As stated elsewhere, there's a very recent study [1] on astronaut heart health that's quite relevant. They studied the cardiovascular health of astronauts for 5 years after their return from long-duration stays on the ISS. They were all perfectly healthy.

For one obvious problem with rotation systems, stations need to be regularly boosted. You'll also need to occasionally reboost the local rotation. This sort of basic stuff is already fairly complex with a static station, and becomes exponentially more so with a local rotation going on. Even moreso because you want to be relatively fault tolerant in case of a partial or failed boost. Then you need to compensate for impacts, docking and undocking, and much more.

It's viable and almost certainly a solvable, but NASA is not the appropriate organization to do so. Their risk aversion makes it unlikely that they'll ever be doing much of anything revolutionary where failure could be catastrophic. They're having a tough enough time just trying to recreate what we already did 50+ years ago.

[1] - https://journals.physiology.org/doi/full/10.1152/japplphysio...

I'm active in this topic and have never heard anything similar to what you've mentioned. And in looking this up, there's a very recent study [1] that's quite relevant. They studied the cardiovascular health of astronauts for 5 years after their return from long-duration stays on the ISS. They were all perfectly healthy.

[1] - https://journals.physiology.org/doi/full/10.1152/japplphysio...

To expand on that - there are many body systems that depend almost entirely on the 1g glodilocks zone. Lymphatic systems movt , venous blood returning deox blood to the heart and even some digestive processes. Keenly dependent on a g value that allows proper muscle tone/function to the systems at play. Too little or too much and and human life becomes non-viable. Throw in the effect of ping ponging between microgravity and 1g and the issues multiply.

Maintain american capacity to put technicians in low earth orbit. People forget a big part of the shuttle mission for example was to capture and put technicians not just on your satellite but any satellite the shuttle was capable of intercepting and getting into the bay. Consider the fact that the shuttle didn’t really die, in fact the airframe form is still flown but its mission is now classified.

I'd be very surprised if they're genuinely out of research ideas to test in space. If that is actually true then humanity has a problem.

>research that couldn't be done with automation

I'd think there is room for both. Automation makes sense, but don't think the versatility of meatbags is entirely there yet.

An entirely different form of research could be done by sending large quantities of normal people into space. Astronauts are such a small sample size (and so thoroughly vetted) that you get a different statistical view.

Horses for courses micromanagement business administration and lobbying gravy train.

Due to research done on mice on the ISS, we have some idea:

"0.33g mitigates muscle atrophy while 0.67g preserves muscle function and myofiber type composition in mice during spaceflight"

https://pmc.ncbi.nlm.nih.gov/articles/PMC12985678/

Obviously, we know that the gravity of Earth is sufficient.

But the results make probable that two thirds of the gravity of Earth might be enough, while the gravity of Mars may create some problems and the gravity of the Moon is very likely to be insufficient, so the time spent on the Moon must be limited, though not so much as on the ISS.

I agree with the previous poster that any spaceship designed for carrying humans to Mars or even farther must be designed to spin and anyone who accepts to go on something else is stupid.

Making a spinning spaceship may be cheap if dual bodies or one body and a counterweight are used. It is likely that the safest solution would be to have 2 identical spacecraft, which could also be used independently but which could be coupled with cables to spin around the common center of mass at a distance big enough to create enough gravity at a low rotation speed.

The problem is not the price but the fact that nobody has tested how difficult is to control such a configuration (avoiding oscillations and instabilities) and how difficult is to solve problems like docking in a manner that does not waste energy (i.e. without changing the rotation speed of the more massive spinning spacecraft, which can be done by having 1 or more docking ports on the rotation axis, like on the hub of a wheel; in the case when the rotating spacecraft would be made with 2 bodies or a body and a counterweight that would be linked with cables, one could have the equivalent of an elevator for transporting crew and equipment from the docking port to the main body or bodies).

But someone must build and test such a spacecraft, otherwise we will never learn how to do it right and which are the real problems that are hard to predict in a simulation.

>We don't even know how much spin we'd need,

Forgive my ignorance on the topic, but surely "same as earth" would be the starting point? With everything less being a trade-off that is suboptimal

Because that’s like saying you’ll develop a fuel additive to stop the body from rusting. Physical damage and weakness can’t be stopped by a pill.

NASA is the goverment agency routinely favored by the general public. They can't meaningfully reduce funding, now that "race to space" with China is heating up.

Nah. It will probably be either the Space Shuttle or Artemis. That is to say, programs that showed NASA lost control of its mission to graft

Avoiding something for such symbolic reasons is negative cargo cult thinking.