Comment by jackfoxy | Hacker News Reader

Comment by jackfoxy | Hacker News Reader

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I've often wondered why NASA never considers artificial gravity through a rotating structure to dispense with the problem of long-term zero-G on the human body. At least I have never seen a media report of NASA taking this seriously, and I have followed media reports of space topics since I was a child. There must be a reason for this. Numerous science fiction writers treated this concept as a given decades ago.

If these are the 5 key findings of the lengthy construction and 15 years of operation of the ISS, this is a pretty lame return (in terms of science) for a huge investment. I suspect the only other thing we can say is we have a lot more experience of human operations (activity) in space. Something to be said for that.

> I've often wondered why NASA never considers artificial gravity through a rotating structure

They most likely have considered this several times.

But to make it work, they would have to build an impractically large structure (it would have to vs twice the size of ISS to work at a reasonable speed) and deal with the difficulties of large rotating structures.

During the ISS program, space medicine has advanced a lot. With a specialized diet and training regime, astronauts have no measurable loss of bone mass any more.

15 years of continuous human presence in space is a huge achievement. At 150 billion dollars, equal to three months of US military spending, it's a bargain.

I expect it largely comes down to cost.

That and the fact that we have plenty of gravity on Earth. We go to space to study things that we can't study on Earth.

The force of gravity in low earth orbit is about 91.7% of the force at sea level.

The apparent force, which is what we experiment with, is much less.

But it's far easier to maintain prolonged free fall in orbit.

There is also about no experience with it, so a lot of work, money and mistakes are needed. Structural integrity is a big challenge. As I see it, it's not that people there do not think about it, it's just not feasible right now.

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