KSP docking tutorial advice

[sturmovik]

I've been playing the game for a few weeks and thought I'd branch into orbital docking. Having considerable trouble with the tutorial, though.

I do fine until I'm within 100 meters or so of the target, that's all regular flight. However, I can't for the life of me control my ship's orientation close to the target. I'm making small and deliberate RCS burns, nothing that should be difficult to control, but no matter what I do I just seem to end up orbiting around the target ship at 50-200 meters. I also can't even manage to cancel my velocity and come to a stop relative to the target ( meaning I can go from closing on the target to opening from it without my relative speed dropping below, say 3.5 mps).

Is real-life docking easier than the tutorial, because I can switch into the target ship and lock it to the docking ship?

I'm fully aware that this is about the hardest thing in the game, and I'm just looking for answers/advice to what I expect is, in fact, my own errors causing this. 

Thank you all!

[vossiewulf]

Copied from another post of mine a couple days ago:

1. When you arrive a few hundred meters away, use regular staging mode controls to point yourself at a spot that's say 50m out on a line from the docking port you intend to dock with.

2. Switch to docking mode and set it to Linear mode. Accelerate toward the starting spot you're aiming for. Do NOT give yourself any acceleration other than purely in the direction you're pointing.

3. When you get close to your intended starting point, accelerate in the reverse/retrograde direction and bring yourself to 0.0m/s relative velocity.

4. Switch to docking/rotational mode, and use RCS to line your craft up as close as possible to the axis of the docking port.

5. Right click on your docking port and select "control from here".

6. Pick which direction is "up", and rotate your craft to be at a zero degree alignment to that up direction, which should be aligned with your intended docking port as well. That way, from this point the up and down RCScontrols will move you up and down relative to the docking port, and side to side works the same. Makes it very easy to know which direction key you need to hit at any given time.

7. Right click on the target docking port and select "Set as Target".

8. If you lined yourself up correctly, on the navball your nose should be pointed very close to the target direction as shown on the navball.

9. From here, it doesn't matter what camera view you're using, as you don't really need to see. All you need to know is the relative speed you're moving, that you're pointed at the docking target, and the distance to the docking port.

10. Use the LINEAR up/down left/right RCS controls to get your nose pointed right at the docking port target.

11. Once aligned, accelerate toward the docking port. Doesn't matter how fast you go, just that you're only moving .2m/s -.3m/s when you get there.

12. Once you get close to the docking port, use the linear RCS controls to once again bring yourself to a dead stop. Use the same steps described above to refine your axis alignment and rotation until it's really really close to the same axis as the docking port. This will usually make your nose move away from the docking port target again, so once again use the linear RCS controls to move you back until your nose is pointed dead at the target.

13. Now accelerate toward the docking port again. Continue to use the linear RCS controls to keep your nose pointed at the center of the docking port. You can switch to fine control mode (capslock on the PC) which can make small adjustments easier.

14. Hit the docking port at .2m/s, if you're lined up right it will instantly dock.

Below, docking a 2000 ton station resource arm and a 77-kerbal orbital bus, complete manual control, no docking mods used.

[bewing]

4 hours ago, sturmovik said:

I do fine until I'm within 100 meters or so of the target, that's all regular flight. However, I can't for the life of me control my ship's orientation close to the target. I'm making small and deliberate RCS burns, nothing that should be difficult to control, but no matter what I do I just seem to end up orbiting around the target ship at 50-200 meters. I also can't even manage to cancel my velocity and come to a stop relative to the target ( meaning I can go from closing on the target to opening from it without my relative speed dropping below, say 3.5 mps).

 

That orbiting dance around your target is something every single one of us has ended up doing, at least once. The problem is that you have residual velocity in the wrong direction.

The key to rendezvous and docking is to learn how to stop. To come to a stop, you need to put your navball in Target mode. Once you've done that, you need to lock your craft Retrograde with SAS. If you burn your main engines gently retrograde while you are in Target mode, you are reducing your relative velocity. When it hits 0.0m/s, you are dead stopped with respect to the other craft. At that point, you can turn around so that you are pointing straight at the other craft, and give your ship a little gas -- 2 m/s is good. That will get you much closer, but you will still miss. Then you come to a stop again. And repeat.

You can also stop by pointing prograde with SAS, and then using your reverse RCS thrusters (your N key).

 

[StrandedonEarth]

Lots of good advice here, so I'll just add this:

(navball docking alignment indicator is the only docking aid I use. As a substitute you can rt-click each docking port and "control from here," then use SAS  to set one to point to normal  and the other to anti-normal. That will make the ports point squarely at face perfectly parallel to each other (but not necessarily pointing at each other), without drifting as you orbit.)

Edited September 19, 2019 by StrandedonEarth
Corrected wording

[Pecan]

On 9/13/2019 at 2:51 AM, StrandedonEarth said:

(navball docking alignment indicator is the only docking aid I use.

+1 wonderfully unobtrusive but gives you all the information you need except separation distance.

[Dan Kerman]

This was the guide that got me thru rendezvous and docking. Learning the NavBall is key... get that down and docking becomes easy.

Illustarted Guide to Docking

[k00b]

On 9/12/2019 at 11:47 PM, vossiewulf said:

7. Right click on the target docking port and select "Set as Target".

/\ this.

then just make sure the target marker is in the middle of prograde and your speed is very low (via NAV target mode - retrograde burning) and then you can't go wrong.

(said tens of hours zooming past crafts and f5 / f9 comboing later...)