Celestia Forums

This is the space elevator model I have made for OA;


It comes to Earth in Sulawesi, so it can be used as an additional elevator if you already have one of the other ones.
Download link;
http://www.celestiamotherlode.net/creat ... nstalk.zip

cool!

I think so, too! Steve has a talent for these sorts of things; I've already mentioned elsewhere that the view very nearly gives me a case of vertigo!

...John...

...Oh... and I just had to mention, this is my 1,000th post. Cool.

What an amazing ride it would be in one of those!

Not that this ponderance of mine has anything to do with your model or this thread... but I'm looking at the image and wondering of 'the real thing' if it were. What if something such as an asteroid (or perhaps more likely, a small meteoroid) were to strike such a structure as this?

I imagine the running edges of the tape itself to be covered with a thinnish layer of nanotech self-repairing material (not invented yet) which will ensure the elevators have a smooth run. If the running edge is hit by a micrometeor the outer layer will self-repair. But the tape itself would be braided, so that a strand or two might be lost, but the tape as a whole would retain its strength.

In practice, the elevator would probably be wider at the top than the bottom, for strength; and the space around Earth would need to be kept clear of space junk and so on. This means that there could be very few, or preferably no artificial satellites in low-earth orbit, and might need some kind of 'vacuum-cleaner' ship which could scoop up the worst of the dust and debris from Near-Earth space.

I've got some ideas for this class of vessel too, by the way.

Finally the Near-Earth volume would need to have sensitive radar systems to detect larger objects so that (hopefully) measures could be taken to intercept them. You will note that the Space elevator is not a simplistic system, so I have set it a few hundred years in the future.

I'm wondering if - as you say a micrometeor struck causing a strand or two of the braid to snap - would this produce something akin to a rubber-band effect? Wouldn't terrific shockwaves run its length?

LordFerret wrote:I'm wondering if - as you say a micrometeor struck causing a strand or two of the braid to snap - would this produce something akin to a rubber-band effect? Wouldn't terrific shockwaves run its length?

Responsible for a "solid" elevator model myself aside, i am wondering if a real one would not look more like a maglev railroad than a tube...

-rthorvald

I had a game years back (still have it), Sid Meyers' Alpha Centauri, in which a 'space elevator' is depicted. It looked very much as eburacum45 described - a braided cable. However, unlike his addon model, the cable passed through the elevator's center.

Sid Meier's elevator can be glimpsed here
http://www.answers.com/topic/spacelevciv4-jpg

A couple more problems involved with the Elevator concept; the cars themselves need a power source, and in my version are powered by a room temperature superconducting cable transmitting energy to the motors within the car; this uses power transmission tech, which only works at short range. Both concepts are speculative of course
Current designs for real elevator cars use beamed power beamed to huge receivers on the car itself; see here
http://news.thomasnet.com/IMT/archives/ ... ipedia.jpg

And the thinnest part of the tape is the part that passes through the atmosphere- this is the most delicate part. I have used an Eder Tower to avoid weather damage at this point; this concept, by Dani Eder of Boeing, involves a fifteen kilometer high solid tower reaching up from the ground.
http://img66.imageshack.us/img66/7071/edertower7jf.jpg

I remember reading something about using induction to generate energy while lift drop down from space, and use that energy to send the lift up. I think I read that off some science magazine.

Steve,

There seems to be a BIG problem with this addon.
Now I know my system is not the most well endowed on the graphics side so I wasn't expecting stellar performance (no pun intended) but I was shocked at just how bad it was.
I was really looking forward to trying out your model, but after downloading 23MB's over dial-up I found that after installing this, everything just freezes and I get a white screen of Celestia death everytime I try to go anywhere near it.

So, I took a closer look....

Your SSC defines 35 sections using the mesh "elevatortape4.3ds". I checked out this mesh in Anim8tor and found it to be 1.3 million faces.
On starting Celestia, the first thing start.cel does is visit Earth from a distance. This means Celestia has to immediately try and
render something like 50 million polygons!!!!!!!!!! (35 x 1.3mil + the rest )

What's the idea Steve? How does this run on your system? If it works OK for you, then I'd really like to know what your config is!!!

AFAIK, on all except the most powerful machines Celestia will experience FPS drops when rendering more than 500,000 - 1 million polys. eg. The DS9 model is about 470K.

Your model I suspect would give even Chris's 8800GTX card a run for it's money!!

I don't mean to harsh, but what's the point of releasing a model of such ridiculous size for Celestia? IMO, this cannot be rendered in anything resembling real-time even with the most powerful graphics, and on most normal machines will just cause a lock-up as I experienced as I ran out of memory.

IMHO, you need to reduce and optimise the size of the "elevatortape4.3ds" model to something like 12000 faces/polygons or less in order to end up with a total size for the elevator of no more than 500,000 polys.

Sorry to be so negative, but I'm always of the belief that constructive negative comments are usually more valuable than positive.
(Sorry, just frustrated after downloading 23MB over dialup)

Well, if the add-on is 28 MB, what do you expect really, especially for an add-on which is mostly going to be a big model?

Hi Chaos,

I actually expected somewhat less than 50 million faces.

My issue is not with the 29MB size of the addon itself...that's not a problem.

The issue is the number of poly's in each section of the elevator (which is replicated 35 times)

By comparison, Runar's Needle (9MB) has sections of approx. 14,000 faces each which means his whole elevator probably weighs in at something less tha 1million poly's, whereas each section of Steve's weighs in at 1.3M faces (more than Runar's entire model).

I suspect that something may have got messed up in the modelling stage for Steve.
For example, when I edited Steve's model and removed the cars, leaving only the elevator tape, there was still something like 200,000 faces in the model. -- A rectangular strip such as this, by itself, should be no more than 6 faces.
(I removed 8 cars, but it's possible of course that I may have missed a couple as it's quite a hard model to edit in Anim8tor)

Cheers

BTW Chaos,

Have you installed it? I'd be interested in feedback on how it performs on your config.

Ok, at your request I installed it, since I was fairly convinced it wouldn't work, because I can't run add-ons such as HD 28185 or Ran without the system slowing down to a crawl/crashing.

My setup is a laptop, Windows XP SP2, 1.83 GHz, 512 MB RAM. Graphics card: NVIDIA GeForce FX Go5200.

The add-on slowed my system to a crawl (as expected), and didn't render the model. So, as predicted, it didn't work. Fortunately I have a fast connection.

Thanks Chaos...

...and your machine is much higher spec'd than mine!

Unfortunately laptop graphics cards (Go series) aren't supported by NVidia's driver package, so I'm actually running drivers of 2004 vintage... not sure how much of an effect that has.

Boux recently mentioned in another thread a site where one can get updates for embedded chipsets. See

http://www.celestiaproject.net/forum/viewtopic ... 353&#85353

Sorry about this; my system doesn't have much of a problem with it, although it is slow. I recently decreased the polys in the elevator cars, but I didn't think about the tape. Looks like I'll have to have another go. I made the tape a long time ago, and I can't remember how I did it. You are right- it really only needs six polys, unless I put a couple of grooves in to signify the running track itself.

Hi Steve,

These posts (the first one in particular) by ElChristou may help...

http://celestiaproject.net/forum/viewtopic.php ... e+optimize

http://celestiaproject.net/forum/viewtopic.php ... e+optimize

Each car currently seems to be about 66,000 poly's. This seems very high to me given their relatively straightforward geometry. Have you removed hidden poly's, and un-nescessary sub-divisions?

I suggest aiming to reduce each car to about 1500-3000 faces if possible, and possibly also reducing the number of cars (ie. some elevator sections could have just tape, with no cars, or you could have 4 instead of 8 cars per segment).
(Bear in mind that in some cases it is easier to re-model from scratch than to optimize (as ElChristou says in his first post).
If you can take some or all of these measures, then I think you will succeed in reducing the total face count for the elevator from 50 million to just 500K - 1 Million poly's.
IMO you will then have an excellent model which should perform well on a wide range of H/W.

Good luck.

I look forward to one day being able to use your lightweight model.

Regards
CC