Messed up my first docking

[PeskyPony]

Hi, I'm a little angry at myself after some time of intense noob docking. I managed to get the magnetic pull between my two space station sections, but after a few in-game days I noticed they had become uncoupled. They're still in the same orbit and just a couple of km apart and with plenty of fuel, but I might have messed something with the docking ports in the design phase. I'd like to see if somebody wouldn't mind checking out my save file and taking a look at my station design to see if maybe my designing is just plain wrong?

It took me a looong time to dock this thing and I don't want to try again, in case the problem is in the design and not the docking itself.

[Superfluous J]

I can check it out, though you'll have to upload it somewhere. Or just the craft files if that's easier.

One possibility: You got the docking, were so tired from doing it that you just quit the game by hitting alt-F4, and now when you load the game back up it's going back to the last autosave which was a few minutes before the actual docking.

And note: All that time you spent was NOT wasted. You are training yourself to dock. What took 30 minutes will take you 15 next time. 10 the next, 5 the time after that, and soon you'll be docking in under a minute.

Edited January 22, 2015 by 5thHorseman

[Newt]

If it is your first serious docking attempt, do not feel bad when it fails. My first serious go at it resulted in an abort when I realized that I had changed the trajectory that both craft were falling out of orbit. The next time I did it I knew all the mistakes I had made, and it went really smoothly.

Usually, if they pull together there should not be an issue in construction, not that I have encountered, anyway. Did you transfer fuel or anything between the two craft?

[Steelsunoa]

It sounds like maybe you quit or went back to the space station before they actually docked. I had a similar problem with my Mun base, the ports sat there and rocked back and forth from the magnetic pull but never fully docked. This was caused by uneven ground levels on the Mun, but it sounds similar...the ports didn't click together yet.

Perhaps due to the crafts shifting in orbit you just moved in too slowly and never fully caught it. I danced around the docking port for what felt like hours my first time, probably from being too careful and being nervous that I would miss and have to start over. I used to use a final burst of monopropellant to lock it in even once I thought I had it, and then used the ] key to see if the game will allow me to switch over to the other craft. That or right click the docking port and see if it says "decouple node", but eventually you will notice the camera shift right away when successful.

I think you will be ok, I would suggest trying again...like 5thHorsemen said, it's great practice!

Edited January 22, 2015 by Steelsunoa

[PeskyPony]

Thanks for the quick replies. I know practice isn't wasted, it's just that I didn't want to keep practicing in case the problem wasn't my flying skills but my building skills. Anyways, I figured I could just as well load a screenshot of my test station. They are both identical, except that the one in the foreground doesn't have RCS (my bad) and the one in the background does. Both are controlled by an unmanned hex probe with a clampotron jr. at the end. I'm trying to connect both sections probe to probe.

5thHorseman, btw, I didn't rage quit or anything but right after I got the magnetic pull and the shaking stopped, I went to the KSC.

[PeskyPony]

I managed to dock them again, I aligned perfectly and approached at 0.1m/s but this time I didn't get a magnetic pull. they just kissed and lightly bounced off each other.

[Superfluous J]

Hm. There is nothing wrong from what I can see. Those are docking ports and they are aimed correctly. As Steelsunoa suggests, right click the (undocked) ports and see if they have an "undock" option. We've seen some rare nasty situations where the ports think they're docked when they aren't and vice versa.

[Forty21112]

If you happened to have SAS on, you may want to turn it off temporarily when you're in about 50-100m of the target.

[moronwrocket]

Try rotating with Q/E, I sometimes have bouncing docking ports that refuse to dock, and then after a slight rotation ca-chunk!

When the docking is successful, you should see the other ships engines show up in your stages view. Also, the camera view will shift to point to the new center of mass.

[PeskyPony]

You both may be right. I don't think I turned SAS off and I definitely didn't try rotating with Q/E (no idea that was possible after docking). But my second attempt was perfectly smooth and slow (0.1m/s for the last 30m) and there was just no magnetic pull from the docks. I *might* not have selected one of the docks (either as "target" or "control from here") but I still managed to have them both touch as in a normal docking.

I'm gonna try again with new stations. Or maybe try docking a new one into either of the old ones.

Is it possible to place the clampatrons the wrong way around when building?

Edited January 22, 2015 by PeskyPony

[Norpo]

Is it possible to place the clampatrons the wrong way around when building?

Yes, actually.

Bad:

Good:

[PeskyPony]

I did it! I had ran out of RCS fuel trying to dock the first time, so I decided to send a refuelling mission and use a different dock, just in case. I highlighted the trouble dock (the Clampotron Jr on the probe, right side of screenshot) so you guys can tell me if it's properly attached. The weird thing is that this docking was much bumpier than the first one, but the magnetic pull helped a lot. Last time I didn't get that, the docks just barely touched and then bounced off.

If I uncouple in order to rotate (and align the solar panels), is it easy to dock back on, or is the uncoupling force a little too great?

[Norpo]

The docking port on the right looks like it was attached wrong. That was probably the source of the problem

Also, if you undock, it shouldn't throw you back TOO far, if at all. In fact, to redock, you even have to move backwards and back in.

[PeskyPony]

Happened again, they bounced off each other with no magnetic pull occuring.

This screenshot is from two seconds after contact. The relative speed is 0.1m/s.

EDIT: Norpo, you sure? If that's the case, the problem was at KSC and easy to fix in the future. That's actually good news since I was thinking I was just garbage at docking. I'll try docking them through the lateral couplings. I want to get it done so I can raise their orbit to 300k and use it as a refuelling station.

- - - Updated - - -

Norpo (or anyone else) could you confirm if they're the wrong way around?:

This is how it ended up:

Edited January 23, 2015 by PeskyPony

[Norpo]

EDIT: Norpo, you sure? If that's the case, the problem was at KSC and easy to fix in the future. That's actually good news since I was thinking I was just garbage at docking. I'll try docking them through the lateral couplings. I want to get it done so I can raise their orbit to 300k and use it as a refuelling station.

Now that I think about it, it might actually be the right way, I don't normally use jr. docking ports, but for the other docking ports an easy way to tell if it's the correct way is if it has a small red hatch. However this doesn't work for jr docking ports, so look at this picture for reference:

The top side is the correct side. Make sure both are facing that way.

Generally using jr docking parts isn't used much, since docking ports are light, and jr docking ports are weak.

EDIT: Something I normally do while docking is if the magnetic forces pull me in too fast, I use RCS to push me backwards so I don't go in too fast.

Edited January 23, 2015 by Norpo

[PeskyPony]

They're both the same rocket, except for the inclusion of RCS on one of them. So both are facing the same way in relation to the rocket.

- - - Updated - - -

Aaaaand it happened again, but with the a different dock. The problem is definitely my docking. What I did was I undocked and rotated and then docked again, no problem. Then I did the exact same thing again but this time no pull. They touched perfectly aligned but just bounced off each other.

This is the aftermath, after trying to re-dock a couple of times. I was properly aligned when doing it, not like in the picture:

I know this is a stupid question, but is there some kind of cooldown on the magnet thing?

Also, will the magnet fail to activate if you come in too fast or not PERFECTLY aligned?

Edited January 23, 2015 by PeskyPony

[Northstar1989]

I know this is a stupid question, but is there some kind of cooldown on the magnet thing?

No cooldown. And I'm really not sure why your docking ports don't seem to be working. I've never had trouble like that before (that I can remember). They seem to be constructed properly, at least... I might try rebuilding the craft- maybe the craft file somehow got a glitch in it...

Regards,

Northstar

[KerBlam]

Yeah.. I've done this before. Got a mission all the way up to my 300km refueeling station, and spent 20 minutes thinking I was going insane because it just wouldn't dock, only to discover that one of my clampotron sr' was mounted back to front. They can be a bit ambiguous if you aren't paying 100% attention. The juniors not so much, it looks like yours are on the right way.

Edited January 23, 2015 by KerBlam

[PeskyPony]

Perhaps there's a minimum distance you need to back up until the magnet resets? I tried a few more times and didn't get the magnet when the docks touched, until I got about 17m away and then I was able to dock:

[Superfluous J]

Once the magnets "turn on" they should stay on until you're docked or get too far away. If you get too far away, they should turn back on when you get close enough again.

If you actually get docked, and then undock, they will stay off until you get far enough away (to keep them from just snapping back in place every time). But if you DO get far enough away (and it's on the realm of a few meters) and come back, they should again dock.

[PeskyPony]

So there is a minimum distance. Good to know.

But I really don't know what's happened with my Clampotron Jrs, they just won't pull me in. I won't be using those again.

Thanks for all the help everyone.

[tomf]

There is a bug that might also be affecting your docking ports where they think they are already docked to something. Thios thread has the details of how might be able to fix that issue.

http://forum.kerbalspaceprogram.com/threads/78863-FIX-Dock-Undocking-Bug-in-0-23-5

[PeskyPony]

Thanks for the link tomf. I tried that method and found the glitched dock in the quicksave file, but after changing it, saving the file and reloading, the problem persisted. I'm convinced it's some sort of glitch, cos I've docked many times since, with no problem, and I don't see any issue with the way I've tried to dock these two:

That's just a couple of seconds after contact, that's why they're not quite aligned anymore, but they were and you can see the relative speed is minimal. In any case, I'm giving up. I'll just leave them in orbit connected with their lateral docks. And I'll never use the Clampotron Jr. again!

Thanks everyone who tried to help.