So I have an annoying problem...

[Terrachova]

...and it's hampering my efforts to build a rocket to land a crew on another planet (just land... not looking to return just yet).

I'll mention I'm using exactly zero mods at the moment.

So! I ran into this issue a few times in the previous version of the game building munar rockets, but it never truly impeded my progress. What it is... well, it seems that either the 'large' size parts are too weak, or I'm strapping too much thrust under the thing - or a combination of both. Basically, after about 30-40 seconds, once I've reached around 200m/s, the rocket breaks in the middle or so, and falls apart. Data shows a structural linkage failure between one of the fuel tanks and a decoupler - or any two of the 'core' parts.

Core meaning, the 'center fuselage' of my rocket. I can take a picture if necessary, I just haven't bothered. Basically, I tend to build my rockets along a central fuselage with large parts (using the 3-man pod), and have extra engines branching off for each stage (currently sets of 4).

Anyway... yeah. This is a bit of an issue. This first stage, when I get enough power into it to launch me into orbit, is to get me high enough to make orbit height so I can adjust and make the extra-planetary burn with the second stage. However, that will never happen if the damn thing keeps breaking halfway through. It doesn't make sense to me either - this is probably the lightest lander and 2nd stage I've strapped to a series of rockets... and it breaks every time. So do some of my older rockets loaded into this one too - no amount of struts seems to help.

So... are there any fixes or solutions to this?

Or, perhaps, a suggested 'working' design to get a 3-man pod to another planet?

Also, yes, this is my first post (or one of)... lurked for a while, never had a reason to post.

[vexx32]

Well, for working designs, there are several in the Spacecraft Exchange.

[Fridgecake]

A picture would help a ton as people could see any glaring inconsistancies.

Other ideas:

Using other struts from different mod packs as I know they have different strengths etc so this could help.

Don't overload your decouplers, sometimes you can do things on 2-3 decouplers rather than 1 so there's less stress at that point.

Try and strut as much as possible and linking the outermost parts to the innermost ones if you can. I'm not sure it'll help but it can certainly reduce the wobbling and that could solve the problem.

Don't go as fast within Kerbin's atmosphere. Try to slow your ascent at higher altitudes after that hard initial burn.

Hope these help

[nhnifong]

This always seems to fix it for me. Somtimes you have to throttle down too. Try not to exceed 4 Gs

[Spyre9]

Use to have issues with that and when turning into my parking orbit, would throttle up and watch the engines punch through the entire thing... awesome to watch! but kinda counter productive to Kerbal-kind.

Simplest rule I have found is watch the G-meter, if that needle is popping out of the top of the green zone your likely to break something so throttle down a little, and when you do throttle back up, do it slowly letting the craft build up it's velocity before adding more thrust.

[EndlessWaves]

I prefer not to use vertical struts but rather learn which configuration of parts are strongest. It results in smaller part counts and consequently larger rockets. Horizontal and diagonal struts to stop wobble seem essential on large rockets though, I haven't yet come across a configuration that lets you get rid of them entirely.

The large parts seem to be able to take similar weights to the small ones, if your stack is more than ~5 3200L fuel tanks high it will have trouble. 4 will often work but 3 seems to be more a generally reliable number when attached to a heavy load.