How to build launch vehicles capable of lifting heavy payloads.

[Klajan]

I would disagree with all those "moar struts". You need to first figure out WHY your rocket disintegrates. To do this take a look at the flight event log and check exactly which part / connection broke first. Think about what forces (gravity / thrust / "shear") are acting on it, and how you can either reduce these forces (for example by distributing it to other parts), or strengthen the part / connection (by replacing it with higher strength parts or adding a few struts to appropriate places). This way you actually learn how to build better and better rockets, rather than those ugly strut-fests which seem popular on the forum these days.

As an example, take a look at the Modular Medium / Heavy Lift ELV Family. The 76 ton-to-LKO variant has only 31 parts while the 42 ton-to-LKO variant has 17 parts. If I remember correctly these vehicles uses only 2 pairs of struts. Remove a pair and see how they wobble / disintegrates, and you'll see why the struts are placed where they are. Reverse that process and you'll see when and where you need (or do not need) struts for your design.

This is way better that the more struts variants. Try to place your Struts only on parts that need them, be it due to strees from engine gimbal/thrust or due to already weak conections like radialy decouplers. Always check your filghtlog which part failed and begin your search for weak connections from there. This works most of the time. Until you reach a certain level. I have not managed to build a rocket lifting a 300+ ton payload into orbit with less that 800 Parts. At least 60-70 % are struts (Only Stockparts of course)

[cecilman69]

In a sec I will upload some photos of one i needed to lift a 120T payload, it got me to orbit but I still had to draw from the fuel station I was sending to dock with my orbital station to perform maneuvers.

[MrPopcup]

Hmmm.. I can lift upto 100 tons to orbit ( maximum 200x200 km ) but I don't use anymods, also using Asparagus staging, last time I used NovaP & KW was in 0.18, Now i'm running vanilla with KerbalEngineer and Lazor docking cam. but anyway, as I said, the trick is using asparagus staging ( does it bother you to have even more fuel in orbit ?! But yeah, I also recommend you to put those cubic things ( like arms ) and then put the docking port on it, that way your spacecrafts will stay relatively far from the core.

[Dkmdlb]

This really bothers me, as I cannot launch 2m modules for my space station without sending every part separately, and eventually making my station twice as big thanks to the ASASs, the Probes and the RCS required for every docking.

If we have to resurrect this thread, let me just add that the way I prefer to do it is to send up modules about 50 tons at a time. I add a little "tender" module to the end of the space station module and connect it via decoupler to the actual station module. The tender has a probe body, batteries, solar panels, RCS, etc. Everything I need to control the whole thing is in the tender module. Then, when I dock the space station module to the station, I decouple the tender and deorbit it.

In this way, you can save on parts, complexity, and weight of the final station. As an example, if you wanted to dock a fuel module to your station, you would normall have a docking port, fuel tank, 4x RCS on each end, RCS tank, engine, probe body, reaction wheels, batteries, solar panels, etc.

Using this method, if you put everything on the tender module, then after you have docked your fuel tank to the station, all the other parts go away with the tender. That leaves you with a 2 part module (docking port and fuel tank) instead of a 20-40 part module.

[TheToxicPixels]

You could use my lifter, capable of putting 300T's into orbit. Here's the video link,

[allmhuran]

Boy, there have been a lot of "heavy lift" question threads recently. I will continue to just post this same thing...

750 ton lift to LKO:

The design "tutorial" (quite simple really) is the following video on my channel.

[Talonsin]

Personally, I got tired of spending my time designing lifters. I went to the addon section and downloaded the 180 ton lifter and I use it for all my heavy stuff. Now I spend my playtime designing ships and bases, the stuff that is fun for me. Find a good lifter on the addon site and spend time playing how you want.

[Agent86]

This is my fairly capable, SSTO ultra heavy lifter design that I whipped up in 10 minutes. It's fairly compact, for a 32 mainsail ship.

It went in the correct direction. This time.

Gravity turn. 32 mainsails vectoring thrust makes it surprisingly nimble.

Don't time accellerate, because it will spin itself into a killer debris field. Each target there is a mainsail and 2 XL engines.

In orbit, at 618 tonnes!

[JiWint]

Make lighter rockets.

The less rocket weighs,the more engines will thrust.

But if that doesn't help,split your payload in small modules.

Pics don't load for me,but if you want for example,load two orange tanks,lift a few smaller tanks with docking ports.

[blizzy78]

Make lighter rockets.

The less rocket weighs,the more engines will thrust.

Not quite. Engine thrust does not depend on mass being moved. It's rather the TWR will go up with less mass, helping the rocket to lift off because of the lower inertia.

[blizzy78]

FWIW, I've made an online engine stack layout calculator than might come in handy when trying to design a lifter that can lift some arbitrary mass. Please see signature.

[Amoun]

edit....wrong post. my bad

Edited August 19, 2013 by Amoun