Detachable ring structure

[Maxo11x]

Hi, I class myself as an advanced ksp player who has gone to most reaches, but I have hit a problem with my current ideas of where I want to go. My game is modded but causally using stock ideas. My problem is:

I have a landing craft that I want to land on the mun from Kerbin.

It has a landing structure that surrounds the launching device that contains stuff I want to leave intact on the mun.

The entire craft needs to land, then detatch the surrounding doughnut-like structure completely as it was built (but maybe without fuel).

I cant return and re-assemble the part with docking ports at a later date (that would be too easy).

 

Please I need help as I really get annoyed with this. If I find a way to do it this will really unlock a lot of techniques for ship designs to use. I am open to all ideas.

[Rocket In My Pocket]

Well, welcome to the forums for starters!

Perhaps a picture would help explain your issue? I'm not sure I understand.

Sounds like a pretty easy problem to me, that's literally what decouplers are for. Just make the ring structure the bottom most part and add a decoupler between. Or use radial decouplers and attach it onto the side. If your issue is the ring structure itself, you can't make closed circuits like that in KSP, without using struts.

Edited November 16, 2018 by Rocket In My Pocket

[pincushionman]

Well, the most straightforward way to leave a structure on Mun is to integrate the structure into a landing stage, with an ascent stage perched on top. When you leave, all that stuff stays behind.

But it won’t be ring-shaped. It could be ring-shaped with a plug in the middle. If the ring is a firm design requirement, things are about to get complicated.

First, you need to understand that the “tree” structure of vessels makes rings notoriously difficult to build. You can build parts into a circle, but the ends that come together won’t be connected even if they look like they are. You have two options to close the shape: struts and docking ports.

Struts will simply connect, but docking ports at each end will still be unattached until physics loads. Search on this forum for more details on building rings.

[Maxo11x]

1 hour ago, pincushionman said:

Well, the most straightforward way to leave a structure on Mun is to integrate the structure into a landing stage, with an ascent stage perched on top. When you leave, all that stuff stays behind.

But it won’t be ring-shaped. It could be ring-shaped with a plug in the middle. If the ring is a firm design requirement, things are about to get complicated.

First, you need to understand that the “tree” structure of vessels makes rings notoriously difficult to build. You can build parts into a circle, but the ends that come together won’t be connected even if they look like they are. You have two options to close the shape: struts and docking ports.

Struts will simply connect, but docking ports at each end will still be unattached until physics loads. Search on this forum for more details on building rings.

This is the point, its a challenge. It would be too easy just to attatch it to a core and detatch from within the core leaving the bootom half in tact... too easy! I am doing this because its a challenge. BTW any mods that would help would be appreciated

 

PS I would post an image of the current design but being fairly new to this forum I dont actually know how to insert an image, so here's an imgur https://imgur.com/gallery/LqoXg2N

[Zhetaan]

It appears to me that you have something somewhat like the descent and ascent stages of the Apollo LM, but with rings instead of stacks.  I can't think of any reason why it shouldn't work, aside from the ring problems that have already been mentioned.

With that specific design, you may find a need for ReCoupler to avoid torsional shifting once you detach the ring structure, especially if the terrain where you land is not perfectly flat.  It wouldn't do to land perfectly and then have the ring fall apart on you.  I'd also caution you to turn down the force on the radial decouplers to zero.  Otherwise, your issue is going to be the precision piloting necessary for both landing and takeoff, but I will assume that you have that part under control.

[Vexillar]

I've had some success using the new-style decouplers to attach radial parts to make a lower stage, allowing the engine of the stage above to fire through it.  Not sure how far that would get you to your design intent.

[Superfluous J]

Do you want to use the same engine for descent as ascent? If so, then decouplers and the Making History structural tubes allow rocket exhaust to pass through. I'd put a decoupler under the engine and a tube under the decoupler, and then attach the "leave it on the surface" stage to the tube radially, so it LOOKS like a ring but isn't really as you can't do that in KSP

If you want a challenge, attach a docking port to the base so future missions can land on it.

[Maxo11x]

On 11/16/2018 at 6:31 PM, Zhetaan said:

It appears to me that you have something somewhat like the descent and ascent stages of the Apollo LM, but with rings instead of stacks.  I can't think of any reason why it shouldn't work, aside from the ring problems that have already been mentioned.

With that specific design, you may find a need for ReCoupler to avoid torsional shifting once you detach the ring structure, especially if the terrain where you land is not perfectly flat.  It wouldn't do to land perfectly and then have the ring fall apart on you.  I'd also caution you to turn down the force on the radial decouplers to zero.  Otherwise, your issue is going to be the precision piloting necessary for both landing and takeoff, but I will assume that you have that part under control.

This stage is actually a modified design from my previous effort where Valentina died upon re-entry so will make it there and back easily. The decopolurs (sorry for spelling, rather dyslexic here and spelling is NOT my strong point) are set to 0, apart from the one below the engine to 10 "for the lolz" but thats rather irrelevant.

I will have a look at the re-Coupler and the terrain I have picked out is relitively flat, and I should be skilled enough at this game that terrain is not a problem to my decents.

On 11/16/2018 at 7:13 PM, 5thHorseman said:

Do you want to use the same engine for descent as ascent? If so, then decouplers and the Making History structural tubes allow rocket exhaust to pass through. I'd put a decoupler under the engine and a tube under the decoupler, and then attach the "leave it on the surface" stage to the tube radially, so it LOOKS like a ring but isn't really as you can't do that in KSP

If you want a challenge, attach a docking port to the base so future missions can land on it.

The 4 engines on the ring structure are designed for decent and then the core would launch me on a full tank. There are other scientific instruments below the lift-off engine that I only require one of (science jnr, mystery goo...etc) and would like them at the bottom for easy access once on the surface (ie I dont need EVA fuel to lift the kerbal to the top of the craft to get the science). I know exactly what you are talking about in the "leave it on the surface" stage being radially attatched to a core point and then just decouple from that, alas this is too boring and not a challange and have done MANY times before. I am simply doing it this way as I want a challenge. I have nothing against this idea as it does work and its valid but as I said I am looking to challenge myself.

 

If it is impossible using stock parts then its impossible, thats why I can include extra mods but still looking for stock sollutions.

[Rocket In My Pocket]

Is this sort of what you are looking to do?

Was working on a single engine MunarLifeRaft that can go from Munar orbit, to the surface, rescue a Kerbal, bring him back to Kerbin, and de-orbit him. (Yes btw, it works.) I liked @5thHorseman's idea of firing through the new hollow parts, so I was building it along those lines.

The bottom ring get's left intact on the surface.

Edited November 18, 2018 by Rocket In My Pocket

[Maxo11x]

On 11/18/2018 at 3:36 PM, Rocket In My Pocket said:

Is this sort of what you are looking to do?

Was working on a single engine MunarLifeRaft that can go from Munar orbit, to the surface, rescue a Kerbal, bring him back to Kerbin, and de-orbit him. (Yes btw, it works.) I liked @5thHorseman's idea of firing through the new hollow parts, so I was building it along those lines.

The bottom ring get's left intact on the surface.

Yes this idea, I am definitely on towards the idea that there must be a core that the radial part attatches onto, I was hoping there would be some way of kinda joining different radial parts together. I suppose this will be impossible for now. Still if there is a mod that allows this.

 

(sorry busy with life so wasnt able to check up on for a bit over the week)