Im trying to dock a spaceship and im so close. Now what?

[FinnBot5000]

I have been trying to dock a ship with a station, and I am really close. I have been following this and this tutorial, and I have had some issues. I have gotten my ships within about 100m, then they seem to speed up (relative) before passing each other within 50 meters and zooming away in the opposite direction. I then point towards target and burn so that my ships start moving towards each other again. I am 99% sure this is the wrong way to do it and I need some help. After doing this a few times (and a few crashes - luckily I quicksaved). I just reset my orbits so that they intersect within about 200 meters of each other in about 6 mins (paused rn). I really need some guidance about how to do that last 200 meters while keeping my speed under 2 m/s.

https://imgur.com/a/BBvWsYq

[HebaruSan]

Do your vessels have RCS nozzles and monopropellant?

[FinnBot5000]

1 minute ago, HebaruSan said:

Do your vessels have RCS nozzles and monopropellant?

yes. The station has a fairbit of propellant, but no main boosters, the ship has just the capsule propellant, but it also has its main booster

[AHHans]

I think you are missing this tutorial:

 

[FinnBot5000]

1 minute ago, AHHans said:

I think you are missing this tutorial:

 

ok thank you I will look at it

[HebaruSan]

1 minute ago, FinnBot5000 said:

yes. The station has a fairbit of propellant, but no main boosters, the ship has just the capsule propellant, but it also has its main booster

Good. RCS and monopropellant are your tools for docking, and the navball is your instrument. With RCS enabled, you'll want to use the IJKL keys to align your target-relative velocity vector  with the target vector . In the screenshot you shared, I think this would be accomplished with some slight K and a bit more of J (but I could be misremembering the mappings. so experiment with those keys to get a sense of how they work). If you get those two indicators aligned and keep them that way, you'll head directly towards the other vessel. Meanwhile, control your speed by pressing N to slow down and H to speed up.

[Starwaster]

To add to what has been said already, also make sure your RCS placement is balanced. When doing rotational movements, your ship should only be changing angular momentum, not introducing translations. The reverse is also true.

Also only keep your relative velocities between the station and your ship small.  Go slowly

[king of nowhere]

RCS make things easier, but they are in no way needed for docking,

23 hours ago, HebaruSan said:

you'll want to align your target-relative velocity vector  with the target vector .

that is indeed true, but you can do it with the main engine easily, you just need to use it carefully. if you don't have a fine hand on the throttles, you can manually limit the engine power.

Two main ways:

if your prograde is close to target (as is the case in the picture) you can point your ship on the opposite side of the target marker and burn; this will accelerate your ship, and it will move the prograde towards your target.

This won't immediately give you a docking, because there's orbital drifting. but it will get you closer. repeat the process when you're closer, and you'll get even closer. eventually, you'll get so close that orbital drifting will be negligible, and you'll dock.

by the way, when you're close enough to target individual parts, you should set the individual docking port you want as target.

On the other hand, if you burn close to retrograde, you can push your retrograde marker towards the target by burning on the opposite side, and it will match your speed to the target, while getting closer.

in this image i'm doing exactly that, in what's perhaps the most complex docking i ever achieved. one ship was coming from jool, in an escape trajectory, it was getting a gravity assist. the other ship was coming from eeloo. But see how my ship is pointing? the retrograde marker is near the anti-target marker, meaning i am moving towards my target - mostly. by burning a little away from it, i am pushing the retrograde direction towards the anti-target. I kept burning in that direction, and i gradually found myself moving towards my target

like this. this is an indication that you're going straight for it. though, since there are still 25 km, there will be some necessary course corrections to perform. but you always do them with the navball.

and if you point retrograde to your target, you can slow down your speed relative to it, until you stop completely. You can also do if if you lost your orientation, then you stop completely, then you point towards the target and you accelerate again.

 

once you are within a few km from your target, your prograde marker is pointing close enough to the target marker , only use the navball to push the two to overlap. you don't need anything else.

[FinnBot5000]

Thank you everyone for your advice, I will try it and see what i can do!