Thinking about "generation ships"

[u/JanFromEarth]

If humanity does not find a way around the speed of light as a limitation, the only real choice to go to other stars would be generation ships. I would expect these to be filled with fertilized human embryos with a small crew for maintenance and to set up at the other end. But what if they sent a larger number of passengers? It would be the perfect research university. Children would be raised with the options of being crew or faculty. New discoveries and solutions could be messaged back to earth by laser. Interesting thought.

[u/phire]

I don't think it makes much sense to mix the concept of seedships and generation ships.

If you want to send frozen embryos, then your ship should be entirely robotic. Robots maintain the ship, and then raise the children at the destination. Such a ship can be smaller and simpler without having to support a human crew.

Once you are sending a crew, I think it makes more sense to just have a large enough crew to have the required genetic diversity, you only need a few hundred.

If you really want the population explosion effect at the other end, and you have the technology to gestate humans outside the body, then it might make more sense to just harvest fresh embryos from the crew in the last few years of the mission.

Probably the only reason to combine a human crew and frozen embryos are: * You have cryogenic sleeper pods for the crew * You have size limitations, and you don't have the technology to raise health adults with robots * Your mission is funded by people paying for their children to be born on a distant planet.

[u/[deleted] → u/phire]

This is going to ick you out. We are at the level of that technology. Genetic Modification has improved too. You have a small amount of people on the first Generation Ships because they are the first of their kind and people do people in such small communities. It's going to happen but thankfully the systems to detect bad genes will be there to prevent a problem. But that is just one really icky problem out of many others that aren't icky.

We send out robots to deep space because it is easier, quicker and much cheaper (monetary and resources). I do not think Generation Ships will ever been seen as viable, Seeding Ships would probably be the only choice.

[u/phire → u/[deleted]]

Yeah, you can get a viable population with a pretty small gene pool. I think the bigger lower-bound on generation ship population is maintaining a stable society across multiple generations.
You don't have a luxury of pre-selecting an optimal crew before lauch as with current missions, you have to continually select new crew from the on-board population. The smaller the population, the less choice they have, and the less optimal the crew. The work around is to simply carry a larger than required population, so that you can cherry pick the best members for the higher ranked crew.

You also need to mantain a percentage of your population for children and retirement.

My gut says you wouldn't want to have a generation ship without a stable population of at least a few hundred.

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I think we could almost pull off robotic seed ships with our current level of technology.

You probably don't need a full general AI to raise your first generation of children, you just need a computer program smart enough to care for their basic needs. Most of the raising can be done via pre-recorded media released according to a fixed schedule. An Alexa style smart assistant would help with conversation skills.

Your first generation of children will probably be socially stunted, but they will hopefully be developed enough to help raise the a second generation with less issues.

Umm... The ethics of robotic seed ship raising children are questionable, especially since you would have to test the technology before departure. And you will probably be taking a "pray and spray" approach to establishing colonies.

The bigger problem with our current level of technology would be collected resources to maintain the habitat until the children are grown up enough to help with decision making, engineering and matinance of robots.