Help! What am I doing wrong in this construction?

[sledgeweb]

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http://imgur.com/a/WCL2K#0

So, I'm trying to build a simplified apollo standing craft. I have a command module, a support module, and a lander module. One in orbit, I want to disconnect the lander module from the service and command module, spin the service and command module around and reconnect (dock) to the lander. The lander itself has an ascent and descent stage. However, I can't get the thing to separate correctly at all.

I'm having a hard time with the lander-can in general because I can't attach things to it easily unless it's connected to the main body of the rocket. Otherwise it is ghosted out. And when I do get it all connected, it doesn't work right when it comes apart as the "housing" that is added when you use a decoupler stays on the detached parts. See images.

The closest I got was having the Service/Command module separate, spin around, and knock the housing away from the lander module. I couldn't seem to dock however, because I can't put a docking port on top of the lander-can. And, I don't like having to knock away the housing with the service/command module.

What am I doing wrong? Any tips to get this working as I have envisioned here?

Edited September 1, 2013 by sledgeweb

[Richy teh space man]

Dat graphics glitch on the 3rd pic

You tried using the wasd controls to put a decoupler upside down on the bottom of your main stage then attaching a normal decoupler to it the right way around?

[thereaverofdarkness]

Your problem is that you're trying to build the parts separately. You need to draw out what you want and get a stack order down so you can build it the way the game recognizes it. It will only let you build a single object at a time, from the root (initial piece) outward. If you remove a large unit from it, the unit stays together but is ghosted to show that it is not currently part of the rocket because it is not attached to the root.

You might try building three separate craft files first, one for each module, just to get a look at the parts order-then you can write that down on paper. Another way would be to start by building a module with its base connected to the top of the rocket, then once the top of the module is complete, you can attach it down below.

[dave4002000]

I'm having a hard time with the lander-can in general because I can't attach things to it easily unless it's connected to the main body of the rocket. Otherwise it is ghosted out.

This is where the Subassembly Manager mod comes in very handy. Build the lander separately and save it as a subassembly. Then once you get the rest of the rocket built, load the lander subassembly and attach it.

http://forum.kerbalspaceprogram.com/showthread.php/38285-0-20-x-Subassembly-Manager

[Mode7]

Stack separator would be better than a decoupler in between those stages. It is completely separate from the craft rather than staying on top of your lander.

[Specialist290]

Also, another tip: Once you're in orbit and on your TE&D phase, undock the lander from the command module (or manually decouple it from the docking port, not the decoupler / separator), then flip your CSM around and pop the stack decoupler / separator from the engine bell once you're in position to dock. That way you won't have to deal with the shroud blocking the access hatch of your command module or being in the way while you're trying to dock.

[sledgeweb]

Also, another tip: Once you're in orbit and on your TE&D phase, undock the lander from the command module (or manually decouple it from the docking port, not the decoupler / separator), then flip your CSM around and pop the stack decoupler / separator from the engine bell once you're in position to dock. That way you won't have to deal with the shroud blocking the access hatch of your command module or being in the way while you're trying to dock.

I've done some revisions based on the feedback here, but am still having this problem:

The service module sits on top of the lander module. So, I have an engine for the service module, then a stack separator, then the top of the landing can (which is a docking port). So, it's not connected (docked) other than the separator creates a shroud. When the separator blows, the shroud stays on the lander module unless I physically knock it off.

What's the best way to connect the bottom of the service module, which is an engine, to the top of the lander module which has a docking ring on top? Such that, I can separate the two and not have a shroud - but also so that it is stable and doesn't go from large to tiny radius?

See descriptions here:

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[Specialist290]

That's the problem I was trying to help you avoid: Instead of blowing the separator to separate the lander and the CSM, right-click on the docking port on top of the lander can, then decouple from there. Pull your CSM away using RCS and flip it over, then blow the separator off the engine. That way you don't have to deal with the shroud getting in the way.

[Spyritdragon]

Try adding a docking port directly under the engine, i,e. flip it so the side that usually points to space faces the engine, attach it (make sure to attach it to the right connector node on the docking port), then attach the lander under it (so the docking port functions as the docking port for the lander). Then you can simply use the 'decouple node' or 'undock' functions on the docking port to decouple your lander.

If that doesn't work, try adding a decoupler under the engine, a docking port facing downward connected to that, then the docking port on the top of your lander docked to that from in the VAB.

When using the first sollution, i'd turn gimbal on that engine off untill you decouple the lander though.

[Mesons]

It will only let you build a single object at a time, from the root (initial piece) outward.

You will need to attach your lander module in a different spot and add the parts there, then re-attach it in the desired location. One way to do this would be to add a structural fuselage where you have the blue decoupler, then attach the can to the fuselage so you can add your other parts.

As for the decoupler shield, you can usually right-click the decoupler and tell it to decouple from the released stage. First you need to select the released stage (be sure to make it controllable with a remote guidance unit or kerbals in the lander) with [ or ], then you can decouple. That has worked for me when I needed it, but there seems to be some bugs with activating the decouple button.

[sledgeweb]

That's the problem I was trying to help you avoid: Instead of blowing the separator to separate the lander and the CSM, right-click on the docking port on top of the lander can, then decouple from there. Pull your CSM away using RCS and flip it over, then blow the separator off the engine. That way you don't have to deal with the shroud getting in the way.

I'm not sure I can do that for a couple of reasons:

1) I don't think the CSM is "docked" to the lander can initially. The CSM has an engine on the bottom. The bottom of the engine is attached to the separator, which is attached to the docking port on the landing can. In that configuration, is it "docked"? Or does that only happen when two docking ring connectors are connected?

2) Even if it is docked... how can I click on it and decouple it with it being underneath the shroud of the separator? When I click there, I get a "decouple" option, but its for the separator.

Thanks for the help - just trying to figure this out. I was pretty happy I actually was able to get it working and managed to dock with the lander... just not very pretty.

[sledgeweb]

Try adding a docking port directly under the engine, i,e. flip it so the side that usually points to space faces the engine, attach it (make sure to attach it to the right connector node on the docking port), then attach the lander under it (so the docking port functions as the docking port for the lander). Then you can simply use the 'decouple node' or 'undock' functions on the docking port to decouple your lander.

If that doesn't work, try adding a decoupler under the engine, a docking port facing downward connected to that, then the docking port on the top of your lander docked to that from in the VAB.

When using the first sollution, i'd turn gimbal on that engine off untill you decouple the lander though.

I'm not sure I can do the first option, because the lander-can is my "main" piece right now. So if I disconnect the CSM, I won't be able to attach anything to it's engine.

I'll experiment with the second option.

Thanks.

[Specialist290]

I'm not sure I can do that for a couple of reasons:

1) I don't think the CSM is "docked" to the lander can initially. The CSM has an engine on the bottom. The bottom of the engine is attached to the separator, which is attached to the docking port on the landing can. In that configuration, is it "docked"? Or does that only happen when two docking ring connectors are connected?

2) Even if it is docked... how can I click on it and decouple it with it being underneath the shroud of the separator? When I click there, I get a "decouple" option, but its for the separator.

Thanks for the help - just trying to figure this out. I was pretty happy I actually was able to get it working and managed to dock with the lander... just not very pretty.

'Salright -- now that I take a closer look at your screenshots, it looks like the docking port on the lander can is positioned in such a way that it's more or less flush with the top of the surface, while I'm used to it still sticking out a little from the top. That would indeed make it a little harder to select on its own. In that case, you might want to consider setting up an Action Group in the VAB so that it decouples from the docking port end.

You're correct in that it's technically only "docked" when two docking ports are properly aligned (and thus instructions to "undock" were probably a poor choice of words on my part), but a docking port with its "port" end connected to something other than another docking port can be used as a budget decoupler with no decoupling force. If you have a stack separator between the docking port and an engine and you decouple using the docking port's "Decouple" option, the separator will hold the shroud in place on the engine while the CSM can be moved into position with RCS and reaction wheels. Then, once the shroud is safely out of the path of the lander's docking port, you can activate the separator, which will remove the shroud and allow you to use the main engine as normal. If it weren't quite as late over here, I'd go ahead and do my own in-game demonstration and upload screenshots, but that might have to wait until tomorrow at the earliest.

That said, if your current system works just fine and this one seems to be overcomplicated for your needs, feel free to keep doing what you already know

[Temstar]

1) I don't think the CSM is "docked" to the lander can initially. The CSM has an engine on the bottom. The bottom of the engine is attached to the separator, which is attached to the docking port on the landing can. In that configuration, is it "docked"? Or does that only happen when two docking ring connectors are connected?

No at build time, anything the docking port is connected to is considered "docked" to the docking port and you get the right click undock option which will sever the connection. You only need two docking ports if you want to "redock".

2) Even if it is docked... how can I click on it and decouple it with it being underneath the shroud of the separator? When I click there, I get a "decouple" option, but its for the separator.

You could just action group the undock. Else build your rocket in a way that the docking port is visible for right click. For example if you use a 1.25m engine as your SM engine you will be able to click on the docking port without the shroud covering it:

http://forum.kerbalspaceprogram.com/showthread.php/28133-0-20-Apollo-style-spacecraft-Apokee-MS

Oh yeah one more hint - the engine shroud that will be connected to the docking port is non-physical so you can just ignore it and dock your CM to it regardless. But if you dig the neat look what you can do is go to the tracking station after LEM separation, then come back to your craft. The shroud will be gone.

[sledgeweb]

Hey everyone, thanks for all the help!

Some of these suggestions I am just reading now, so I will have some design changes. But, I've been experimenting with the docking/decoupler thing and got it working! Kind of... well, that part worked great, but the rest of the mission was 50/50.

Here's the story of my flight if you are interested:

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Thanks again, I think I've got some new things to try now - but at least I have it working!

[Specialist290]

Glad we could help, and nicely done! Sounds like that was quite the learning experience Hopefully those lessons will all go into the Mark 3.

[sledgeweb]

Glad we could help, and nicely done! Sounds like that was quite the learning experience Hopefully those lessons will all go into the Mark 3.

Thanks! LOL, yes, my Kerbals save billions on research and development by just trying stuff and learning by experience! I'm sure NASA would actually do some measurements and know if the engine was longer than the landing gear prior to construction - but my Kerbals just like to put things together and see what happens!