Help with this Rocket Collapsing.

[Rockhem]

I am launching a propulsion module for my interplanetary vehicle, but when i use the single mainsail section of the asparagus, it collapses. I just want to deliver this to a 100km equatorial orbit! Here is a pic of the rocket, and the .craft file.

Pic:

.craft file: https://www.dropbox.com/s/fitp637kqtl18ie/Propulsion%20module.craft (it's stock .20)

I really need help with this!

Edited May 26, 2013 by Rockhem

[Panichio]

What do you mean by 'it collapses'? Does the propulsion stage you are trying to insert into orbit get destroyed by the launch stage? If so, it's probable because when you have very heavy payloads, and the launch stage is under it, the thrust will end up causing the launch stage to destroy the payload. A workaround for this is to try and build the launch stage 'around' the payload, so that the center of thrust is not so far below the payload.

[Pursuedtank]

It looks like it is far too long with not enough struts to keep it stable, when you are down to a single mainsail stage. I quite often find that a single mainsail can shake a craft apart, or collapse it. You may want to try to launch it in a couple of parts and dock them in orbit, or do what Panichio said and build around the payload.

[Rockhem]

It looks like it is far too long with not enough struts to keep it stable, when you are down to a single mainsail stage. I quite often find that a single mainsail can shake a craft apart, or collapse it. You may want to try to launch it in a couple of parts and dock them in orbit, or do what Panichio said and build around the payload.

I have launched this exact same payload before with this kind of lifter, but i just have no idea why it doesn't work now.

[Panichio]

with this kind of lifter

So is there a small change in the lifter? Maybe it has an increase in thrust which is causing it to collapse.

[Rockhem]

So is there a small change in the lifter? Maybe it has an increase in thrust which is causing it to collapse.

Nope, using the exact same config. (no change in thrust)

[Rockhem]

I also dont know how to make a launch vehicle "around" the cargo , I have never done that before.

[Panichio]

Nope, using the exact same config. (no change in thrust)

So you're saying that you have launched this exact same rocket before and it has worked? Was this in a previous version? Are you sure you haven't made any changes to it since the last time you flew it?

[Pursuedtank]

I also don't know how to make a launch vehicle "around" the cargo , I have never done that before.

You would use radial decouplers so that you payload was in the middle while the lifting rockets are surrounding it, as in you would loose the center mainsail and have the outside ones. You would need a small rocket at the bottom of the center and you would need to reconfigure the surrounding booster to deliver it into orbit but it could be done.

[legoheli]

Use the structural hardpoints to make your struts longer as well.

[Epic DaVinci]

I have a theory.

You have used a Tri-coupler mid way through the Rocket, in order to reverse from Tri back to single, you have used the tri coupler upside down. The problem with this, is it only attaches onto one of the points instead of all 3. Before the seperation of the first stages this is re-enforced with struts, but once they go, the whole force of the engine is being put through one of the three fuel tanks in the Tri-stage.

get rid of that bit and im sure it will work.

[Vanamonde]

Epic DaVinci is correct; you do not have 3 columns supporting that segment of the rocket, but one column and two off-center engines that are wiggling loose somewhat. But you still haven't specified exactly how the rocket is failing, so that may or may not be part of the problem.

[Rockhem]

So far I have This:

I don't know how to improve on it to make it a orbital rocket, any tips?

[Epic DaVinci]

get rid of the 3 Nuclear engines in the middle, replace them with a singular Mainsail, the thrust from them is nowhere near enough to lift the center stage.

[Uberick]

I would recommend moving your struts, such that they go from the top of one fuel tank, to the bottom of the adjacent fuel tank

See this horrible pic (when looking from the outside of the rocket towards the center with it pointing up.)

[] X []

[] X []

[] X []

Such as this:

http://i.imgur.com/kNPSEFp.jpg' alt='kNPSEFp.jpg'>

Edited May 25, 2013 by Uberick

[Uberick]

Also, with fuel lines, try to place them on the bottommost tank, otherwise the tanks will feed from the bottom up, which will move your Center of Gravity towards the nose of the rocket, which can make it unstable when trying to perform your gravity turn.

Sorry for my super run on sentence.

[Uberick]

In regards to the ship in the original post, if you have trouble with the longer, final stage being wobbly in the early stages of liftoff, you can build a scaffolding around it to hold it in place. I launched this space station as a single piece by using I beams and struts to hold it in place. . .

http://i.imgur.com/XdxhGd1.jpg' alt='XdxhGd1.jpg'>

[AceGamer]

Struts and maybe shorten it abit!

[Panichio]

Your launch stage is looking good so far, if it isn't reaching orbit, try asparagus staging with it, and maybe even some boosters or smaller stages attached to give the launch stage some more dV.

[Rockhem]

get rid of the 3 Nuclear engines in the middle, replace them with a singular Mainsail, the thrust from them is nowhere near enough to lift the center stage.

The nuke engines are not part of the lifter, they are cargo. plus the 3 double tanks in the middle.

[PirateAE]

is it blowing up form not staying stable, add a few delta winglets to the "lifter stages" and is thats not enough Dv, go outwords on teh redial seperators, also move your fuel linbes done to teh bottom and make sure they are A all there, and B in teh right drection, if the fuel burns not all "even" it will become unstable as you go up, if its blowing up on teh launch pad, add the launch stablizers, and set them to detach as you fire your engines. second you Can use the nukes to "help carry" the whole rockent up of you use the set up form teh last pic you posted, just fuel line into it, untill all your outter stages are gone it wont touch the inner fuel tanks

[Vanamonde]

How about replacing the upper pairs of gray tanks with single oranges? That would give you fewer joints to flex/fail.

[Atanar]

You can't cluster the nuclear engines like that anyway, the jettison of the cover would blow them away.

[Rockhem]

You can't cluster the nuclear engines like that anyway, the jettison of the cover would blow them away.

So how would I go about fixing this so I can get this load into orbit? I have done it before I must have done something wrong this time...

[sal_vager]

You can cluster the LV-N's if you rotate them with A or D when mounting them, so their fairings will blast outwards