How to launch my station's arms

[AlpacaMall]

I'm building a space station, which will have six arms that ships can dock to:

At first, I tried launching the middle section all as one piece, but it was too draggy and wouldn't fit in the 3.75m fairing. So I launched just the core and put the arms on docking ports, to be sent up later.

However, now that the core's in its proper orbit, I'm having trouble figuring out how to launch the arms. The regular docking port is the only node on the entire arm, and so I can't find a way to decouple the arms from whatever ship I send them up in, due to this bug. Decouplers stay attached to the arms, and docking ports can't release the arms when placed radially.

The only solutions I can think of is to send the arms up with unshielded docking ports, and bring an engineer along to swap them out with the shielded ones, but adding six extra docking ports and a crew reentry pod seems like a hassle. Are there easier ways to put the arms on the station?

[Serenity]

58 minutes ago, AlpacaMall said:

easier ways to put the arms on the station?

You can use Radial Decouplers on those structural parts, with the separation/explosive side connecting on them

and at the back side of the radial decoupler you can have whatever you want, a rcs robot a docking port, up to you.

Then you can move them and dock them and then you can decouple and deorbit the few debris or destroy them from the tracking station.,

Put separation power to zero to avoid explosions.

Its a bit tricky so test with something small first to see how it works.

Edited May 30, 2021 by Serenity

[AlpacaMall]

9 minutes ago, Serenity said:

You can use Radial Decouplers on those structural parts, with the separation/explosive side connecting on them

and at the back side of the radial decoupler you can have whatever you want, a rcs robot a docking port, up to you.

Then you can move them and dock them and then you can decouple and deorbit the few debris or destroy them from the tracking station.,

Put separation power to zero to avoid explosions.

Its a bit tricky so test with something small first to see how it works.

That was my first thought, but the bug I linked prevents me from doing that; the decoupler always stays attached to the arms, not the ship carrying them, no matter which way the decoupler is rotated. And since the decoupler is technically the parent of the arm, I can't use an engineer to detach it.

[Serenity]

2 hours ago, AlpacaMall said:

That was my first thought, but the bug I linked prevents me from doing that; the decoupler always stays attached to the arms, not the ship carrying them, no matter which way the decoupler is rotated. And since the decoupler is technically the parent of the arm, I can't use an engineer to detach it.

The trick to overcome this is to make the robotic arm or whatever the decoupler is backwards placed  as separate craft and then load the main craft and bring it in as a subassembly thingie, its a bit wonky, need experimenting with rout parts, but it will work if its created as a separate craft, except if there is some new bug introduced with the latest version, i am gonna be honest i havent played much lately.

Edit: I might be missing the point and what you really need but maybe it will help but i feel like i am missing something

Edited May 30, 2021 by Serenity

[jimmymcgoochie]

Do you need shielded docking ports? If not, just use the normal version and the arms will be symmetrical, making assembly easier. Alternatively, use the docking ports themselves as decouplers to save some parts and avoid the bug at the same time.

[seyMonsters]

3 hours ago, jimmymcgoochie said:

Do you need shielded docking ports? If not, just use the normal version and the arms will be symmetrical, making assembly easier. Alternatively, use the docking ports themselves as decouplers to save some parts and avoid the bug at the same time.

The man speaks the truth... your girder sections make the shielded docking ports look a little odd so either swap them out for standard ports ( then it’s just a standard mission as they will have attachment points in the VAB at both ends) or swap the girders for solid structural tubes for a better asthetic, in that case put a probe core and a few rcs ports on it with a tank inside the housing and dock it as its own craft...

 

 

alternatively....  send up all 6 in a fairing with a tug craft under them , on orbit, undock the tug from the section under them ( stock fairings with multiple attach nodes). Open the shielded docking ports, and have the tug attach, pull out the arm and position it on your station... 

would it help if I drew a diagram / made a video for you? ;-) 

 

 

[18Watt]

If you have Breaking Ground, you could mount the arms on hinges attached to the center part.  Then you could launch it inside a fairing, and deploy the arms in orbit.   I know that’s not the question you asked, just an alternate solution.

[king of nowhere]

8 hours ago, AlpacaMall said:

However, now that the core's in its proper orbit, I'm having trouble figuring out how to launch the arms. The regular docking port is the only node on the entire arm, and so I can't find a way to decouple the arms from whatever ship I send them up in, due to this bug. Decouplers stay attached to the arms, and docking ports can't release the arms when placed radially.

you know, i really can't figure this out. it's really not relevant here.

You will need 2 docking ports on your arms: one to dock the ships, and one to dock to the station, because now you will need to dock them to the station. So, you have the arms with clamp-o-trons on both sides. And sticking clamp-o-trons to each other is not difficult at all.

Did you actually try to send up the arms? can you post pictures of how you tried to launch them?

I've launched stacks of docked parts many times without ever having problems with decoupling them.

You can also put a radial decoupler on the sides of the arms, so it won't matter if it stays attached.

[AHHans]

Another solution is to launch the arms as they are in a way that you can decouple them in orbit - where they would just drift uncontrollably without any external help. And then have a small tug that can dock to the shielded docking port and maneuver each arm to their destination.

[18Watt]

Ok, I have two possible solutions for you.

The first one involves using the 'Not Rockomax Micronode', which is a small cube.

Spoiler

Delivery vessel mounts docking ports radially.  I have two, but use however many you need.  Mount the Not Rockomax cubes to the docking ports.  Then add your structural beams as needed.

In space, you can undock your beams as needed.  I would make the delivery vessel capable of positioning the beams on your station BEFORE decoupling.

But yes, this works.

Here's method 2.  Uses a EP37 Engine plate, but I think this would work on any part.

Spoiler

Start with a place to mount docking ports.  I used an engine plate, but any part should work.

Add docking ports, facing the engine plate.

Add the rest of the beams, ending with the shielded docking ports.

The docking ports facing the engine plate can be undocked now.

Yes, this works.

 

 

[18Watt]

Here's another way to do it, since you need the regular docking port to be the one which is free.

Spoiler

This looks a little goofy, but it works.  Mount your arms on a second plate, which is on a long pole.  The pole can later be decoupled.

After launch, open the shielded ports.

Release the upper docking port.  The arm will fall onto the other docking ports.

It falls straight down, and the shielded port is now the one which is attached to your vessel.  The regular port is free.

Yup, works just fine in space too!  As before, open the shielded docking port(s).

Release the other end.  The magnetic pull will suck the shielded port to the other port.  Repeat until all your arms are attached at the shielded port end.

After all the arms are attached the correct way, release the center port or decoupler, which is holding the long beam.

Let the beam fly away, now your regular docking ports are free.  You still need a way to maneuver them into place, like RCS- I just had a probe core for testing.  

 

 

[AlpacaMall]

11 hours ago, AHHans said:

Another solution is to launch the arms as they are in a way that you can decouple them in orbit - where they would just drift uncontrollably without any external help. And then have a small tug that can dock to the shielded docking port and maneuver each arm to their destination.

Dammit, I knew there was something simple I was forgetting... Thanks!

 

16 hours ago, jimmymcgoochie said:

Do you need shielded docking ports? If not, just use the normal version and the arms will be symmetrical, making assembly easier

Open docking ports are supposed to be murder on the frame rate, so I use the shielded ones to prevent that.

 

12 hours ago, king of nowhere said:

You will need 2 docking ports on your arms: one to dock the ships, and one to dock to the station, because now you will need to dock them to the station. So, you have the arms with clamp-o-trons on both sides. And sticking clamp-o-trons to each other is not difficult at all.

That would work if I didn't use the shielded docking ports, which don't have a node in the VAB. That's what I was originally considering with the engineer; send the arms up with two normal docking ports, easily attach them, then have the engineer swap out the docking ports. 

[Single stage to ocean]

Don't want to be rude, but just suck it up and launch it without a fairing. Use SRBs and dirt cheap parts and put it at the bottom of the rocket for stability, the drag will keep it pointing right, if it was on top it would flip.

[AHHans]

5 hours ago, AlpacaMall said:

Open docking ports are supposed to be murder on the frame rate, so I use the shielded ones to prevent that.

I'm not sure if I would use such strong language, especially with only six docking ports. But there definitely is an effect.

[Fraktal]

It's very minimal. Couple months ago I tested it to see if it was the reason why my station had low FPS and the performance impact of 14 open docking ports was something like 2-3 FPS on a low-end PC, way less than merely having a 40+ part station.

Edited May 31, 2021 by Fraktal