High TL 9 vs TL2+RPM

[starslayer]

One of the major things you need to address if your not going for a scenario like my own (IE- their reasons for needing a planet are entirely self-imposed) is why they are bothering with a populated system.

The concept that their home system is an absolute mess is a perfectly good reason to go out, but why bother making landfall ever again, genetic engineering can get rid of those pesky legs and replace them with another set of useful arms, beef up bone structures, and restore the damages from the rigors of space travel (which they'd need to do to have generational ships anyway); and asteroids would be a better source of raw materials than a planet.

A planet(s) that has life would actually be a detriment to colonization, because now there are factors that you aren't prepared for (IE that that life is likely incompatible with your own, and even if compatible you are not going to have resistance for the local diseases, which resources and time are going to have to be spent immunizing the colonists against). It's far easier to colonize the vastness of space and extract your required materials from abundant asteroids then deal with silly (and expensive to escape) gravity wells.

'lack of fuel' is generally confusing as well- what possible fuel could a culture advanced enough to build generational ships need that can't be extracted and refined on their generational ships from stellar dust clouds and the limitless electricity that comes form solar extraction and atomic reactors. Even our TL-8 society today uses predominantly hydrogen derived rocket fuels with the exception of booster rockets, which are really only needed if you are going to be leaving gravity wells. Generational ships are going to want something super high-efficiency like ion drives (which already exist at TL8), and are really reaction-mass ignorant (IE the mass itself could just be water- the big important factor is electricity to drive the mass)- hence I went with their 'need' to be on a planet (or even being near a star for that matter) being entirely self-imposed.

If you can build generational ships and are late TL9 you can do just fine (and arguably do better) with nothing more than raw materials, which will be easier to access from completely unpopulated asteroids. If they don't have the technology for extraction from asteroids, then they don't have the technology for extraction on planets- if they don't have the space (IE all the extraction tech is in the storage bays) then they could easier build a dome on an asteroid to run the technology then try to safely get it planet-side and set up there. If they don't have the tech to build some domes to start extraction- how were they going to do it on what were presumably hostile planets without atmosphere and life? Or even better how ARE they going to do it for planets that likely have INCOMPATIBLE atmosphere and life.

Basically for advanced societies- once you can get off planet long term, there's not too many reasons (at least non self-imposed reasons) to NEED to go back, and you'd have to be downright evil to put those self-imposed reasons above the value of an indigenous also space faring society.

When I mention experimental technology breaking down- I literally mean experimental technology that is not needed in space (IE maintaining actual farms in a traditional sense rather than say, solar grown seaweed farms that then get broken down in to requisite materials and 3d printed into a variety of dishes); it is pretty conceivable that right now in TL8 we could (if cost were no issue) put a permanent self-sufficient colony on the moon or mars (it would be risky because we have not experimented with it, but a generational ship HAS experimented with it, and perfected it, by nature of being a generational ship).

Again without selfish, and downright evil, reasons motivating them, it would seem strange to me that the majority of those on the generational ships even WANT to make planetfall for any reason more then raw exploration (which would encourage interaction rather than conquest); while I am sure that most people on the ships would want more space, and their may be real reasons why they want to get closer to another sun (more solar power so that they can take reactors offline- that can be achieved by space stations and asteroid/moon colonies.

So I think you need to spend some time really pondering the 'why bother with the inhabited worlds, and why not just view the habited world as a 'pit stop', or why not just colonize the planetoids that the mage society won't touch (due to toxic or no atmosphere)