Docking

[kerpalmasheen]

I see people docking ships in ksp all the time, when i try i can never line it up right, how do i do it?

[Gargamel]

Moved to GamePlay questions. 

This was right in the forum you posted the question to:

 

[king of nowhere]

In addition to the above guide, I'll say that part 5 can easily be done without RCS. You just have to be extra careful to lining everything up first, so that the small lateral corrections won't be needed.

For that, I recommend raising your speed relative to the target at 0.5 m/s, because the more time pass, the more your orbit drifts (you will move away from your target because you are in different orbits), which veers you offway, so you don't want to be too slow. without rcs, you can't correct for those little drifting. though you can correct for it in the same was you do in step 2, if you are stll far enough from your target that you have the time to turn around the ship, use the engines for some corrections, and turn the ship around again.

the most important thing about docking without rcs is that you can fail, and if it happens it's not a problem. Now you are close to your target, moving slowly, so you basically go back to step 3 and try again. it takes roughly 1 m/s, so you're not losing much.

another hint: sometimes your trajectory is off-course because of residual speed. when you set your speed as 0.0, it can still be up to 0.04 m/s in any direction, the navball approximates. and those 4 cm/s are few, but when you are moving at 0.3 m/s they actually matter. For more precision, if you have a crew, you can use iva view; any crew pod will have a navball, and that navball has 2 decimal digits on its speed. so you can brake down to 0.00 m/s. It's more precise, which matters if you don't have an rcs to fine-tune stuff.

 

rcs is generally light and makes your life easier, so it's a good idea to have some; but if you're desperate for mass reduction, you can skip it.

Personally, I generally play with kerbalism, that adds random parts malfunctioning, and an rcs is just another set of potential malfunctions to worry about. my kerbalism ships are already overnegineered with multiple redundant systems, I skip the rcs just for the sake of simplicity.