Realistic, near-term, rotating Space Station

[Twark_Main]

No Feedback. I can do that. Let's try to get ourselves back on track.


What commuting and shift schedule do you envision for the workers commuting between the two stations?

Does it follow the ISS rule of always having enough space in the docked transport vehicle(s) for the entire crew, as a lifeboat?

[Coastal Ron]

I would say warn your investors...

No one at this stage has "investors". We are all at the stage called "ideation", working on ideas. In fact what we are working on is well in advance of any possible need, because humanity doesn't need rotating space stations yet. Everything we propose is guesses at this point. EVERYTHING.

Which is why so much of what you say is irrelevant, because you keep saying "investors" this or "investors" that. YOU have no idea what investors will want, because YOU have no idea what they will want to invest in years from now. Because it is way too early for them to care (and yes, I happen to know quite a few investors).

Nevertheless, I wish you good luck in all your endeavors, and I mean it sincerely.

I choose, in my spare time, to work on the idea of near-term rotating space stations because I think somewhere in the near future they will be needed to expand humanity out into space. And I support those things that help humanity expand out into space.

Your comments to me, certainly recently, have done NOTHING to help humanity expand out into space, and if anything you have made yourself into a distraction of that cause. Which is unfortunate and sad, because sometimes you can actually contribute to a topic on NSF. But not here recently, that is for sure.

[mikelepage]

It’s been good to see the recent updates from VAST space.

https://x.com/vast/status/1971719930157703654?s=46

There is of course a whole thread for VAST, but as long as their roadmap retains a heavy emphasis on rotational gravity space stations, I’d suggest they’re probably the closest to implementing anything that’s been talked about here.

As much as the founder is a billionaire, it will also be great to see the company be there first to make money from their LEO space station efforts. The questions they need to solve are expensive ones.

[catdlr]

It’s been good to see the recent updates from VAST space.

https://x.com/vast/status/1971719930157703654?s=46

There is of course a whole thread for VAST, but as long as their roadmap retains a heavy emphasis on rotational gravity space stations, I’d suggest they’re probably the closest to implementing anything that’s been talked about here.

As much as the founder is a billionaire, it will also be great to see the company be there first to make money from their LEO space station efforts. The questions they need to solve are expensive ones.

Some previous renders of their rotational gravity space stations

[mikelepage]

It’s been good to see the recent updates from VAST space.

https://x.com/vast/status/1971719930157703654?s=46

There is of course a whole thread for VAST, but as long as their roadmap retains a heavy emphasis on rotational gravity space stations, I’d suggest they’re probably the closest to implementing anything that’s been talked about here.

As much as the founder is a billionaire, it will also be great to see the company be there first to make money from their LEO space station efforts. The questions they need to solve are expensive ones.

Some previous renders of their rotational gravity space stations

Somehow I completely missed their announcement of Haven 2 particularly the 5- and 9-module ISS replacement strategy. While it's tempting to be frustrated at this as evidence of their artificial gravity ambitions receding further into the future, it does seem the most realistic way to get experience at building and operating large stations, which any rotating space station will be.

What I find interesting is that every one of those Haven-2s is designated as a Falcon Heavy launch, but the 7-meter diameter, center core module is assuming Starship chomper variant (or perhaps New Glenn with custom fairing) is operational. It also borrows from the SpaceX mentality by making a production line for space-habitats.

What I like about the strategy is that depending how fast Starship progresses, they have the option to leave the 5 module station as a standalone microgravity station, and move straight to ~7 meter modules for an artificial gravity station.

[StraumliBlight]

Somehow I completely missed their announcement of Haven 2 particularly the 5- and 9-module ISS replacement strategy. While it's tempting to be frustrated at this as evidence of their artificial gravity ambitions receding further into the future, it does seem the most realistic way to get experience at building and operating large stations, which any rotating space station will be.

Haven-1 will perform artificial gravity tests.

Haven-1 will be in orbit for three years, enabling four separate missions with four crew aboard each mission. These missions will last ~ten days, and we will be testing the capabilities of artificial gravity in between these missions.

[catdlr]

Why is it that they have all the room available on that slide, but use small print and icons?   

[Coastal Ron]

It’s been good to see the recent updates from VAST space.

https://x.com/vast/status/1971719930157703654?s=46

There is of course a whole thread for VAST, but as long as their roadmap retains a heavy emphasis on rotational gravity space stations, I’d suggest they’re probably the closest to implementing anything that’s been talked about here.

As much as the founder is a billionaire, it will also be great to see the company be there first to make money from their LEO space station efforts. The questions they need to solve are expensive ones.

Since what they are working on is so short term, I think their work is better described as being a testbed, and we have an NSF thread for Artificial Gravity Testbeds.

I would suggest that once VAST gets to the point of building a station that they plan on inhabiting for the purposes of work (or living), then it can be considered a space station. But if all they are doing is short-term tests, then that is more of a testbed.

My $0.02

[mikelepage]

It’s been good to see the recent updates from VAST space.

https://x.com/vast/status/1971719930157703654?s=46

There is of course a whole thread for VAST, but as long as their roadmap retains a heavy emphasis on rotational gravity space stations, I’d suggest they’re probably the closest to implementing anything that’s been talked about here.

As much as the founder is a billionaire, it will also be great to see the company be there first to make money from their LEO space station efforts. The questions they need to solve are expensive ones.

Since what they are working on is so short term, I think their work is better described as being a testbed, and we have an NSF thread for Artificial Gravity Testbeds.

I would suggest that once VAST gets to the point of building a station that they plan on inhabiting for the purposes of work (or living), then it can be considered a space station. But if all they are doing is short-term tests, then that is more of a testbed.

My $0.02

While I appreciate the pedantic desire for clear language Ron, haven't we long since established that this forum only has enough people interested in the topic to sustain one rotational gravity thread at a time? In which case I might suggest (only a little facetiously) that we should lock this thread and move to the testbed thread, since pretty much by definition, we don't know what's realistic or near-term until we've done the tests. 

The better thread distinction might be:
(1) Cool rotational gravity space station designs being tinkered with by forum members, and discussions arising from them
(2) Discussion of planned or in-progress test work towards rotational gravity spacecraft.

But isn't that a pretty good summary of what we use this thread for?

[JulesVerneATV]

The first Haven station is expected to launch May 2026, Redwire said it will have paylaods it acquired Belgium-based satellite design and development company

from reports online they say Haven stations are designed to test various types of artificial gravity environments

'The Haven-1 flight article has been painted. Next, key components including the hatch and domed window will be integrated ahead of pressure and load testing in Mojave, CA.'
https://x.com/vast/status/1976840186358382805#m

[Habitant]

I think a space station with artificial gravity should be a priority. The main argument I have received against this concept is that it would be too costly, so I want this thread to focus on cost.

Hi all, signed up here to discuss space habitats. I searched this thread for a mention of the 2018 book: "The High Frontier: An Easier Way" by Tom Marotta and Al Globus (Review at NSS) and found nothing. That book takes the main idea by Gerard O'Neill to use a rotating cylinder, combines it with more recent research, namely adaptability to 4rpm and low radiation at equatorial low earth orbit, to suggest a minimally sized (56m radius, 112m length) O'Neill cylinder (a smaller "Kalpana") with very little radiation shielding. Of course, it's also vastly lower cost.

When again combining the idea with ThinkOrbital's proposal for Orb2, in particular in-space assembly using robotic electron beam welding and Starship's projected capacity and cost, I think we have something viable!

Being a cylinder, it offers both 1g and zero g environments (and everything inbetween, if desired). And it uses the least amount of material per surface area with gravity for rotating space station designs. The high ceiling (i.e. the other side's floor) makes it feel much less claustrophic than other designs.

[Coastal Ron]

I think a space station with artificial gravity should be a priority. The main argument I have received against this concept is that it would be too costly, so I want this thread to focus on cost.

Hi all, signed up here to discuss space habitats.

Welcome to NSF! And yep, this is a good thread for that.

I searched this thread for a mention of the 2018 book: "The High Frontier: An Easier Way" by Tom Marotta and Al Globus (Review at NSS) and found nothing. That book takes the main idea by Gerard O'Neill to use a rotating cylinder, combines it with more recent research, namely adaptability to 4rpm and low radiation at equatorial low earth orbit, to suggest a minimally sized (56m radius, 112m length) O'Neill cylinder (a smaller "Kalpana") with very little radiation shielding. Of course, it's also vastly lower cost.

Yes, there is a general familiarity with O'Neill cylinders, and the reason why they are not discussed much is that they are not "near-term". To build such structures in space requires humanity to have moved out into space in such a way that they can spend vast resources to accumulate the material needed to build, and then occupy, such large structures.

The largest structure humanity has been able to build and maintain so far is the ISS, which is only 450mT, and we still haven't built any rotating space stations. So O'Neill cylinders are more fantasy than near-term right now.

What kind of rotating space station do you think humanity could build as a first try, using known materials and near-term capabilities?

[Habitant]

Thanks. Electron beam welding has been demonstrated in space as early as 1969. In 1980 the Russians also showed that robotic electron beam welding in space was possible.

I think a 56m radius 112m length cylinder is beyond our near term capabilities.

With New Glenn and Starship both featuring a cargo bay that‘s >19m long, perhaps a cylinder of that height – resembling a disc – is within our reach.
We can decrease the radius a bit further by moving to 5rpm. Not everyone will be able to deal with it, but it could be an acceptable compromise. That‘s a 37.8m radius (237.5m circumference). That means the parts required for the side of the cylinder could fit into 6 or so Starships (assuming pre-bent Titanium sheets 8m x 19m x 25mm at 18 tons each). So that‘s still very ambitious! 4,512 sqm of surface with gravity. 85,287 cubic metres of volume (73 tons of air at 0.7 bar). Perhaps doable within a few years. We could also try half that height: 9.5m. What do you think?

[Robotbeat]

I think it’s quite feasible to do large scale welding in space in the relatively near term, ie after Starship is doing regular trips and is fully reusable.

But it’ll take a concerted effort to do it. No one is doing that at the moment, though some startups are hoping to. They don’t have the capital to do it at the moment.

[Habitant]

I think getting Bezos to do it is the best bet. He has the money and he loves the idea of space habitats. I think visualizing different sizes of space habitats (using virtual reality, so you get a good impression of the actual size) can be a next, easy step.

[Coastal Ron]

Electron beam welding has been demonstrated in space as early as 1969. In 1980 the Russians also showed that robotic electron beam welding in space was possible.

For large scale assembly, welding is one method to connect material together, but not the only way.

I think a 56m radius 112m length cylinder is beyond our near term capabilities.

Maybe we have the technical ability, but it would not be the first choice for anyone to build. There are too many unknowns we have to conquer before deciding that such a structure is worth building.

With New Glenn and Starship both featuring a cargo bay that‘s >19m long, perhaps a cylinder of that height – resembling a disc – is within our reach.

The most significant barrier to doing more in space has been the cost of moving mass to orbit. Now we appear to be on the cusp of a significant reduction in the cost of moving mass to space, however the question is whether that is enough to create reasons for housing humans in rotating space stations. So business models for "Why" rotating space stations should be built is still an unknown.

We can decrease the radius a bit further by moving to 5rpm. Not everyone will be able to deal with it, but it could be an acceptable compromise.

And that is one of the big unknowns we have to spend time investigating. What RPM, what radius, what amount of centripetal acceleration is the sweet spot, or at least good enough? We'll probably need to do a lot of experimentation to figure all of that out before committing to large rotating space stations. Are you familiar with SpinCalc?

That‘s a 37.8m radius (237.5m circumference). That means the parts required for the side of the cylinder could fit into 6 or so Starships (assuming pre-bent Titanium sheets 8m x 19m x 25mm at 18 tons each). So that‘s still very ambitious! 4,512 sqm of surface with gravity. 85,287 cubic metres of volume (73 tons of air at 0.7 bar). Perhaps doable within a few years. We could also try half that height: 9.5m. What do you think?

Good you are thinking of how the material will get to space!

As to the design, usually the next step for a lot of folks on this thread is to create a drawing to share. And the norm is that you'll iterate your idea over time to address things you have discovered need to be improved.

[Vultur]

I think one of the use cases for large rotating space stations is to have living space at higher than lunar but less than Earth gravity, much closer to Earth than Mars is. An Earth orbit station can have short enough communication lag to participate in Earth's "infosphere"; Mars can't.

I don't see why you would design one to have full 1g, that's available on Earth. And it might very well be desirable to have somewhat lower gravity.

[Habitant]

Yes, i know spincalc.
I think having 1g available is a big plus, if only to maximize productivity and minimize health risks. With a cylinder, you can add higher floors with less and less gravity and there is of course a zero g area around the spin axis.

[Coastal Ron]

I think having 1g available is a big plus, if only to maximize productivity and minimize health risks.

We can only imagine what the use cases will be for early rotating space stations, since no one today is funding the development of them. And hopefully there will eventually be many use cases for rotating space stations, and people on this thread have proposed a wide variety of artificial gravity levels for a variety of reasons. For instance, the use cases I'm focused on will use Mars-level gravity as a standard, which I'm assuming will be cheaper to provide than Earth-level gravity.

With a cylinder, you can add higher floors with less and less gravity and there is of course a zero g area around the spin axis.

Lots of designs proposed that have multiple floors, and making use of all available "space" or room will be important.

There is a phenomenon that you should be aware of, if you aren't already, that could affect cylinder type designs. It is called the intermediate axis theorem (aka tennis racket theorem) that must be kept in mind. Lots of math on this, but essentially if you have a long cylinder it will want to tumble end over end unless there is a stronger force at work. Which is not a problem if you built your station to tumble like that (see the VAST 2035 artificial gravity station concept), but it could be a problem for O'Neill cylinder stations.

[Vultur]

Yes, i know spincalc.
I think having 1g available is a big plus, if only to maximize productivity and minimize health risks. With a cylinder, you can add higher floors with less and less gravity and there is of course a zero g area around the spin axis.

I don't think near term rotating stations, assuming they exist, will be about "productivity" at all. I doubt there's any job that's most easily/efficiently done in a rotating station. I think the likeliest near term cases for rotating stations are research on partial gravity levels and recreation in partial gravity levels, and neither one of those wants 1g.

(If you have people living for long periods of time in deep space away from significant gravitational bodies, then you might want rotating stations to avoid microgravity health effects. But I don't think that's near term - the currently planned Beyond LEO human efforts are focused on Moon and Mars, not deep space/asteroids.)