Agreed. Genentic engineering will probably be helpful, but first we do as you say, have to know what to engineer for. Then of course we’ll have a kind of speciation event and we’ll risk having a kind of genetic apartheid based on people who work in space vs. planetside. It could get sci-fi dystopia levels of ugly if we don’t work to prevent those outcomes.

We already limit astronauts and many other professions based on genetic properties: height, tollerance to high g-forces, eyesight etc. Even things used as health indicators like resting blood pressure are influenced to a significant degree by genetics.

I think we will survive adding a few more genetic properties to the job requirements, especially since jobs on planets will vastly outnumber jobs in outer space for the forseeable future.

Sounds like Gattaca. It a very slippery slope when you start to genetically engineering people.

How do you engineer for space? Increasing telomere length is merely a stop-gap. Random mutations due to solar radiation are exactly the mechanism that evolution exploits to make progress (as well as other sources of entropy), the chemical makeup of DNA is poorly suited to space travel: you can't just genetically engineer that way.

You shorten the inter-generational period, i.e. make people breed rapidly (in space). The mutations will take of themselves.