Having trouble with the docking tutorial?

[Bubba Fett]

I've been playimg KSP for a long time and while I had trouble with it at first, I now find rendezvous and docking to be quite easy.
Since I knew how to do it long before the tutorials existed, I never had a reason to run them until a couple of days ago when i decided to have a look at the docking tutorial.

It's actally a fairly difficult example of a rendezvous since you're trying to match orbits with a ship that's in an inclined elliptical orbit. Even though I've done this many hundreds of times, I found it a bit challenging to do it exactly the way they tell me to so I figured I'd offer some advice to people that are having trouble with it.

It's very important that you exactly match your inclination. If you don't, your encounter won't be close enough to trigger the next step of the tutorial. If your first inclination burn only gets you to .2 degrees, do a second or even a third burn till you get to 0.0 or at the absolute worst, .1 degrees. Each of these burns should take place right at the AN/DN markers.
If you can't get your inclination to match exactly, try to time your transfer burn so that your intercept happens right at the AN/DN markers. That's the point where your 2 orbital planes cross and it's easier to get a close intercept.

When you set up your transfer burn, make your AP high enough so that your orbit crosses the target orbit and you get 2 intercepts. The orange marker is the first intercept and the purple marker is the second one. You'll try and use the first one. If your intercept isn't close enough after dragging around your maneuver node and playing with the prograde control, try using the radial control on your maneuver node. (the blue handle)
This will give you finer control over your intercept position than dragging the position of the maneuver node or adjusting the prograde control. Keep in mind that you can get more precise control by putting your mouse pointer over the control handle and rolling the mouse wheel rather than pushing or pulling the handle.
When you do your transfer burn, make a note of how long it takes to complete the burn.

When you're approaching your intercept the tutorial recommends dropping your relative velocity to 45m/s at about 15km and doing your approach at the lower speed.
While this works, in most missions you'd be better off to set a maneuver node at the intercept point to use as a marker. You don't need to try and match orbits with it, just use it as a marker for the time when you're at your closest approach to your target. Then, you burn all the way down to 0m/s at your closest approach. This is why you made a note of how long your transfer burn took. Assume this will take about the same ammount of time and start your burn that much time before your closest approach.
This will place you much closer to your target for your final approach. This will work for the tutorial.

The tutorial also recommends dropping your velocity to 0 then lining up with your target and using RCS to approach at up to 10m/s. Monopropellant is heavy and RCS thrusters have lower ISP than most engines so this is wasteful. You're better off to use your main engine till you get very close to your target and are moving very slow.
When the navball is in target mode, your prograde and retrograde markers show your relative velocity vector. If either is directly on top of your target marker, you're heading directly toward it.
If your prograde marker is visible and you apply thrust, it will pull the marker toward the center of the navball and increase your relative velocity. You can use this to pull the marker over your target icon.
If your retrograde marker is visible and you apply thrust, it will push the marker away from the center of the navball and decrease your relative velocity. You casn use this to push the marker toward your target icon.
Once you get to about 1km distance, you should be down to about 5m/s relative velocity and facing your target with your prograde marker over the target icon. I'd advise using docking mode since it allows you to seperate your rotation and translation. Turn off your RCS thrusters for rotation mode so they don't affect yoru velocity vector.
In docking mode, W/S will control your approach speed while A/D/shift/CTRL will push around your prograde marker. (assuming you're in linear mode)

When you build a ship for a mission that requires docking, right click on your RCS thrusters and turn off rotation. This will cause them to only fire for translation and your reaction wheels/pod torque will handle rotation.

When you approach you should put your camera in the locked mode. This will align the spine of your ship with the top of your screen and make the RCS system work in a more intuitive manner. When you're building a ship for a docking mission, you can also put an object on the spine of the ship as a marker so you can align it with the top of your screen by rolling the ship. This way you can use the free camera but still have your RCS system work in a more intuitive manner. This object can be a light, antenna, or anything that you can recoginze from the rear of the ship. On the tutorial ship, the single pipe on the poodle engine points to the spine of the ship. When building ships for docking, don't forget lights. Docking is difficult enough when you can see what you're doing. Trying to do it on the dark side of a planet when you forgot to add lights adds a whole new level to the challenge.

Set your docking point as your control point and your target docking port as your target as told to by the tutorial. If you're docking with something your size or smaller like in the tutorial and your alignment is a bit off, touching the ports may give you a magnetic connection. Slowly thrust backwards with your RCS and it will probably pull the other ship with you and drag you into alignment like pulling a trailer.
If you're docking with something much larger like a station and you get a magnetic connection but your angle is off, use your RCS to push you sideways and your ship should pivot into position.
Of course, getting better alignment before you get the magnetic connection is the real solution. Also, once you get your magnetic connection, turn off your SAS as it may keep you from pulling into the proper alignment. Multiple reaction wheels on a station operating at the same time can also cause a station to shake itself apart.

Anyways, hopefully these tips will help you get through the docking tutorial, build stations, refuel in orbit and all the other fun stuff you can do once you learn this.

[maj.solo]

Can't be that difficult .... running to test .... no problem.

Only tiny problem was satisfying the turtorial script so the tutorial could move on.
It said ok "we wait till you are 15km from target and then we fine tune the approach". It didn't understand I was close until I was 1km from target.

Also docking without docking port alignment indicator is quite hard when you have 3 axis to think about + the rotation of your ship so you know what W A S D will do.

Docking port alignment indicator makes it 10 times as easy and once you figure that one out and trust it blindly you can dock 200 times quicker in the dark without turning on any head lights. You simply need not see what you are doing. Pure instrument flying is enough.

[Bubba Fett]

I agree that docking is quite easy once you know how to do it. However I've seen a few messages recently from people that were having trouble with the tutorial probably because they're not close enough to trigger the next step.
For instance, .1 degree of orbital inclination probably won't be a problem for a rescue contract in LKO, but for an orbit at 1000km it can make your orbits diverge enough that your intercept distance will be above the 5km it takes to trigger the next step.
In your example, at 15km, the tutorial expects you to drop your relative velocity to 45m/s, then at 1km stop and do your final approach using RCS.

I'm also a big fan of Docking Port Alignment Indicator, but many players don't use mods and even with it lights are a good idea to keep from breaking off solar panels and other stuff that your instruments don't show you.
Also, docking without DPAI isn't all that hard and is something you often need to do while you're waiting for it to get upgraded after a new version of KSP.
Keep in mind that eventually modders move on from KSP and stop updating their mods so it's not a bad idea to learn how to fly without assists.

[Onafa]

Beautiful post. I just learned how to do this a few days ago and this would've helped so much.

[maj.solo]

No it is just that docking port alignment indicator allowes me to be very agressive when I dock and saves me A LOT of time. I dock manually also using claw and whatever only I have to check, move camera check, move camera, check, looking at the ship which RCS thrusters lit up when I press W A S D etc, so when you go from using docking port alignment indicator you then think .... oh this is the neanderthal way ....

Also docking port alignment indicator does not have any save state and does not use the save files or anything and so is less likely to be broken after a update then all the other mods.

[TheRedMafiaPanda]

Ngl iv been trying to play this tutorial to get a handle on docking and the closest iv ever gotten was 700 meters

[✪KSPBugger✪]

Originally posted by TheRedMafiaPanda:

Ngl iv been trying to play this tutorial to get a handle on docking and the closest iv ever gotten was 700 meters

Take it slow. Once youre within around 2 km, slow down to match the targets speed. Then aim at the target and give it a small nudge on the throttle(i recommend getting to 5 m/s). Then timewarp until you are 100m away from your target. Find the nearest docking port compatible with the one on your ship, and dock!(RCS is recommended).

[DEAD MEAT]

Old post, if they still ain't got it down solid from 2016, they never will.