how to dock?

[Kaaybon]

hello, ive been playing KSP for a little over a month now, and i still am not able to manage to successively complete a docking. now this would not bother me except its making me not want to play this game anymore. if i cant dock, i realy cant go to other planets or moons. now ive watched the Scott manly videos, and other videos on how to dock, and i still cant figure it out. could someone please help?

[creator1629]

what specific problem are you having, is it getting a rendezvous between the 2 ships? or is it the docking procedure itself? how close are you able to get before you have problems, within 1000m? 100m? or is it a problem that happens within the last few meters?

[sumghai]

The MechJeb mod has the Rendezvous Guidance and Docking Autopilot features that can (mostly) automate the docking process.

[Kaaybon]

i can get to about 1000m, then everything goes to hell,but even getting to that is difficult for me. and the one time i tried docking between two ships already next to each other (apollo style craft) it still went horribly

[Kerbol Prime]

You have to take it nice and slow. Once your within a few kilometers you want to cut your relative velocity to the target. Once your target velocity is close to zero, find the target marker. If you have ports in wierd places you should do control from here on the port. So point torwards the pink target marker and use RCS with translation controls. H/N is forward/backwards, IKJL is up/down/left/right. So use H to move closer. When close enough set your target docking port as the target and get closer. Once within a few meters try to align yourself (it actually won't matter that much, so don't sweat if you don't get it perfect) then use IKJL to make sure your prograde marker is over your target marker. Use IKLJ to keep the prograde centered while you move forward with H and slow down with N. Once your sure you will hit the docking port at 0.2 or 0.3 meters/sec turn of SAS so the magnetism can pull the ports together. I learned how to dock from a tutorial video once that was not by a pro like Scott. Yes he is great but sometimes you need someone who has recently learned how to dock so you can learn it more easily. Sadly the video was lost in the forum crash.

[OUScooby]

I've been having a lot of trouble with docking as well and MechJeb seems to get it wrong if I have multiple docking ports on my ship, it always tries to point it in the wrong direction. When I try and do it my self I end up with a craft spinning widely out of control. I'm beginning to wonder if the placement of my RCS thruster blocks is the reason I can't keep my ships under control. I there a generally accepted right and wrong way to incorporate the thruster block into your rocket design?

[creator1629]

ok so basically when you are attempting to dock there is a part where you are using your main engines to approach your target and when you get close enough you stop using your main engines and use primarily your rcs to orient as well as move your ship. at 1000 meters you should still be using your main engine, by the time you get to within 100 meters or so that is when you start using rcs. note that this value is just an approximation an can be changed depending on the circumstances. at 1000 meters you will want to burn towards your target as indicated by the marker on your navball, note the relative speed of your craft to the target which should be displayed above your navball. this speed is what you have to control, for example if your target is 10,000 m away and you are moving at 100 m/s toward your target, thats fine, but if you are only 1000 m away then you would close that gap in 10 seconds which is clearly way too fast. so here is the order, burn towards the target, close the gap a bit, then turn your ship retrograde and burn again to kill the speed, the closer you can get to 0 m/s relative velocity the better. then point at the target and burn once again noting not to let it get too fast, then burn retrograde again to kill the speed. so its burn towards then burn away (rinse and repeat, but each time the speed of approach gets slower as you get closer) until finally you get within 100 m or so. at this point you will want to switch to pure rcs. remember to get familiar with the controls, and to make it easier, push the "v" button till you get the chase camera. note that the WASD as well as the Q and E keys will control your pitch, yaw, and roll, while the translational movements are controlled with IJKL (as in shifting your ship up down left and right without changing orientation). the H key moves you forward while the N key moves you back, which makes it easier to slow down now since you dont have to turn your whole ship around to slow down, just hold the N key. now with these controls you inch your way towards your target. remember to always try to kill your relative velocity so you dont fly off too far, for example for every shift to the right, tap left, for every shift up, tap down. its all about gradual controlled movements, and rotate the camera often to confirm your orientation especially when you get close. you can also use the "[" and "]" keys to switch to your target vessel and turn it so its docking port faces your other ship to make the approach easier.

[Kaaybon]

ok, thanks, the whole, hn ijkl was never really explained, this might help me out alot. it still gonna take me some time before im gonna be able to dock, but this should help alot.

[OUScooby]

My problem is that my craft will pitch and roll and spin when using the IJKL & HN keys

[Vanamonde]

My problem is that my craft will pitch and roll and spin when using the IJKL & HN keys

That means your thrusters are not placed symmetrically around the center of mass. In the VAB, temporarily remove the lower stages and turn on the COM marker so that you can adjust the thruster placement around it.

[CalculusWarrior]

My problem is that my craft will pitch and roll and spin when using the IJKL & HN keys

In your case, the RCS thrusters are not properly aligned with the Centre of Mass, and hence creating a moment about it. You can fix this by showing the CoM in the VAB and properly aligning a single set of RCS thrusters on top of it, or for larger designs, place two sets of thrusters at equal distances from the Centre of Mass.

[OUScooby]

What if I have fuel three large fuel tanks mounted radially around a large size center fuel tank, do I put RCS thrusters on the radial tanks, or just the center one? And how many thrusters is enough? I usually set the symmetry tool to three, I figure, three axis of movement three thrusters, or is more better?

[Ditchbuster]

I think it is generally best to put 4. To keep the craft from rotating when you translate it needs to fire 2 (if around the center of mass) opposite of each other otherwise it needs 2 partials to cancel one at full.

and if you put them aligned with your command pod it will work better as they will be more or less linked to the keys when doing translation movements

Edit: i am assuming the quad block thrusters

Edited May 30, 2013 by Ditchbuster
assuming quad block

[Vanamonde]

Yes, three-fold symmetry means that along one axis there is twice as much mass on one side as on the other side of that axis, and it seems to make the other axis misbehave as well. It's better to mount things in pairs or put the odd piece in the center. As for the thrusters, if they are not also mounted in pairs at right angles to each other, some will be trying to help by firing at goofy angles, causing all kinds of mayhem.