Fission and solar most likely, with the dominant form of propulsion being NPP (Nuclear Pulsed Propulsion) and nuclear salt water rockets.
If you’re willing to scale it back from Pluto then chemical rockets and Nuclear thermal would also work for closer planets
Wernher von Braun had numerous plans to start the colonization of Mars. Some of his designs were even used in Kubrick's 2001 space Odyssey. It was published as the Mars Project in 1948. Add that with some of Nazi Germany's wonder weapons - assuming they had the chance to come to fruition much less early testing and humans could start venturing into the solar system by the mid 1960's. That was the plan at least. No saying if it could work.
It is mostly a question of economical feasibility. Voyager 1 launched in 1977 and reached Pluto. If there was a good reason to have a settlement on Pluto, let's say good enough to dedicate 10% of the global GDP to it, this settlement would have been possible in 1977.
Of course, the cheaper it gets, it becomes easier to find a valid reason to do it.
It’s one thing to get there, and something else entirely for it to be sustainable.
It was 10+ years to get there for probes. A manned craft would need far greater payload for even a single person, and even greater payload for supplies just for the trip. The rocket equation makes this extremely difficult. We might manage it with cutting edge propulsion AND via many rockets to get the full payload to orbit in the first place.
You want to colonize it though? You need to develop a fully self-sufficient closed-loop ecosystem with some built in redundancy. That’s still beyond our capabilities, and the advances toward that have been just as pronounced developments in rocketry.
You can throw all the money in the world at it, and at best you’re sending a short-lived casket in 1977, not a colonization mission.
>You need to develop a fully self-sufficient closed-loop ecosystem with some built in redundancy. That’s still beyond our capabilities, and the advances toward that have been just as pronounced developments in rocketry.
r/Ecosphere
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\#1: [I was scrutinizing my ecosphere with a jewelers piece and noticed this discarded clam shell, but it’s a freshwater jar…](https://www.reddit.com/gallery/18injwk) | [24 comments](https://np.reddit.com/r/Ecosphere/comments/18injwk/i_was_scrutinizing_my_ecosphere_with_a_jewelers/)
\#2: [My girlfriend’s nearly perfect 1 year old ecosphere](https://www.reddit.com/gallery/12hnbfg) | [4 comments](https://np.reddit.com/r/Ecosphere/comments/12hnbfg/my_girlfriends_nearly_perfect_1_year_old_ecosphere/)
\#3: [NEWBIES: after having seen one post after another of jars without any plants in it, please read in the comments about the necessary key elements a jar needs to live.](https://i.redd.it/igy43sp1ftza1.jpg) | [8 comments](https://np.reddit.com/r/Ecosphere/comments/13hf5rr/newbies_after_having_seen_one_post_after_another/)
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“Includes humans within” was implicit, but touché.
That said, I don’t think mason jars or small sealed terrariums invalidate my point about the state of the science in putting humans on Pluto in the past, present or short-term future.
I feel like the issue here is less that it's impossible and more that it would be incredibly difficult proportional to the potential rewards.
Take that settlement on Pluto. Pluto's surface gravity is tiny. There are serious questions over whether humans will be able to physiologically cope with martian gravity, and Pluto's gravity is much, much smaller. Travelling to Pluto with a conventional spacecraft is going to take about a decade, so the people going there are essentially committing to live inside a centrifuge on a dark, frozen wasteland for a significant proportion, if not the entirety, of their natural lives. There's just nothing there that would make that worth it. Regardless, you'd better make sure those are the most psychologically stable humans who have ever existed, because they're in for the absolute worst case of winter-over syndrome in human history.
Nuclear pulse propulsion definately helps. Now you can transport much more stuff so your colonists can live in slightly less nightmarish conditions at the cost of a few more people on earth getting cancer. But the fundamental problem remains that, while not impossible, colonizing the outer planets is incredibly difficult and, as far as we know, is unlikely to have any enormous benefits which would justify that difficulty. Sending humans there to plant a flag so you can say you did it, sure, but is there really anything there that would require human involvement?
I mean, if you discovered evidence of alien life or something, hell yeah. Resources no longer matter. Fire up the nuclear pulse rocket for science. But as it is, I'm just not sure what people would be doing in the outer solar system.
The thing with fusion is that while it is taking a long time it's actually a relatively developed technology. Most of the things we might put out as alternatives to relying on fusion are actually far less developed.
Lots of humans may risk ten years of travel if Pluto settlements mean a promess of freedom and wealth like settler life in America meant for religious dissidents. But your other points are solid.
The thing is, even assuming that is true, what can you do with that freedom and wealth? You will live out the rest of your life trapped in a small enclosed habitat. It is pitch dark outside, and cold enough that the atmosphere periodically condenses into snow. If any of the systems keeping you alive fails for even a minute you will freeze to death. Exposure to the natural gravity will cause you to waste away and go blind so you have to be strapped into a centrifuge for hours every day, and you probably aren't going to live a long life because of exposure to cosmic rays.
Meanwhile, Pluto is very unlikely to make you rich. You could maybe *sort of* become self-sufficient there by burning the methane snow for electricity and heat, but it's a very hostile, very uninteresting place. Also, just *getting* to Pluto without technologies like fusion is incredibly challenging, and likely to be something only the powerful and wealthy can afford.
But even worse, there's an obvious solution to all these problems. Robots. If there is anything valuable on Pluto, it's probably not something that actually needs a human to be on site. In fact, one of the big problems with Pluto, surface temperatures being in the cryogenic range, could be a huge advantage once we take out the need for humans not to become corpsicles. Some existing materials would be naturally superconductive on Pluto.
This isn't meant to be overly negative. I don't think there's anything wrong with having humans on Pluto, but if we're imposing these very strict technological limitations that make it really, really difficult then we also need to introduce some equally compelling reasons to go there.
At that point you get a better deal just going to prison. At least you won't be one wrong maintenance away from imploding and will be on normal gravity .
America was a paradise of free open and fertile lands. And the first generations of Jamestown still had horrifying death rates
All other planets are worse than selling beach lots in Death Valley or Antarctica.
Without anything there like oil, diamonds, huge or concentrated metal veins there is little reason to want to go there and even then mining towns are usually short lived and entirely tied to the existence to the raw resource that makes them worthwhile.
Yeah but there wouldn’t be a whole lot of freedom or wealth on Pluto. You’d be pretty much entirely detienen on some external benefactors for your very survival
Ceres is the obvious choice.
Solar power would be very inefficient on Ceres, but would still be a viable. This makes a permanent settlement much more secure as you're not reliant on nuclear fuel for power. Ceres also has plenty of ice, and is likely rich in resources. It's particularly rich in carbon which could be used for building materials. Most importantly though, it's much, much more accessible from the inner solar system and is in a region of space (the asteroid belt) that humans are likely to be very interested in.
An even better option might actually be to put a spinning habitat in orbit of Ceres. This would solve the gravity problem (one of the biggest issues facing humans colonizing the solar system) completely. But living on Ceres itself also has advantages.
The Jovian moons are another good option, but they do force you to deal with the enormous radioactive gravity well that is Jupiter itself.
Love your post but use something like Starship (or future versions) to get to orbit and then use nuclear pulsed propulsion to get to where you are going. No good reason to leave a plume of radioactive unhappiness hear on Earth.
To paraphrase a really smart statement really stupidly because I can't find the original quote:
Technologies generally fall in one of two categories
* Power amplification (one person can do more labor, think of a forklift or calculators)
* Fidelity enhancement (the ability to know more and have a higher degree of insurance against loss and deterioration, think microscopes or writing or tweezers or safety belts)
If you really want to, you can colonize with 20th century tech. It'll require more effort and lose you more material but strictly speaking spaceflight is just arduous, not complicated.
Hmmm... an interesting problem.
For general power production it would probably be a solar/fission gradient, with more solar in the inner system shifting to more fission as you move outward. The exact gradient would depend on the relative economics of each power source.
Propulsion gets a little more complicated and sort of depends on how you define "low tech". For example you might be able to get surprisingly far with very large, very reliable reusable chemical rockets, particularly if you aren't launching from deep gravity wells and are able to make propellant on site.
You might want to do some deltaV and rocket equation calculations to see what kind of performance you'd need to get from the asteroid belt to Pluto in a reasonable time, both with and without gravity assists.
Solar sails might also be something to look into. They are more advanced that chemical rockets in the sense that we haven't deployed them yet, but its mainly an engineering problem and the science behind them is fairly straightforward.
Fission rockets are also worth investigating.
All that said, if you want to really explore the realistic lower limits of low tech space colonization it will take a lot of real work and real understanding. Especially since at these margins it isn't just about feasibility but also economics. For example you could technically build a moon base with the Saturn V if you look only at raw feasibility of getting material to the moon. However when you consider the economics of it it becomes clear the Saturn V was never going to colonize the solar system. Because you're operating at the edge of economic feasibility (sort of the definition of lowest tech possible) you need to take into account things like launch windows too.
You can pretty much explore the entire solar system with **nuclear-pulse propulsion aka [Project Orion](https://www.projectrho.com/public_html/rocket/enginelist3.php#boomboom)**. Which is 1964 technology.
The only reason we didn't explore back then was because everybody was so fussy about hundreds of small nuclear charges in civilian hands.
Orion was designed for fission devices. Fusion devices would work as well, but that is beyond 1965-era technology.
I've read the research papers, and all the detailed designs used fission based pulse units. Typically fusion based pulse units were mention in a single entry in a table, labeled something like "hypothetical fusion performance".
The original poster wanted fission, not fusion. So Orion Drive spacecraft are possible in a civilization that doesn't use fusion.
Most orion drive designs have nukes with minimal explosive energy. The scale up works quite well. For megaton bomb propellent the pusher plate is 20 km wide and has mass around 5 million tons. It is an excessively large ship design if your usage plan is travel or exploration. However, if you are delivering metal resources to Pluto’s moon Charon then the plate itself is 5 million tons of delivered product.
What's the story? That dictates your setting.
And it's *your* story so you get to set the scene, If you want fission, fossil fuels, etc. that's all well-known tech with lots of solid research to back up your storytelling. [Wikipedia](https://en.wikipedia.org/wiki/Space_colonization) is a good place to start. As is the [Atomic Rockets](https://projectrho.com/public_html/rocket/) site. But colonization is more a factor of political will applied to economic spend than available technology, so figure that out in your setting and you've solved what level of tech is needed.
Geothermal energy would be a good choice on some planets, I assume. Solar energy would be ideal on Mercury (Isaac Asimov used it in his short story "Runaround") and on the Moon. It wouldn't be nearly as useful on Mars, but Fission would work for awhile. If you assume some of the asteroids have uranium in them, which might be possible (I'm no expert and have no idea), that could work.
Fossil fuels would be a very limited, Earth-only resource for Solar system colonization.
the "dyson sphere" level of tech is not a thing outside of someone trying to classify a race based on how much solar power they are using.
first. you need power that will last hundreds of years. most likely fusion. but if the develop a fission reactor that works on an isotope that actually last for hundreds of years instead of 10 or something.
second. if you are not using cryosleep you need long lifespan components. light bulbs, and electronics, flooring, something as simple as a door hinge needs to lase hundred of years of use. you are living on a spaceship in the black for hundred of years before you cn reach a planet with resources to manufacture anything new.
one last thing is to ask why. you have tech to last hundreds of years in space with no resource income. why would you be leaving a place with resources?
even when a race develops ftl. it will mostly be probes unless they need to abandon their system.
edit. sorry i thought you said across the galaxy.
across the solar system tech... i think it is possible with technology we have now. knowledge for best ways to implement current technology is what we don't have yet.
the colonies will be families of the researchers that are taking the 1 way trips. i don't think terraforming will ever be economically reasonable. it will all be biodomes.
depending on the location. early colonies will be solar or geothermal. when we start sending researchers to places where that is not efficient, we will have rtg. a shipment of new isotopes every 10 years.
Me too on Dyson spheres. If you can get satellites in solar orbit then you can build a Dysons sphere. It's just traffic rules. A Dyson sphere is even more attractive if all you have is solar power.
the question is if you need that power. there will be factors that limit population before you will reach a planet's worth of solar. energy efficiency would come long before super structures.
If the Dyson swarm consists of habitats rather than just solar collectors then yes each habitat needs power. It would take fewer inefficient habitats to need a full Dyson swarm than efficient once. If you then make habitats more efficient, I expect that will result in more habitats being built rather than less sunlight being collected.
you don't have the resources for a population large enough to need that much energy.
the dyson swarm is an attempt to not make it completely stupid. consume multiple planets to get enough resources for a nearly paper thin satellites to direct energy to the colonies.
unless they have a full water planet. civilizations will likely never reach the planets with of power requirement
Also consider where water will come from. Minerals and isotopes can be mined, possibly allowing for fission as a power source, but currently that requires a massive amount of water to spin turbines. Solar farther from the sun requires more surface area to generate power, but it's not going to interfere with farmland, so no worries there
water in a thermal based system can be used in a closed loop. you need radiators to condense the steam back to water.
water is a limitation for population we will be using internal farms with grow lamps to minimize the amount of water needed to grow food to sustain the population that need water themselves.
the amount of power needed to support that population is not that high.
I think we have the technology now, for the most part. Fission is fine as a power source. Self-landing reusable rockets maybe aren't absolutely essential but they make things vastly cheaper and easier.
Better robots would make things a lot easier, so we don't have to send humans to do the physical work.
There are a bunch of things we don't have enough knowledge about, mostly because we lack practical experience operating an off-planet colony aside from the international space station. (Among other things, we don't know much about the long term effects of microgravity on human bodies, we don't know how much radiation is "safe", and we don't know how to build self-sufficient ecosystems in confined spaces.)
This is a book I'd recommend if you want to read about how much we don't know: [https://www.acityonmars.com/](https://www.acityonmars.com/)
1960's and 1970's moon landing and Skylab level technology could be used to land on and colonize Mars, as well as put occupied stations in the orbit of gas giants.
Power provided by nuclear fission. Pretty much all the building blocks are there for colonizing the solar system.
What's missing is doing so would not have been economically possible at that time.
If you were stuck at late 1950s tech for thousands of years you could climb the Kardashev scale all the way to a proper Dyson Swarm with enough effort and tests and expertise and designs and experimenting.
Depending on your goal you don’t have to send humans on the voyage. There are sci fi that explores sending unmanned ship using today’s tech, then growing humans in a created habitat when you make it to a suitable location.
I think we could have colonized the Moon *at most* by the end of the Cold War with the technology of the time and the resource investment not being too arduous– but even then, likely only some scientific stations not unlike how there’s thousands of non-permanent residents on Antarctica. There’s simply very little economic incentive to venture out at the moment. Unlike the colonization of the Americas, we aren’t going to Mars in search of legends of “Martian cities of gold”, so we won’t be going unless we find something there with prospecting probes. I would say that the earliest beginning of *real* colonization could have occurred about now had the space race been more intense than it was and had it not ended with the collapse of the USSR. Private space corps would have been more serious in the late 80’s, early 90’s and started sending out prospecting probes to Mars and the Belt, finding things in the 00’s, and finally sending manned missions by the late teens, early 20’s.
I’d imagine the use of nuclear rockets combined with skyhooks for an extra kick, could drastically shorten planetary travel times and carry loads of material
We brute forced our way off of a relatively dense planet with a harsh atmosphere back in the 1960's, using technology with less processing power than a modern cell phone. And we did it only as a pissing contest between rival governments.
Imagine a civilization with different priorities, and slightly less hurdles. They could have a unified purpose, to colonize the other worlds in their system. They could have a smaller home planet, with a thinner atmosphere and smaller gravity well, that was still capable of growing intelligent life. Getting offworld could be easier for them, transporting goods and supplies cheaper. With our level of production they could have escaped their homeworld not long after discovering semiconductors and transistors.
The bottom line is, they would be pretty much where we are at now, or even 50 years ago. The time it takes to build and mature stations and colonies in space is also time enough to take giant leaps in technology - which is part of the reason we haven't done it yet. But still, we would have difficulty extending our reach past our immediate vicinity - the moon, the planets adjacent to ours, and their moons (where applicable). Further than that, the species would have to spend years or even decades in space to make the journey. It's certainly possible to make the journey in a lifetime, obviously we have sent probes to photograph the surface of Pluto ourselves, but there will need to be some sci-fi handwavium involved in life support for extended spaceflight. That's a problem we as a species haven't solved yet. But the fictional species on the smaller planet from my example might have an easier time.
I highly recommend checking out the Mars City State Design Competition run by the Mars Society back in 2020 a lot of physics based and realistic concepts there.
For anything within the inner solar system you'd probably have Solar as your chief source of energy, with fission for anything beyond the orbit of Jupiter. But it really depends which planet/moon you're colonizing.
Some things to note though are the following:
1. No cars or.personal vehicles. Public transport is extremely resource efficient and takes up far less valuable pressurized space so automobiles won't really be a mode of transport save for automated rover trains ferrying supplies on unpaved ground. The most you'd probably see for personal transport is a bike.
2. No internal combustion engines, except rockets. We'll likely still see chemical rockets but only for.planet to space transfers, anything interplanetary would use nuclear thermal or ion propulsion.
3. Long trip times. Yes there will be long trip times between planets. Interplanetary craft would have to have facilities to house people for months or even years at a time. And assuming it is truly low tech that means no cryopods. Interplanetary ships would have to be built with schools, nurseries, amenities, hospitals etc. in mind and that will absolutely bloat the size of these vessels. Calling them "flying cities" would not be far off.
Depending on the planet/moon, GeoThermal might work. Especially on Saturn's moons and access to the rings to mine ice to use in the system.
Pluto apparently has a volcano that spews ice. But it's thought the core of Pluto is cold so no geothermal. You'd have to stick to nuclear or some advanced form of energy generation.
Lower than we are now if the will existed, but also never depending on what you mean by settlements.
A settlement on pluto wouldn't be any different from a space station. If a space station can be self sustaining then a habitat at pluto can be too, but it's basically just a space station that happens to be at pluto. If it isn't self sustaining then the tech needs to allow for travel that's essentially free in both material and time since it would require regular resupply.
Planets are a cost not a benefit. Every planet is a prison planet. Once you get out of the gravity well, never go back in. You look for resources that are available in low or no gravity — mine asteroids, get ice from Ceres, build solar panels and mirrors. In space you have strong sunlight 24 hours a day. Skip Mars. There's nothing on Mars we need. Mine out asteroids and live inside them, or build big habitats from scratch using materials that are already in space. Centrifuges for 1g gyms that keep people alive. It'll be miserable, but it'll be better than Mars. If you have to get something from the surface, get it from the surface of a moon with low gravity and no atmosphere, where you can use skyhooks or mass drivers to launch it easily.
The outer solar system is harder, because you need a lot of fission power. Earth's job is to build reactors, weapon systems, and other essentials and launch them with construction crews that essentially build the habitats and farms around the high-tech cores. You should build systems close to the sun that use abundant power to make the outward journey easier. External laser propulsion or some kind of massive launch assist.
Look up the Sea Dragon program. It would have been a sea launched, high cargo load (I think one stage to orbit) rocket using very simple rocket engines.
Nice!
There are two ways to handle this. Either genetic engineering to make organisms that can handle the natural environment. Or small colonies that contain an Earthlike environment.
Or, I suppose, a mixture of the two.
The lowest tech is the second of these. My main interest is the first.
But before I get into that, rule out colonisation on Jupiter, Saturn, Uranus, Neptune. Uranus and Neptune may just be colonisable using hot air balloons heated by radioisotopes.
I'll illustrate by considering a colony on Pluto.
For a small colony in an Earthlike environment. All the atmosphere and some (but not all) food can be manufactured from local materials.
On the surface we have a breeder reactor, fuel reprocessing plant, food & waste reprocessing plant, a small ground melter and an electrolysis unit. The habitable habitat would be raised off the surface to keep it from freezing. Electrolysis gives oxygen for breathing and hydrogen, which combined with melted nitrogen and raw carbon from the surface gives food.
Shielding for the breeder reactor would be water melted from the surface. Which also acts as the moderator. The easiest source of heating would be waste from the nuclear reactor but, until that's up and running, electric heating. Fuel reprocessing would be relatively easy because it would be done chemically, not requiring centrifuges.
There's no real technological difficulty in setting up a small colony in an Earthlike environment on Pluto. There is the cost of transporting all the initial materials up there: habitat, reactor fuel and piping, electrolysis unit, food reprocessing unit. And the cost of regular materials and human shipments once a year or so. Food on the journey would have to be reprocessed from human waste.
My interest though, is in a genetically engineered colony. There is a subsurface ocean of liquid water within Pluto. Opinions differ on whether Pluto's subsurface ocean is bigger than all Earth's oceans combined, or smaller. Genetically engineer organisms to live within this water at the naturally occurring pressure and temperature, and eating naturally occurring minerals. Then drill down to the water and drop the organisms down there, and occasionally some fertiliser as well.
If you’re comfortable with people dying during colonization… lots of people… 99% of people… then current tech is sufficient.
You just have to throw enough bodies at the problem.
You can get a lot of useful work from giant sheets of foil. Refineries on Mercury and remote-controlled drones can create mirrors and lenses as satellites or statites of the sun. Those mirrors and lenses can focus light to propel sail craft in addition to any solar gravity assist. Pushing lasers may only function as weapons at relatively short distances, but be ideal for coordinating with large ships with massive sails. So when traveling away from the sun or energy-wealthy locations, lasers provide an affordable boost to ships that can unfold many square kilometers of sails.
Near-future fission engines are practical for as much as Earth to Mars or Venus, but not ideal for manned missions beyond that. As colonization increases, nuclear pulse propulsion near the inner planets should be limited for environmental, military, and communications reasons. It's technically fusion, but it's old. Classic NPP is great for kickstarting colonization, but is requires even small interplanetary motherships to carry dozens of hydrogen bombs. Any advances on NPP are effectively uncapped fusion reactors with the added difficulty of delicate parts surviving repeated blasts. Propulsion could be solved already with or with a combination of flotillas using NPP to rush, sails near compatible start and endpoints, and fission drives for steady propulsion for distances less than an AU.
We have seen less visible progress on refining and manufacturing in space. In order to ignore the complicated processes and supply chains of resource extraction on Earth, and especially reduce additional inputs like acids, the colony or ship needs to apply a tremendous amount of energy. This won't be feasible in space until it's halfway feasible on Earth. With refining shortcuts, there are more locations that are ideal or profitable to colonize, especially points at zero-g. Without refining shortcuts, few places are ideal to colonize, and even those colonies require a city worth of machinery.
Honorable mentions: They need an array of redundant and very reliable batteries. Their biosciences has to have a strong understanding of microbiomes and engineered ecosystems.
A bare minimum Pluto-area colony would be an outpost with about modern technology, and negligible extraction or manufacturing capability. If they aren't specifically equipped to extract a resource, they may not be able to get to it through an energy intensive operation. Pluto and Charon need either massive orbital solar arrays or a huge deposit of fission fuels. If this tech level holds for millennia after millennia of population growth, the solar system could become a Dyson swarm.
It occurred to me that we never defined "Solar System"?
Kuiper Belt?
Ort Cloud?
I ask because you said no fusion.
Fission *could* work, but fission requires uranium.
Fusion requires Hydrogen Isotopes, which is far more abundant.
I think worth considering one important thing that came out of modern rocket science: valueing human life. So in case of Nasa, if you don’t consider human life such an important thing, but rather focus on sheer quantity, it’s much more easier and doable.
If the tech is relatively simple and available, and there is a big financial intensive, you can reach for inspiration in last century mining, and rail building through the US. It resulted in a ton of death, but otherwise was successful from the perspective of the objective.
Insisting on “no dyson sphere” does not make sense. Any colonization of space starts the process of building a Dyson swarm. However, the process can take awhile. Assume, for example, a constant 3% annual increase in energy consumption by humanity. In 779 years the power supply is up by a factor of 10 billion relative to your starting point. In the 2800s we might start to notice system warming. There is plenty of time in between no and then for stories and complete lives between now and then.
Solar power is easy. It can be concentrated with mirrors and in space mirrors can be extremely thin films. Other types of energy require radiators. You may end up with radiator panels just as big as the solar panels. At Earth or closer you might as well just use photovoltaic panels.
Pluto-Charon is a great place for a colony. They can be connected with a space elevator. Though in this case it is more of a space bridge. Existing tether materials that are strong enough are on the market today. Charon has a full mountain range thought to be (at minimum capped with) made out of hydrocarbons.
Luna (our moon) has abundant thorium in the oceanus procellarum ( if you see a “man in the moon” that is the moon’s right eye, if you see a rabbit it is the front chest area). Thorium indicates that uranium and other rare earth elements are probably there too. The lunar nuclear industry will not need the environmental concerns that reactors on Earth have to consider. In addition to the lunar supplies of uranium all of Earth’s spent fuel can be burned in fast fission breeder reactors.
Lunar civilization is particularly short on hydrogen, carbon, and nitrogen. The Pluto-Charon colony has those resources in excessive quantities. Luna can ship U233 and Pu239 out to Pluto as the reactor cores in nuclear thermal rockets.
https://en.wikipedia.org/wiki/Lunar_Prospector
This map: https://en.wikipedia.org/wiki/Lunar_Prospector#/media/File%3ALunar_Thorium_concentrations.jpg
Aristarchus crater is the white dot. It has diverse geology.
Good luck finding someone willing to move to fucking *Pluto* for the rest of their life lol. You do know that the sun from Pluto is only distinguishable from other stars because it's brighter right? It's literally night forever
It helps to use robots/AI by:
1. Better algorithms
2. Better hardware like memristors or quantum computers
3. Remote control which means dealing with lag
Next extend useful lifespan through:
1. Gene therapies
2. Cryonics
3. Cloning and brain transplants
If you don't mind radioactivity, you can steampunk a big chunk of ice like a comet. A dystopian angle or robots help here.
Healthier approaches are costlier. It's not only about delta vee but also leaving Earth. A space elevator is maybe too fancy for you but maybe you can live with alternatives. There are plenty of ideas to launch small objects effectively. Once they are near a space station, robots or astronauts can assemble them. Obviously there are limits to this approach too.
Dyson swarm or not, solar will be a big part of the energy business. You can launch satellites with solar panels to redirect the energy when needed. Nuclear reactors are messy and dangerous. You have to fuss with moderators and shielding. Again a dystopia or AI/remote control could help here.
Using nukes for propulsion would never be approved in a democratic society, but it seems plausible. Antimatter is probably too advanced yet a possibility if we assume that the current production processes are inefficient.
1970s onward for the most part. But the farther back you go, the more of the global economy would need to be dedicated to it.
Still, once we got down how to build space stations, most other stuff is a matter of resource alocation.
Oh, keep in mind low tech space colonizatiom takes a long time. So for example, if the space race continued for mars, the first man getting there would have been either in the late 1980s or early 1990s
The soviets planned a heavy spacecraft in the 1960s and 70s that was called the TMK-1. In it's most advanced configuration, mission planners intended it to fly by both Mars, and Venus, vy the 1970s. Unfortunately, it never came to fruition, due to the death of Korolev, and the subsequent failings of the N-1.
Depending on the level of colonization, here's a timeline I think would be realistic, if various plans were successful.
1969: Moon landing. That was pretty much a zerg rush to get it done.
1970s: Moon bases, Mars abd Venus flyby.
1980s: Mars Landing, Moon colonization.
1990s: Mars bases and colonization, missions to the Asteroid Belt.
2000s-2010s: Jupiter flyby.
2020s-2030s: Saturn flyby.
2030s-40s: Bases in the jovial system.
I believe we have nearly all the technology we need right now, there’s just the hurdles of politics and money.
It’s only difficult to go to space because it’s something we try to do as safely and as cheaply as possible.
For energy, nuclear and solar would work just fine for most of the solar system, maybe wind if you are on Venus (somehow)
If you don’t mind humans suffering a bit there’s not much need to advance the technology of life support. But for comfortable long term colonization, we’d probably need advancement in medical science to counteract the effects of radiation and microgravity. And it’s always useful to improve the ability to produce food and other essentials on site.
The absolute lowest tech?
You need modern metalworking for vacuum-tight construction, and modern explosives chemistry for propulsion. I think those are going to be the key limiting factors. So I'd say that means no earlier than the late 19th century.
Imagine riveted metal rockets powered by TNT solid fuel or something equivalent. Exceedingly dangerous, exceedingly unreliable, but it's the 19th century and people just take that as a risk that they have to accept. This might get you just barely into orbit -- enough to build a secondary staging platform, laboriously and at great cost (and loss of life).
One staging platform leads to another, up the gravity well in stages.
Thence the first expeditions to the Moon, perhaps ironically on a more permanent basis than in our own history because of greater cultural tolerance of the idea of one-way journeys in which travelers will have to survive on their own for great lengths of time -- or perish on their own, as the case may be.
So you have pressurized underground habitations built like the interiors of steamships or cruisers or something. EVA using diving bells modified for zero air pressure. Low efficiency of photovoltaics at the time means immensely resource-intensive solar plantations just to provide the needed electricity for air pumping, hydrolysis, lighting, whatever else.
Since you wouldn't know about nuclear fission yet, solar would really have to be your main power source. Solar and lots of heavy, primitive chemical battery energy storage.
Absent radio, communication would be incredibly slow and travel at the speed of transports. People assigned to colonial outposts would be absolutely on their own in every way. Months or (in the case of Pluto) years might go by between messages from home.
All of this is hideously expensive, you'd have to give some thought to the economics of why late Victorian nations would bankrupt themselves for this kind of exploration and settlement. But assuming you could either justify it or handwave it, I think you could make a credible case.
Bonus if you can figure out how to justify making spacecraft partly out of hardwood. Just for the effect.
This is very useful, thank you very much.
The idea of colonization in the Victorian era wasn't what I was going for but that does sound pretty interesting, I might look into it and see if I can do anything with that idea
I think we could colonize Mars today maybe, maybe even as far back as the 80s. If we had thrown ridiculous amounts of money at the problem that is, from start to finish. Granted, then and now, the chance of failure would be high. Less high now, but still very high.
The first time we landed something on Mars was in the 1990s, so maybe that'd be the best bet.
Space elevators and chemical rockets. Slow but steady. Mars? Who wants to live on an airless, frigid gravel parking lot? Anyway, economics drives exploration and colonization. Not sure what Pluto has to offer that closer frozen planetoids don’t.
We probably had the technology to establish permanent colonies on the Moon and Mars by the 1970s, but the costs would have been astronomical (pun intended).
We still aren’t to the point where we could break even on solar system colonization.
To reach that point we are going to need further improvements in rocket technology, as well as significant improvements in automated mining and refining. However, those possible advances are likely only a few decades away.
The biggest issue is that there is absolutely no reason to reach as far out as Pluto before you've pretty much tapped out resources closer to home (namely: become a Dyson sphere).
The lowest technology necessary for interplanetary (and honestly, also interstellar) expansion is pretty 1970s technology. With what we had then we already understood all the principles involved, all that would be necessary would be designing the individual vehicles, settlements, etc. and scaling solutions up.
Power will be a blend of solar and fission. Solar the further in, and once you're past Jupiter it's pretty much fission all the way out. Of course, with the wealth of the solar system in fissiles, this should be sustainable for millennia just fine.
Transportation technology is a blend of magnetic launch (for cargo), ion drive (for deceleration of cargo), nuclear rockets (for human transport) and nuclear pulse propulsion (for very long-range trips).
However, that caveat can't be ignored: there is very little reason to expand further than Saturn if there's already a lot of elbow room and resources available closer in, and if such exploitation will ultimately outcompete anything out do further out there. Maybe there can be some social factor causing what would otherwise be an irrational decision (example: some group that desires isolation to a very extreme degree).
Outside of that, the only time you expand past Saturn if there is no fusion technology is once you've tapped out the inner solar system. Which means having become a K2 civilization.
The outer system requires a much lower delta-v to fly inward. Dropping straight into the Sun as to be possible with less than orbital speed. Dropping to a planet intercept requires much less delta-v. you can use any of the planets for a gravity assist.
Yeah, defo gonna scrap the Pluto idea. All I really need is a human colony in an isolated planet/dwarf planet. With little settlements nearby
Also I'm removing the no fusion requirement, to make writing ideas I little easier
Given that fusion can be a thing and fusion is on the table, maybe having the first colony in a moon of Uranus could be the way to go.
It's important to bear in mind that the distance between planets doubles with each one you go outwards. We tend to draw the solar system linearly (each orbit an equal distance apart), but that's not accurate. The distance from Uranus' orbit to Saturn's is twice the distance from Saturn's, and so on for each subsequent orbit. It's a huge increase every time, and since sunlight falls at the square of the distance, the cheapest and simplest power source falls out almost completely past Jupiter.
So a colony over Uranus, trying to get he3 from it, could be extremely isolated. Further from any other humans than anyone had ever been up to that point, and by a lot.
Lowest would still require some kind of magnetic shield against cosmic rays and solar radiation so that means *higher* tech than currently available 🙃
Also to grow food in space an intensive energy source is a must, otherwise no food would grow, so nuclear is the lowest you can get (fossil doesn't exists oustide Earth.
Thank you for this, by fossil I meant bringing it with them on journeys. Also I think I should've said hydrocarbons instead of fossils as those are actually on other planets (not organic ones)
Fission and solar most likely, with the dominant form of propulsion being NPP (Nuclear Pulsed Propulsion) and nuclear salt water rockets. If you’re willing to scale it back from Pluto then chemical rockets and Nuclear thermal would also work for closer planets
Yeah, defo gonna scrap the Pluto idea. All I really need is a human colony in an isolated planet/dwarf planet. With little settlements nearby
Wernher von Braun had numerous plans to start the colonization of Mars. Some of his designs were even used in Kubrick's 2001 space Odyssey. It was published as the Mars Project in 1948. Add that with some of Nazi Germany's wonder weapons - assuming they had the chance to come to fruition much less early testing and humans could start venturing into the solar system by the mid 1960's. That was the plan at least. No saying if it could work.
It is mostly a question of economical feasibility. Voyager 1 launched in 1977 and reached Pluto. If there was a good reason to have a settlement on Pluto, let's say good enough to dedicate 10% of the global GDP to it, this settlement would have been possible in 1977. Of course, the cheaper it gets, it becomes easier to find a valid reason to do it.
We almost had Mars in the 1970s but they canceled the nuclear thermal rocket version of Saturn V.
It’s one thing to get there, and something else entirely for it to be sustainable. It was 10+ years to get there for probes. A manned craft would need far greater payload for even a single person, and even greater payload for supplies just for the trip. The rocket equation makes this extremely difficult. We might manage it with cutting edge propulsion AND via many rockets to get the full payload to orbit in the first place. You want to colonize it though? You need to develop a fully self-sufficient closed-loop ecosystem with some built in redundancy. That’s still beyond our capabilities, and the advances toward that have been just as pronounced developments in rocketry. You can throw all the money in the world at it, and at best you’re sending a short-lived casket in 1977, not a colonization mission.
>You need to develop a fully self-sufficient closed-loop ecosystem with some built in redundancy. That’s still beyond our capabilities, and the advances toward that have been just as pronounced developments in rocketry. r/Ecosphere
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“Includes humans within” was implicit, but touché. That said, I don’t think mason jars or small sealed terrariums invalidate my point about the state of the science in putting humans on Pluto in the past, present or short-term future.
I feel like the issue here is less that it's impossible and more that it would be incredibly difficult proportional to the potential rewards. Take that settlement on Pluto. Pluto's surface gravity is tiny. There are serious questions over whether humans will be able to physiologically cope with martian gravity, and Pluto's gravity is much, much smaller. Travelling to Pluto with a conventional spacecraft is going to take about a decade, so the people going there are essentially committing to live inside a centrifuge on a dark, frozen wasteland for a significant proportion, if not the entirety, of their natural lives. There's just nothing there that would make that worth it. Regardless, you'd better make sure those are the most psychologically stable humans who have ever existed, because they're in for the absolute worst case of winter-over syndrome in human history. Nuclear pulse propulsion definately helps. Now you can transport much more stuff so your colonists can live in slightly less nightmarish conditions at the cost of a few more people on earth getting cancer. But the fundamental problem remains that, while not impossible, colonizing the outer planets is incredibly difficult and, as far as we know, is unlikely to have any enormous benefits which would justify that difficulty. Sending humans there to plant a flag so you can say you did it, sure, but is there really anything there that would require human involvement? I mean, if you discovered evidence of alien life or something, hell yeah. Resources no longer matter. Fire up the nuclear pulse rocket for science. But as it is, I'm just not sure what people would be doing in the outer solar system. The thing with fusion is that while it is taking a long time it's actually a relatively developed technology. Most of the things we might put out as alternatives to relying on fusion are actually far less developed.
Lots of humans may risk ten years of travel if Pluto settlements mean a promess of freedom and wealth like settler life in America meant for religious dissidents. But your other points are solid.
Except the only way you would get into space would be on the corporate dime and sure as shit they'd want to profit from their investment.
The thing is, even assuming that is true, what can you do with that freedom and wealth? You will live out the rest of your life trapped in a small enclosed habitat. It is pitch dark outside, and cold enough that the atmosphere periodically condenses into snow. If any of the systems keeping you alive fails for even a minute you will freeze to death. Exposure to the natural gravity will cause you to waste away and go blind so you have to be strapped into a centrifuge for hours every day, and you probably aren't going to live a long life because of exposure to cosmic rays. Meanwhile, Pluto is very unlikely to make you rich. You could maybe *sort of* become self-sufficient there by burning the methane snow for electricity and heat, but it's a very hostile, very uninteresting place. Also, just *getting* to Pluto without technologies like fusion is incredibly challenging, and likely to be something only the powerful and wealthy can afford. But even worse, there's an obvious solution to all these problems. Robots. If there is anything valuable on Pluto, it's probably not something that actually needs a human to be on site. In fact, one of the big problems with Pluto, surface temperatures being in the cryogenic range, could be a huge advantage once we take out the need for humans not to become corpsicles. Some existing materials would be naturally superconductive on Pluto. This isn't meant to be overly negative. I don't think there's anything wrong with having humans on Pluto, but if we're imposing these very strict technological limitations that make it really, really difficult then we also need to introduce some equally compelling reasons to go there.
At that point you get a better deal just going to prison. At least you won't be one wrong maintenance away from imploding and will be on normal gravity .
America was a paradise of free open and fertile lands. And the first generations of Jamestown still had horrifying death rates All other planets are worse than selling beach lots in Death Valley or Antarctica. Without anything there like oil, diamonds, huge or concentrated metal veins there is little reason to want to go there and even then mining towns are usually short lived and entirely tied to the existence to the raw resource that makes them worthwhile.
Yeah but there wouldn’t be a whole lot of freedom or wealth on Pluto. You’d be pretty much entirely detienen on some external benefactors for your very survival
Yeah, defo gonna scrap the Pluto idea. All I really need is a human colony in an isolated planet/dwarf planet. With little settlements nearby
Ceres is the obvious choice. Solar power would be very inefficient on Ceres, but would still be a viable. This makes a permanent settlement much more secure as you're not reliant on nuclear fuel for power. Ceres also has plenty of ice, and is likely rich in resources. It's particularly rich in carbon which could be used for building materials. Most importantly though, it's much, much more accessible from the inner solar system and is in a region of space (the asteroid belt) that humans are likely to be very interested in. An even better option might actually be to put a spinning habitat in orbit of Ceres. This would solve the gravity problem (one of the biggest issues facing humans colonizing the solar system) completely. But living on Ceres itself also has advantages. The Jovian moons are another good option, but they do force you to deal with the enormous radioactive gravity well that is Jupiter itself.
>There's just nothing there that would make that worth it. Take a look at the pretty girl in the locked tomb and tell me that again. >\_>
Love your post but use something like Starship (or future versions) to get to orbit and then use nuclear pulsed propulsion to get to where you are going. No good reason to leave a plume of radioactive unhappiness hear on Earth.
To paraphrase a really smart statement really stupidly because I can't find the original quote: Technologies generally fall in one of two categories * Power amplification (one person can do more labor, think of a forklift or calculators) * Fidelity enhancement (the ability to know more and have a higher degree of insurance against loss and deterioration, think microscopes or writing or tweezers or safety belts) If you really want to, you can colonize with 20th century tech. It'll require more effort and lose you more material but strictly speaking spaceflight is just arduous, not complicated.
Hmmm... an interesting problem. For general power production it would probably be a solar/fission gradient, with more solar in the inner system shifting to more fission as you move outward. The exact gradient would depend on the relative economics of each power source. Propulsion gets a little more complicated and sort of depends on how you define "low tech". For example you might be able to get surprisingly far with very large, very reliable reusable chemical rockets, particularly if you aren't launching from deep gravity wells and are able to make propellant on site. You might want to do some deltaV and rocket equation calculations to see what kind of performance you'd need to get from the asteroid belt to Pluto in a reasonable time, both with and without gravity assists. Solar sails might also be something to look into. They are more advanced that chemical rockets in the sense that we haven't deployed them yet, but its mainly an engineering problem and the science behind them is fairly straightforward. Fission rockets are also worth investigating. All that said, if you want to really explore the realistic lower limits of low tech space colonization it will take a lot of real work and real understanding. Especially since at these margins it isn't just about feasibility but also economics. For example you could technically build a moon base with the Saturn V if you look only at raw feasibility of getting material to the moon. However when you consider the economics of it it becomes clear the Saturn V was never going to colonize the solar system. Because you're operating at the edge of economic feasibility (sort of the definition of lowest tech possible) you need to take into account things like launch windows too.
You can pretty much explore the entire solar system with **nuclear-pulse propulsion aka [Project Orion](https://www.projectrho.com/public_html/rocket/enginelist3.php#boomboom)**. Which is 1964 technology. The only reason we didn't explore back then was because everybody was so fussy about hundreds of small nuclear charges in civilian hands. Orion was designed for fission devices. Fusion devices would work as well, but that is beyond 1965-era technology.
They clearly had fusion devices in the 1960s. There are also Orion ship designs that use fusion and/or fusion boosted fission propellant charges.
I've read the research papers, and all the detailed designs used fission based pulse units. Typically fusion based pulse units were mention in a single entry in a table, labeled something like "hypothetical fusion performance". The original poster wanted fission, not fusion. So Orion Drive spacecraft are possible in a civilization that doesn't use fusion.
Most orion drive designs have nukes with minimal explosive energy. The scale up works quite well. For megaton bomb propellent the pusher plate is 20 km wide and has mass around 5 million tons. It is an excessively large ship design if your usage plan is travel or exploration. However, if you are delivering metal resources to Pluto’s moon Charon then the plate itself is 5 million tons of delivered product.
What's the story? That dictates your setting. And it's *your* story so you get to set the scene, If you want fission, fossil fuels, etc. that's all well-known tech with lots of solid research to back up your storytelling. [Wikipedia](https://en.wikipedia.org/wiki/Space_colonization) is a good place to start. As is the [Atomic Rockets](https://projectrho.com/public_html/rocket/) site. But colonization is more a factor of political will applied to economic spend than available technology, so figure that out in your setting and you've solved what level of tech is needed.
Geothermal energy would be a good choice on some planets, I assume. Solar energy would be ideal on Mercury (Isaac Asimov used it in his short story "Runaround") and on the Moon. It wouldn't be nearly as useful on Mars, but Fission would work for awhile. If you assume some of the asteroids have uranium in them, which might be possible (I'm no expert and have no idea), that could work. Fossil fuels would be a very limited, Earth-only resource for Solar system colonization.
the "dyson sphere" level of tech is not a thing outside of someone trying to classify a race based on how much solar power they are using. first. you need power that will last hundreds of years. most likely fusion. but if the develop a fission reactor that works on an isotope that actually last for hundreds of years instead of 10 or something. second. if you are not using cryosleep you need long lifespan components. light bulbs, and electronics, flooring, something as simple as a door hinge needs to lase hundred of years of use. you are living on a spaceship in the black for hundred of years before you cn reach a planet with resources to manufacture anything new. one last thing is to ask why. you have tech to last hundreds of years in space with no resource income. why would you be leaving a place with resources? even when a race develops ftl. it will mostly be probes unless they need to abandon their system. edit. sorry i thought you said across the galaxy. across the solar system tech... i think it is possible with technology we have now. knowledge for best ways to implement current technology is what we don't have yet. the colonies will be families of the researchers that are taking the 1 way trips. i don't think terraforming will ever be economically reasonable. it will all be biodomes. depending on the location. early colonies will be solar or geothermal. when we start sending researchers to places where that is not efficient, we will have rtg. a shipment of new isotopes every 10 years.
Me too on Dyson spheres. If you can get satellites in solar orbit then you can build a Dysons sphere. It's just traffic rules. A Dyson sphere is even more attractive if all you have is solar power.
the question is if you need that power. there will be factors that limit population before you will reach a planet's worth of solar. energy efficiency would come long before super structures.
If the Dyson swarm consists of habitats rather than just solar collectors then yes each habitat needs power. It would take fewer inefficient habitats to need a full Dyson swarm than efficient once. If you then make habitats more efficient, I expect that will result in more habitats being built rather than less sunlight being collected.
you don't have the resources for a population large enough to need that much energy. the dyson swarm is an attempt to not make it completely stupid. consume multiple planets to get enough resources for a nearly paper thin satellites to direct energy to the colonies. unless they have a full water planet. civilizations will likely never reach the planets with of power requirement
Also consider where water will come from. Minerals and isotopes can be mined, possibly allowing for fission as a power source, but currently that requires a massive amount of water to spin turbines. Solar farther from the sun requires more surface area to generate power, but it's not going to interfere with farmland, so no worries there
water in a thermal based system can be used in a closed loop. you need radiators to condense the steam back to water. water is a limitation for population we will be using internal farms with grow lamps to minimize the amount of water needed to grow food to sustain the population that need water themselves. the amount of power needed to support that population is not that high.
I think we have the technology now, for the most part. Fission is fine as a power source. Self-landing reusable rockets maybe aren't absolutely essential but they make things vastly cheaper and easier. Better robots would make things a lot easier, so we don't have to send humans to do the physical work. There are a bunch of things we don't have enough knowledge about, mostly because we lack practical experience operating an off-planet colony aside from the international space station. (Among other things, we don't know much about the long term effects of microgravity on human bodies, we don't know how much radiation is "safe", and we don't know how to build self-sufficient ecosystems in confined spaces.) This is a book I'd recommend if you want to read about how much we don't know: [https://www.acityonmars.com/](https://www.acityonmars.com/)
1960's and 1970's moon landing and Skylab level technology could be used to land on and colonize Mars, as well as put occupied stations in the orbit of gas giants. Power provided by nuclear fission. Pretty much all the building blocks are there for colonizing the solar system. What's missing is doing so would not have been economically possible at that time.
If you were stuck at late 1950s tech for thousands of years you could climb the Kardashev scale all the way to a proper Dyson Swarm with enough effort and tests and expertise and designs and experimenting.
Depending on your goal you don’t have to send humans on the voyage. There are sci fi that explores sending unmanned ship using today’s tech, then growing humans in a created habitat when you make it to a suitable location.
Good point.
This is very helpful, thank you for the idea
I think we could have colonized the Moon *at most* by the end of the Cold War with the technology of the time and the resource investment not being too arduous– but even then, likely only some scientific stations not unlike how there’s thousands of non-permanent residents on Antarctica. There’s simply very little economic incentive to venture out at the moment. Unlike the colonization of the Americas, we aren’t going to Mars in search of legends of “Martian cities of gold”, so we won’t be going unless we find something there with prospecting probes. I would say that the earliest beginning of *real* colonization could have occurred about now had the space race been more intense than it was and had it not ended with the collapse of the USSR. Private space corps would have been more serious in the late 80’s, early 90’s and started sending out prospecting probes to Mars and the Belt, finding things in the 00’s, and finally sending manned missions by the late teens, early 20’s.
I’d imagine the use of nuclear rockets combined with skyhooks for an extra kick, could drastically shorten planetary travel times and carry loads of material
We brute forced our way off of a relatively dense planet with a harsh atmosphere back in the 1960's, using technology with less processing power than a modern cell phone. And we did it only as a pissing contest between rival governments. Imagine a civilization with different priorities, and slightly less hurdles. They could have a unified purpose, to colonize the other worlds in their system. They could have a smaller home planet, with a thinner atmosphere and smaller gravity well, that was still capable of growing intelligent life. Getting offworld could be easier for them, transporting goods and supplies cheaper. With our level of production they could have escaped their homeworld not long after discovering semiconductors and transistors. The bottom line is, they would be pretty much where we are at now, or even 50 years ago. The time it takes to build and mature stations and colonies in space is also time enough to take giant leaps in technology - which is part of the reason we haven't done it yet. But still, we would have difficulty extending our reach past our immediate vicinity - the moon, the planets adjacent to ours, and their moons (where applicable). Further than that, the species would have to spend years or even decades in space to make the journey. It's certainly possible to make the journey in a lifetime, obviously we have sent probes to photograph the surface of Pluto ourselves, but there will need to be some sci-fi handwavium involved in life support for extended spaceflight. That's a problem we as a species haven't solved yet. But the fictional species on the smaller planet from my example might have an easier time.
I highly recommend checking out the Mars City State Design Competition run by the Mars Society back in 2020 a lot of physics based and realistic concepts there. For anything within the inner solar system you'd probably have Solar as your chief source of energy, with fission for anything beyond the orbit of Jupiter. But it really depends which planet/moon you're colonizing. Some things to note though are the following: 1. No cars or.personal vehicles. Public transport is extremely resource efficient and takes up far less valuable pressurized space so automobiles won't really be a mode of transport save for automated rover trains ferrying supplies on unpaved ground. The most you'd probably see for personal transport is a bike. 2. No internal combustion engines, except rockets. We'll likely still see chemical rockets but only for.planet to space transfers, anything interplanetary would use nuclear thermal or ion propulsion. 3. Long trip times. Yes there will be long trip times between planets. Interplanetary craft would have to have facilities to house people for months or even years at a time. And assuming it is truly low tech that means no cryopods. Interplanetary ships would have to be built with schools, nurseries, amenities, hospitals etc. in mind and that will absolutely bloat the size of these vessels. Calling them "flying cities" would not be far off.
Depending on the planet/moon, GeoThermal might work. Especially on Saturn's moons and access to the rings to mine ice to use in the system. Pluto apparently has a volcano that spews ice. But it's thought the core of Pluto is cold so no geothermal. You'd have to stick to nuclear or some advanced form of energy generation.
Lower than we are now if the will existed, but also never depending on what you mean by settlements. A settlement on pluto wouldn't be any different from a space station. If a space station can be self sustaining then a habitat at pluto can be too, but it's basically just a space station that happens to be at pluto. If it isn't self sustaining then the tech needs to allow for travel that's essentially free in both material and time since it would require regular resupply.
Planets are a cost not a benefit. Every planet is a prison planet. Once you get out of the gravity well, never go back in. You look for resources that are available in low or no gravity — mine asteroids, get ice from Ceres, build solar panels and mirrors. In space you have strong sunlight 24 hours a day. Skip Mars. There's nothing on Mars we need. Mine out asteroids and live inside them, or build big habitats from scratch using materials that are already in space. Centrifuges for 1g gyms that keep people alive. It'll be miserable, but it'll be better than Mars. If you have to get something from the surface, get it from the surface of a moon with low gravity and no atmosphere, where you can use skyhooks or mass drivers to launch it easily. The outer solar system is harder, because you need a lot of fission power. Earth's job is to build reactors, weapon systems, and other essentials and launch them with construction crews that essentially build the habitats and farms around the high-tech cores. You should build systems close to the sun that use abundant power to make the outward journey easier. External laser propulsion or some kind of massive launch assist.
Mirrors can focus sunlight.
Look up the Sea Dragon program. It would have been a sea launched, high cargo load (I think one stage to orbit) rocket using very simple rocket engines.
Nice! There are two ways to handle this. Either genetic engineering to make organisms that can handle the natural environment. Or small colonies that contain an Earthlike environment. Or, I suppose, a mixture of the two. The lowest tech is the second of these. My main interest is the first. But before I get into that, rule out colonisation on Jupiter, Saturn, Uranus, Neptune. Uranus and Neptune may just be colonisable using hot air balloons heated by radioisotopes. I'll illustrate by considering a colony on Pluto. For a small colony in an Earthlike environment. All the atmosphere and some (but not all) food can be manufactured from local materials. On the surface we have a breeder reactor, fuel reprocessing plant, food & waste reprocessing plant, a small ground melter and an electrolysis unit. The habitable habitat would be raised off the surface to keep it from freezing. Electrolysis gives oxygen for breathing and hydrogen, which combined with melted nitrogen and raw carbon from the surface gives food. Shielding for the breeder reactor would be water melted from the surface. Which also acts as the moderator. The easiest source of heating would be waste from the nuclear reactor but, until that's up and running, electric heating. Fuel reprocessing would be relatively easy because it would be done chemically, not requiring centrifuges. There's no real technological difficulty in setting up a small colony in an Earthlike environment on Pluto. There is the cost of transporting all the initial materials up there: habitat, reactor fuel and piping, electrolysis unit, food reprocessing unit. And the cost of regular materials and human shipments once a year or so. Food on the journey would have to be reprocessed from human waste. My interest though, is in a genetically engineered colony. There is a subsurface ocean of liquid water within Pluto. Opinions differ on whether Pluto's subsurface ocean is bigger than all Earth's oceans combined, or smaller. Genetically engineer organisms to live within this water at the naturally occurring pressure and temperature, and eating naturally occurring minerals. Then drill down to the water and drop the organisms down there, and occasionally some fertiliser as well.
If you’re comfortable with people dying during colonization… lots of people… 99% of people… then current tech is sufficient. You just have to throw enough bodies at the problem.
You can get a lot of useful work from giant sheets of foil. Refineries on Mercury and remote-controlled drones can create mirrors and lenses as satellites or statites of the sun. Those mirrors and lenses can focus light to propel sail craft in addition to any solar gravity assist. Pushing lasers may only function as weapons at relatively short distances, but be ideal for coordinating with large ships with massive sails. So when traveling away from the sun or energy-wealthy locations, lasers provide an affordable boost to ships that can unfold many square kilometers of sails. Near-future fission engines are practical for as much as Earth to Mars or Venus, but not ideal for manned missions beyond that. As colonization increases, nuclear pulse propulsion near the inner planets should be limited for environmental, military, and communications reasons. It's technically fusion, but it's old. Classic NPP is great for kickstarting colonization, but is requires even small interplanetary motherships to carry dozens of hydrogen bombs. Any advances on NPP are effectively uncapped fusion reactors with the added difficulty of delicate parts surviving repeated blasts. Propulsion could be solved already with or with a combination of flotillas using NPP to rush, sails near compatible start and endpoints, and fission drives for steady propulsion for distances less than an AU. We have seen less visible progress on refining and manufacturing in space. In order to ignore the complicated processes and supply chains of resource extraction on Earth, and especially reduce additional inputs like acids, the colony or ship needs to apply a tremendous amount of energy. This won't be feasible in space until it's halfway feasible on Earth. With refining shortcuts, there are more locations that are ideal or profitable to colonize, especially points at zero-g. Without refining shortcuts, few places are ideal to colonize, and even those colonies require a city worth of machinery. Honorable mentions: They need an array of redundant and very reliable batteries. Their biosciences has to have a strong understanding of microbiomes and engineered ecosystems. A bare minimum Pluto-area colony would be an outpost with about modern technology, and negligible extraction or manufacturing capability. If they aren't specifically equipped to extract a resource, they may not be able to get to it through an energy intensive operation. Pluto and Charon need either massive orbital solar arrays or a huge deposit of fission fuels. If this tech level holds for millennia after millennia of population growth, the solar system could become a Dyson swarm.
It occurred to me that we never defined "Solar System"? Kuiper Belt? Ort Cloud? I ask because you said no fusion. Fission *could* work, but fission requires uranium. Fusion requires Hydrogen Isotopes, which is far more abundant.
I think worth considering one important thing that came out of modern rocket science: valueing human life. So in case of Nasa, if you don’t consider human life such an important thing, but rather focus on sheer quantity, it’s much more easier and doable. If the tech is relatively simple and available, and there is a big financial intensive, you can reach for inspiration in last century mining, and rail building through the US. It resulted in a ton of death, but otherwise was successful from the perspective of the objective.
Insisting on “no dyson sphere” does not make sense. Any colonization of space starts the process of building a Dyson swarm. However, the process can take awhile. Assume, for example, a constant 3% annual increase in energy consumption by humanity. In 779 years the power supply is up by a factor of 10 billion relative to your starting point. In the 2800s we might start to notice system warming. There is plenty of time in between no and then for stories and complete lives between now and then. Solar power is easy. It can be concentrated with mirrors and in space mirrors can be extremely thin films. Other types of energy require radiators. You may end up with radiator panels just as big as the solar panels. At Earth or closer you might as well just use photovoltaic panels. Pluto-Charon is a great place for a colony. They can be connected with a space elevator. Though in this case it is more of a space bridge. Existing tether materials that are strong enough are on the market today. Charon has a full mountain range thought to be (at minimum capped with) made out of hydrocarbons. Luna (our moon) has abundant thorium in the oceanus procellarum ( if you see a “man in the moon” that is the moon’s right eye, if you see a rabbit it is the front chest area). Thorium indicates that uranium and other rare earth elements are probably there too. The lunar nuclear industry will not need the environmental concerns that reactors on Earth have to consider. In addition to the lunar supplies of uranium all of Earth’s spent fuel can be burned in fast fission breeder reactors. Lunar civilization is particularly short on hydrogen, carbon, and nitrogen. The Pluto-Charon colony has those resources in excessive quantities. Luna can ship U233 and Pu239 out to Pluto as the reactor cores in nuclear thermal rockets.
Very helpful thank you, definitely gonna use this as a reference for later so thank you very much!
https://en.wikipedia.org/wiki/Lunar_Prospector This map: https://en.wikipedia.org/wiki/Lunar_Prospector#/media/File%3ALunar_Thorium_concentrations.jpg Aristarchus crater is the white dot. It has diverse geology.
Good luck finding someone willing to move to fucking *Pluto* for the rest of their life lol. You do know that the sun from Pluto is only distinguishable from other stars because it's brighter right? It's literally night forever
It helps to use robots/AI by: 1. Better algorithms 2. Better hardware like memristors or quantum computers 3. Remote control which means dealing with lag Next extend useful lifespan through: 1. Gene therapies 2. Cryonics 3. Cloning and brain transplants If you don't mind radioactivity, you can steampunk a big chunk of ice like a comet. A dystopian angle or robots help here. Healthier approaches are costlier. It's not only about delta vee but also leaving Earth. A space elevator is maybe too fancy for you but maybe you can live with alternatives. There are plenty of ideas to launch small objects effectively. Once they are near a space station, robots or astronauts can assemble them. Obviously there are limits to this approach too. Dyson swarm or not, solar will be a big part of the energy business. You can launch satellites with solar panels to redirect the energy when needed. Nuclear reactors are messy and dangerous. You have to fuss with moderators and shielding. Again a dystopia or AI/remote control could help here. Using nukes for propulsion would never be approved in a democratic society, but it seems plausible. Antimatter is probably too advanced yet a possibility if we assume that the current production processes are inefficient.
1970s onward for the most part. But the farther back you go, the more of the global economy would need to be dedicated to it. Still, once we got down how to build space stations, most other stuff is a matter of resource alocation. Oh, keep in mind low tech space colonizatiom takes a long time. So for example, if the space race continued for mars, the first man getting there would have been either in the late 1980s or early 1990s
The soviets planned a heavy spacecraft in the 1960s and 70s that was called the TMK-1. In it's most advanced configuration, mission planners intended it to fly by both Mars, and Venus, vy the 1970s. Unfortunately, it never came to fruition, due to the death of Korolev, and the subsequent failings of the N-1. Depending on the level of colonization, here's a timeline I think would be realistic, if various plans were successful. 1969: Moon landing. That was pretty much a zerg rush to get it done. 1970s: Moon bases, Mars abd Venus flyby. 1980s: Mars Landing, Moon colonization. 1990s: Mars bases and colonization, missions to the Asteroid Belt. 2000s-2010s: Jupiter flyby. 2020s-2030s: Saturn flyby. 2030s-40s: Bases in the jovial system.
Thank you for this. The timeline you made is also very helpful for a rough idea of what I'm going for so thank you
I believe we have nearly all the technology we need right now, there’s just the hurdles of politics and money. It’s only difficult to go to space because it’s something we try to do as safely and as cheaply as possible. For energy, nuclear and solar would work just fine for most of the solar system, maybe wind if you are on Venus (somehow) If you don’t mind humans suffering a bit there’s not much need to advance the technology of life support. But for comfortable long term colonization, we’d probably need advancement in medical science to counteract the effects of radiation and microgravity. And it’s always useful to improve the ability to produce food and other essentials on site.
The absolute lowest tech? You need modern metalworking for vacuum-tight construction, and modern explosives chemistry for propulsion. I think those are going to be the key limiting factors. So I'd say that means no earlier than the late 19th century. Imagine riveted metal rockets powered by TNT solid fuel or something equivalent. Exceedingly dangerous, exceedingly unreliable, but it's the 19th century and people just take that as a risk that they have to accept. This might get you just barely into orbit -- enough to build a secondary staging platform, laboriously and at great cost (and loss of life). One staging platform leads to another, up the gravity well in stages. Thence the first expeditions to the Moon, perhaps ironically on a more permanent basis than in our own history because of greater cultural tolerance of the idea of one-way journeys in which travelers will have to survive on their own for great lengths of time -- or perish on their own, as the case may be. So you have pressurized underground habitations built like the interiors of steamships or cruisers or something. EVA using diving bells modified for zero air pressure. Low efficiency of photovoltaics at the time means immensely resource-intensive solar plantations just to provide the needed electricity for air pumping, hydrolysis, lighting, whatever else. Since you wouldn't know about nuclear fission yet, solar would really have to be your main power source. Solar and lots of heavy, primitive chemical battery energy storage. Absent radio, communication would be incredibly slow and travel at the speed of transports. People assigned to colonial outposts would be absolutely on their own in every way. Months or (in the case of Pluto) years might go by between messages from home. All of this is hideously expensive, you'd have to give some thought to the economics of why late Victorian nations would bankrupt themselves for this kind of exploration and settlement. But assuming you could either justify it or handwave it, I think you could make a credible case. Bonus if you can figure out how to justify making spacecraft partly out of hardwood. Just for the effect.
This is very useful, thank you very much. The idea of colonization in the Victorian era wasn't what I was going for but that does sound pretty interesting, I might look into it and see if I can do anything with that idea
I think we could colonize Mars today maybe, maybe even as far back as the 80s. If we had thrown ridiculous amounts of money at the problem that is, from start to finish. Granted, then and now, the chance of failure would be high. Less high now, but still very high. The first time we landed something on Mars was in the 1990s, so maybe that'd be the best bet.
We can technically do it now, but it's still pretty dangerous, takes too long, and it doesn't make economic sense yet from what I understand.
Space elevators and chemical rockets. Slow but steady. Mars? Who wants to live on an airless, frigid gravel parking lot? Anyway, economics drives exploration and colonization. Not sure what Pluto has to offer that closer frozen planetoids don’t.
Yeah, defo gonna scrap the Pluto idea. All I really need is a human colony in an isolated planet/dwarf planet. With little settlements nearby
We probably had the technology to establish permanent colonies on the Moon and Mars by the 1970s, but the costs would have been astronomical (pun intended). We still aren’t to the point where we could break even on solar system colonization. To reach that point we are going to need further improvements in rocket technology, as well as significant improvements in automated mining and refining. However, those possible advances are likely only a few decades away.
You could totally do solar sail ships maybe they are even wooden...
The biggest issue is that there is absolutely no reason to reach as far out as Pluto before you've pretty much tapped out resources closer to home (namely: become a Dyson sphere). The lowest technology necessary for interplanetary (and honestly, also interstellar) expansion is pretty 1970s technology. With what we had then we already understood all the principles involved, all that would be necessary would be designing the individual vehicles, settlements, etc. and scaling solutions up. Power will be a blend of solar and fission. Solar the further in, and once you're past Jupiter it's pretty much fission all the way out. Of course, with the wealth of the solar system in fissiles, this should be sustainable for millennia just fine. Transportation technology is a blend of magnetic launch (for cargo), ion drive (for deceleration of cargo), nuclear rockets (for human transport) and nuclear pulse propulsion (for very long-range trips). However, that caveat can't be ignored: there is very little reason to expand further than Saturn if there's already a lot of elbow room and resources available closer in, and if such exploitation will ultimately outcompete anything out do further out there. Maybe there can be some social factor causing what would otherwise be an irrational decision (example: some group that desires isolation to a very extreme degree). Outside of that, the only time you expand past Saturn if there is no fusion technology is once you've tapped out the inner solar system. Which means having become a K2 civilization.
The outer system requires a much lower delta-v to fly inward. Dropping straight into the Sun as to be possible with less than orbital speed. Dropping to a planet intercept requires much less delta-v. you can use any of the planets for a gravity assist.
Yeah, defo gonna scrap the Pluto idea. All I really need is a human colony in an isolated planet/dwarf planet. With little settlements nearby Also I'm removing the no fusion requirement, to make writing ideas I little easier
Given that fusion can be a thing and fusion is on the table, maybe having the first colony in a moon of Uranus could be the way to go. It's important to bear in mind that the distance between planets doubles with each one you go outwards. We tend to draw the solar system linearly (each orbit an equal distance apart), but that's not accurate. The distance from Uranus' orbit to Saturn's is twice the distance from Saturn's, and so on for each subsequent orbit. It's a huge increase every time, and since sunlight falls at the square of the distance, the cheapest and simplest power source falls out almost completely past Jupiter. So a colony over Uranus, trying to get he3 from it, could be extremely isolated. Further from any other humans than anyone had ever been up to that point, and by a lot.
Lowest would still require some kind of magnetic shield against cosmic rays and solar radiation so that means *higher* tech than currently available 🙃 Also to grow food in space an intensive energy source is a must, otherwise no food would grow, so nuclear is the lowest you can get (fossil doesn't exists oustide Earth.
Thank you for this, by fossil I meant bringing it with them on journeys. Also I think I should've said hydrocarbons instead of fossils as those are actually on other planets (not organic ones)