Docking training is extremely difficult to complete!!!

[mkm8595]

Hey,

I'm new to Kerbal Space Program. I'm playing the docking training level. But it is extremely difficult even if I follow every single thing told. I can't even get near the stranded vehicle. Please help me complete the training.

Thanks.

[Blu_C]

This is something that is best left to a video. Scott Manley has one

that, although for an older version of the game should still teach you what you need to know.

If you told exactly what you are having trouble doing I could give more specific advice. Are you having trouble with the docking itself? The rendezvous? Something else completely?

[cephalo]

I just finished it myself. The problem is that the quest has trouble keeping up with what is actually happening and when the 'next' button should light up. What you can do though, is delete any old maneuver nodes and create new ones, that seems to get things going again. It's a very important training exercise, it's a shame that it is so fiddly like that.

[Cardano]

the Docking itself is made *massively* easier with an add on like :

Docking Port Alignment Indicator

the rendezvous is just a matter of setting up a close-but-not-same orbit and working the 'point of closest intercept' unless you really want to get help there and then

MechJeb is your savior.

going vanilla - i'd work with what cephalo said. if the game seems to be stuck - deleting the maneuver node and re-making it seems to make it happier.

Cheers - Cardano

[egoego]

I had problems with this tutorial too. But not because I was unable to dock, (thanks to Scott I know how that works) but because the Next button gets stuck really really easy.

[Pecan]

And just because no-one has said it yet ... docking isn't easy! It becomes easy (or at least easier) with practice but it took NASA a long time to work it out too :-)

Stick with it.

[Starwhip]

And just because no-one has said it yet ... docking isn't easy! It becomes easy (or at least easier) with practice but it took NASA a long time to work it out too :-)

Stick with it.

This. It is really hard. (Edit: the first time)

I made a docking tutorial a while ago, should still be in my signature.

[Alshain]

This is something that is best left to a video. Scott Manley has one

that, although for an older version of the game should still teach you what you need to know.

If you told exactly what you are having trouble doing I could give more specific advice. Are you having trouble with the docking itself? The rendezvous? Something else completely?

I can not emphasize NOT watching that video enough. Scott does some great videos but that one is not one of them. He even says it in the video at 8:20, "it's not the best way but the easiest way". Quite frankly, it's not any easier or harder... just wasteful, he wastes so much fuel bring his relative speed to 0 several times which is not necessary. You can adjust your heading without killing all of your relative speed simply by burning ahead of the prograde marker to pull it toward you (and the pink marker) or burning behind the retrograde to push it away from you (and the pink marker) which one you choose depends on how fast you are approaching your target and if you want that to be faster or slower. You don't have to bring your craft to a 100% stop every time.

I wish people would stop sharing that video, it's an awful tutorial. You need to learn it correctly the first time, not learn a bad way and then have to learn a good way again later.

Edited May 12, 2015 by Alshain

[GoSlash27]

https://www.youtube.com/watch?v=sQGc7qSICOQ

Pick up the tips from this video at 3:00 in.

This isn't exactly the way I do it, but the technique of "pushing the marble" and keeping the closure rate at a fixed ratio of distance to target is how I achieve rendezvous.

Generally, I break it up into 4 stages: orbit, intercept, rendezvous, and docking.
-Orbit is simply establishing an LKO orbit.
-Intercept is using the maneuver node to generate a burn that places me in close proximity to the target. This phase also includes any inclination correction.
-Rendezvous is the process described here, where I transform my closure to the target into an exact match of it's orbit at 30m distance from it.
-Docking is where I align my port with the station's port and gently close to a hard lock.

The tutorial is difficult because the process is difficult. Once you get the hang of it, the whole system is yours.

Good luck!
-Slashy

[X5-599]

In my opinion the Docking training is difficult not only because the process is hard but also because the steps leave out important things (at least that's what I gather). Here's where I get stuck: I get the correct inclination and set up a rendevouz at about 3km separation. Then, if I remember correctly, you are told to burn retrograde until your speed drops below 50 m/s. Until this point everything works but then you are told to use your RCS thrusters to make your speed drop to zero. But it says to start this when separated from the target at about 10km. Problem is that once your speed drops below 50 m/s your orbits don't intersect anymore. Meaning you don't get any closer than you currently are. In my case we are always at least 43 km apart. So either the instructions are wrong or there are important steps missing. I started everything EXACTLY when and how I was told by the training text.

[Reactordrone]

.... Until this point everything works but then you are told to use your RCS thrusters to make your speed drop to zero. But it says to start this when separated from the target at about 10km. Problem is that once your speed drops below 50 m/s your orbits don't intersect anymore. Meaning you don't get any closer than you currently are. In my case we are always at least 43 km apart. So either the instructions are wrong or there are important steps missing. I started everything EXACTLY when and how I was told by the training text.

The training scenario uses the stop/start method. Once your speed is zero relative to the target you point at it and increase speed, if you drift away you zero out again and then point at the target and speed up again. It does get you there but it's not very efficient and the tutorial isn't terribly clear.

[WeirdCulture]

And just because no-one has said it yet ... docking isn't easy! It becomes easy (or at least easier) with practice but it took NASA a long time to work it out too :-)

Stick with it.

Buzz Aldrin wrote his thesis for Doctorate of Science in Astronautics about docking in space.

[Sonny_Jim]

I think the main problem is that it has bugs, it wouldn't let me click the next button until I had created a new blank manuever node, even though I had already created one and burned until my closest approach was under 1km.

The other problem is that in my opinion, it asks you to match velocities way to early, rather than 60km distance you should start matching at something like <10km.

[Jaeleth]

My first docking was an harrowing experience... I didn't even knew how to properly use the navball, let alone the retrograde / prograde or other indicators, I ended up making the entire approach visually, using the map ( didn't have patched conics by then, nor knew how to properly set something as "target" ). I had no idea what " burn retrograde to target" meant so I ended up pointing nose towards target, visually, not on navball (lol) and flew tighter and tighter spirals around it, all the time trying to figure how, in 3D, was I pointing myself towards target movement.

Finally I got myself within 50 meters of target and more or less at same speed... My hands were sweating, at least 1 hour had passed and I still had to complete docking... Real nigthmare lol.

Just be persistent, watch the videos, and familiarize yourself with the keyboard. A tip: rotate the ship in a way that, from your point of view, when you press "left" the ship goes left and when you press "up" the ship goes up, move very slowly and make sure you rotate the view frequently to have a clear 3D picture of what's happening, preferably watch it frequently from directly above ( or below) and directly left (or right).

[mrklaw]

I find the intercepts difficult to use combined with the tricky camera in the orbital map view. You either zoom out so you can see everything but then you can hardly click on the right thing, or you zoom in to get a better view and then can't see how things are around the orbit.

I need to practice more - I did the tutorial one and one rescue mission around Kerbin but still need to figure stuff out. Especially how to launch and not be too far away from intercept - if your orbits are similar it takes ages at 4x time warp just to get within a decent range to intercept.

[Mahnarch]

My first docking took forever.

I finally had to download Mechjeb and watch it do it once (watching others' videos never helped - since I couldn't rotate stuff, myself).

When I saw what it did there was the longest, "OOOOOOOHHHHHhhhhhhh!" from somewhere in the room.

[ajburges]

Ya, docking is hard the first time. Most people here have developed intuition about docking (and orbital mechanics) that allows them to customize their approach to taste.

This is a simple approach.

First stage (after orbit in same direction) is intercept. It sounds like you have this figured out but I'll include it regardless. Match inclination with target (you can do this later, but it makes node placement harder). The larger orbit has less rotational velocity. Preferably the larger orbit is "ahead" of the lower, but the cyclical nature of orbits will get you a rendezvous regardless. What you don't want is two intercepts. There is little difference in period in that case. Regardless your goal is to plan and execute a node to create an intercept point. The less distance at intercept, the less fuel you need to burn for rendezvous. The planning is best done with intuition, but you can simplify it by creating a single intercept of the orbital traces (so one orbit "rolls" in the other) and mofiying the orbit at the intersection to get an intercept.

Once you intercept, your nav ball should automatically switch to target mode. You don't need the map from here. To close distance, burn on a heading between target and retrograde so that your prograde and target markers align (once you develop the intuition, you actually want progeade to be slightly off of target to account for the rotational velocity). Mind your heading (to keep on target), speed and distance (to avoid overshoot) to target. Your goal is to reach less than 1m/s within 30-50 m from target. Intuition is important here. TWR determines your acceleration and thus which closing speed distance combinations are controllable. Most ships can zero speed with less than 10 seconds.

Once you rendezvous, you need to dock. Don't touch main throttle without developing proper intuition. Rotational velocity of orbit will cause ships to gradually rotate along the normal axis. Aligning ports to this axis allows you to ignore attitude adjustments (tools and/or intuition are almost required to dock along a non-normal axis). Use RCS translate so that the target and (anti-)normal indicators align. Then give a little trust to add a prograde marker to the set. Keep these three aligned (stop the ship to do so if you lack intuition to correct in route) and you should dock.

I strongly recommend learning to dock on simple ships (low part count, docking port aligned to control direction and in line with CoM). You want to develop your intuition four maneuvers before dealing with the challenges brought from complex craft. OTOH, dealing with such craft strengths your intuition, so don't avoid them forever.

[Jaeleth]

I find the intercepts difficult to use combined with the tricky camera in the orbital map view. You either zoom out so you can see everything but then you can hardly click on the right thing, or you zoom in to get a better view and then can't see how things are around the orbit.

I need to practice more - I did the tutorial one and one rescue mission around Kerbin but still need to figure stuff out. Especially how to launch and not be too far away from intercept - if your orbits are similar it takes ages at 4x time warp just to get within a decent range to intercept.

If target is on equatorial, low, anti-clockwise(west) to east orbit, launch when target is around 35 degrees longitude less than launchpad, you should get pretty close to target. If you need to warp faster exit fly mode, ger back to space center, open tracking station and, keeping your eyes kn map but not flying any ship, just fast forward what speed you like

[almagnus1]

I tend to use a very time inefficient (but effective) method for getting a rendezvous.

Step 1:

Get into an orbit that is smaller than the targets if it's ahead of you, or larger than the target's if it's behind you.

Step 2:

Figure out where the two orbits intercept, and on the other side of the planet from YOUR position (not the targets), create a maneuver node and add orbits until you're reasonably close. Once you will be reasonably accelerate time to burn off most of the excess until your ~5 minutes from the maneuver node (or however long you think you need to make an intercept maneuver node). What this is doing is getting the orbits to align reasonably close, and it's the time inefficient part of this process.

Step 3:

Scrap the existing maneuver node, then create another at about halfway between your current position and the intercept. Fine tune it to get as close as you can, then execute the node.

Step 4:

Keep repeating Step 3 until you've got an intercept that's within about 1km or so from the target.

Step 5:

Pay attention to your distance from the target after the last node, and when you are about ~2km away from the, switch the navball to target mode, and kill velocity relative to the taget. Once you have killed relative velocity, accelerate up to 20 m/s while keeping the target prograde and your prograde vector on top of each other. While you are closing distance, use RCS or burns to retrograde/prograde to combat drift.

Step 6:

Once you're within 500 m of the target, slow down to ~10m/s, then drop to 5m/s once you within 100m of the target. The point is to stay under control, and on target. Once you have a better understanding of what you're doing, you can start to speed up.

Like many of the others here, I use the NavyFish docking port UI as I can't figure out how to read the ingame UI to determine where I am in space. This is also something that you're going to have to screw up several times before you get a feel for what you're doing.

Hopefully this helps, and if there's something I'm massively derping on, someone will likely point it out.

[davidpsummers]

I think you hare having problems with the rendez-vous rather than the final docking? As an aside, I will say that if you want to dock two docking ports (and you will), the final approach is the hardest thing (mostly because you are working on a 3-dimensional problem on a 2-dimensional screen). For that, the Docking Port Alignment Indicator that was previously mentioned will be important (and, I think, is probably closer to the tools that NASA used?) Without it, it is quick difficult. That said, I'm a big believer in doing the docking manually a few times first.

[davidpsummers]

Looking over the comments, the video by GoSlash27 may be too ambitions (trying to launch directly into docking with the target) for beginners.

Here is how I do it....

As to your problem (which is getting close) I agree there are some good videos out there. But I'll run through it once...

Part one, getting kinda close....

1) Get into an orbit that is similar, but not identical to the target.

a) You want the orbits to touch at one point (or one crosses the other a bit).

Usually, for low Kerbal rendezvous, I set the periapsis of the ship to touch the orbit of the target and the apoapsis to be maybe 100 km higher than the target orbit.

c) The orbit have to line up (have the same inclination). In the map, click on the target and choose "select as target". Then you will see "AN" (ascending node) and "DN" (descending node) labeled on your orbit with a number (the number of degrees by which the planes of the orbits don't match).

d) These points are the places where your obit plane crosses the plane of the target orbit. At one of these you have to burn to make them match. Burn straight north (if the number is negative) or straight south (if the number is positive) until the number is zero. (Closer to zero you get, the easier the next steps will be).

e) At, or near, the point where the orbits touch, you will see the indicator(s) of closest approach. (If you can't see them, the orbits don't line up or they don't cross").

f) You will also see where the target will be when you reach the closest approach (and hovering over the closes approach indicator will show how far you will be from the target you will be at closes approach). (the intercept.)

e) If you put a maneuver node just past the closest approach, it will show you the next closest approach after the maneuver node (ie on the next orbit).

f) Your keep clicking on the maneuver node to set it ahead one orbit, you will see the next closest approach on the next orbit(s).

g) As you do this, you will see the indicator of where the target is move showing its position on the different closest approaches.

h) Do this until you get a close approach.

i) then use the node to adjust that approach (burning prograde or retrograde) until it is as close you are can get it. (A few km's or less, hopefully).

j) make sure you don't adjust the orbit so you hit the atmosphere or ground, if that happens, try the orbit before or after instead.

k) For me, with an orbit bigger than the target one, I usually can see the position at closest approach get closer and closer as I advance orbit by orbit. I do this until it passes the intercept. Then burning retrograde moves it back to match up. This has the advantage that I'm bringing the orbits closer together (with will make final approach easier).

l) Once done, you wait until you reach this closes appoach and then match speeds.

Step two, getting close.

a) When you are within 25-50km of the target, use your nave ball (set on "target" rather than "orbit") to turn your ship so that if points away from the relative direction of motion (the yellow circle with three lines sticking out and a cross inside). This is the direction that you will need to be pointing to kill the relative velocities (and match orbits).

as you get close to the intercept setup above, switch out of map mode. When you are within 25-50km of the target, you should be able to see the target indicated on your screen with the distance listed.

c) You intercept indicators will be telling you how close you can expect to get.

d) At that point, the target will be off to the side moving laterally.

e) Just before this point (allowing time for a burn, you will have to play with this until you get a feel). Do a burn away from the direction of relative velocity (as above) until the relative speed (as indicated on the nave ball) is as close to zero as possible.

f) If you burn too much, flip around and burn again to get to zero.

g) Now point your ship toward the target.

h) Do a gentle burn to move slowing toward it.

i) If you have RCS thrusters, you can use them to try and line up the relative velocity indicator with the direction the target is in. (Making you move more directly right toward)

j) When you get as close as you are going to (or before you run into it), flip away from the relative velocity and do a burn as with "e & f" above. (Or use your RCS thruster to kill you relative velocity.)

k) You are now relatively motionless with respect to the target, but closer than you were with step e & f)

l) repeat steps g-k again until you close enough for the stranded Kerbal to EVA and fly to your ship.

[GoSlash27]

Looking over the comments, the video by GoSlash27 may be too ambitions (trying to launch directly into docking with the target) for beginners.

I absolutely agree with this. Launching into a direct rendezvous is overly ambitious even for seasoned KSP vets.

I didn't link the video for that, though. I linked it because it explains and demonstrates the concepts of "pushing the marble" and "the rule of ten" during the rendezvous.

These are key to the whole process. Or at least they were for me.

Best,

-Slashy

[maceemiller]

Docking for me is the most beautiful part of KSP. Keep attempting it and soon it will just click

[mrklaw]

Those Phoenix videos were helpful - they have several scenarios. I think they key part for me is not worrying about matching your orbit completely. Seems like you just need one part to align for that initial intercept, and then your adjustments in target mode result in your orbit ultimately matching the target through pushing/pulling the marble.

[X5-599]

The training scenario uses the stop/start method. Once your speed is zero relative to the target you point at it and increase speed, if you drift away you zero out again and then point at the target and speed up again. It does get you there but it's not very efficient and the tutorial isn't terribly clear.

Thanks. I know this is quite a difficult maneuver. But I also feel that the training should explain it a little better. I'm really not that good understanding written text. Especially if it's about a complex topic such as this. IMHO there should be as little ambiguity as possible.