Craft desintegrates!

[angeldust]

Hello everybody!

I'm having a problem with my first major Rocket - the Dunodan!

As the Name suggests, it shall go to Duna, with 3 KErbals, Probes and other stuff. This Rocket should bring the main Part into LKO, but the lifter always desintegrates!

What am I doing wrong? No matter how many struts I use, the inner asparagus stage always breaks apart and hits the rocket. Ironically, the Taks connected via struts are doing just fine!

Why won't the linkage work?

See here my craft file: https://www.dropbox.com/s/ic5hygbq465ruab/Dunadan.craft

Please help!

PS: you can give constructive feedback on other possible improvements as well =)

[Johnno]

Since you are using mods please note down which ones, people without those mods installed can't open the craft file.

You could also post images, which could help with initial visuals only help.

[TheBadAstronomer]

Is your craft wobbling? Using powerful engines like the mainsail could cause the ship to oscillate and fall apart.

[Mmmmyum]

I'm just going to guess you're trying to put over 500 tons on those inner decouplers. Around that weight no amount of strutting will keep a booster on

[SRV Ron]

Since you are using mods please note down which ones, people without those mods installed can't open the craft file.

You could also post images, which could help with initial visuals only help.

So far looking through the Craft file, there is Mechjeb, that leaves me out checking it.

Radical couplers are quite strong but will easily break upon twisting. Bracing asparagus stages gets complex since if you just ringe brace them, you have problems with the last two pair causing unwanted spin and possible failure. This pattern works well for my designs.

Engines were dropped prior to orbiting.

All SRB force went on the radical decouplers. There are no braces to the inner ring, just a ring of braces around the boosters only. Without that pattern of braces, the boosters would tear off near burnout. As you can plainly see, only one SAS controller is needed to help out the one in the Stayputnik. This design is very stable in flight.

Edited December 2, 2013 by SRV Ron

[Smidge204]

Protip: Pressing F3 gives you a mission log you can use to track down what failed.

[00:00:00]: Liftoff!!

[00:00:05]: Structural failure on linkage between Rockomax Jumbo-64 Fuel Tank and Hydraulic Detachment Manifold.

This thing is ridiculously overbuilt for that payload. Took me three tries but I eventually got it into orbit... your staging is messed up and there is no reason to be using docking ports since your lander ship that isn't equipped for docking (you need RCS for that, unless you're Scott Manley - and you're not.)

Use more struts.

Managed to land it on Duna. I had to hack out whatever part that needed a mod (MechJeb is fine though) so if you see anything missing...:

That was not fun without landing legs.

The solar arrays on the big fuel tank block the nuclear engines when angled a certain way, causing the ship to be uncontrollable.

You really need a few smaller arrays on the capsule itself - ditch those Gigantor arrays.

The engines mounted radially to the big tank are *nearly* useless. Good to get out of Kerbin SOI but that's about it.

Staging is messed up for the upper/interplanetary portion. Didn't bother to check for action groups though.

You have WAY too much fuel for this mission. Nuclear rockets are stupidly efficient and if you stick to those then you can easily reduce that Jumbo-64 to a tank half that size... and that means mess lass to lift into orbit, which means less fuel and a less complex ship. Less is more.

=Smidge=

Edited December 2, 2013 by Smidge204

[GamerMitch]

Mechjeb has torn apart some of my fragile ships before. If you are using Mechjeb, try using throttle smoothing(should be in utilities) and limit accel to "Number here" m/s^2

[canuckster]

Using asparagus staging on heavier rockets never works for me, I just add another circle of orange tanks instead, does the job.

[Soda Popinski]

I had a similar issue with my stack falling apart on the launch pad. I was trying to get a 70t payload into LKO using a 6 Jumbo / Mainsail Asparagus setup. The straw that broke the camel's back was the Mainsail on the middle rocket stage (stage 4?). With that in, the whole thing would collapse under it's own weight. If I replaced it with a Skipper, I was fine. I still had to throttle up slowly or else the stack would collapse on the way up to orbit (using Ferram Aerospace + KIDS).

So watch that weight in the middle.

I ended up doing some creative strutting, using radially mounted girders and struts like a suspension bridge / truss crane.

[Taki117]

So, I just downloaded and test flew the included craft file (Had to delete the dish) All I added was a couple of stock struts (I use B9 and much prefer there struts). I have included the result of this test flight.

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I tested it with both autopilot and without. I would like to point out that the seprotrons on the inner tanks need to either go on top and facing outwards, or be removed as I have a feeling that's where the issue is coming from. (You could also balance them out) Other than that it works just fine.