Apollo Style Payload Fairings

[The Flying Kerbal]

Right guys, I'm really stuck on this one, but I know you will know how to do this.

Here's a rocket I cobbled together to experiment with the payload bay fairings of the type used in the Apollo Saturn V.

It's called the Anaconda because the lump reminded me of a photo I saw of an anaconda after it had eaten.  But I digress... the idea is to try to suss out how to recreate the type of fairing Apollo used to house the LM.  However no matter what I try, I hit one of two problems.

The first is this:

I've just discarded the fairing, there were no stack decouplers involved here, the fairing was being used as the only connection between the two parts.  The payload I want to dock with is the command pod which is resting on the base of the fairing.  Although it looks like the rocket has separated, it's actually not, when I make a turn or use RCS, both sections behave as if they are still joined, right down to the control surface moving on the fins.

In this case I had disabled the Interstage Nodes and Truss Structure, but I had tried them active in previous launches, and the only difference was the truss structure was visible.

So then I thought maybe I needed a stack decoupler to separate the two sections.  So I put one on the nozzle of the Terrier engine and tried again.  This time the rocket did split in two, but.. well see for yourself:

 You see that shroud... well here's the thing, it only exists to be a pain-in-the-neck.  I first thought I would gently nudge it away with the CSM, but it just allowed my space craft to pass through it like this:

"OK" says I to myself, "maybe if I dock it'll just disappear as it doesn't seem to actually be there", but no suck luck... this is what happened when I tried that:

 This is as far as I could go, once I was in this position the shroud acted like a wall, it wouldn't move out of the way and it wouldn't let me push it, even with the engine at full power I couldn't advance any further towards the capsule I wanted to dock with.

So I'm stuck good 'n' proper.  I've run out of ideas to try and so I'm pestering you to help me out here.

And while I'm at it I may as well clarify a few other points about this type of fairing use.  The little target capsule is resting on the actual base of the fairing, there isn't a stack decoupler or docking port holding it in place; is that right, would it automatically detach if I could dock with it, or does it need equipment to separate it from the base?  When it's in its housing, the Terrier engine of the CSM doesn't come into contact with the capsule, but the way this has behaved so far - and I did try putting a small decoupler between the two - I'm wondering if maybe I need something in there as well.

Anyway, that's my problem; I hope somebody will be able to explain how to reproduce this type of fairing using the stock parts.  Apologies for all the screenshots, but they made it much easier to explain than me trying to do it in words.  Thanks everyone.

[Reusables]

If you connect the payload stage with docking port jr., you can enable staging on the part. For this enable 'Advanced Tweakables' option on the Esc menu if it's disabled. Or you can simply decouple it instead of undock. (on the right click menu)

Since you are using fairings as shroud, you may as well disable the engine shroud. It's one of tweakables of engines.

[bewing]

The only thing you need to do different is to use a stack separator instead of a decoupler.

You do have interstage nodes turned on -- that's the only way you can make a fairing that looks like what you've built. As long as something remains connected to that interstage node (in this case the decoupler or the upper stage), the fairing will remain intact. As soon as everything has been detached from that node, the upper end of the fairing will delete itself.

 

 

[Cpt Kerbalkrunch]

If you have advanced tweakables enabled, in the VAB, right-click on the Terrier and disable the shroud. I think that might solve your problem. Then you can just decouple from the docking port.

Nice. I stop to make a burn and got beat to the punch.

Edited April 30, 2017 by Cpt Kerbalkrunch

[The Flying Kerbal]

So, that's another one sorted then... thanks guys! 

[Chaos_Klaus]

You can (and should) do an apollo style fairing entirely without the extra nodes.

Build your CSM. Then attach the docking port of the lander directly to the engine of the CSM. The docking port can be staged to seperate the CSM from the lander later. You may have to enable staging for the port as a tweakable. Disable the shroud on the CSM engine to make it look better.

Below the Lander, add a decouper and a fairing base. Build the fairing and close it around the CSM.

Done.

The fairing base itself can not decouple any parts, except the actual fairings. Anything you want to detach from it has to have a decoupler.

Using a stack seperator between lander and CSM is not advisable, because it will be in the way when you decouple and turn around to dock again.

Edited April 30, 2017 by Chaos_Klaus

[Scarecrow]

I agree with Chaos-Klaus method. Attach lander docking port directly to engine of the stage above, ensuring that you have disabled the fairing for that engine. 

[Snark]

Incidentally, aside from the pure-stock solutions described above:  if you're open to using mods, SpaceY has some really nice conical cargo bays that work beautifully for this purpose.  Picture a conical part with a 3.75m base and a 2.5m top, which opens as four "flower petals" hinging outwards from the base.  Stick a stack separator on top and you're all set.