Space elevators

[IvanSanchez]

We're all familiar with the concept of space elevators, right?

And since KSP2 will have colonies and orbital shipyards and some kind of milk-run logistics system to send resources from one colony to another, it kinda makes sense to have space elevators.

I guess this would need something like:

• A "ground anchor" colony building: build via KSP2's BAE but only near the equator
• A "counterweight anchor" part/building, meant to be attached to an asteroid. Or part of a big (i.e. massive) fuel dump station.
• A "cable spool" part. Buildable/launchable only from colonies with a "ground anchor" building.
• A four-part mission/contract to:
  • Build the ground anchor
  • Put a counterweight in a specific equatorial orbit (have a vessel of N tons in orbit, with the counterweight anchor part)
  • Launch a vessel with the cable spool part (from the colony with the ground anchor) to the counterweight; rendezvous and dock (in less than half an orbit or so)
  • Maneuver the counterweight exactly into its very specific final orbit.

And when the cable is unspooled and tensioned then, boom, a new orbital station appears in stationary orbit just above the colony, as the colony sends up a lonely "elevator stop" module/building (then player opens up BAE at the station and adds more modules/buildings using the colony's resources).

And I'm not thinking about a Kerbin elevator, but rather Mün & Minmus elevators. If KSP2 is gonna have inter-planetary logistics and economics, then I want to optimize resource launches from Kerbin's moons.

---

I know there'll be a fraction of KSP players that will oppose this, with arguments like "but tensile strength" and "but tidal forces" and "but lagrangian points and escape velocities" and "but navigation hazard". So I'll remind you folks that KSP2 is a game and not a hardcore simulator, and I, for one, prefer unrealistic tensile strengths and ignoring problematic bits as long as the game teaches me something cool about futuristic space travel.

So I wish for space elevators in KSP2.

[Bej Kerman]

Skyhooks as well while we're at it, utilizing KSP 2's far superior physics. Such structures could be used for Kerbin as well. 

[MKI]

8 hours ago, IvanSanchez said:

it kinda makes sense to have space elevators.

BUT, using space elevators seems very un-kerbal like. For a space faring race that as-far-as-we-know devotes 100% of their resources to flying to space on rockets, building a giant space elevator to save costs through a massive orbital structure... seems too sane, and would require Kerbals to spend their time on material science rather than more boosters ;D

 

On a more practical note, what technical limitations exist for even rendering something like a space elevator in the game? Since its an "orbital sized structure" I assume it presents its own technical problems compared to the new "larger" structures the game is adding to support colonies/large-space-ships. Something the size and scale of a space elevator might suck up a lot of development work for something that doesn't need to exist thru cannon-logic. (Kerbals build and fly rockets!)

 

Gameplay wise it would make practical sense to have a space elevator in a lot of cases to support orbital projects. But I think having automated launches/resupply missions would give the same effect without having to deal with the potential technical limitations of rendering a space elevator. 

Edited August 3, 2021 by MKI
grammars

[Neoks]

if we don't have spaces elevators we may use mass drivers to deliver and launch cargo on low gravity moons (or planets?)  and no atmopheres for an inter planetery logistic system i will be i think less hard to render it and build they can run on a near colony power source and i think it will be  easier to setup than space elevators and it's will be only use for cargo not kerbal because the acceleration will kill any kerbal and imagine you have an mun and minmus colony you could send cargo with the mass driver to the minmus colony very easy 

let me know what you thinking abbout this idea

[Rejected Spawn]

Let me just be the one to kill the party mood. Space elevators are only really sensible (yes even by Kerbal standards) on somewhat low gravity bodies that rotate reasonably fast. Which is the last place you'd have any use for one since, as Neoks already mentioned, mass drivers are a good option there. Though I'd argue that mass drivers are usable for manned vessels too, just don't fire them at maximum force and you still get at least 500dV to start your journey with.

Elevators only make even the slightest shred of sense with extremely limited payloads, if it would be treated as a cheat object in the game that teleports payloads instantly from ground to space then sure you could use one more creatively but that really doesn't fit with the essence of the game in my eyes and I think a lot of players would object to this, not to mention the devs probably don't want deliberate cheats in vanilla gameplay. The entire game is being made to handle ships bigger than what would make KSP1 go down in flames and blow out your local power grid, we're talking the possibility of making ships that can carry thousands of times what an elevator can in even an optimistic scenario. And those giants can be automated to some unknown extent to cut down on repeat manual flights.

The only remaining argument in uncrippled favor of elevators is "because they're kind of cool", and that I agree with. Can't really say that factor alone justifies their addition to the game though.

 

Almost forgot to mention but "skyhooks" are complete insanity, if any such project is ever attempted in real life it will be one for the history books under the chapter of how to nearly guarantee that everyone involved will die horribly.

[IvanSanchez]

17 hours ago, MKI said:

BUT, using space elevators seems very un-kerbal like. For a space faring race that as-far-as-we-know devotes 100% of their resources to flying to space on rockets, building a giant space elevator to save costs through a massive orbital structure... seems too sane, and would require Kerbals to spend their time on material science rather than more boosters ;D

Your argument is... unbeatable. You won.

17 hours ago, MKI said:

On a more practical note, what technical limitations exist for even rendering something like a space elevator in the game?

...if the devs would choose to "conveniently ignore" the tether, then none. IMHO there's no real need to simulate the entire tether but rather the parts next to the station and the counterweight. (By "next to" I mean "in the same physics bubble".)

Alternatively, the tether could be split in pieces as long as the diameter (or the radius) of the physics bubble, so collisions could be calculated. But this would mean hundreds of "vessels" and orbit calculations.

A remaining issue would be subjecting the counterweight to constant acceleration (remember, it's at high orbit, but hovering over both the anchor and the station). An ultra-cheap way of cheating this would be setting the state of the counterweight as "landed"

13 hours ago, Neoks said:

If we don't have spaces elevators we may use mass drivers to deliver and launch cargo

The problem I see with mass drivers (and launch loops) is that they can be potentially bigger than the physics bubble, and can not be "conveniently ignored". Even with the KSP2 improvements to the physics engine (and due to  my our very limited knowledge about the technical capabilities of it), I think simulating a mass driver (or mass-driver-like) launch system poses significant (software) engineering challenges.

Whereas an elevator can be simulated with an anchor, a station, a counterweight and a conveniently invisible tether that the player cannot interact with. So IMHO elevators can be simulated, mass drivers can not. The hard problem of a moving vessel in contact with the launch infrastructure could be worked around by disabling collisions during the launch maneouver (so in essence the physical vessel "pops" into existence at the end of the driver, with full velocity) - but I think having a structure potentially bigger than a physics bubble can be problematic.

And yes, of course I would like to put my kerbals on top of a hypersonic railgun train and accelerate them into orbit at 10G (what KSP player wouldn't?!). I'll be happy if I'm proven wrong on my "mass drivers can not be easily simulated" hypothesis.

The same goes with skyhooks - simulating a kilometers-long cable under dynamic acceleration can be a bit of a nightmare.

11 hours ago, Rejected Spawn said:

Elevators only make even the slightest shred of sense with extremely limited payloads, if it would be treated as a cheat object in the game that teleports payloads instantly from ground to space then sure you could use one more creatively but that really doesn't fit with the essence of the game in my eyes

I'm going to disagree here.

Elevators would make sense in planets (or moons) with no way of synthesizing fuel in-situ - there would be a need to land fuel tankers on a regular basis, and a launch system which uses only electricity makes sense, even with a limited payload throughput capacity. From the looks of it, KSP2 is gonna have some kind of logistics system in place, and I would expect those "automated milk runs" to have a cost, so I think that developing orbital infrastructure for cheaper milk runs does indeed fit the "essence" of the game (at least, from my point of view).

BTW, what's the expected throughput of an elevator? There are some numbers for a hypothetical Earth elevator, but this is 10-times-denser-than-Earth Kerbin we're talking about, and AFAIK there's no numbers for elevators on different moons (yet).

Again, we different players have different visions/wishes of what KSP2 will play like. I guess we'll have to wait and see what the final thing looks like.

[BuranAce]

The thing with skyhooks is it would be very hard to use. Basically docking at Mach 12 in the atmosphere, not to mention you need to dock in under 2 minutes. We could obviously nerf it and say its due to Kerbin's properties (such as we need to go around Mach 1 and only having 5-10 minutes to dock, making them usable).

[MKI]

4 hours ago, IvanSanchez said:

.if the devs would choose to "conveniently ignore" the tether, then none. IMHO there's no real need to simulate the entire tether but rather the parts next to the station and the counterweight. (By "next to" I mean "in the same physics bubble".)

Alternatively, the tether could be split in pieces as long as the diameter (or the radius) of the physics bubble, so collisions could be calculated. But this would mean hundreds of "vessels" and orbit calculations.

A remaining issue would be subjecting the counterweight to constant acceleration (remember, it's at high orbit, but hovering over both the anchor and the station). An ultra-cheap way of cheating this would be setting the state of the counterweight as "landed"

I'd put this into the bucket of "fake it" most of the time. In the sense the tether doesn't have physics, it just rendered how it would look if there was physics. Rendering hundreds or even thousand of parts of the tether would probably destroy the game's performance, so that probably isn't an option. So faking the tether would probably be the most sensible option. 

This all would mean requiring different physics calculations and logic just for the space elevators. Which would be cool, but would require a good amount of effort to support within the game. 

 

4 hours ago, IvanSanchez said:

The problem I see with mass drivers (and launch loops) is that they can be potentially bigger than the physics bubble, and can not be "conveniently ignored". Even with the KSP2 improvements to the physics engine (and due to  my our very limited knowledge about the technical capabilities of it), I think simulating a mass driver (or mass-driver-like) launch system poses significant (software) engineering challenges.

You can make mass drivers in KSP 1, just usually not at the scale required for a lot of situations, so its possible just not super useful in KSP 1. All of which is possible because Kerbal parts are made of adamantium and can handle stupid amounts of acceleration no problem. 

Mass drivers in my mind seem "more kerbal", who doesn't want to blow something up and launch it via what is essentially a cannon? Just like the space elevator however, it seems "too sane" as its focus is on cost savings rather than rocket flying. 

There is also the option to again "fake it" and build mass driver facilities with their own logic. Something as simple as making it smaller/shorter/simpler than what's physically possible could mean its just another colony building you can use to magically send up supplies to your orbital stations. Similar to a space elevator, but it doesn't have to be located on the ground in a specific spot, nor does it have to deal with rendering a tether.

 

Both are cool, but each have their own implementation costs that may or may not be worth it. With the orbital building and what not however, I think both should be considered (if they haven't already) as a way to explain how supplies are getting into orbit beyond just "more rockets"... but if its just more rockets I'm fine with that too hahaha. 

 

 

 

[herbal space program]

My biggest (but by no means only) problem with space elevators is that I just don't think they are compatible with the level of technological development presumably encompassed by the scope of this game.  Building one that is remotely plausible would be a bigger effort by orders of magnitude than just building your reaction-powered interstellar colony/exploration ship on orbit. The latter could also conceivably be achieved with "around-the-corner" technologies, while the former is still mostly a pure pipe dream in terms of actual implementation. On top of that (and as has been pointed out), modeling one as any kind of interactive physical object rather than a purely visual stage prop is pretty much out of the question, so its actual use would basically amount to triggering a cutscene. To me that idea just seems kind of at odds with what the game as we know it is all about. And lastly, what you get for having one , i.e. a cheap and easy trip to synchronous orbit and only synchronous orbit, doesn't seem like anything particularly unique or valuable to me.  Just having fully automated supply missions for on-orbit construction projects would provide far more gameplay value without creating a stark discontinuity in  the whole conceptual framework IMO.

Electric mass drivers OTOH,  as a cheap and easy means of delivering mined resources from various low-gravity extraction outposts to Kerbin or orbital construction projects, seem much more within the plausible scope of this game to me.  And they would actually solve a real gameplay problem, which is how to deliver various types of remotely located Unobtanium to the places where they are needed without flying a separate mission every time.  They would also obviate the need to provide resource-return fuel at every mining outpost, at the price of transporting the parts there and constructing it in situ. I also don't think the argument that they would break the physics bubble is valid either, at least not for the toy-sized Kerbolar system and the no-atmosphere, low-gravity bodies where I would envisage their use.  Orbital velocity on Minmus is around 170 m/s, and on Mun it's around 650 m/s.  So a 10g mass driver would need to deliver its acceleration for only 1.7 seconds on Minmus and around 6.5 seconds on Mun to launch its payload to orbit. For Mun that would mean a length of around 2.1km, which is pretty unwieldy but still smaller than physics radius, but on Minmus it would only be 112.5 meters, which is totally doable! And of course the max  G tolerance of Kerbals in their command pods as well as other parts is actually 50 rather than  10.  At 40g, a Munar orbit-capable mass driver would only measure 0.5 km, and a Minmus escape-capable one would measure only 50m. That seems eminently doable to me.

 

Edited August 4, 2021 by herbal space program

[Neoks]

yes my favorite thing is mass driver, i love them.  They are easy to work with and easy to build , and will be a nice building in a colony for low grav planets and moons .

and i think mass driver require less resources and energy tha space elevators

[Admiral Fluffy]

In my opinion, the only way to have Mass Drivers (In Antmo) not be too OP is have them put you on a suborbital orbit thing

Morr infor later have 2 go

[herbal space program]

1 hour ago, Admiral Fluffy said:

In my opinion, the only way to have Mass Drivers (In Antmo) not be too OP is have them put you on a suborbital orbit thing

I think the way to keep them from being OP is to make them require an immense amount of electrical power and also to require the transport, landing, and physical assembly (by qualified engineers with robotic cranes, etc.) of both a (heavy) base station and however many (lighter, but large) driver segments as are needed to reach the required ejection velocity.  Each segment could perhaps telescope out from 10 to 25m for installation. Aiming them more than a few degrees from their build angle should also require re-assembly, and especially long ones should moreover require an appropriately angled slope to support them. Factoring all those things in, I think they could be brought into balance fairly easily.

Edited August 5, 2021 by herbal space program

[Dientus]

I agree with @Rejected Spawn  and   @herbal space program. With it moving away from the "building and flying rockets" vision that Nate has stated was a core feature, among other aforementioned reasons, the only way I ever see it happening is with a mod.

 

And HOW it happens in a way that makes sense and is worth having is another discussion entirely. I would be curious about how a good modder would solve certain issues if they took this on.

 

[Brofessional]

Who needs a space elevator when you have kerbals?

[probe137]

16 hours ago, Brofessional said:

Who needs a space elevator when you have kerbals?

what is happening in the image

[Admiral Fluffy]

1 hour ago, probe137 said:

what is happening in the image

Kraken.

What else?

[SOXBLOX]

This is a mod thing. I don't see it happening in the base game...

[KerikBalm]

I would rather have mass drivers and beamed power propulsion.

Gotta love massive laser arrays that with a little tweaking turn Mun into the death star....

[Nirgal]

On 8/13/2021 at 10:38 AM, KerikBalm said:

I would rather have mass drivers and beamed power propulsion.

Gotta love massive laser arrays that with a little tweaking turn Mun into the death star....

Definitely would love some beamed power propulsion for sending tiny probes to other stars before 'proper' missions. Telescopes can only tell you so much..

 

[Bej Kerman]

On 8/4/2021 at 12:13 AM, Rejected Spawn said:

Almost forgot to mention but "skyhooks" are complete insanity, if any such project is ever attempted in real life it will be one for the history books under the chapter of how to nearly guarantee that everyone involved will die horribly.

And you base this on absolutely nothing, correct? Moot point given that rockets are already risky, orbital mechanics already requires stupid precision like skyhooks will, and skyhooks would reduce the size of rockets and the amount of explosive substances they have to take.