63

Stability Nothing beats the radiation shielding of 1,000 kilometers of magnetic field + 100 kilometers of air + (at night) 6,000 kilometers of water and rock. For heat, nothing beats 22 billion cubic kilometers of atmosphere to dissipate, by whatever means necessary, heat concentrations. You can have 1 terajoule nuclear blasts, or multi-terajoule meteor ...


46

The same way we do now. I work for a multinational company, with colleagues distributed across a dozen time zones. When I need to schedule a meeting with many people, I simply open Outlook, and look at their calendar to find a free time that is within normal working hours for everyone. I don't need to do any mental calculation of what time it is where, the ...


39

Unless I'm living underwater, if a large hole appears in the side of my home due to some incident, my immediate emergency response is put on warm clothing. My second is to cover the hole with anything that might be handy: piece of wood, a piece of plastic, just enough to keep the heat in and weather out. It might be uncomfortable until more permanent repairs ...


37

Important things to remember about orbital mechanics: not all orbits are equally useful where less useful orbits intersect more useful ones, the less useful ones will not be used changing the plane of an orbit requires a lot of energy What this means is that surprisingly big chunks of sky will not have much debris in them... especially directly over the ...


36

Totally plausible if you lose your navigation computer - space journeys aren't straight lines! As much as star-trek and the like may make us believe: Space isn't a big open 3d region where you just pick a direction and head that way and get there. If space was that simple, it would be basically impossible to come back to your point of origin unexpectedly ...


34

The solution for this is intercalendary days, like you suggested. This is needed any time something doesn't divide neatly. Our day doesn't divide neatly into our year so the rule is: February 29th exists when the year is divisible by 4 Unless the year is divisible by 100 Unless the year is also divisible by 400. So 2000 and 1600 are leap years, 1900 wasn't....


34

3000 BC To make Space colonization now viable, safe, and common, you need to start back in ancient Egypt. Instead of war between different cultures, the pharaohs will have to unify humanity more than it is in our timeline. The first Milestone of Egypt is the expansion to the Roman Empire's dimensions in 1500 BC. It's a society that will be united by one goal:...


33

Trading in promises Two mechanisms can play a part here but essentially you don't have to wait for the ore to return to sell your investment, it's all about share value and the promise of a return. Shares in a business are proportional to their promise of return - sometimes even if that return hasn't happened yet the implication that in the future the profit ...


32

Frameshift: Andrew Brēza had the right idea but got it backwards. It's not that the planet has a surplus of oxygen. Rather, it has a major deficit in carbon. The air isn't toxic at all, it's lacking CO2. Animals (including humans) don't use CO2, they won't care. Plants need CO2 to grow. You either need to import all the carbon your plants need, or you ...


31

People need boron, because plants need boron. https://en.wikipedia.org/wiki/Boron Boron is a chemical element with the symbol B and atomic number 5. Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, it is a low-abundance element in the Solar System and in the Earth's crust.[11] It constitutes about 0.001 percent ...


28

Planets are fail-safe. A space colony has to be operated and maintained by competent and responsible people. Most people aren't and this is not entirely bad (we need the other kind of people to make innovations here and there or to run the administration). Well, a planet can be screwed up as well, but it takes a lot of effort. A space colony can be destroyed ...


27

354 Thousand https://godbolt.org/z/zoPYsz If you bring 10,000 embryos on the first ship, and 10,000 on the second ship, you'll run out in the 25th year, and 58th year. I modified your death rate so that when people hit 70 years old it shot up to 10% per year. As otherwise we had hundreds of 100 year olds. That link allows you to change the values and they ...


27

I'm probably gonna have to go for "not in the next few centuries", and it isn't beyond the realms of possibility that the answer will be "never". Here's the thing: it is rubbish out there. Radiation soaked, freezing or roasting, gravity all wrong, toxic razor sharp ultrafine dust everywhere. Terraforming anything in any meaningful sense ...


26

Let's use the 1989 Rockwell International Integrated Space Plan as a reference point. It had a biplanetary civilization (i.e., permanent presence on the moon) by 2010 (we didn't make it). But it shows you in pretty good detail what you'd need to do to make it. Said simply, you need to have everything it shows between 1989 and 2010 happen by 2020. Once ...


22

About 4.5 billion years ago. You'd have to tinker with the formation of the inner planets, making Mars large enough to hold on to its atmosphere & water (and give it a stronger magnetic field, working plate tectonics, and so on). Venus could be spun up to give it a day of around 24 hours, and perhaps a moon similar to Earth's moon. Then, assuming the ...


22

Crash Test Dummies So you have various machines building a new base on a new world in preparation for occupation at a later date by their lords and masters - the meat bags. That includes not just the habitats themselves but the myriad of miscellaneous components humans will need when they arrive. Power sources, vehicles, tools and equipment, green houses... ...


21

This isn't an Either-or Proposition. Terraforming is going to be a long process, and will require using resources on the target planet to successfully complete. You'll need to build infrastructure dirtside to change the atmosphere, and place the biologicals you need to support Human life. So instead of just searching for a single Earthlike planet, and ...


21

Fun thing about cylinders full of air: they make for really nice musical instruments. An OC necessarily has a very tenacious hull. You could land some machines on its outside and have them bang at the hull without damaging it. Just keep banging rhythmically 24/7 until everybody goes crazy. They'll eventually give up. If you want to be really annoying, you ...


20

Lithium, like boron (covered in another answer), is relatively rare because few processes have produced it since the Big Bang created a tiny percentage -- but it's useful both as a chemical and as a component of one of the "easiest" pathways to nuclear fusion -- including aneutronic fusion of lithium and deuterium, which is likely to be very ...


20

Don't. At least, not more than you strictly have to. For day to day operations, your input should not be necessary. If it is, fire the person at the head of the Martian org chart and get someone more reliable. If you're a large enough company to consider opening a satellite office on another planet you're large enough to find someone competent to put in ...


20

Counterpoint: This mission isn't a good investment and would probably never take off Mainly, 70-150 years is a very long time. Hell, 150 years ago humanity didn't have powered flight, let alone space travel, and if anything, the rate of technological progress has only gotten faster. Furthermore, while investors are fundamentally gamblers, all our modern ...


19

On earth we have relatively well defined national borders No, we really don't. There's hundreds of poorly defined or contested borders Your borders will initially be implicit (each point on the surface will belong to the closest installation). Forming a voronoi graph. Eventually a treaty will be arranged declaring the border to follow a natural feature or ...


18

If it works with your general scenario, they could just have a regular week, but switch the Earth timezone they sync with West every ~2 days. They would drop a day when they cross the date border, but would always have someone on Earth that shares their weekday and roughly time of day. Of course the would not work if ground control is based in one or few ...


17

The oldsters had all been vaccinated. The youngsters not. In the real world, I got the smallpox vaccine when I was a kid. My younger brother did not. They stopped giving it to kids in the US between the years we were born. In your world the old folks all got a vaccine that came out of use or was modified 25 yeas ago. Younger persons got a different ...


17

Since the lack of a magnetic field would pretty much force any large scale habitation to be done underground and any time spent outside being expensive and needing shielding it wouldn't be at all difficult to use Earth time. They could use Earth time underground and translate to Martian on the rare occasions they go out which would mostly just be specialists ...


17

Make Nixon more ambitious, (and make Apollo 13 a success) After the lunar landing, Nixon was presented with 4 choices. Ranging from "Lets colonise mars" to "lets play it really safe and not go past LEO". Nixon chose to play it safe and we spent the next 50 years using a space shuttle to go up to LEO only. Nixon's choice was validated by ...


17

Because 'Oil Rigs' are just the beginning Wikipedia's Asteroid Mining article states that in the next 50 to 60 years, we will run out of phosphorus, antimony, zinc, tin, lead, indium, silver, gold, and copper. A lot of that is available in various asteroids in space, so that's where we'll begin. And sure, asteroid mining will start as a thoroughly unpleasant ...


16

To make Paris a city of ruins will not affect the issue. Phillipe Petain. The best way to not tear the place up with fighting is to not fight. In World War 2, the French surrendered Paris to the approaching Germans without a fight. Fighting seemed pointless, and would destroy their beautiful city. https://www.washingtonexaminer.com/weekly-standard/...


15

Beavers that have never seen running water in their entire lives will start gathering twigs on hearing it. We aren't that programmed, but we may not prove to be absolutely blank slates. Living in space may prove to be subtly (or egregiously) badly suited to human beings, even those born on space station or space ship. Perhaps we need genuine gravity, and ...


15

You really only have three main options to get into orbit: Rockets / continuous thrust Space elevator As a Projectile from a "Big Gun" (All of your velocity acquired at once) Space elevators have been discussed to death and back. They are the gold standard for cheap space access but are by far the most difficult to construct and maintain. Not to ...


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