[littlestymaar]

The problem isn't health “risk”, there are risks but there are also health effects that will come with certainty. For instance, low gravity deplete your muscles pretty fast. Spend three month in space and you're not going to walk out of the reentry vehicle.

This effect can be somehow overcome by exercising while in space but it's not perfect even with the insane amount of medical monitoring the guys up there receive.

[Robotbeat]

Then just provide spin gravity for the crew habitat.

[littlestymaar]

“just”

It's theoretically possible for sure, but we've never done that in practice and it's far from trivial.

[MobiusHorizons]

Good points. Spin “gravity” is also quite challenging to acclimatize to because it’s not uniform like planetary gravity. Lots of nausea and unintuitive gyroscopic effects when moving. It’s definitely not a “just”

[Robotbeat]

Yeah, “just.”

Every child on a merry go round experiences it. Every car driving on a curve. And Gemini tested it once as well. It’s a basic feature of physics. Now why NASA hasn’t decided to implement it in decades is actually kind of a mystery.

[MobiusHorizons]

Relevant Scott Manley video: https://youtu.be/nxeMoaxUpWk?si=QOO9KJCGS_Q8JeyR

Relevant tom Scott video: https://youtu.be/bJ_seXo-Enc?si=m_QjHpLaL8d8Cp8b

There is a lot of research, but it’s not as simple as operating under real gravity. Makes many movements harder and can result in getting sick.

[littlestymaar]

1g of acceleration is enormous compared to a child in a merry go round actually.

> And Gemini tested it once as well.

From Wikipedia:

They were able to generate a small amount of artificial gravity, about 0.00015 g

So yes, you need an effect 60 000 times stronger than this.

And you want that to be relatively uniform over the size of an astronaut so you need a very big merry go round.

Nuclear fission is also a basic feature of physics, that doesn't mean engineering a nuclear power plant is straightforward.

[Robotbeat]

It’s not, actually. I’ve swung my kids around at multiple gees.

[jjmarr]

Kids enjoy having their head and feet at different levels of gravity.

When was the last time you spun yourself around in a desk chair?

[bigfatkitten]

If it’s that straightforward, why haven’t you done it?