.9kg. I put the efficency at 33%. The system is water-cooled, temperature is 313K. This represents not just the hand crank but any electrical systems... one would imagine that it would be a bit uncomfortable to fire the gun while cranking, so that system can be thought to include a 0.5kJ energy storage, maybe in a flywheel or something. Or maybe it makes more sense to have the system operate non-electrically, skipping the crank altogether. Anyway, I think that with these limitations, it was reasonable to include the black box generator.