How does living in space affect the human lifespan?

One of the many things we don’t know for sure. But we do have data, thanks to our life sciences experiments on the ISS.

As has been mentioned, the body experiences reduced stress, however that leads to a number of detrimental factors like bone and muscle degradation, heart malformation, and the “chicken leg” syndrome, causing one’s fluids to collect in the chest and head.

Our bodies are adapted to living in a state of constant low-grade physical stress.

Also, long duration spaceflight increases the risk of cancer due to radiation bombardment.

NASA spaceflight requirements on this are very strict, and the risk of developing cancer over an astronaut’s lifetime may not increase by more than 3% (bad news for your manned Mars mission).

So all of that seems pretty grim, and living in space may never actually be a feasible option.

Not sure why you’d want to, I like not feeling like I have a head cold, personally. But that’s just me. What we don’t know is what the actual, measurable effects on human lifespan these detrimental things actually have.

It will almost certainly shorten lifespan, but by how much? We don’t yet know.

It also appears that the damage is reversible for the most part.

Astronauts appear to fully recover from the physical effects of prolonged micro gravity within a couple of weeks, less the radiation damage, obviously.

Interesting question: would an astronaut recover in a <1G environment? Would it be a period of time that is proportional to the gravitational field strength? The moon would be a great place to test that and I swear, if you suggest a rotating space station, I’m going to go ape-shit. Not only “no,” but “hell no.”

An international moon village (ESA proposal) would probably be cheaper, once you factor in all of the additional research opportunities that the lunar surface may offer.