Megastructures, tips, tricks, traps, kraken repellent?

[steuben]

On the back of an envelope I have a sketch for a ship. My quick calculations put it at a dry mass in double digit megaton range, length is in the km range, crew one to two thousand kerbals and kerbalinas.

I'm looking for suggestions/recommendations on the following:

1. how to design it out. I'm thinking of a keel and spar design. Four or six modules hanging off each spar, in two rows in line with the keel.

2. my module movers. LfO or Mono?

3. fueling the construction. farm d and e asteroids or Minmus for the fuel? The ship itself will be fueled from Minmus.

4. how to reduce encounters with the kraken and it's slightly more benign cousin the lag monster.

5. anything else that I should be aware of

constraints and notes:

1. I'm working with stock parts. But, I'm not modless, I'm working with KER, RCS Build Aid, and Hyperedit in the design.

2. I know I'm going to have to do this in multiple launches. modules will probably be in the hundred ton range. which points to thousands of launches, or kilo-ton lifters, or both.

3. I am well aware that I will be melting silicon supported by a liquid cryogen cooler. with the projected part count.

Edited August 26, 2015 by steuben
added adiitional note

[Sharpy]

How many parts is it?

I don't think any contemporary computer can handle anything above 500 parts at any reasonable framerate. Trying to operate near a 1000+ parts monstrosity will drop your framerate below 1FPS making every operation so hard to perform, you'll really wish to drop the whole design.

Maybe, just maybe, if you create huge modules of 400 or so parts each in their own physics bubbles and then painstakingly bring them together you'd be able to assemble it, though I wouldn't hold my breath, and even then it will be about useless as both it and any craft within range will run at <1FPS.

my final advice would be: don't do it. Or at least wait until 1.1; I'm not sure if it can fix that problem but I'm completely sure 1.0.4 is not up to the task.

Edited August 25, 2015 by Sharpy

[Xannari Ferrows]

Firstly: Good lord, whose channel did you watch this time? You should know that there will be plenty of bugs with this kind of plan, and maybe even Mr. NaN.

4 modules hanging off each spar would make the whole thing likely more accessible, so if you are going to make regular trips up to it, god help your computer, and you probably want to have as much elbow room as possible.

I'd personally go monopropellant, but it can depend on the module you're bringing up as well. Monopropellant if you want fine movement, and LFO of you want to not take a day.

You could design a module made to hold the asteroids, if you haven't already thought of that. Just be warned though: Mr. NaN loves asteroids.

To avoid encounters with the trio, use as little docking as possible, and try to clip as little parts as possible. Also, time warp is not your friend here.

You're crazy.

Can I break the mold for a minute? I know you said you were only using stock parts, but KW would allow you to build heavier, slightly more efficient lifters, and cut down on your launch counter.

[Snark]

+1 to what previous posters have said about trying to work with huge numbers of parts. 1.0.4 is really not up to it.

Now, if you're willing to think slightly more modestly (i.e. a few hundred parts, ship mass of a few thousand tons, etc.), and you're simply looking for "how can I assemble this thing in orbit" and want tips for large structures (especially if they have to have engines on them and withstand acceleration):

Big structures that are connected via docking ports tend to be very "floppy"; docking ports aren't very stiff connections. One way to solve that (which I also find fun, since it gives kerbals a reason to EVA) is with deployable struts from the Kerbal Attachment System mod. There's a part included with that mod which is basically a "strut socket". So you put those sockets around your docking ports on each section of your ship. You launch it, dock it to the main structure, and then send out a Kerbal on EVA to place a strut by first clicking on a socket from part A and then on a socket from part B.

This allows setting up struts between the two sections, which results in a nice, stiff design.

I've used this technique successfully (and it was fun!) to put together a deep-space exploration ship. I'm running TAC-LS (so ships need to bring along food/water/oxygen), and Outer Planets (so missions take many years), and UKS (so it's possible to make a ship that's fully self-sufficient with greenhouses and such, but it takes a large crew and many different types of modules). Assembled a 2000-ton ship in three sections, works like a charm, no floppiness at all.

Edited August 25, 2015 by Snark

[steuben]

to answer in sequence

How many parts is it?

first order approximation... 2400... no sorry. i dropped a decimal point. 240,000. dry mass maybe not in the megaton range... 72 kilotons which doesn't feel right.

Firstly: Good lord, whose channel did you watch this time?

CBC about 25, 26 years ago on a Sunday evening, 7:00 PM, 7:30 in Newfoundland. But that might be a good idea, a video series on getting this thing built.

You're crazy.

Yes. Yes I am.

Yeah the docking ports are floppy. If I recall correctly you can minimize it by using multiple ports. However, that was back in the 0.2x's. I think things got redone for either .9x or 1.0x. But i'm not sure.

As for the 1.04 will melt if I try.

By the time i'm ready to build it, 1.5 will probably be out.

[Asharad]

My current built is at 400 parts and growing. I did experience spontaneous implosion once, but a quick save fixed that.

[Sharpy]

2,400 might be vaguely possible on a very strong computer, although already useless. Maybe 10,000 if you tweak physics and graphics for performance (although it will behave wonky and look crap). 240,000 - nope, not a shade of a chance. Especially that even if you got some magical computer that could run it, the structure would behave like jelly.

One way to really big ships is Tweakscale. Thanks to it you can reduce the part count by making already big parts much bigger. But it you want the huge number of details, your plan is simply not realistic for KSP.

[kerbiloid]

Stanford Torus mod looks like what you describe.

http://forum.kerbalspaceprogram.com/threads/84106-0-90-Stanford-Torus-0-6

As you can see, it consists of just several complicated parts, so part count is very low, which allows FPS to be more or less appropriate.

A funny problem with it.

As any craft gets loaded only when it is inside the physical range from you (usually, ~2 km),

this huge torus appears at lightning speed right before your face when you approach to it.

Another sample of super-structure is Katlantis Hotel from an old movie.

Also with low part count as I can see.

Wayland has several beautiful samples.

http://forum.kerbalspaceprogram.com/threads/24677-%280-23%29-Wayland-Corp-Development-and-released-download-Thread-%28new-parts%29

So, maybe if you use Ubiozur Welding Continued mod to pack many parts together, the Kraken will be indulgent to you.

http://forum.kerbalspaceprogram.com/threads/107273-0-90-UbioZur-Welding-Ltd-Continued-2-1-1-%282015-01-14%29?p=2113214&viewfull=1#post2113214

Of course, TweakScale can be useful to increase your creation.

Edited August 26, 2015 by kerbiloid

[Mikki]

Hi steuben

This is something that makes my liquid cooled i7 4770 4-core CPU slightly boil:

My system can handle about 450 parts without lag, 550 still good playable, 700+ parts start attracting various krakenattacks, namely out-of-warp insta-whobble/ unplanned disassembly/ random explosions/ bending/ non responsive UI.

I keep limiting myself to "reasonable" 500 parts for a interplanetary assembly, no way around in 32-bit. I wait for a 64-bit release, however.

In my system launching a 1000+ part 3000+ tonne vessel results in immediate CTD...... (Windows 10)

[Sharpy]

In my system launching a 1000+ part 3000+ tonne vessel results in immediate CTD...... (Windows 10)

In all fairness, vessels behave a little better in vacuum - keyword "a little". You can get away with roughly twice the part limit of Kerbin (if you count the launch stages). So if you can get three 500-part modules into orbit (on top of dispsable 200-part launch stages) you should be able to assemble a 1500 part orbital station.

Still a far cry from 240,000.

also keyword: station. Don't try to move it.

[eonmoon]

the only way I see if you want a really huge ship like that, will require mks/oks of the UKS systems by roverdude, extraplanetary launchpads to have a orbital spacedock, and ubio? weld to make your parts fused to cut down your part count for a mega vessel

edit make sure crew modules aren't part of the weld, cause welding welds the doors shut

[GluttonyReaper]

You might want to check this guy's stuff out:

He's kind of known for building massive ships.

[xtoro]

Use procedural tanks and structures. This might reduce your part count below 100k

[Norcalplanner]

I'm going to put in a plug for Kerbal Joint Reinforcement and SpaceY. KJR strengthens all the connections, including docking ports, reducing the need for struts. SpaceY includes 3.75m and 5m docking ports which are much stronger than anything in stock. The largest station I ever built, with room for over a thousand Kerbals, was launched in three big sections, with the only connection between sections being a 5m docking port.

P.s. Think really hard about whether you want to do this. A two minute docking maneuver will take 30 minutes or more due to lag.

[Snark]

Just to bring things back to the original poster's question-- 240K parts is utterly, mathematically insane. Complexity of physical simulations goes up with the square of the number of parts. It's not just that "1.04 can't handle it," but rather "no version of the game can handle it until computers are thousands of times more powerful than they are now." Going to 1.1 with multithreading, etc. might (I say might) raise the number-of-parts ceiling by a small factor, on the order of "how many cores do you have in your machine". So maybe, for example, you'll be able to get away with a 2000-part craft where now you can only do 500, that sort of thing. (Again, just rough speculation.)

But there's no way it's even vaguely going to allow super-complex systems like you're describing.

So, as far as this thread is concerned: Does that mean that your question is answered (i.e. "No, I can't do this, and will never be able to for the foreseeable future, so further discussion is pointless")?

Or are you interested in big-ships-in-general, and you're still interested in techniques for (say) a 1000-part ship, or things of that general order of magnitude?

[steuben]

If I wasn't aware about the issue of the part count before starting the project, I am now. It no longer needs to be communicated, reiterated or discussed. I am aware of just how hard I will be pushing ksp and my machine.

The OP question set still remains open.

Techniques for the kilo-part range will be entertained.

[Admac]

Lol @ a 240000 parts

Step 1) get mech jeb for that auto docking

Step 2) Read good series of books

Step 3) Maybe clean the house a bit?

Step 4) Pick up an interesting hobby, like wood working or bonsai.

Step 5) launch next part...

I went crazy and did a 2000 part vessel early early 1.02ish and it was like an hour ish to dock an agile light lander to it. I honestly hove no idea how long it would take if the scene parts were much higher than that. I mean with the right packs you can build awesome 100ish kerbal stations that fully loaded are 4000ish tons with centuries of life support and deployable shipyards and a lander and still be under 100 parts. In my opinion that's closer to where the fun lives. Not to dis on bonsai or anything. And having a clean house is pretty sweet, so there are perks to each way.

[Snark]

Aside from using Kerbal Attachment System to add deployable struts around docked sections (to add stiffness), another tactic is to use mods that allow you to keep part count down. Tweakscale has already been mentioned. Another handy one is RoverDude's UKS/MKS mod-- it has some parts that can help keep part count down, including:

- A variety of spherical fuel tanks in many sizes, up to a monster that weighs >2000 tons when full. (And can be configured to be either LFO or liquid-fuel only, in case you're looking to power it with nukes.) All the fuel you need, just one part.

- A nuclear reactor that generates oodles of electricity. Again, one big part.

Porkjet's mod Atomic Age includes a large nuclear-powered engine that gives 450 kN thrust, so does the work of 7.5 LV-N's in one part.

[Mikki]

Hi steuben

However, to reduce partcount i suggest "STOCK FUEL SWITCH" Mod, make any tank LF only (for the nuke engines...), gives you more freedom in your interplanetary vessel designs.

Actually i use KJR too, no way around it with large assemblys. The amount of struts (draggy) can also be massively improved with KJR.

Good luck with going AWESOME!

[tbarcello]

+1 to what previous posters have said about trying to work with huge numbers of parts. 1.0.4 is really not up to it.

Now, if you're willing to think slightly more modestly (i.e. a few hundred parts, ship mass of a few thousand tons, etc.), and you're simply looking for "how can I assemble this thing in orbit" and want tips for large structures (especially if they have to have engines on them and withstand acceleration):

Big structures that are connected via docking ports tend to be very "floppy"; docking ports aren't very stiff connections. One way to solve that (which I also find fun, since it gives kerbals a reason to EVA) is with deployable struts from the Kerbal Attachment System mod. There's a part included with that mod which is basically a "strut socket". So you put those sockets around your docking ports on each section of your ship. You launch it, dock it to the main structure, and then send out a Kerbal on EVA to place a strut by first clicking on a socket from part A and then on a socket from part B.

This allows setting up struts between the two sections, which results in a nice, stiff design.

I've used this technique successfully (and it was fun!) to put together a deep-space exploration ship. I'm running TAC-LS (so ships need to bring along food/water/oxygen), and Outer Planets (so missions take many years), and UKS (so it's possible to make a ship that's fully self-sufficient with greenhouses and such, but it takes a large crew and many different types of modules). Assembled a 2000-ton ship in three sections, works like a charm, no floppiness at all.

Oh, i really wanna show you what happened to me yesterday when i was reinforcing with struts. And I can, because i got it ON VIDEO! I'll still have to upload it to my youTube channel. Same nickname, check it out on weekend, it will be in my fails playlist.