Space Elevators... is it too large or does it fit into the game?

[NutellaSandwich]

41 minutes ago, Lo.M said:

carbon nanotubes

I'm talking about carbon nanothreads, which aren't carbon nanotubes. 

Hey, look new page!

Edited January 22, 2021 by NutellaSandwich
new page.

[Lo.M]

9 minutes ago, NutellaSandwich said:

I'm talking about carbon nanothreads, which aren't carbon nanotubes. 

Nanowires are made of the same material.

 

[harrisjosh2711]

18 hours ago, Bej Kerman said:

The point is that the cost of sending said small rocks on space elevators is that it'll be cheaper than sending them on big oil barrels in the long run. If you could have a theoretical launcher that uses no fuel but takes in electricity only and has a large one-time cost for the construction, then it would get cheaper than even the most reusable oil barrels.

I would need to know the operating cost of the elevator to make any kind of real financial analysis.  It isn't just a one time cost. Thousands of technicians, mechanics, & engineers would need to be employed and trained.  Constant maintenance would be required, daily inspections, etc. I imagine a scenario where the elevator is shut down months at a time for repair, closed more often than open. The ultimate money vacuum if you will.

[K^2]

5 hours ago, NutellaSandwich said:

Hmm, I've found this material called diamond nanothreads. Obviously, this material probably will fail for the reasons stated above, and that no one knows how to produce this material in large enough lengths (yet), but it seems promising. Could this material work?

Graphene is basically the limit. You can't do significantly better in strength.

Diamond nanothread specifically, has a Young's modulus about half of that of graphene, so ultimate strength is going to be lower in roughly the same proportion. I'm not sure there are actual values for it, but from Young's modules we can estimate ballpark. The interest in this material exists for similar reasons to nanotubes - both are weaker than graphene sheets, but easier to make into practical materials. Diamond nanothreads might very well end up at the core of strongest materials we end up manufacturing in bulk, but all of them will have less ultimate strength than just graphene. That is pretty much the limit of what's possible for any material.

[probe137]

I think a good alternative to a space elevator would be a skyhook. Basically it's a spinning hook that spaceships can latch onto and get yeeted into space or onto the body it's orbiting. The best part about it is that we can build one now.

[crenelatedcheese]

The tidal forces from different gravity would rip apart the elevator. I agree with K^2, its much easier to build a ramp, and there's nothing you can do on planets with atmospheres except those slingshot things.

 

[LittleBitMore]

Perhaps for very very very late game, but I'm still very unsure about it at all. I'd love to see other groun-based launch assisting devices that can be built into colonies, like a runway that's actually a rail that hurls a rocket at an angle.

Space elevators, while cool, eliminate the fun and Kerbally part of every mission that is getting off the ground. I only want Kerbally solutions to that problem, like the rail launcher I described-- space elevators seem almost too sensible and boring for KSP

[Incarnation of Chaos]

On 1/22/2021 at 11:33 AM, harrisjosh2711 said:

I would need to know the operating cost of the elevator to make any kind of real financial analysis.  It isn't just a one time cost. Thousands of technicians, mechanics, & engineers would need to be employed and trained.  Constant maintenance would be required, daily inspections, etc. I imagine a scenario where the elevator is shut down months at a time for repair, closed more often than open. The ultimate money vacuum if you will.

Sounds like someone has experience either with aviation or similar, my half-brother is a rewire on B-52's and it's astonishing just how many people and man hours goes into keeping those planes flying and current.

And that's just avionics! Like you said, this thing would demand each square millimeter of that tether inspected daily. Likely using Ultrasonic or other NDT methods to look for any potential flaws opening up.

But then again, what do you even do if you find a micro-fracture in this thing? This isn't like a piece of steel where you can weld it, or a component on a aircraft where it could just be replaced. That tether has to be perfect, on the a t o m i c level 24/7, 365. You can't just Spackle over the defect with some CNT paste, that wouldn't give it the same strength. Nor can you remove a section and replace it, at that point you just sent the rest hurdling downwards about to give the people on the equator a very, very bad day/night.

You'd almost need multiple tethers, each able to be swapped to carry the load of the elevator in real time.  Which just further increases complexity and the risk of any little thing going wrong.

[Kernel Kraken]

I think it would work if it was a large, expensive late-game objective. Once you've finished assembling it, it locks into place in orbit like a moon. That way, you wouldn't need a physics range extender or several threadrippers.

[Incarnation of Chaos]

19 hours ago, Kernel Kraken said:

I think it would work if it was a large, expensive late-game objective. Once you've finished assembling it, it locks into place in orbit like a moon. That way, you wouldn't need a physics range extender or several threadrippers.

KSP2 is using the same rigid-body physics as KSP1. It doesn't matter how many cores you throw at it, all the calculations would be on a single core.

That being said, make it a single static "Part" and throw it on rails after construction like you mentioned and it solves that issue.

It would eliminate the possibility of building it piecemeal...but realistically it wasn't ever really going to happen with how the game handles physics.

[StarStreak2109]

IMHO, KSP (regardless of which version) is about launching rockets into space. Thus space elevators and other alternative means of getting stuff into space have no place in it.

[Bej Kerman]

32 minutes ago, StarStreak2109 said:

IMHO, KSP (regardless of which version) is about launching rockets into space. Thus space elevators and other alternative means of getting stuff into space have no place in it.

That logic does not check out. KSP is a game about orbital mechanics, and maglev rails, space elevators, etc. don't take away from that. You can launch a rocket into space using a maglev to reduce the mass and still have a rocket that still has to go the rest of the way; you will still need the skill and knowledge to go further than low orbit. Reducing the mass of your rockets and increasing their payload potential will be an inevitable requirement for building orbital construction facilities. That brings up another hole in your logic - if we shouldn't be allowed to get a kick into orbit, then starting in space from an orbital VAB is probably forbidden.

Edited January 31, 2021 by Bej Kerman
clarification

[pandaman]

Personally I think space elevators are nothing more than a SciFi dream.

I don't think it is a case of it 'making sense', we all have our own styles of play, so what makes sense to me me not to you.  But if any of this is actually possible in game then why not, someone will do it at some point.

[MKI]

There are a few answers to "if this fits in the game".

1. Game engine wise, unless you fake it, it wont make it in the game. Faking it would require some engineering work so you can just "magically get stuff into orbit". This fake version could fit in the game, as it would automate the "get this huge thing to orbit". Which is a problem I'm sure is solved somehow so the game isn't grindy after you already have done it and automated it. A 100% legit built version just wont work with the game engine, so it has to be faked. I don't see this game as a "space elevator building simulator" so the entire thing would have to be automated/cut down to the point its more an explanation for other game-play mechanics, than anything your actually focused on.

2. It shouldn't matter if its physically possible in real life to build one, or even practical. If it adds to the game, and has a "close future" solution, then it could be in the game. If anything having it as an option for low gravity planets would again add to the game as a quick solution to get to space.

3. Automated rocket launches to get stuff into orbit work just as well, and sticks with the Kerbals know best, which is building rockets. A space elevator could come into the game as an explanation for being able to automate getting stuff to orbit, but I don't see it being much more of a focus. The same way you don't have to build the KSC runway infrastructure, a space elevator could follow suite. 

 

[Guest]

10 hours ago, MKI said:

Automated rocket launches to get stuff into orbit work just as well, and sticks with the Kerbals know best, which is building rockets.

This, a space elevator as a colony endgame would remove the need for a reusable rocket/spaceplane system, it would be a cheap way out of a potential huge gameplay loop of designing and refining reusable designs to make automated routes more efficient.

 

[dave1904]

Space elevators are as fictional as warp drives. Teleportation to orbit is probably more like likely. I would probably be cheaper per KG to use the space shuttle at 1 billion per launch than develop, build and maintain something like that. 

On smaller planets it would be cheaper to build a rail to "drive" into orbit. That being said rocket fuel is still cheaper and simpler. 

Just imagine building a space elevator with no atmosphere to protect it. By the time you're finished it would be destroyed. 

[Lo.M]

28 minutes ago, dave1904 said:

Space elevators are as fictional as warp drives.

No technology is fictitious, they are hypothetical, warp drives are NOT fictitious, they are a technology of some centuries in the future, of course we will not have a Star Trek, Star Trek is fictitious.

[dave1904]

6 hours ago, Lo.M said:

No technology is fictitious, they are hypothetical, warp drives are NOT fictitious, they are a technology of some centuries in the future, of course we will not have a Star Trek, Star Trek is fictitious.

You get the point don't you........

[Kernel Kraken]

An idea for cheap, non-rocket launches is cannons. In NASA's project HARP, they picked up some 16" guns from the US Navy and just shot a bunch of stuff straight up. I think that sounds like a lot of fun.

 

[Wubslin]

7 hours ago, dave1904 said:

Space elevators are as fictional as warp drives. Teleportation to orbit is probably more like likely. I would probably be cheaper per KG to use the space shuttle at 1 billion per launch than develop, build and maintain something like that. 

On smaller planets it would be cheaper to build a rail to "drive" into orbit. That being said rocket fuel is still cheaper and simpler. 

Just imagine building a space elevator with no atmosphere to protect it. By the time you're finished it would be destroyed. 

 

7 hours ago, Lo.M said:

No technology is fictitious, they are hypothetical, warp drives are NOT fictitious, they are a technology of some centuries in the future, of course we will not have a Star Trek, Star Trek is fictitious.

What is even going on in this thread??? Warp drives are totally speculative (and probably impossible) technology, space elevators are not. An atmosphere is not required to "protect" a space elevator, it's a huge detriment to it. The less crap you have in the way of your elevator the better. The only real consideration about practical space elevator operation is being a complete obsessive freak about keeping your orbital airspace clear of debris.

Space elevators are likely not going to exist on Earth because of materials science constraints. As for smaller bodies, it's completely possible and there's tons of advantages to stealing planetary rotational energy as your mechanism of getting into orbit. What's impossible about it? It's a cable between two spinny things. The math checks out there. The same goes for skyhooks - they really would do better somewhere without an atmosphere and are best utilized at scales where materials need to be magic and the factor of safety needs to be 1.0001. Imagine Ceres, for instance. Building a space elevator off Ceres would likely be trivial using modern materials science. It has a rotational period of only 9 hours. Climbing a big rope out to a counterweight held taught by being synchronous with its rotation can give you like half a kilometer per second of delta-v, "completely free". 

For more massive bodies lacking an atmosphere, the ideal launch system would be a linear accelerator. It would simply be a powered maglev track hugging the surface of the body. You get in your rocket, and the track speeds you up until it can gently let you go and your altitude starts to increase. You do a couple of "kick off" binormal phase burns to make sure you don't decapitate any skyscrapers, do a puny circularization burn at the top of your arc, and you're in orbit for next to nothing. The tallest end of the track might not even need to be much more than a hundred meters off the ground. The only downside as compared to a space elevator is that you don't have a big crazy space station thing with a catch ramp that could be used to slow down incoming spacecraft. That big counterweight would after all have artificial spin gravity pointing towards its "ceiling"... easy to build a big landing strip on.

[dave1904]

1 hour ago, Wubslin said:

 

What is even going on in this thread??? Warp drives are totally speculative (and probably impossible) technology, space elevators are not. An atmosphere is not required to "protect" a space elevator, it's a huge detriment to it. The less crap you have in the way of your elevator the better. The only real consideration about practical space elevator operation is being a complete obsessive freak about keeping your orbital airspace clear of debris.

Space elevators are likely not going to exist on Earth because of materials science constraints. As for smaller bodies, it's completely possible and there's tons of advantages to stealing planetary rotational energy as your mechanism of getting into orbit. What's impossible about it? It's a cable between two spinny things. The math checks out there. The same goes for skyhooks - they really would do better somewhere without an atmosphere and are best utilized at scales where materials need to be magic and the factor of safety needs to be 1.0001. Imagine Ceres, for instance. Building a space elevator off Ceres would likely be trivial using modern materials science. It has a rotational period of only 9 hours. Climbing a big rope out to a counterweight held taught by being synchronous with its rotation can give you like half a kilometer per second of delta-v, "completely free". 

For more massive bodies lacking an atmosphere, the ideal launch system would be a linear accelerator. It would simply be a powered maglev track hugging the surface of the body. You get in your rocket, and the track speeds you up until it can gently let you go and your altitude starts to increase. You do a couple of "kick off" binormal phase burns to make sure you don't decapitate any skyscrapers, do a puny circularization burn at the top of your arc, and you're in orbit for next to nothing. The tallest end of the track might not even need to be much more than a hundred meters off the ground. The only downside as compared to a space elevator is that you don't have a big crazy space station thing with a catch ramp that could be used to slow down incoming spacecraft. That big counterweight would after all have artificial spin gravity pointing towards its "ceiling"... easy to build a big landing strip on.

Nothing impossible about it but its extremely impractical. I never said it was impossible. I said it is as fictional as a warp drive because its pointless and I stand by that point. Whats the point in building a space elevator for 500ms? I do not think 500ms will make any relevant difference to us if we have the technology to be sending things from cities on ceres? We will never be shipping anything from anywhere if we need the "free" 500ms. Meteorites and other natural objects are very much a concern. 

[shdwlrd]

2 hours ago, Wubslin said:

What is even going on in this thread???

The typical conversation between technical feasibly and the actual ability to build whatever. Also the practicality of the different ways to get stuff into orbit. You can add the need of some to have whatever in the game for reason of "just because" to the people who don't think it fits within KSP and shouldn't be added.

Personally, it's up to the devs if they want to add space elevators to the game or not. I can see this one going either way.