Gravity Space Station Design Idea

Here is an idea that popped into my head today. Perhaps I've seen it before and just didn't realize it. Basically its a modified Von Braun wheel.

I was thinking that initially it would be expensive to build an entire wheel in order to create artificial gravity. Then I thought, perhaps one could have simply a central rotator, and then poles that stretched out into the distance to two capsules. But after more thought I realized that while this would work, it would be impossible to get new supplies like food, water etc.... I thought about it a bit longer, and all of a sudden a carnival ride came to mind. Its those ones that have a cable hooked to a compartment, and then spins around until liftoff.

This is an idea that might work. There would be a central motor that would be vertical. This could turn a capsule that would have a "spool" that would be horizonal. The spool is a motor that would unravel (or reravel) two tethers. As it unravels, and as the rotor turns the capsules would be pulled out straight.

My idea is not to have these capsules be all that big. Just big enough for 1 person each, maybe 7 feet by 7 feet. The person could sleep, and stand up and walk around. There would be one on each tether each acting as a ballast for one another. Since they aren't huge, I would think this would make the tether not need to be some supernaturally strong material. I'm guessing we would have the technology today to create perhaps two 300 foot strong cables (600 foot diameter).

Now the good part is since they are connected to the same spool, you could pull them back in at a consistent rate until they dock with the capsule. Below the rotor section could be another capsul with supplies.

Unfortunately I can't upload a picture but I hope my description is clear enough. Again, somebody has probably already thought of this. But I think it could work. It enables one to create a balanced centripetal force, and it allows access to a main area that would remain 0 gravity.

Here is one of the rides I was talking about:

If I understand you right then there would be an alternative to make it possible that the capsules can get supply of water. food etc.: There could be an elevator going up and down between the central rotator and the capsules.

What about that?



Dipl.-Volkswirt (bvb) Augustin (Political Economist)

What you're suggesting has been brought up many times over the years, though the pods at the ends of the tethers have generally been bigger. The main use would be longduration interplanetary trips though a station with nodes at the ends of the tether and a docking/utility node at the center of gravity is certainly possible.

The nice thing about this approach is that you actually can generate fairly high rotational gravity in a single craft by building your spacecraft in two parts (hab pod and drive module) and spinning it perpendicular to the long axis before uncoupling your modules and running out the tether.



You could launch a craft capable of doing this.

Cheers,
ErikM

That looks good. I pictured it as having two tethers so as to maintain balance, but perhaps it doesn't need that. The advantage is that the tethers can easily be withdrawn to bring the capsules into the main core (for supplies etc...). They get the distance they need to create the artificial gravity while not making it dizzying like a Disney ride. At the same time it would be much cheaper than building an entire wheel until space costs came down. It seems to me that this should be entirely feasible with todays levels of technology.

I've searched on google a time ago for this problem/idea, and you can find a great deal. I found a site where they actually stated that several people tried to calculate how fast the craft should go round.

Here are some interesting and somewhat basic explanations:

http://regentsprep.org/Regents/physics/ ... efault.htm
http://www.spacefuture.com/archive/arti ... tats.shtml
http://www.spacefuture.com/archive/inha ... vity.shtml

Especially in the 2nd and third link, they give some real numbers to how fast it should go. I porbably interpret it quiet wrong, but i think the numbers should give some basic idea how fast the station should go.

In the 2nd link, there is a table with these numbers which have rpm in it and also m/s. From 6 to 10 m/s, it would possible generate something like 1g. 10 m/s is not much, but to generate that exactly and to maintain that at a constant rate requires a lot of energy. If you can make such station in orbit, you cant make any windows in it. You would get crazy of the stars moving all the time. So no windows would be preferable. If people want to look outside, you might want to consider building an area more at the center of the station where you have 0g. Problem then is, the station is spinning fast around you!

Best way would be to get off the station all together. Another problem for a station like this is movement of people, and weight on every square meter. If someone moves, it generates a different angle of force on the side (which is the bottom for the person inside it) of the craft. The only real solution would be to make the craft significantly heavier then all the persons and cargo on the station at one spot. Problem now is to get all these things in orbit Led would be the most logical things to use, but a station which could actually have som use would take several thousands of trips to it, just to install this led 'shield'\. (A positive side-effect of this would obviously be that you're better protected from radiation).


Problem of supplying cargo and people to this station would be to make a large axis at the center of this station. If you can enter a shuttle/vehicle into this axis. You can gently adjust to the rotation speed until you reach the middle of these axis when you're in sync of the rotation. Then there should be no problem getting on to the station.

Problem would be, off course, if the gentle increase in rotation of such a vehicle would make anyone sick.


I suppose its doable right now, the technology we would use is allready available, the only reason not to built it is money, and the lack of affordable spactravel. BUt thats the same i guess.

Wouldn't the thing speed up significantly as you wound the arms in? something like an ice skater does during a spin.

Concerning the increasing spin as the tether was rewound, I think the person inside would experience great dizziness if the speed remained the same but the radius shrunk. To solve this would require first slowing the rotation down to zero, then respooling the tether.

Just several moments ago the thought came to my mind that it might be a - academic - thought to simply gather asteroids and comets and keep them concentrated cose around each other.

To do so they might be connected - see the thread about it - or clumped together by applying ice where too is a thread about.

There will be a critical point where the assembly will start to pul more rocks to it by its own gravity.

Since there is the idea to bake lunar dust applying microwaves it might perhaps be possible to bake the rocks together the same way.

Around this body a space station might be built where gravity woud be experienced. As the body grows the spin rate of the station might be reduced.

And parts of the station might be built into the body...



What about that? It's an academic thougt only.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

Why not build the station core in two parts? One part would spin, and have the pods connected to it to generate Ersazt (fake) gravity, the other would be stationary, to allow craft to dock.

For those who are not aware, Mars Direct and I believe Nasa's current Mars DRM plan both use tethers to create gravity on the way to Mars. The difference is instead of splitting the capsule, the *empty* TMI booster stage is used as a counterweight.

This means stuff doesn't need to go back and forth, the tether doesn't need to be wound in, just released, and if the tether breaks you just lose your deadweight, half your mission doesn't go flying off out into deep space.

If you are doing anything important with you tether (like transmitting power or holding your ship together) it become a huge liability.

Both halves would fly off if the tether breaks, both the crewed module and the upper stage.

Unless the crewed module masses a lot more than the empty upper stage. But then it'll be harder to generate gravity.

How about two cores but a conical shaped external core for varied gravity?

Yes, but you only have to recover one. And your pilot(s) will be in it.

Then the crewed one has to have enough fuel to correct it's course.

If 1/5 gravity was enough, then how big would our wheel have to be going at 1RPM?