Beyond The Sprues

Modelling => Ideas & Inspiration => Engineering Dept. => Topic started by: kengeorge on January 07, 2017, 09:59:53 AM

Title: wheels in space
Post by: kengeorge on January 07, 2017, 09:59:53 AM
I'm hoping that somebody here has the brain's I don't have to answer my question,or at least point me in the right direction.
So here is the question, I want to know what is the minimum diameter of a rotating ring to impart either half or full earth gravity whilst in orbit, as I'm trying to design something like the circular space station in 2001 and need to know if Its too big, small or just right.

ken
Title: Re: wheels in space
Post by: Kerick on January 07, 2017, 10:34:19 AM
Depends on the angular velocity, ie, RPMs and radius.

https://en.wikipedia.org/wiki/Rotating_wheel_space_station (https://en.wikipedia.org/wiki/Rotating_wheel_space_station)

This gives a description of a 250 ft diameter ring at 3 rpms giving 1/3rd G.

Here is a calculator

http://www.calctool.org/CALC/phys/newtonian/centrifugal (http://www.calctool.org/CALC/phys/newtonian/centrifugal)

100m radius at 3 rpm gives just over 1 G. Hope this helps.
Title: Re: wheels in space
Post by: Frank3k on January 07, 2017, 11:13:42 AM
There's also SpinCalc (http://www.artificial-gravity.com/sw/SpinCalc/) which will tell you if the spin rate is outside of what most people will tolerate (with references!)

Title: Re: wheels in space
Post by: kengeorge on January 07, 2017, 08:24:40 PM
Thank you kerick & Frank3k for your help.
My idea is to have a rotating ring space station to provide low artifical gravity so astronauts heading to & from the moon can acclimatise to their enviroments.
Now I can get on & design it.   
Title: Re: wheels in space
Post by: mrvr6 on January 08, 2017, 12:50:30 AM
would it be possible to have a big ring and adjust the rpms to give different g? i dont see why not.
how would you counterbalance the ring? have weights on a track of sorts on the outer perimeter?
Title: Re: wheels in space
Post by: kitnut617 on January 08, 2017, 01:09:18 AM
IMHO, I think it will be a very long time before you see anything like that. NASA wasted a very good opportunity to having something along those lines when they were launching Space Shuttles, the huge external tanks which were just expendable after the launch could have been designed to create a wheel station. There was 135 shuttle flights, that could have made a fair size space station.

Can't remember right now, but someone posted some pics of just that so I know it was considered. They just didn't implement it --  :-X

I also don't think just creating a centrifugal force is the right way to duplicate an earth like environment, you also need a magnetic field like the earth's  ---
Title: Re: wheels in space
Post by: GTX_Admin on January 08, 2017, 04:32:26 AM
IMHO, I think it will be a very long time before you see anything like that. NASA wasted a very good opportunity to having something along those lines when they were launching Space Shuttles, the huge external tanks which were just expendable after the launch could have been designed to create a wheel station. There was 135 shuttle flights, that could have made a fair size space station.

Can't remember right now, but someone posted some pics of just that so I know it was considered. They just didn't implement it --  :-X


Some options:

(https://spacefrontier.org/wp-content/uploads/2013/05/etco-orbiter.jpg)

More details (https://spacefrontier.org/sts-lab-a-low-cost-shuttle-derived-space-station/)

(http://www.astronautix.com/graphics/s/stsetst1.jpg)(http://www.astronautix.com/graphics/e/etwic88.jpg)

(http://i37.photobucket.com/albums/e68/GTwiner/Image4_zpsy7qkz51b.gif)(http://www.astronautix.com/graphics/e/etgop2.gif)

More info:

http://www.astronautix.com/s/stsexternaltankstation.html (http://www.astronautix.com/s/stsexternaltankstation.html)
http://aeromaster.tripod.com/grp.htm (http://aeromaster.tripod.com/grp.htm)
Title: Re: wheels in space
Post by: Frank3k on January 08, 2017, 09:11:41 AM
I also don't think just creating a centrifugal force is the right way to duplicate an earth like environment, you also need a magnetic field like the earth's  ---

If you have to produce 1g (or 1/3g or 1/6g) there are three ways: spin the sucker, add mass or sprinkle some skiffy pixie dust and cast a magic gravity spell, like they do in almost all SF shows and movies.

At my previous job, my boss studied the inner ear and how it affected balance. We had chairs and swings that could move/rotate people at very high accelerations to see how large angular accelerations affected the inner ear and the eyes.
I asked him a  few times about rotating spacecraft and he didn't think it would be difficult to adapt except at the extremes of small size/high g.

For magnetic fields, that's also not a show stopper. Run a current through coils (which could function as a means of propulsion if designed right) add some polyethylene and water shielding and that should greatly reduce the effects of charged particles and most cosmic rays.

If we hadn't wasted 30 years on the Shuttle/ISS we might have had a space wheel by now.
Title: Re: wheels in space
Post by: Weaver on January 08, 2017, 08:06:16 PM
The problem with all the re-usable tank schemes was that a tank isn't a habitat, and it takes a lot of work and equipment to make it into one. That equipment has to get up there somehow, which means either more shuttle flights or putting it in the tank (in compacted form) on the ground to start with.

What you really need is a pre-equipped (on the ground) habitat/tank which can convert empty fuel volume into pressurised habitation volume once it's in orbit. Astronauts can then unpack and build the interior in shirt-sleeve conditions, which is vastly easier than trying to do it in space suits. This seems feasible, if an 'interesting' design problem (sliding internal tank bulkheads?), however Bigelow's inflatable habitats may have effectively stolen it's lunch.
Title: Re: wheels in space
Post by: kitnut617 on January 08, 2017, 11:18:25 PM
One of the links Greg attached to his post says more or less the same thing Harold  ---- which is what I said in my first post, the tanks could have been designed from the get-go for use as a wheel station.

I think until the solution to create artificial gravity is found, humans just aren't going anywhere in space --- floating around just handicaps everyone

Title: Re: wheels in space
Post by: Weaver on January 09, 2017, 06:14:21 AM
Atomic Rockets' space stations page:

http://www.projectrho.com/public_html/rocket/spacestations.php#id--Designs--Space_Shuttle_External_Tanks (http://www.projectrho.com/public_html/rocket/spacestations.php#id--Designs--Space_Shuttle_External_Tanks)
Title: Re: wheels in space
Post by: Jeffry Fontaine on January 09, 2017, 10:21:41 AM
Furnishing the insides of these now empty fuel tanks sounds like the perfect opportunity for Ikea to develop their own special line of flat-pack furniture that can be assembled in a zero-g or near zero-g environments.  :) 
Title: Re: wheels in space
Post by: Weaver on January 09, 2017, 10:26:07 AM
Furnishing the insides of these now empty fuel tanks sounds like the perfect opportunity for Ikea to develop their own special line of flat-pack furniture that can be assembled in a zero-g or near zero-g environments.  :)

"This bookcase must NOT be fastened to the walls using nails or woodscrews"  :o
Title: Re: wheels in space
Post by: elmayerle on January 09, 2017, 10:55:14 AM
Furnishing the insides of these now empty fuel tanks sounds like the perfect opportunity for Ikea to develop their own special line of flat-pack furniture that can be assembled in a zero-g or near zero-g environments.  :)

"This bookcase must NOT be fastened to the walls using nails or woodscrews"  :o
Of course not, that's what double-sided sticky tape is for; though suitably sticky strips of Velcro, applied to wall and bookcase, will also work.