On ‎4‎/‎12‎/‎2018 at 3:04 AM, swansont said:

To get 1g at that rotation, the radius needs to be almost 40m long. The outer rim is moving 20 m/s, but you have your ~38 meter climb to transition to that speed.

That is a long distance 40m = 131 feet!  Imagine that length pressurized and shielded from cosmic rays?  What would that cost?  Then how about counter-rotating another balanced pair of sleeping modules?  You don't want them to smash into each other rotating in opposite directions.  This project seems to be way beyond affordable or practicable.  That would also be a scary place to sleep isolated so far from the hub.

Edited April 13, 20187 yr by Airbrush

19 minutes ago, Airbrush said:

That is a long distance 40m = 131 feet!  Imagine that length pressurized and shielded from cosmic rays?  What would that cost?  

That's smaller than the dimensions of the ISS, which is > 100m long

"...A 2011 NASA proposal for a demonstration project preparatory to the final design of the larger torus centrifuge space habitat for the Multi-Mission Space Exploration Vehicle. The structure would have an outside diameter of 30 feet (9.1 m) with a ring interior cross-section diameter of 30 inches (760 mm). It would provide 0.08 to 0.51g partial gravity. This test and evaluation centrifuge would have the capability to become a Sleep Module for ISS crew."

https://en.wikipedia.org/wiki/Artificial_gravity#Proposals

I guess 0.51g is better than zero g.

9 hours ago, Airbrush said:

and shielded from cosmic rays? 

Unless it takes you are really long time to get to bed, that's not a critical requirement.

Edited April 14, 20187 yr by John Cuthber

On ‎4‎/‎13‎/‎2018 at 5:37 PM, John Cuthber said:

Unless it takes you are really long time to get to bed, that's not a critical requirement.

If you are climbing down a ladder over 100 feet, wearing only your pajamas, you would hope the tunnel walls are thick enough to block micro-meteors and cosmic rays.  I'd rather sleep in zero g in the thickest, most shielded module of the space station.

Here is an idea I've had about making human existence on Mars or the Moon more bearable. If astronauts could at least sleep (or maybe even recreate) in a centrifuge that creates one g of gravity. It would look like a merri-go-round in the park. People would go to bed in a chamber that rotates to creates one g to simulate what it is like to sleep on earth. Is this kind of centrifuge possible?

Here is an idea I've had about making human existence on Mars or the Moon more bearable. If astronauts could at least sleep (or maybe even recreate) in a centrifuge that creates one g of gravity. It would look like a merri-go-round in the park. People would go to bed in a chamber that rotates to creates one g to simulate what it is like to sleep on earth. Is this kind of centrifuge possible?

This is hardly a new idea. Using rotation to simulate gravity has been a staple of sci-fi for decades. There was an exercise centrifuge in Kubrick's 2001, released in 1968. The space station was in the form of a - much larger - rotating wheel, for the same reason.

Edited April 12Apr 12 by exchemist

There are also several threads showing the calculation of how large it must be to be practical. (fast rotation and small runs into problems)

edit: such as one you started:

Here is an idea I've had about making human existence on Mars or the Moon more bearable.

Could we start with making human existence right here on earth more bearable?

Could we start with making human existence right here on earth more bearable?

We could, but microbiology prefers a more comfortable environment... 😉

The basic principles seem sound but the engineering and construction difficulties and costs seem prohibitive. Even doing a test version on Earth seems difficult.

They would have to have a very large diameter or else the mismatch between what the eyes say - an "unmoving" room - and what the inner ears say - turning around - can be nauseating. Ideally the rotation rate should be slower than the inner ears can detect, although some people may naturally cope better with higher rotation rates, and perhaps people can use anti-nausea medication.

On the ground such a structure may be best done as using tilted circular railway rather than a wheel or centrifuge on an axle. Like bends on regular railways, the durability depends on the stability of the track and underlying groundwork.

The entry/exit presents some serious challenges, as would connections for the air ventilation, plumbing and electrical supplies.

Edited April 13Apr 13 by Ken Fabian

On 4/13/2025 at 4:12 PM, Ken Fabian said:

The basic principles seem sound but the engineering and construction difficulties and costs seem prohibitive. Even doing a test version on Earth seems difficult.

They would have to have a very large diameter or else the mismatch between what the eyes say - an "unmoving" room - and what the inner ears say - turning around - can be nauseating. Ideally the rotation rate should be slower than the inner ears can detect, although some people may naturally cope better with higher rotation rates, and perhaps people can use anti-nausea medication.

On the ground such a structure may be best done as using tilted circular railway rather than a wheel or centrifuge on an axle. Like bends on regular railways, the durability depends on the stability of the track and underlying groundwork.

The entry/exit presents some serious challenges, as would connections for the air ventilation, plumbing and electrical supplies.

I've never heard of a centrifuge for sleeping on the Moon or Mars. For such a centrifuge, the bed you are laying on would orbit at an ANGLE. The weak gravity of the Moon (or Mars) adds to the artificial gravity from the centrifuge, perceived as one g, in one direction, at an angle to the axis of rotation, to simulate sleeping in bed. A very large diameter centrifuge would be necessary for a large space station, like in 2001 A Space Odyssey the occupants could jog around the wheel in a great circle. Weird Coriolis effects would make people sick. Why would it not be comfortable to just SLEEP inside a smaller-sized centrifuge chamber, on the Moon, like maybe 50-foot diameter? That way at least 8 hours a day can be a one-g therapy session.

Edited April 17Apr 17 by Airbrush

@Airbrush Yes, the 'floor' would need to be angled, like the sides of a pie dish to get the correct artificial horizontal. It would ideally be a curved surface in both directions although probably tolerable to have rooms with a flat floor if the diameter is very large.

The weird Coriolis effects have effects on movements in particular directions, (but not other directions) and are going to be noticeable whilst moving around but the inner ear driven sensation of being unbalanced and turning around won't go away by staying still, it will be all the time. Sounds a bit like lying down drunk only you don't sober up and get over it. Little 'stones' in the ear canals as well as fluid motion make those sensations.

Again, I would have to search for the specific experiments - I seem to recollect much larger diameter than 50m being needed to be turning slowly enough to be imperceptible. 100's of metres to kilometres? It did sound like it is hard to get used to and even people who seemed okay for a while usually found it harder to tolerate as time went on. The experiments used a rotating room in regular gravity - rotation but not in the same plane as would happen in space or as a centrifuge in different gravity - but the idea was that the ears detect that rotating motion in any direction.

Edited April 17Apr 17 by Ken Fabian

Threads merged. Please take a moment to review what was discussed. Feelings of deja vu might occur