GURPS Spaceships: TL8 Retro-tech Space Opera setting idea

[seasalt]

So, I've been intrigued by the possibility of a mil-sci-fi/space opera setting with an extremely restricted tech level. Basically, seeing if some classic sci-fi tropes about interplanetary wars and politics can be done in a retro-tech style that has nothing anywhere close to bending the laws of physics. Not only does it not give very much in the way of speculative technologies (just the extreme bare minimum to make space colonization, travel and habitation possible), but it actually takes away a bit of technology that exists in the 20th century.

As per the aesthetic in 'Brigador' (which is otherwise soft sci-fi), one of the assumptions is that metal-oxide semiconductor microprocessors were never invented. In this alternate history, mankind is stuck with hybrid integrated circuits and never manages to progress past them (https://en.wikipedia.org/wiki/Hybrid_integrated_circuit). This is a world where, hundreds of years in the future, something as simple as a modern smartphone is impossible to conceive of (the reason for this is to starkly limit the potential of automation and make piloting depend on the human element). Not only is there no FTL, no artificial gravity and no reactionless drives, there isn't even fusion power - this is a civilization which has spread out into the solar system with nothing but the power of splitting atoms, deployed on a vast scale.

Major inspirations include Policenauts, The Moon Is a Harsh Mistress, the Red Planet books, and the obscure PC space combat game "Children of a Dead Earth".

What other sci-fi timelines accomplish with speculative physics bending technology, in this setting, has been done by the "Egyptian Pharaoh" method: lots of time (~400 years of spaceflight), lots of toil and lots of lives, spent by governments which have socially and technologically stagnated for an extended period of time. Without the information age to revolutionize society and turn it inward, the nations of the late 20th century turned their attention to expanding outwards, at any cost.

A variety of low-tech space travel methods are used. Huge amounts of people and components were lifted from Earth using space elevators and skyhooks, supplemented by old fashioned liquid-fueled rockets. Colonies throughout the solar system were built and are now maintained using an "interplanetary railway", with mostly-unmanned cargo vessels propelled using massive space-based railguns (for both acceleration and de-celeration), nuclear lightbulb engines, and solar sails, using the orbital transfer method to send materials and goods with a minimum of delta-V. Military and other high-priority vessels, meanwhile, make use of Orion drives and nuclear saltwater rockets. Nuclear thermal rockets serve as a middle ground.

Rules-wise, this would be a TL 8+1/-1 setting: generally limited to TL 8, but with some TL9 metallurgy, engineering and biotechnology (from Biotech, the TL9 bone-strengthening drugs and circulatory system enhancements that make long-term exposure to low gravity just barely survivable), with the closest thing to super-science being hibernation chambers that bring metabolism to a crawl and slow aging to 1/10th of normal during cold sleep. (In the case of warships, it would be normal for 75% or more of the crew to be in cold sleep at any given time, rotating in and out, only waking up the entire crew if trouble is anticipated). With TL9 orion drives, which are usually 'fine quality (efficient)' due to being refined over several centuries, interplanetary missions are much more viable than in the real world... unlike modern spaceship design, an efficient Orion drive vessel that devotes about a third of its mass to propulsion will have a big-dick delta-V of 40 or more with plenty of room left over for payload.

Even so, traveling between planets takes months. Going from the inner planets to the outer planets and vice-versa generally takes two or more years even with a fast ship (which is why colonization has focused heavily on the inner planets and less than 5% of extraterrestrial humans live in the asteroid belt or beyond). The main human colonies are on Mercury, Venus, and Mars, each of which has multiple large colony cities with millions of inhabitants established by various earth nations.

Out of these, only Mars is partially terraformed, mostly by crashing hundreds of comets and icy asteroids into it, melting the ice caps, and blocking solar winds with a giant magnetized shield, resulting in an atmospheric density roughly 15 times greater than pre-colonization. By the current era of 2442, a human being can survive on the surface without a pressurized spacesuit (they'll still need a respirator, though, and most people still travel in pressurized suits and vehicles for comfort). There is a long way to go before it can be called "habitable" - cities are still domed, and the only life forms thriving outside of sealed habitats are bacteria and hardy lichens. Because it's been colonized at a large scale during a time of increasing tensions and made heavy use of convicts as a source of colonists, Mars seems poised to become a proxy battleground - it is becoming dotted with military bases, and the independent settlements in the vast wastelands between core cities are often lawless, violent hellholes. Approximately 40 million live there scattered among 5 colonial nations and independent settlements.

Venus is completely un-terraformed and has had numerous "balloon cities" constructed floating in its upper atmosphere (it is actually the most favored extraterrestrial home by members of the ruling classes, since it has a more comfortable Earth-like gravity - although having a city suspended by giant balloons sounds like a scary way to live, the smaller pressure gradient means these are some of the safest colonies to live in, as well, since a hull breach means toxic gas starts seeping in, rather than getting blown out into hard vacuum). Because of the snowballing abundance of solar system resources and space-based large scale industry, Venusian cities are being built rapidly and attract the most immigration, giving it a population of 70 million.

Mercury's main cities are inside craters in the polar regions where the sun never reaches. Other dwellings are excavated underground, and there are also 'mobile cities' made entirely of slowly-crawling vehicles that are forever on the move on giant train tracks, taking advantage of the planet's slow rotation to stay out of the deadly daytime. Since a "day" on Mercury lasts roughly half of an earth year, temporary breakdowns in the engines of these train-cities are easily repaired before there's any danger. Because of abundant solar energy and solar winds, and the fairly low gravity, it is actually cheaper to grow food on Mercury and send it to other colonies using ships with solar sails than it is to rely on exports from Earth. Along with its incredible wealth, this makes Mercury the largest and most important human colony by a large margin, with a population of almost 150 million. Unlike the later colonies, Mercury was built during a time of rapproachment and cooperation, and the bulk of the population came there from impoverished african and south american nations rather than the great imperial powers. In contrast to the other colonies where the conflict tends to be between the proxies of the great power blocs of earth, Mercury's administration is semi-independent and has developed its own cultural identity. The business interests on Mercury succeeded in preventing it from becoming militarized, stopping the nightmare situation which is developing on Mars and Luna. However, the political situation is far from stable; life on Mercury is generally quite miserable and most of the planet's wealth and productivity do not benefit the common man living there. Like most colonies, the death rate far exceeds the number of children who manage to become healthy adults. It is stalked by the shadow of revolution.

Perhaps the worst-off colony is, ironically, the one closest to earth on Luna. It was among the first to be colonized on a large scale, which meant that it suffered the worst from early-generation mistakes. Since extraterrestrial life was even more miserable and deadly in the early years, it was colonized almost exclusively with convicts, political prisoners, and impoverished populations facing food shortages in the middle east and south asia. The microgravity on Earth's Moon is hell on the human body even compared to Mercury or Mars, and unlike Mars, building a giant magnetic shield to block cosmic radiation was not feasible, meaning that any time spent aboveground brings the constant risk of radiation poisoning. Even with modern medical technology (which is usually only available to the rich there), 90% die before their 50th birthday from cancer, heart disease, or accidents. The lunar colonies became trapped in vicious cycles of political and religious extremism, mirroring and amplifying the cyclical problems of their source nations on earth. The first and only atomic war in human history was fought on the moon's surface, as the lunar colonies which had embraced radical Islam mostly exterminated the non-muslim populations and declared a 'caliphate', mirroring a similar political entity on earth covering what was once Pakistan, the Gulf region, Indonesia, and large parts of south Eurasia. This has caused the great power blocs (China, the Soviet Union and the U.S.A.) to move in to fill the vacuum and reclaim and re-colonize the devastated areas, setting up a deadly no-man's-land.
(continued next post)

[seasalt]

Out of the outer planets, only Titan, Callisto and Ganymede have populations in the (single digit) millions, and most of the human presence in such remote reaches of space consists of isolated mining operations. Living conditions there are harsh even compared to Mars, Mercury or Luna, which slows the rate of expansion to a crawl after the initial effort. These have been mostly colonized by the Soviets, the European Space Alliance, and Japan, and the slow-to-nonexistent earthside population growth in these regions has further hampered their ability to grow. So far, the moons of Uranus and Neptune only have small research outposts with a handful of scientists. The kuiper belt has virtually no civilian inhabitants, but it does host a number of hidden military bases where the great powers have squirreled away some of their silo ships as a "second strike" contingency as part of the mutually-assured-destruction strategy.

Aside from planets, Ceres and Eros have been semi-colonized - "semi" because the microgravity makes permanent inhabitation impossible. Generally, the inhabitants of such places only remain there for 5 to 10 years, but some sign contracts to work there until they die. After 10 years, no medical technology can make a person acclimated to extreme microgravity capable of surviving planetary gravity again, and living longer than 20 years in such conditions is a rarity. Attempts at colonizing smaller asteroids in the asteroid belt have been disastrous - getting to and from them is very difficult due to their high speed, momentum, and often eccentric orbits, and a single missed shipment means starvation or asphyxiation. There are dozens of "ghost colonies" laying abandoned among the asteroid belt whose stories ended with mutiny, starvation, cannibalism and mass-suicide.

Along with countless thousands of small and medium sized space stations (most of which have rather small crews relative to their size, rarely more than a few thousand) there are several massive cylinder-stations. The largest of these, "New Virginia", is approximately 30 kilometers long and has a population of over 15 million, with plenty of room to expand (much of the interior is still "rural" and sparsely inhabited). There are also a dozen so-called "transit colonies" which are on permanent interplanetary orbits, going back and forth on a set route between various destinations, with populations ranging between a few hundred thousand and several million. Second to the cities of Venus, these are seen as some of the most desirable places to live, since they provide earthlike gravity and 50% sea-level atmopsheric pressure. Inhabitants need regular dramamine and other drugs to compensate for motion sickness from coriolis effects, but this is a minor inconvenience compared to the intense drug regimens, nutritional micromanagement and intense exercise regimes required to survive on low-gravity or microgravity colonies. However, these space colonies obviously lack any natural resources of their own, and are utterly dependent on trade and imports to survive long-term.

Overall, although space colonization has been enormously profitable on paper and most of the governments and corporations involved consider it wildly successful, the reality of space colonization has been a story of callousness, inequity, suffering and death. Impoverished earth-born people are launched into the heavens by the thousands each year, where they labor in unimaginably harsh conditions until their bodies give out so that CEOs, bureaucrats and national leaders can give optimistic presentations about growth and expansion. Even on the "nice" colonies of Venus and the O'Neill cylinders, labor conditions are extreme, and stress and despair drive many to madness, drug addiction and violent crime. The slow demilitarization and removal of nuclear weapons from earth has given way to a new arms race in space - no matter how many resources the solar system has, it will never be enough for leadership classes obsessed with the fear that rivals will overtake them, leading them to demand more and more sacrifices that their nation, ideology, religion and way of life might survive. While industry grows, social development has stagnated. Every middle class individual on Earth can have a solid-gold toilet if they want one, but in most ways their lives have improved very little in 500 years, and poor nations remain mired in old-fashioned problems like lack of education and food scarcity.

Instead, all the wealth of space is now being used to construct fleets of massive warships, stored in underground silos and docked with space stations scattered throughout the solar system. There have already been dozens of 'limited nuclear exchanges' (and much more short-duration non-nuclear fights) in the past century, and each time, diplomats have had a harder and harder time forcing that genie back into its bottle... and it seems inevitable that eventually, it's going to come all the way out, and humanity itself will die screaming.

While border and political tensions on Mars and Luna and the threat of a revolution against the Mercury authority are destabilizing enough, there is another pivotal event which the solar system watches with bated breath: more than 250 years ago, the first great nuclear-pulse-powered generation ship was sent out to explore Alpha Centauri. Beset by countless problems, its initial crew of 50,000 has dwindled to less than 7000 weak and sickly descendents due to the primitive state of space-based survival and reproductive technologies when it was launched, but the vessel is still going, and is now a mere 7 years away from its destination. As it has gotten closer, messages sent back have implied that the planet Proxima Centauri B seems to have large oceans of liquid water on the surface, combined with gravity almost identical to earth's. But rather than joy, this discovery has fueled unbridled paranoia, as every political leader becomes convinced that if one of their rivals manages to reach and colonize this planet first (the initial exploration ship's inhabitants were intended to be colonists but will not survive past a few more generations, and much of the colonization equipment they brought with them had to be cannibalized long ago to keep the ship's life support running) will own the future of humanity...

Tonally, this will be a bit like the darker entries in the 'Mobile Suit Gundam' franchise, where if a war starts in space (and it will - this is a mil-scifi game, after all) it starts a path that leads inevitably to extinction, yet there's enough wiggle room for leaders to think it might be winnable that they aren't incentivized enough to avoid it. One of the classics of the sci-fi genre is protagonists being put in a position where they are forced to choose between following orders and performing an action that will lead to atrocity or catastrophe... with the addition of fog of war meaning that the situation will be far from clear cut, and recklessly acting to try and prevent armageddon could be the very thing that ends up causing it. Needless to say this probably wouldn't work well for an extended campaign in GURPS and would probably be more of a one-shot or vote-driven CHYOA thing. But, it would certainly be an excuse to really 'open up the throttle' on the Spaceships ruleset and some of those rarely used rules for adventuring and fighting in extraterrestrial environments. Part of the reason for the decision to have "retro-tech" and lack of computing technology is so you can have situations with space marines in TL9 armored spacesuits sending out combat patrols on airless wastelands and trying to kill each other with TL8 rifles shooting depleted uranium slugs, with no auto-targeting AI or automated weapons creating situations where being seen gets you instantly sniped with infallible accuracy from 10 kilometers away.

[seasalt]

I also had some thoughts on a pretty significant overhaul of the spaceship construction rules to fix how stupidly fragile they are. Space combat should be lethal, getting hit by a cannon shell (let alone a nuke) should be scary, but the rules as written are ridiculous to a degree that goes well beyond realism. Even if it were realistic, large warships having the durability of soap bubbles that disintegrate when the enemy so much as breathes on them doesn't make for interesting combat scenarios.

I might make another post with all the changes I had in mind, but the gist is this:
1) All armor values increased by 500% and made semi-ablative
2) All HP values for ships are 200%
3) All weapons have their damage reduced by 1 step relative to SM. The standard armor divisor is removed. Instead, proximity detonations deal 1/10th damage, with a RCL of 3 rather than 1. Cannons can also use "flechette" shells which deal 1/100th damage with a RCL of 1. This is in addition to accuracy being reduced as per the retrotech rules freezing sensors and computer systems at TL7.
4) No missiles smallter than 64mm, and defensive ECM penalties are doubled against missile attacks. Emphasis is instead on "torpedoes" which are built as small automated (tele-operated) spaceships that try to ram their target.
5) If an armor component is destroyed by a hit, any damage carrying over gets a 0.1 wounding modifier. Hits to any components besides volatile fuel tanks, engines, armor or weapons get a 0.5 wounding modifier.
6) Normal nukes deal 1/10th listed damage for close-proximity/impact detonations (in space, most of their energy is wasted). 'Casaba howitzer'-style directional nukes deal the listed damage but cannot be used to make proximity detonation attacks.
7) Ships with orion drives or nuclear saltwater rockets triple the acceleration bonus to their dodge if their engine is facing the attacker, since the engine will tend to obliterate any incoming ordnance and blind targeting sensors (and gunners, often permanently!). However they also suffer twice the acceleration penalty to their own attacks. to the rear, if they accelerated.
8) Ships with less than a complexity 8 computer in their control component can't make ballistic attacks at further than point-blank range. No building snub fighters around a single big spinal-mounted cannon and sniping battleships to death while they struggle to hit your SM+6 ass.

I should note that I've done some paper combat with these rules modifications and spaceship combat is STILL horrifically lethal even with all these defense buffs and damage nerfs, even without nukes being used. It just means that warships can barely survive a couple of hits from the enemy's main guns and still manage to limp away, if they're lucky, instead of popping like balloons from a single shot. Let me know your thoughts!

[johndallman]

You need a line about rich sources of uranium and thorium in the asteroids or on Mercury. Several hundred years of using this much nuclear power without fusion will have depleted Earth's supply of them quite badly.

[Rupert]

Originally Posted by johndallman

You need a line about rich sources of uranium and thorium in the asteroids or on Mercury. Several hundred years of using this much nuclear power without fusion will have depleted Earth's supply of them quite badly.

That also means a strong incentive to using fast breeders and plutonium reactors, which can mean a (relatively) ready source of weapons-grade plutonium for any reasonably competent terrorist group.

[whswhs]

Originally Posted by Rupert

That also means a strong incentive to using fast breeders and plutonium reactors, which can mean a (relatively) ready source of weapons-grade plutonium for any reasonably competent terrorist group.

Will it? I had the impression that you couldn't get plutonium from thorium reactors.

[Rupert]

Originally Posted by whswhs

Will it? I had the impression that you couldn't get plutonium from thorium reactors.

You get it from fast breeders that convert U238 into plutonium, thus allowing the use of far more of the available uranium (which is almost all U238 rather than the U235 you want for a conventional reactor). Though actually it looks like reactors set up to produce power rather than P239 for bombs utilise the plutonium in the reactor itself rather than converting U238 and then removing the P239 for use elsewhere (as a reactor intended for P239 production would).

[seasalt]

Originally Posted by johndallman

You need a line about rich sources of uranium and thorium in the asteroids or on Mercury. Several hundred years of using this much nuclear power without fusion will have depleted Earth's supply of them quite badly.

As I understand it, some of the asteroids in the solar system are chunks of ancient planets that broke apart. So, although most asteroids will have very little in the way of fissionable elements, you only need to get lucky every once in a while to find an asteroid that contains 10 times more than the richest mine on earth. Also, I know it's poorly explored IRL, but as I understand it Mercury would have a lot of heavy elements and probably has huge amounts of uranium that could be extracted.

Also, as I'd said, most of these fissionables are being used in reactors, not blown up to push orion ships around. Most of the bulk transit is done by nuclear lightbulbs burning cheap hydrogen. And since these are all breeder reactors producing plutonium, it can be kept up for a long time. Before they were used as warships, the orion drive and saltwater rocket vessels were the "emergency" ships for when something went wrong during regular supply lines with low-energy-expenditure orbital transfers, and vital supplies or personnel need to be rushed somewhere ASAP.

I might add it as a setting element that the superpowers realize they will indeed start running out of fissionables in a few more centuries and that their painfully slow attempts to develop fusion power are yet another thing that is raising the threat of war and threatening to upset the balance of power.

[Fred Brackin]

Originally Posted by seasalt

As I understand it, some of the asteroids in the solar system are chunks of ancient planets that broke apart.

I haven't heard that recently (more like in pre-WWII SF).A quick google went to the concept that asteroids were the remnants of bodies that were prevented from becoming planets by Jupiter's gravity.

Without Earth-like geology it is generally believed that you don't get high cocnentrations of anything but the most common elements. Everything else will be there but dispersed all through the more common stuff. Probably on a molecular level.

If you want to get fabulously wealthy on anything but iron, nickel and water (and Ceres appears to be 25% water) you'll need as yet uninvented tech that separates atoms by mass.

If you do have such tech though it'll automatically separate the U-235 from the U-238 and you can easily make Hiroshima-type bombs rather than the more powerful Nagasaki-type Plutonium bombs.

[Anthony]

Originally Posted by Rupert

You get it from fast breeders that convert U238 into plutonium, thus allowing the use of far more of the available uranium (which is almost all U238 rather than the U235 you want for a conventional reactor). Though actually it looks like reactors set up to produce power rather than P239 for bombs utilise the plutonium in the reactor itself rather than converting U238 and then removing the P239 for use elsewhere (as a reactor intended for P239 production would).

Breeder reactors normally produce more fissionables than they consume. You can of course take the produced fissionables and burn it again, keeping no net production, but there's no real way you can run a breeder reactor that can't trivially be turned into a factory for bomb fuel, at least by its operator.

Originally Posted by seasalt

As I understand it, some of the asteroids in the solar system are chunks of ancient planets that broke apart.

Not really, but they might as well be -- M-type asteroids contain the elements (siderophile minerals) that on a planetoid large enough to be differentiated would mostly be buried in the core. However, that's about as good as it gets, the factors that produce exceptionally enriched veins are geologic or hydrologic, and don't exist until until you're dealing with very large objects.