Hi

I'm having a little problem with parts detaching themselves from my craft for no particular reason. Here's an example :

Exhibit one : I have nose cones and RCS fuel tanks attached on top of a fuel tank/engine assembly, itself being attached to radial decouplers and fastened with structural struts. The RCS tanks are not free floating, i.e they are attached to either the fuel tanks orthe decouplers :



I'm on a transfer orbit to the Mun, far away from any atmosphere or space junk I might collide with. There are no RCS boosters that could blow them away as I manoever. The Kerbal seen EVAing is not to blame either, as he never touched the parts in question and was in the process of being evacuated to free up space in the module for a rescue mission.

A couple of quick burns and orbit adjustments later :



RCS tanks and nose cones have detached themselves. On earlier tries, two engines also separated, forcing me to abort mission.

I thought maybe centrifugal force building up as did fast rolls to stabilise would be to blame, creating shearing forces the parts are not designed to withstand, but I wasn't able to reproduce the effect on purpose (barrel rolling to the point of redecorating the inside of the module with Kerbal guts).

Has anyone had a similar problem ? Is this a well known adverse effect of space manoeuvering I should be aware of, or simply a bug ?

I'm having alot of fun with KSP, but this little issue is currently preventing me from rescuing two Kerbonauts from previous missions currently trapped on the Mun.

Cheers

Nico

I have never seen that problem. If it was just the nose cones I would say dont use them (they are broken and only add weight and looks anyways since there is no aerodynamic model in the game yet.)

If it is other things also then maybe try to better support them? From the second picture they dont look to be centered on the decoupler (could just be an illusion though.) If they do pop off do they come off with or without the decoupler?

You can run extra bracing from the main body to the decoupler where it attaches to the 4 external tanks to give more support if need be.

They are aligned, they're just slightly smaller than the fuel tanks. No aerodynamics yet you say ? I thought they were only missing the re-entry friction mechanisms... That would explain my inability to make anything other than rockets "fly" for more than ten seconds

Anyway, I'll be removing the nose cones from my designs, and looking forward to the implementation of aerodynamics...

Cheers

Nico

There are some aerodynamics, you can build and fly planes around with lift and such.

I think whatever drag modeling there is, it's really simple. If there wasn't any drag at all and I turned off my engines in level flight in atmosphere, I shouldn't be seeing a rapid loss of speed. Aircraft in atmosphere would coast at speed like they were in space then (which they don't in my experince).

You can break things by subjecting the mto enough force, usually under acceleration. But if you can't reprodue it, it might be some buggy part behavior.

I've seen odd things happen with parts before. The other thing is that only the initial thing you attached to the decoupler is attached. Anything you the attach to that object, will not be attached to the to decoupler. If that makes sense.

Basically it might be possible for the RCS and nose cone to smack into the decoupler. If you somehow created the force to do so.

The fins and wings generate lift. You can actually make a engineless device that is just wings in a radial pattern and it will take off and fly up into space. There is some form of drag but it is calculated very basically.

I am not sure, as I am viewing on my phone. There appears tobe a gap between the rcs tanks and the fuel tanks. What is there.

Also is this rocket from an earler build and you copied the rocket config into this latest version?

Also are you using any mods?

Hm... No mods, at least not on this particular module, no config edit, just plain default manual stuff. The damage was sustained while in "map" view as I accelerated to raise my periapsis and establish orbit, so I did not actually witness the damage occur.

I've noticed that sometimes boosters or engines attached in a radial pattern around a central body will point slightly inwards when applying high thrust if not fastened properly. If Ryujin is right about parts not being attached to the decoupler itself but to the part attached to the decoupler, that effect would have caused the RCS tanks (attached to the fuel tanks) to push against the decouplers, creating lateral shearing force that would cause them to break away. At least that's the best explanation I can find.

The earlier case of engines detaching could have been caused by collision with the free-floating RCS tanks as the vessel was rolling...

Cheers

Nico

What I was meaning was,did you build your rocket from scratch in version .16 or did you build it in a previous version and import it to this latest version.

I only ask as with .16, rockets built in previos versions need to be rebuilt in current version.

In addition, many parts do list a drag component with their stats. I think drag is simply calculated as these stat's added together for all parts on a ship. That means, for example, that a fuel tank will have x drag regardless of whether or not a more aerodynamic nose cone is attached on top of it. I've built modded ships with solar panels sticking out like giant sails, and they've had zero impact on launch speed.

The "space kraken" perhaps? I have heard of such things before, it would seem that is the cause. It tends to happen at high speeds due to issues with position tracking apparently.