Space Elevator (I swear it's good!)

[Gargamel]

ok Ok OK! I hear you! It's been requested ad-naseum, and it can't be done it's been said. But I have an idea.... bear with me. If this type of idea has been proposed and shot down, well, forgive me. But read on, I think it may work and would be a huge bonus to the game.

We know there's a physics limit, so a true elevator can't be done. But what about simulating one?

Ground base: Add into the tech tree, a unit, or unit's of varying strength, that would represent the ground base/anchor for the elevator. These units would be very, very heavy, but would be launchable by a heavy booster so it might be landed on other bodies. The heaviest unit would be able to support lifting the lighter ones into orbit on the elevator. Each size unit would have a max lifting capacity, and would require the matching sized orbiting station and filament to operate.

Orbital Station: This would be made up of a variety of parts. First off would be the core, manned, so the kerbals could monitor and control traffic up to, down from, in, and out of the station. Then the orbital anchor unit, this would be the main mass of the station and where the elevator would be attached to. These would need RCS and probably some decent engines to make some adjustments to remain in geosynchronous orbit over the base.

The elevator itself would be made of Karbon nano tubes (Sorry! Couldn't help myself!). These would be lofted into orbit in containers similar to fuel tanks. The light weight elevator would use the full size 1.25m tanks, while the medium 2.5m, and heavy 3.75m. It should require at least 6-8 tanks worth of filament up there to dangle it back to the surface, and there would need to be a spare on the station for tension adjustments (Not actually simmed, just having a tank with >25% capacity would suffice). So it would require many launches to build the elevator. The orbital station/anchor would have a resource (filament?) that would have to be transferred from the filament tanks, and once it's full (6-8 tanks worth) and the spare is present, the elevator would be operable.

So how's it work? Take the magic of Hyper-edit and mix in some Construction Time, and it might work. When you build an object/payload to be lifted, it would spawn on the base object (obviously only KSC bases would spawn items, others on other bodies could attach to it through a docking port or such). It then starts to lift, and is despawned. After a certain amount of time based upon the size of your elevator, speed of the car, and mass of the payload, the payload would respawn on the orbital station. There it could be detached and docked to a conventional craft, and a something else could head down, or another payload heads up.

So there actually isn't a physical object spanning the space in between the ground and orbital units, we just get the functionality of one.

Each filament can only support it's max weight, and only in one direction at a time, but you can have multiple cars (another item that needs to be included, and matched for the appropriate size filament) on one filament as long as it doesn't exceed the max weight. If you have a station with two filaments on it, you can have an up filament and a down filament. Filament can only be produced in bulk on Kerbin, maybe tiny amounts could be produced from an insane amount of ore in orbit. This would allow a small elevator orbiting another body to eventually create enough filament to upgrade to a bigger elevator, but the anchors (ground and orbital) and station would have to be imported.

Like I said, I think it's plausible as I've seen all the elements of this idea function in other mods. The time delay might get tricky, but the rest should be doable for a skilled modder. The orbital construction aspect makes it good for gameplay, and the different levels of the pieces make it 'realistic' as you'll have to traditionally launch heavy payloads repeatedly to build one. Or one could whackjob a single launch. Switch out mass and weight where appropriate, I used them interchangeably here.

I would love to tackle this myself, but I have neither the skill, nor the time to do it or learn to do it. But maybe I've planted a bug in a modder somewhere who might take this on....

Edited June 9, 2015 by gargamel

[Kagame]

I support this thread. Mostly because all of my plans for world domination include a space elevator.

[*Aqua*]

You make it look easy but it isn't. There's a number of gameplay and technical problems. Some of them:

• How do you 'place' the orbital station and anchor at the right place?
  If you put the station in it's orbit first how do you know where to place the anchor on the ground? Or the other way around: If you place the anchor somewhere on a planet, how do you get the orbital station exactly above it? Even with mods like MechJeb it's impossible.
  
• How do you attach the anchor to the filament?
  
• What happens if you ram the space elevator? Just 0.1 m/s are enough to let a real one collapse. Note: Docking ports can easily accelerate small crafts to 1.0 m/s.
  
• Some celestials have a SOI which doesn't reach to geostationary orbit heights. What now?
  
• Also this lifting process is a no go. Your stuff just disappears and reappears after some time in orbit.
  Playing with the extraplanetary launchpads is way better than that.
  
• Why not just use extraplanetary launchpads? It let's you build stuff in orbit.
  

You wrote a lot of text but you basically only said "lots of parts", "heavy parts" and "magic." Seriously, this stuff takes months to develop! At least! And for what? To hyperedit your craft into orbit? I don't see the rewards for that work.

There's no enhancement of gameplay. You just lift stuff to orbit, put it somewhere and press a button and that's it. I at least expected the elevator to let us bring stuff down to the ground again. And I expected to be able to collide with it in midair. And I want to be able to get off it half way. In short, I want to mess with it and do all kinds of stuff. But your idea includes nothing of that.

Sorry for being so harsh but I needed to bring you back down to Earth.

[Gargamel]

You make it look easy but it isn't. There's a number of gameplay and technical problems. Some of them:

• How do you 'place' the orbital station and anchor at the right place?
  If you put the station in it's orbit first how do you know where to place the anchor on the ground? Or the other way around: If you place the anchor somewhere on a planet, how do you get the orbital station exactly above it? Even with mods like MechJeb it's impossible.This has been done in game, placing objects in geosynchronous orbits is not a trivial matter, but is doable. Just a matter of timing and planning. One "cheat" that immediately comes to mind would be to hyperedit a tiny placeholder craft into the correct position until you can rendezvous your first station piece to that location. That would make the initial placement trivial for the planning stage.
  
• How do you attach the anchor to the filament? You don't, it's just simulated.
  
• What happens if you ram the space elevator? Just 0.1 m/s are enough to let a real one collapse. Note: Docking ports can easily accelerate small crafts to 1.0 m/s. See above, there is no actual filament, just the mechanics of it. If you ram the station, then you knock it out of it's orbit, just like you would any other station. Given the onrails nature of the engine sometimes alters the position of objects, there should be a small window that the station could occupy, and if there is enough RCS remaining on the station (some arbitrary amount), then the station would be automatically adjusted back to it's proper position upon spawning.
  
• Some celestials have a SOI which doesn't reach to geostationary orbit heights. What now? Well then, obviously, a space elevator is not possible for those bodies.
  
• Also this lifting process is a no go. Your stuff just disappears and reappears after some time in orbit.
  Playing with the extraplanetary launchpads is way better than that. That's kind of the point, it uses the EPL's mechanics, along with some hyperedit, to simulate the lifting process.
  
• Why not just use extraplanetary launchpads? It let's you build stuff in orbit. Because there has been a call for this type of mod, and some people would enjoy a mod that would put gameplay limits on it.
  

You wrote a lot of text but you basically only said "lots of parts", "heavy parts" and "magic." Seriously, this stuff takes months to develop! At least! And for what? To hyperedit your craft into orbit? I don't see the rewards for that work.

There's no enhancement of gameplay. You just lift stuff to orbit, put it somewhere and press a button and that's it. I at least expected the elevator to let us bring stuff down to the ground again. And I expected to be able to collide with it in midair. And I want to be able to get off it half way. In short, I want to mess with it and do all kinds of stuff. But your idea includes nothing of that.

Sorry for being so harsh but I needed to bring you back down to Earth.

I find it difficult to understand your arguments in the last part, in one section you argue that getting stuff to the proper orbit is nigh impossible, but in another you imply it's nothing to get these to orbit. I didn't consider stopping midway, but that would be easily accomplished. If you are spawning an object at X altitude, then it will (should) be trivial to have it spawn at Y altitude instead.

As for collisions, there's no way for the game to model that, the physics engine limits us to a max ship size and spawn distance, this is just an idea to work around that limit while gaining the functionality and game play of an elevator.

- - - Updated - - -

But, on principal, I really don't accept any argument that says "But why?". Just look at the list of mods we do have, there are a lot of them that I ask Why? But there's many people that love and use those mods, and I would never tell them they are playing the game wrong by using those mods.

- - - Updated - - -

But any discussion that helps refine this idea into a workable project I do welcome. That's what these forums are for. Just maybe somebody will say, Yeah, that's doable......

Edited June 11, 2015 by gargamel

[sarbian]

As for collisions, there's no way for the game to model that, the physics engine limits us to a max ship size and spawn distance, this is just an idea to work around that limit while gaining the functionality and game play of an elevator.

Never say never. The colliders just need to be there when you are near the cable. Spawning colliders dynamically and moving them around is not that hard, even more so when they need to follow a shape as simple as a cable or ribbon.

I am not saying that this project is easy, but it is doable. What is needed is someone that want to and can do it.

[Gargamel]

Never say never. The colliders just need to be there when you are near the cable. Spawning colliders dynamically and moving them around is not that hard, even more so when they need to follow a shape as simple as a cable or ribbon.

I was thinking that, but I didn't want to suggest it as it might make it to complex. If it is fairly simple, then It would definitely be a bonus. Having to make sure all your other launches avoid that location would make it more interesting.

[spikes2020]

I have a question, i'm also working on the math now... but could you build a space elevator on Gilly? I mean it isn't really worth it as the gravity is so low. But for science!

Reason i believe that this could work;

1 Gilly has a fast rotation 5m/s at its peaks. Its radius is 13000m + maybe some for mountains

2 Orbital speed are extremely low

3 2.5km added arm might achieve orbital speeds or even escape velocity.

[Tex_NL]

I have a question, i'm also working on the math now... but could you build a space elevator on Gilly? I mean it isn't really worth it as the gravity is so low. But for science!

...

Short answer: No.

Long answer: Any stable space elevator has its centre of mass just above geosynchronous orbit. The wiki clearly states Gilly synchronous orbit is at 42.14 km. See short answer.

[spikes2020]

Ah yeah rotational velocity 0.0002416 rad/s rotation so at 13,000m your moving at 3.1408m/s

So if they clocked in at 5m/s the tallest hill on Gilly would be 20,695m so even attaching 2.5km above that is no place near 42.14km

Well i tried...