104

The story can be summed up as follows. Von Braun is captured by the Soviets, not the Americans. Failure to beat the Soviets to the Moon extends the Space Race. An extended Space Race means space colonies are feasible in the 80s. Nuclear war happens, the Earth is rendered uninhabitable. The remnants of humanity launch colony ships into space. But really it ...


99

Immunity to Disease Your lunar citizens live in a perfect environment! They have all the food they need, they have recycling that, frankly, removes most bacteria from their lives. Atmosphere is constantly recycled, which includes scrubbing. Water, too, is recycled, scrubbed and clean for use. In fact, the colony has been disease-free for, well... ...


86

Exo-bacteria is more likely to be harmless than harmful There are a couple assumptions that you're making that really aren't the case. To start with, microorganisms that our immune systems have no defense against Our bodies are really good at recognizing anything foreign in them. In order to evade our immune system, bacteria (and viruses) need to have ...


77

The simplest way is probably to leave them with a shortage of unobtainium. A substance named for obvious reasons, that happens to be required for the production of FTL drives. Perhaps the limited quantity they had in their existing drive was destroyed (causing the accident) or dispersed in the accident. Either way, they're now limited to space habitats and ...


76

Last time I looked into this I was amazed these experiments (mammalian conception to delivery in orbit) had not been done. I figured I just had not found it and so I dug in this time. For mammals, they have not been done. Pregnant rats have gone to space and come home and delivered so microgravity is not immediately lethal to a fetus. Rats mated in space ...


74

First off, the issue with relativity is solved. No kidding! Barycentric time (TCB) is a time scale that an atomic clock would perceive were it co-moving with the sun. This, of course, is a technical phrasing which means it's as though the clock were fixed with respect to the movement of the sun, but outside of its gravity well. It ticks about 490ms/year ...


71

Is this a realistic way to colonize and explore the universe? No. Apart from problems with generational ships, which you'll find discussed on Worldbuilding SE in other questions, there is a fundamental flaw in the reasoning: they get to work making the planet livable for the people who want to have a sky over their head The people you have described ...


63

Their ship and her payload were designed as a colony expedition. They had not just asteroid mining craft, and seeds for hydroponics, and modular habitat sections, they also had the blueprints and machine tools to replicate them. And they had the engineers to read the blueprints and use the tools. For the stardrive, they had just the operators' maintenance ...


62

Earth is big.[citation needed] The mass of Earth is about $6 * 10^{24}$ kilograms. Not all of that mass is usable to make spaceships, of course, but let's just hand-wave that and look purely in terms of how much stuff we have. The Star Trek spaceship USS Enterprise is 3,205,000 metric tons; that's $3 * 10^9$ kilograms. In one year, there are about $3.154 *...


60

The primary way to hide something in space is to make it uninteresting. Start with a boring asteroid, made out of silicate rock rather than metals or organic compounds that are worth mining, orbiting somewhere that's inconvenient to reach, but not so inconvenient that people will go there for the achievement. In Earth's solar system, this would be a main-...


59

What you suggest is possible, but the solution is a major problem, for larger reasons. We have sent probes to crash into Jupiter. It is physically possible to send waste into a gas giant. Just as it is theoretically possible to send waste now into the Sun. However, the primary issues encountered commonly with waste is economic and logistical. Waste is not ...


56

As the water "falls" from shower head height towards the drain at the floor, it would be moving at a fixed velocity and be rotating slower than it should at the increased radius of the bottom of the shower, so it would tend to lag the rotation and bend backwards to the direction of spin. The relative strength of this effect would be dependant on the overall ...


55

The Asteroid belt. It has similar requirements for life-support systems as the moon. With the additional need perhaps for some areas with simulated gravity. It is next closest in terms of energy required to get to and from the orbits. It is still close enough to the sun that collecting solar energy is workable (the farthest out we have used solar panels is ...


54

Slow being a little less than half the speed of light, thanks to getting a very large boost as they start their journey. Slow down there! literally. At that speed it's not really a generation ship since you can get to many other stars within the original crews lifetime. And there are hazards to going that fast. Lets assume the ship is, say, 10X the ...


53

This isn't our land anymore, kiddo. There was a time in the past your old grampa here would oversee all of those mining operations, from the Red Hills all the way to the Prima City. It was such a sight - all those white, shiny domes, resting on the red blessed lands of Mars. Heh, Red. Red meant money, back then, kid. Nowadays it means just death and a ...


49

Materials exposed to vacuum for extended periods often become brittle and/or literally lose mass over time. Outgassing, cold-welding, decomposition of alloys back to their constituent materials, coronal arcing due to ionization from exposure to ionizing radiation, acceleration of outgassing and decomposition again due to ionizing radiation exposure are all ...


48

If nothing else we would need planets for raw materials and therefore have at the very least mining colonies or penal camps. You can't produce metals, plastics and all the rest from nothing. Also you can't have a closed ecosystem without it eventually deteriorating, there is always a loss however fractional. Evaporation, energy, food and everything else ...


45

An assembly hall (town hall). The reason those churches get used for other things is that there are reasons other than worship for everybody to gather at times. A church's main hall is only in use for a few hours a week, so gatherings at other times are feasible. Your need for those gatherings doesn't go away just because your society doesn't have ...


44

In the savannah of the universe, stars are the watering holes needed to sustain life, but full of predators and dangerous. Colonies are fixed targets, perhaps there are some hostile alien entities around most stars that are hostile to other forms of life (or all life). Note: in the far future these entities could easily be of terrestrial origin, out of ...


44

They would throw rocks, literally. The fuel needed to push any given mass out of the moons very small (relative to the earths) gravity well & into the earths (& it's all down hill after that) is going to be negligible in comparison to what it takes to get stuff off of the earth. A big rock inbound from orbit isn't going to need any explosives. And ...


44

You will likely have an easier time if you pick a Slavic language that uses a Roman alphabet. Like Czech or Slovak (which are very similar to each other). Then you don't have to deal with the unknown alphabet and words that are more removed from Latin/etc. Take Slovakia. It's got some pretty straight-forward place name conventions. I do a lot of genealogy ...


44

As every project manager knows, scope creep is the root of all evil. At the beginning, it was just about sending one ship to another planet. Easy, just a matter of time. Then someone said something about food diversity, citrus fruits and, for whatever reason, pineapples. So a team was split up to figure out how to grow pineapples on a space ship and in a ...


43

According to this lovely image from NASA (article here), the source of onboard oxygen in current spacecraft is mainly water electrolysis. The hydrogen so produced is processed with carbon dioxide to reclaim some of the water and produce either solid carbon waste, or acetylene for propulsion. This isn't a 100% closed cycle, so you'll have to add more water ...


42

Antimatter. It's insanely expensive to produce artificially, with estimates of up to $62.5 trillion per gram of antihydrogen. Naturally occurring antimatter in any decent quantity would be beyond lucrative - it would also provide whoever controlled it with a nearly unbeatable energy and weapon edge. However, it couldn't be laced into the geology of the ...


41

Because they're beautiful. I don't know what exactly your habitats offer in terms of technology, but nothing short of full VR would convince me personally to live in a space station where nature is confined to parks and you cannot stand on a mountaintop and watch over miles of untouched taiga. This is an important factor for human well-being, don't ...


41

A non-obvious loss area would be Genetic diversity. After several thousand years of carefully controlled plant growth, and several thousand years of inbreeding, unless care was taken to maintain genetic diversity in plants and animals (including humans), a single mutated bacteria could take out a key component of the self sustaining ecosystem.


40

I worked on a science fiction story centered on Mars for a while, and I intend to pull it off the back burner at some point. My primary driving economic factor for Mars turned out to be pretty simple: As humans began to expand into space, mars became the logical breadbasket for the solar system. Mars has a carbon dioxide atmosphere (mostly) which is not at ...


37

Random. I am reminded of the teeth of the numbat. http://animaldiversity.org/collections/contributors/anatomical_images/family_pages/dasyuromorphia/myrmecobiidae/ The numbat has more teeth than any other land mammal. Tooth number and shape vary between individuals. It does not matter to the animal because none of the teeth are used at all. The numbat ...


36

My choices: Ganymede and Callisto (and maybe Titan) This is perhaps a bit of a buzzkill, but I honestly would not recommend colonizing much in the solar system besides the Moon and Mars. Here's why I would take a lot of bodies off the table: Mercury - Too hot on its sunny side for colonization (up to 700K) and too cold on its dark side (down to 100K). ...


36

Space is big. Really big. Looking for a particular asteroid somewhere in the solar system is pretty analogous to looking for a particular rock, somewhere on Earth. Unless you already have a really good idea where to look, you're not going to find it. As such, I would suggest that he doesn't need to take any measures to hide it, just place it out of the ...


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