Docking - why won't my ships join?

[BattleMetalChris]

I'm having my first go at docking. I don't have any problems with intercepting, approaching the target and manoevering, but they won't dock when I get there!

I have a Clamp-o-tron Docking port on the target vessel and a Clamp-o-tron Jr. on the nose of the docking vessel. I line them up using RCS - the approach speed is less than 0.1m/s and both are almost exactly aligned. From what I've read, once they're close enough they should magnetically clamp together, but this never happens. I just barely nose forward and it just gently nudges up against the other ship and pushes it away.

Have I got the wrong docking ports on? Do I have to activate the docking ports somehow? I have a Kerbal in both vessels, able to control them.

Here's a picture:

Edited April 28, 2014 by BattleMetalChris

[Pecan]

...I have a Clamp-o-tron Docking port on the target vessel and a Clamp-o-tron Jr.

Is as far as I read - docking ports have to be the same size to dock :-)

ETA: Having read the rest of your post you seem to be doing very well otherwise - I suppose you were beating your head against it getting better and better but still not getting a result :-( Theory is that you click target docking port and 'set as target' and click your ship's port and 'control from here' but if you're doing all the rest without that then it doesn't matter. Stick compatible ports on the ships and you'll have no problems as far as I can see. Enjoy.

Edited April 27, 2014 by Pecan

[FenrirWolf]

As far as I'm aware, you need matching-sized docking ports for it to work. So a Jr could only attach to another Jr, for instance.

[BattleMetalChris]

lol.. ok, thanks

..looks like a new ship and a rescue mission is in order then.

[Supernovy]

You could try sending up a docking adapter with a junior port on one side and a standard port on the other.

[RexKramer]

Further words of encouragement: If you got that close, your docking skills are spot on! As already posted, the docking collars have to be the same size, which looks like the only reason your docking didn't work.

Trust me, you are in good company. Most of us have had elaborate missions go wrong because of a minor error. Even NASA has had similar issues. Might be frustrating now, but in a few days you will be able to laugh at how a minor part discrepancy made your docking impossible. Again, getting two vessels that close, and aligned properly is not easy. You appear to have mastered the process of getting two vessels together and lined up.

[Claw]

If you want to get fancy, you can edit the save file and manually swap out the regular docking port for a jr. Takes one line of code change if you're feeling brave.

[BattleMetalChris]

If you want to get fancy, you can edit the save file and manually swap out the regular docking port for a jr. Takes one line of code change if you're feeling brave.

Nah, I'd consider that 'cheating' too much (for now, at least), especially when the lives of four Kerbals are at stake..

I like the idea of sending up a docking adapter, I think I'll try that.

[cantab]

If you do send an adapter, I advise either:

Have the transport place it on the target ship, then back off and let the docking ship in. (Or place it on the docking ship first, but that may affect RCS balance for the docking ship)

Or:

Have the adapter be fully autonomous with its own probe core, RCS fuel and thrusters, and solar panels.

What you want to avoid is attempting to dock with something that's floating in space uncontrolled. That's possible but a major pain in the backside, especially if the thing you're trying to dock to is tumbling and you consider using timewarp to stop rotation as cheating. I learnt it the hard way when I brought some drop tanks to attach to a ship, and the tanks were just a fuel tank and a single docking port.

[Mitchz95]

... using timewarp to stop rotation as cheating.

I thought that didn't work any more? Since 0.23.5 my ships always start shaking again as soon as I stop time-warping.

To the OP: Once you have the docking port thing sorted out, remember to shut down SAS before docking. Sometimes it prevents the connection from being made.

[Pecan]

Have the adapter be fully autonomous with its own probe core, RCS fuel and thrusters, and solar panels.

Good advice. My adapters have core and solar panels just so I can engage SAS to stop them tumbling. They are still light enough that it doesn't interfere with the actual docking.

[FREEFALL1984]

That image is the epiphany of the term so close yet so far.

[Starwhip]

That image is the epiphany of the term so close yet so far.

Agreed.

I did this once. The results were catastrophic: generally involved bits of solar panel reentering Kerbin's atmosphere when I became "angry".