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Mnemosyne - a picture of Solar System in the 27th century
DISCLAIMER - This is unrelated to OA, but I did inspire myself quite a bit by it I gotta admit. It's very much a work in progress so don't be surprised by completely unfinished parts. It's rather long so I upload it as .html files on a file hosting site. It's hard SF, but with looser constraints than OA (FTL Acculbiere drive is possible in Mnemosyne, nearly every Gaian world with organics develops life by abiogenesis and complex life isn't that rare even if by no means occurring on every lifebearing world) yet at a much lower tech level (best human drives are antimatter catalyzed fusion and those are only used by 1 faction, AI is only sophont - transsapients don't exist etc.) and focused on the Solar System for now.

So here it is: - Mnemosyne - Mnemosyne Ship Designs

BONUS - Satis, an AreanLacustric (by the old Dollan's PCL "cyclically active Arean world that can be very Earthlike when its going through its wet/active part of its cycle" definition, not the OA's "young Marslike planet with a moderate ocean cover that will inevitably dry out" one) planet that I eventually plan to incorporate into Mnemosyne as the homeworld of a hostile alien species, also WIP: (this one is in .pdf format)
Busy with various things, but will give this a read thru and offer feedback later this week or over the weekend.


So, I had some time tonight and decided to start taking a look at these files.

However, it appears that in order to see them I am required to add a tab to my Chrome that will subject me to notifications, adverts, and changing my search engine to (gag) Yahoo. None of which I have any desire to do.

If you can move these files over to Google Docs or Google Drive and post a link so people can view them, I'll be happy to take a look at this. But there is absolutely no possible way I am going to jump to through the hoops the current links seem to want to me jump through.


Thinking about it, another option might be to attach the files to posts here in the forum.

That might or might not be easier depending on the file formats.


(05-15-2020, 01:25 PM)Drashner1 Wrote: So, I had some time tonight and decided to start taking a look at these files.

However, it appears that in order to see them I am required to add a tab to my Chrome that will subject me to notifications, adverts, and changing my search engine to (gag) Yahoo. None of which I have any desire to do.

If you can move these files over to Google Docs or Google Drive and post a link so people can view them, I'll be happy to take a look at this. But there is absolutely no possible way I am going to jump to through the hoops the current links seem to want to me jump through.



I apologise for the trouble but I tested downloading them and it required me to do no such things. Choose free download, don't click anything else. You aren't required to do anything else. But I wikl add them as an attachments and remove the links. I didn't intentionally expose anyone's PC to anything else than my files so I apologise if my chosen file host turned out to be sketchy.

I won't use Google anything, won't expose my Google account with my real name anywhere, sorry.

EDIT - Attached now.

Attached Files
.pdf   Satis.pdf (Size: 37.27 KB / Downloads: 9)
.htm   mnemosyne_ship_designs_redone_-_wip.htm (Size: 75.18 KB / Downloads: 4)
.pdf   mnemosyne_-_wip.pdf (Size: 61.97 KB / Downloads: 12)
in case someone doesn't want to download this file

Kuiper Hegemony’s “gear shifting” space fighter/pursuer Persecutor:

Drive type: D-He3 fusion pulse
Maximum Isp: 800 000 s
Thrust power at maximum Isp: 196.2 GW
Thrust power at minimum Isp: 490.5 GW (higher power is possible at low Isp because of propellant cooling)
Mass ratio: 1.7
Total mass: 51 t
Dry mass: 30 t
Fuel mass: 21 t
Kinetic energy at maximum speed (4162.95 km/s):
Pure fusion mode:
Thrust power: 196.2 GW
Isp: 800 000 s
Thrust: 50 kN
Acceleration (fully fueled): 0.1 G
Acceleration (empty tank): 0.17 G
Propellant mass flow:

Short range travel mode:
Isp: 400 000 s
Thrust: 100 kN
Acceleration (fully fueled): 0.2 G
Acceleration (empty tank): 0.34 G
Propellant mass flow:
Mixed mode:
Isp: 200 000 s
Thrust: 200 kN
Acceleration (fully fueled): 0.4 G
Acceleration (empty tank): 0.68 G
Propellant mass flow:
In the pure fusion mode, only plasma resulting from the D-He3 reaction itself is used for thrust. In the travel and mixed mode, small amounts of reaction mass are added to boost the acceleration to levels suitable for quickly leaving planetary orbits, lowering the specific impulse to still very high, but worse levels. In planetary atmospheres, it can adjust its drive to use air as reaction mass and use smaller fusion pulses.
Chase mode/orbital maneuvering mode:
Thrust power: 392.4 GW
Isp: 100 000 s
Thrust: 800 kN
Acceleration (fully fueled): 1.6 G
Acceleration (empty tank): 2.72 G
Propellant mass flow:
Attack mode:
Thrust power: 490.5 GW
Isp: 50 000 s
Thrust: 2 MN
Acceleration (fully fueled): 4 G
Acceleration (empty tank): 6.8 G
Propellant mass flow:
This mode injects a lot of reaction mass into the engine to increase the mass flow, dramatically increasing thrust and cooling efficiency, enabling a boost to thrust power but increasing fuel consumption, useful for situations such as pursuits where high thrust is desirable, and long range is not needed, or when a quick escape or lift off from a planet is necessary.
High-G (Kamikaze) mode:
Isp: 10000 s
Thrust: 10 MN
Acceleration (fully fueled): 20 G
Acceleration (empty tank): 34 G
Propellant mass flow:
Generally only used when ramming enemy ships, this mode produces bone-crushing acceleration good for making that final plunge into the enemy ship when no other option is available, Kamikaze style.
Note these are just the main drive modes as in use by the Kuiper Hegemony, Isp and thrust can be adjusted at will.
Classified report of the Mercurian Federation of Free People:
Information about the Persecutor space fighter, codename Skimmer:
The craft has reached levels of drive miniaturization previously though impossible, despite its small size, it utilizes power amplification technology, enabling enormous amounts of thrust, apparently through the use of extremely heat resistant materials and high efficiency magnetic nozzles, along with disregard to pilot safety, these craft can masquerade as civilian craft for months to years, keeping the pilots in hibernation, upon awakening, they’re capable of devastating hit and run attacks. The sight of a Skimmer fighter venting coolant, with radiators glowing white hot, has became a new symbol of terror in the outer system, as the weapon systems often slightly overheat the craft, meaning a glowing fighter venting coolant has just finished executing a raid.

Jupiter’s express passenger ship Jove:
Drive type: D-He3 fusion pulse
Maximum Isp: 800 000
Thrust power: 6.71 TW
Mass ratio: 2
Total mass: 2500 t
Dry mass: 1250 t
Fuel mass: 1250 t
Pure fusion mode:
Isp: 800 000 s
Thrust: 1.72 MN
Acceleration (fully fueled): 0.06 G
Acceleration (empty tank): 0.12 G
Propellant mass flow:

Medium range travel mode:
Isp: 400 000 s
Thrust: 3.44 MN
Acceleration (fully fueled): 0.12 G
Acceleration (empty tank): 0.24 G
Propellant mass flow:
Short range travel mode:
Isp: 100 000 s
Thrust: 13.76 MN
Acceleration (fully fueled): 0.48 G
Acceleration (empty tank): 0.96 G
Propellant mass flow:
Rapid maneuver mode:
Isp: 25 000 s
Thrust: 55.04 MN
Acceleration (fully fueled): 1.92 G
Acceleration (empty tank): 3.84 G
Propellant mass flow:
The Jove can carry 300 passengers in the waking accomodation configuration or several thousand passengers in the hibernation configuration at high speed through the whole Solar system, however it isn’t really fit for trips to the Oort Cloud although it can technically do them, unlike slower ships seats on it are often hard to get even in the moneyless economy of Jupiter’s moons. If you can travel on Jove, you’re likely at least a somewhat important person.

Independent cargo hauler:
Total mass: 12000 t
Fuel mass: 6000 t
Structural mass: 1000 t
Payload mass: 5000 t
Mass ratio when full: 2
Mass ratio (no cargo, full fuel): 6
Delta v at max Isp: 3398.73 km/s
Maximum specific impulse: 500 000 s
Thrust power: 5.8 TW

Freight mode:
Isp: 500 000 s
Thrust: 2.35 MN
Acceleration (fully loaded and fueled): 0.02 G
Acceleration (fully loaded, dry): 0.04 G
Acceleration (no payload, fully fueled): 0.034 G
Acceleration (no payload, dry): 0.24 G
Orbital mode
This trader's cargo hauler isn't too fast and doesn't accelerate too well, but it can carry a huge amount of cargo up to Uranus and back without the need to refuel, thus eliminating the risk of the other party in the trade not obeying their part of the deal.

“Space bus”:
Total mass: 200 t
Dry mass: 100 t
Fuel mass: 100 t
Mass ratio: 2
Max Isp: 450 000 s
Thrust: 59 kN
Thrust power: 130.23 GW
Average acceleration: 0.04 G
Acceleration (fully fuelled): 0.03 G
Acceleration (empty tank): 0.06 G
What kind of feedback do you want on this?
critique of the timeline? how to improve on the descriptions and history?

I think it's a little weird that the kuiper hegemony has "pirate" raids on mercury, given how relatively far they'd have to travel compared to targets. Also weird that their "corporatist economy" is dependent on piracy in order to thrive, especially with a population of ...30 billion, which I'd expect would require more stability?

also i know we're talking about an speculative economy 600 years from now, filled with weaponized fusion torch spacecraft, but the economics of stealing something as dangerous as antimatter from orbital factories and spacecraft sounds, as if somali pirates or al queda stole nuclear weapons and nuclear submarines on a regular basis.

"It lacks the hybrid fusion-antimatter drives of the Mercurian Federation and the exotic nuclear propulsion systems used by the Commonwealth of Jupiter, but it makes up for that by the use of unusual solutions to long standing problems and the ability to miniaturize heavy and power hungry components (as well as its willingness to ignore safety rules). Rumour has it that their latest project is reclaiming the homeworld of humanity, Earth, helping the inhabitants back to their feet and taking vengeance to all that have betrayed Earth. Because of this, other powers have been toying with the idea of imposing a trade embargo on the Hegemony, preventing it from trading with any spacefaring polity, however, this move has been so far prevented by Mercurian’s deep belief in free trade and movement, as well as the fear Hegemony inspires in the rest of the Sol system."

-not that i've ever been to space, but having worked in a few mildly dangerous environments, ignoring safety rules seems like a very unnecessarily deadly and  ***expensive*** quality in a culture.
-given how comparatively easy it is to track and destroy spacecraft in space, and the relatively greater distances between objects in the outer solar system, why would the kuiper belt host a powerful and fear-inspiring culture compared to somewhere closer in-system?
(05-16-2020, 03:10 AM)MichaelPoole Wrote: I apologise for the trouble but I tested downloading them and it required me to do no such things. Choose free download, don't click anything else. You aren't required to do anything else. But I wikl add them as an attachments and remove the links. I didn't intentionally expose anyone's PC to anything else than my files so I apologise if my chosen file host turned out to be sketchy.

I won't use Google anything, won't expose my Google account with my real name anywhere, sorry.

EDIT - Attached now.

No worries - it was a minor complication (I wouldn't even raise it to the level of minor irritation) and not the result of anything you were deliberately doing.

Thanks for attaching to your forum post. Going to start reading through it now and will loop back with feedback in the next few days.

This AM, I read through the Solar System summary you posted.

I'm also not sure exactly what type of feedback you're looking for here, but will post my general thoughts that came to mind while reading. Due to long habit I am likely to come at this from an OA perspective, although I understand that this is not OA and that you are making different design choices than we have, although you did say this is a hard science setting. I understand that the document is a WIP and so some of this may be resolved as it progresses.

General 'high level' feedback below mostly:

1) Probably the biggest thing that stood out for me across the document are the very high population numbers you give for various places. Mostly due to the short time frame (maybe 500 years?). It feels unlikely that such large numbers of people could be produced in such a short time. Not so much in terms of raw breeding (humans can breed like bunnies under the right circumstances) but:

a) Can this many people be produced in the time between the colonization of a given location and 'now'?

b) Can infrastructure to support this many people be produced be produced fast enough to support the rate of population growth? This is particularly notable for civs in the outer system and Kuiper belt where heavy elements are going to be rare.

c) Why would the colonists want to reproduce at this rate in the first place? They are presumably a high tech civ with access to advanced gengineering and life extension - but they can't produce birth control? High tech/wealthy cultures in RL tend to experience negative or slowed population growth - why is that not happening here?

d) What do all these people do?

2) The overall timeframe doesn't feel long enough to do all the things you describe unless a highly notable (approaching Singularity level) jump in capability occurred early in the timeline. You do mention nanotech and AI and such, but don't really delve into them in a way that makes it feel realistic that (for example) Mars could be fully terraformed in the time available. Things like trying to make artificial black holes and such out on a small body in the outer system also seem far to advanced given everything else described.

3) You talk about fusion and amat-fusion spacecraft a good bit. But are the performance numbers you mention realistic? Virtually all fusion and amat drives I've ever seen described in any level of detail top out around 10% of c or so and you have one pure fusion design apparently hitting 40% of the speed of light, which is better than any fusion drive I've ever heard of except a Bussard ramscoop and those have a host of issues of their own. If you've actually got the numbers on these (or even a good chunk of them) that's great. But then the backing info needs to be provided to help it feel realistic and not just 'numbers pulled from the air'. Waste heat from the drives and the issues with getting rid of it don't seem to be a consideration.

4) You spend some time talking about amat production being theoretical to a rumor but then also talk about the Kuiper civ making raids for antimatter. It seems like the situation could be one or the other but not both at once.

5) You talk about the Kuiper civ using piracy - but that doesn't really make sense to me. If they have the capability to support a high tech civ of 30 billion people in the Kuiper Belt, what could they possibly need from the rest of the solar system that would require pirate raids instead of just direct resource extraction from empty asteroids or the like? Similarly, if they can produce ships that can get from the Kuiper Belt to the rest of the solar system to conduct raids, what could they be needing and what kind of thing would they raid to get enough of whatever to be worth the bother?

6) You mention the Kuiper civ using unique approaches to problem solving but don't explain what that is or what it looks like. But since you called it out, the reader really wants to know what you mean by this and to see examples.

7) You talk about domed cities on Callisto - Note that Callisto (and all the Galilean moons) are inside Jupiter's radiation belt and being on the surface would be distinctly unhealthy. There are various artificial methods that could protect against radiation and you mention gene-tweaking - but not in the case of Callisto and this is a big enough deal it should be mentioned. Callisto's population numbers are another 'why and how?' experience.

8) You mention black hole based torch drives, which I realize there are some papers about - but I don't personally find the idea at all convincing for various reasons I've yet to see answers provided for. A good chunk of the reason why we don't have such drives in OA, although people have asked about them many times over the years. But as you say this is not OA and your setting can certainly work on a different set of starting assumptions (ie Technology X is developed or turns out to be workable in your universe, but doesn't in the OA verse). Just including this for completeness.

9) You mention a nuclear war on Earth and then later an interplanetary war - and it seems to have little or no impact on anything or anyone other than reducing Earth's population a large amount. It seems likely that this would have various other negative consequences that could slow down or curtail things like population growth across the solar system or tech development or the like.

Ok, I think that covers my general thinking on this.

Hope this helps,

1. Do you realize that the world population as long into the past as Mnemosyne is in the future (630 years) was just 350-400 million while now it is 7.8 billion? As wiki says, it took over 200,000 years of human history for the world's population to reach 1 billion, and only 200 years more to reach 7 billion. Do you really find my numbers farfetched considering humanity now has the resources of the full Solar System at its disposal? People aren't biologically immortal or live in post-scarcity in my setting either, so yes, they're gonna have kids. At the point tech is in 2650, habitation and paraterraforming of "uninhabitable" bodies is routine, so it's no problem to provide more living space. As for the Kuiper Belt, larger bodies provide more than enough rock, fusion fuel and organics, plus, the Kuiper Hegemony isn't exactly keen on consumption and raids other polities to keep its economy from collapsing. By corporatism, I mean the fascist "class collaboration" system of state controlled "unions" negotiating between employers and employees (so the whole nation can unite to conquer and slaughter other nations), not a cyberpunk "government by corporations", just to be clear. They aren't supposed to be generic space pirates, the reliance of their economy on plunder reflects the reliance of real life Nazi economy on it, Wages of Destruction is a good book about it. What do they do? Well, let's say that due to Kuiperians being run by an AI and several AI related...incidents, humanity isn't exactly keen on automating everything.

2. Doesn't feel long enough? Compare 2020 to 1390, which is as far in the past as 2650 is in the future. There's plenty of time, especially considering no Great Expulsion or Nanodisaster. I personally don't believe "Singularity" or transsapienthood will be a thing, which is why I don't incorporate it into my setting - humans are already Turing complete universal intelligences, really advanced AI can do the same faster, but that's a quantitative, not qualitative difference.

3. I actually included radiator mass in my ship masses and it's implied that for example the Kuiperian's Persecutor radiators running at max power glow white hot and risk melting down. I'd put in far higher thrust power values if I didn't care about that. Their thrust powers aren't really much greater than those of some crazier 1950s Orion designs, for instance. Where do you see pure fusion designs stated to reach 0.4 c? I stated antimatter catalysed designs to reach that speed, pure fusion peaks at 0.18 c with staging and mass fractions like modern chemical rockets, common Solar System traveling speed is more in the thousands of km/s ballpack. I spent hours at ProjectRho and Orion's Arm for that matter

4. It's as "secret" as the Manhatten project was. Meaning, it's supposed to be secret, but it's really an open secret at this point, and something others are interested in too. Kuiper Hegemony are pirates and fascists and have no interest in airing this secret as they like to "harvest" their source and not share with others, plus, what they say is taken about as seriously as what ISIS says. Imagine ISIS saying "USA has secret antimatter weaponry", nobody but the lunatic fringe would believe it. Furthermore, Mercury is ran in a very minarchist/libertarian manner, so they aren't exactly protecting it the best and yes, all in all, the situation in the Solar system is a powder keg, that's the point.

5. They steal technology and wealth of the inner polities because their economic system is about as "efficient" as USSRs or fascist war economies. Why did USSR last 70 years and could run the largest empire in the world, send people to space, amass a thermonuclear arsenal while it couldn't even maintain a regular delivery of sausages in the shops? Based on your logic, USSR was an "unrealistic polity". I'm not making "rational" polities limited by raw resources, I'm making polities as actually existed, crippled by ideology, short sighteness and self-sabotaging economic systems. Plus, a lot of it is ideologically motivated, they want to keep their people in a state of constant tension and warfare to achieve their goal of eventually reconquering Earth and restoring it to its former glory while punishing all those who rebelled against it. Why did Stalin promote Lysenko or Mao kill sparrows and told peasants to melt down farm tools? How could 35 million people starve in a nation that was among the first practicers of agriculture on Earth and had a lot of fertile soil?

6. They aren't afraid to do stuff like trying to create a black hole by massive lasers or focused thermonuclear explosions because they don't care about things like "civilian safety" much. Think early 1950s Soviet nuclear program (safety level "let's put unfiltered plutonium waste into the nearest lake, this cannot go wrong, ever").

7. Callisto barely gets any radiation from the belt and nearly every human in the system has some tweaks, pretty much everyone has some radiation resistance just to cover the general radiation risk of living in space, the people in especially radiated places just have extra tweaks. The domes are fairly thick, they're not plexiglass. A lot of the housing is deep underground and this actually applies to nearly every world in the setting. Callisto is freely exploited because it's a super-stable undifferentiated mix of rock, organics and ice (= all you really need to sustain life) and because Europa and Io are off-limits and Ganymede is a little too alive and irradiated for comfort.

8. It's an experimental technology, I was inspired by Isaac Arthur, and keep in mind this is not an OA clone.

9. Really? Because I did clearly imply that it destroyed the whole beamrider infrastructure of Solar System. One of the reasons why the Solar System is so "irrational" is that it's effectively post-apocalyptic. However also, at that point, Earth wasn't some life-giving center of the human world, but a hated, parasitic, totalitarian polity. It was nuked for a reason, and there's a reason why Kuiperians, descended from a group of Earth refugees, are perhaps the nastiest human faction in the settings.

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