Mars??? That’s more than a bit of a stretch. The astronauts in the ISS right now weren’t up there for a significantly longer period of time compared to their peers. Absolutely no way it would disqualify them from a mission happening a decade from now which is an absolute best case scenario for mars and frankly even the moon the way the current political climate is in the US.
Ignoring the fact that, again, the astronauts in question weren’t in space for any appreciably longer time than anyone else on the ISS.
They’ll be too old to participate in the mars mission a minimum of a decade from now.
You have literally no idea what the radiation exposure allowances will be for a manned mission to mars when it happens, or what advancements we’ll make to radiation shielding should we ever actually send a manned mission to mars.
> You have literally no idea what the radiation exposure allowances will be for a manned mission to mars when it happens
These are well known and documented, to the degree we know things about human deep spaceflight.
> what advancements we’ll make to radiation shielding should we ever actually send a manned mission to mars
These are unknown. But they will, barring new technology, require mass. Which means more shielding comes at a cost. Which incentivises low-rad experienced astronauts.
