Why this rocket fails at launch?

[vtgbart]

Hi guys,

I must say, for the first time I got stuck in KSP. BUild this rocket in carrer mode, hope to fly to Duna and back - dV ~ 12 000 m/s, but rockets keep desintegrating shortly before or shortly after launch. Can't figure what did I wrong. Could you tackle this problem. Youo can download a part file from here:

http://rapidshare.com/share/1EEE82789553CFFCEB2C53394512BF63

many thanks

vtgbart

[TheKerbinator]

Could you post some images? It could save us a lot of time if we don't have to download the craft file and whatnot.

[Newnard]

I downloaded and tried the .craft file. Had to edit out some parts because you are using a mod (MechJeb) that I don't use, but I don't think that has anything to do with your problem.

I worked on it for a while and made some improvements, but it was still breaking when I finally gave up. Here are the improvements that seemed to help:

1) Move the launch gantries down so that they are supporting the structure from the bottom instead of letting it hang from the top.

2) (more) struts tying jumbo-64 fuel tanks to each other vertically.

Here are the improvements that I think you should make but I didn't try yet:

3) Build wider, instead of taller. Your rocket is so tall that it is breaking under its own weight.

4) Use the kind radial decoupler that leaves some space between the tanks, instead of the hydraulic detatchment manifolds. This allows you to do the following two steps:

5) Put a strut connecting each radial decoupler to its parent tank, and

6) Put a strut or two connecting each radial decoupler to the tank it is supporting.

Good luck!

[Sirrobert]

If your rocket keeps failing over and over and over, it's time to stop trying to fix it. Just throw it away and design something new, that'll be faster