Another idiot who can't dock.

[King_Gus_Man]

That's me, I just cannot make it happen. I've read every post on the forum that I could reasonably find about it. I've read the wiki pages I could find. I watched the Scot Manley tutorial on docking. I still just cannot do it.

Here's my problem, 2 orbits, both are nearly perfect circles. (Less than 1000 m between Ap and Ep). I wait for the ship in the lower orbit to be right behind the one in the higher orbit, burn pro-grade which pushes ap out and gets me an encounter, (usually between 1km and 4km, but I've gotten as close as .1km). Now that I have an encounter I have to kill relative velocity, so I burn retrograde, relative velocity is under 5m/s, but now the other ship is as close as it will get on its own, and if I burn at the other ship to keep it that close my relative velocity goes way up. If I keep relative velocity down to a manageable level, the other ship runs away and I have to wait for another encounter.

Am I missing some key trick? I've tried doing everything with RCS (as one tutorial suggested) I've tried getting to about 100m before I start using RCS (as another suggested), I've tried not using RCS at all (just to see if I could do it, I can't). I hate to lose, but this docking thing is making me think about giving KSP up.

Edited November 27, 2013 by King_Gus_Man

[Zwer.ch]

While reducing your relative speed, make sure that you still go towards the target ship. It's easy to burn too much retro, so you will move away from your target ...then it runs away.

[DartBoris]

Maybe not the most effecient way, but easiest for me.

1. Get to somewhat nearby distance , even 10 km is okay. Kill all relative velocity to <1m/s

2. Aim just at target , get 5-10 m/s (depending on distance) relative vel , velocity vector must just aim at target vector on navball

3. Fly =) Use rss in translation to keep velocity vector on target's vector.

4. Slowdown at 100-50m , killing rel vel to 0 again.

5. Switch camera to chase view , point just behing the ship - this will help a lot with rss translations , they will become intuitive as WASD

6. Slowly coast to the point 10-15m from docking port normal , like on docking trajectory. Stop once there.

7. Point docking port , burn small speed and dock. Use rss to keep on docking trajectory. RSS on low-power (capslock) can help.

[annallia]

Only thing I can suggest is get mechjeb.

I was a horrible docker (still not great at it) but I learned how by just putting two ships in orbit and watching mechjeb rendezvous and dock them. After a while I quit using mech jeb for the docking and just for the rendezvous, eventually I got that part down pat as well.

[Sirrobert]

Only thing I can suggest is get mechjeb.

I was a horrible docker (still not great at it) but I learned how by just putting two ships in orbit and watching mechjeb rendezvous and dock them. After a while I quit using mech jeb for the docking and just for the rendezvous, eventually I got that part down pat as well.

Also Mechjeb smart ASS is great for lining ships up correctly if you want to do it manually. Or half manualy

[kookoo_gr]

In order to have a docking you need to switch at the target speed indicator, just click at the speed on the navball (it will cycle through: surface, orbit,target) you set that indicator at target (also notice that it auto switch to target once close to the target). in order to dock you aim your ship at RETROGRADE and burn until the speed relative to target is close to/or zero. then you aim at the TARGET (pink circle with a dot) and start a burn. once you are at a closer range you zero your speed and approach and dock with rcs. If you are under 1km i suggest you aim for a relative speed close to 5m/s for a beginner it's a good speed.

[Dogface]

I had watched all the youtube tutorials too (including Manley's). But you need to find the one that makes sense to you. The link below is the tutorial that finally got me to understand rendezvous and docking. It is a very simple method and explanation. LOVE IT!!

Absolute Beginner's Guide to Kerbal Space Program - Part 7 - How to Rendezvous and Dock

here are some other good tutorials that didnt help me, but might help someone else:

Orbital Rendezvous And Docking Tutorial For Kerbal Space Program 0.18

Scott Manley

Kerbal Space Program : Docking Tutorial Part 1 Beginners

AddMeGamers

[lajoswinkler]

Don't... watch Manley's video. It's too complicated and only makes sense to people who already know what are they doing.

There are tutorials on this forum, countless tutorials, and they really help.

[voneiden]

Am I missing some key trick?

I think based on your description you're not actually using the target mode in the navball. Have you selected the target vessel through map view? If yes, does your Navball read "Target" instead of the usual "Orbit" ( Here it reads orbit: http://wiki.kerbalspaceprogram.com/wiki/Navball )?

If yes to both then once after zeroing out relative velocity, you aim at the target and accelerate a bit and you should start closing in. If the approach is slow you may have to correct your trajectory a few times because the direction your ship is flying in and the direction of the target will be drifting slowly apart.

Edited November 23, 2013 by voneiden

[celem]

It sounds like you are doing it just right, but once at a close encounter are never quite getting the relative velocity down.

My bet is also on problems with orbit/target settings on your navball.

Once you get your nice close 1km intercept you want to burn retrograde all the way to 0.0ms. Leave em hanging dead relative to each other. They will try and slowly drift since their orbits wont be perfect matches, but it gives you a nice static frame of reference for the final RCS approach. While burning rcs to approach the target (h), you want to use the strafedrive (ijkl) to bring your green prograde marker over the purple target prograde, otherwise you drift just past him on a relative drift. Remember that once the navball is in target mode the green markers are your speed relative to target, so you want them to sit directly over the purple markers to get a straight approach-vector.

Keep at it, you understand the problem and seem to be doing it 99% right.

Edited November 23, 2013 by celem

[Kulebron]

Then when you're close, choice is

1. switch to each of the ships, set the other's docking port as target, approach and dock

2. if you can't turn target (it's a huge space station), switch camera to chase mode, align and dock. Docking in KSP is tolerant to up to 30 degrees of axis misalignment and maybe more.

Looking from behind to align with the station's port.

It's learnable when you know some key things, like cancelling out the velocity in navball, using translation controls (and having RCS on the ship ), and using this chase camera. Until learning this camera trick docking was very painful (I know there's a plugin, but was lazy to use it.)

Edited November 23, 2013 by Kulebron

[Kasuha]

Scott Manley's rendezvous and docking video tutorial is not particularly good. Not only what he does are not always the best steps, but he also often does not explain what he's doing in sufficient detail and performs actions while talking about something else, making it hard to follow him.

Recently he also grew too dependent on all kinds of mods.

The question is if you want to learn how to rendezvous and dock without mods (which is not only possible but not even particularly hard) or if you just want to get the docking done no matter what in which case just install corresponding mods and let them do the work while you have fun doing things you enjoy.

2 orbits, both are nearly perfect circles. (Less than 1000 m between Ap and Ep).

There's no need for that. All you need is one orbit inside the other. They don't have to be circular. It even usually helps with maneuver placing if they are slightly elliptic.

I wait for the ship in the lower orbit to be right behind the one in the higher orbit, burn pro-grade which pushes ap out and gets me an encounter, (usually between 1km and 4km, but I've gotten as close as .1km).

What can help you in this phase is, even before you get to that encounter point, put a maneuver there and match the orbits after the maneuver. It will tell you exactly which direction you should burn and how much.

Now that I have an encounter I have to kill relative velocity, so I burn retrograde, relative velocity is under 5m/s, but now the other ship is as close as it will get on its own, and if I burn at the other ship to keep it that close my relative velocity goes way up. If I keep relative velocity down to a manageable level, the other ship runs away and I have to wait for another encounter.

You're getting to the second phase of the rendezvous. At this point you should not care about orbits anymore because orbital effects are very small at this range. So just make sure you have selected your target and your navball is switched to target mode. Switch from map view to ship view. After you killed relative velocity, just turn towards the target and burn towards it. Forget about your orbit, just make sure your speed is low enough that you will be able to stop before you overrun. My rule of thumb is speed about 1% of the distance, i.e. 100 m/s at 10 km, 10 m/s at 1 km, 1 m/s at 100 m. Of course you can go higher as you become familiar with it.

After you burned towards the target, turn around and use short burns at low thrust to kill relative velocity gradually keeping your relative speed proportional to the distance as you get closer. If you stop or your speed is too low, just turn around again and burn towards the target again. That should get you however close you want.

In this phase it is often beneficial to have a ship with engines turned forward and action groups to switch between rear and front engines. It will save you a lot of turning around. Later when you become better at it, they become gradually obsolete as you'll be able to do it without turning around, just by gradual braking until you're close enough to dock.

When you get close enough that it becomes feasible to start docking, kill your relative velocity completely and continue using RCS.

Edited November 23, 2013 by Kasuha

[celem]

If I keep relative velocity down to a manageable level, the other ship runs away and I have to wait for another encounter.

Just noticed this bit when Kasuha highlighted it. If this is a really big issue, and the window of time in which you are at intercept is too small to perform a stress-free dock then there may be an issue with how you plot the intercept.

If your intercept is at a really steep angle you will find docking almost impossible because the orbital effects are more powerful than your fine-manouever abilities. Their individual trajectories are a problem if they are trying to pull away from each other at 20ms the whole time. Ensure you intercept like you would on a planet, try and come up behind and parallel to it with the lowest possible relative speed and the longest 'encounter' window. Should give you both more time to pull it off and less orbital interference

[Kasuha]

If your intercept is at a really steep angle you will find docking almost impossible because the orbital effects are more powerful than your fine-manouever abilities. Their individual trajectories are a problem if they are trying to pull away from each other at 20ms the whole time. Ensure you intercept like you would on a planet, try and come up behind and parallel to it with the lowest possible relative speed and the longest 'encounter' window. Should give you both more time to pull it off and less orbital interference

In fact, by burning retrograde to the relative velocity vector, you're also fixing the inclination difference. By killing relative velocity you're getting on very similar orbit as your target. It's not perfectly the same orbit as you are in different place, but if you close the distance fast enough, you'll not notice any difference to what would happen if you were just floating in space without any orbital mechanics intrusion.

And this "fast enough" is definitely nothing like "very fast". Just take your time, keep closing the distance, eventually killing relative speed and burning towards the target again if your direction diverges from the target too much. Later you can learn how to "hunt" the relative speed vector around navball to always go towards the target, too.

Edited November 23, 2013 by Kasuha

[PirateAE]

thing i learned about docking my first time, was; it takes time, dont try to over drive into it, or youll have a harder time. Just like flying an aircraft IRL, you need to let the craft react.

[Taki117]

If you are having trouble lining up your docking ports (And are not adverse to using mods) you could get the Docking port alignment indicator by Navyfish All it is is a little window that pops up when you select your target as a docking port and it shows your relative orientation and speed, as well as distance from the docking port, not the center of the station.

[CaptainArchmage]

A good way to line up docking ports it to switch between craft and orientate the ports so they point at each other. It requires some micromanagement because you have to usually fix your target and control points each time you switch, but it works.

If you need to do docking above Kerbin, try it above the point where KSP renders terrain in full detail and make sure the orbits stay in those regions, above 250km I think. This reduces the drift from your target, allows you to alter your orbit without intersecting the atmosphere, and it also increases framerate. Alternatively, you can try to keep Kerbin out of the camera view when docking. Because of the shorter orbital periods, docking in Low Kerbin Orbit is probably harder than docking in orbit around many other celestial bodies, such as the Mün.

[HeadHunter67]

Get NavyFish's Docking Port Alignment Indicator. It will help you to more clearly understand and orient your approach.

It sounds like you have the hang of rendezvous (although you could use a better method of tightening up the encounter distance). I highly recommend PebbleGarden's videos for more information on that - it's how I learned to rendezvous.

[LtKraftKrackers]

i cant really offer much advice that hasn't been said yet, but, yes, i believe the most important step on this, is to have your desired craft set as target on map view. This way when you get close enough, you get the targets relative speed and your Nav-ball goes into target mode. Now, here is the part that seems to me it has not been mentioned. It might be that i'm too impatient, but i have never killed my relative speed until 100 meters from target. I usually just "pull" my prograde marker or "push" the retrograde. why? Because i prefer to align my prograde marker with the "pro-target" one. you know, the pink, circular one with a dot in the center. if you align your prograde and and "pro-target" one, it means you are heading straight for your craft. Then its all about keeping them aligned and killing your relative speed as you get closer. Use your better judgement on that.

Hope this helped you.

[LtKraftKrackers]

Sorry, I believe my explanation of "pulling" or "pushing" is not clear, so here comes another paragraph.

when on target mode, your nav-ball displays a different kind of prograde and retrograde. these 2 markers are now telling you the direction you are going relative to the craft you have set as target. you also have the "pro-target"(circular, pink, dot in the middle) and the "anti-target" (thats how i call it) which is the pink triangular one. Now, when you burn, the prograde marker will be "pulled" towards your heading (heading, at least here, means the marker that shows where you are pointing). When you burn in retrograde, you "push" the retrograde one, as it tries to move away from your heading. now, you can use these two principles to align your prograde and retrograde markers with the "pro-target" and the "anti-target". if you align the prograde and "pro-target" you should have a really close Rendezvous in no time. Then, you can use your better judgement to dock. I believe it will come to you

[Tank Buddy]

When you have your encounter, you wait until ~30 to the encounter to cut out your relative velocity. (Make sure you are in "target" mode and cut the velocity to under .5 m/s, just by burning retrograde) This way you will get as close as possible.

This is where you went wrong: all you have to do is point at the target and burn. Do this in map view and watch as the encounter gets smaller and closer to you. You don't have to worry about what the relative speed is because it's going straight towards the target.

When you get within a 100 m, cut your velocity and use RCS to maneuver towards the docking port. If you wish, you can switch to the target vessel and click "control from here" on the desired docking port, set the ship that you were going to dock to as a target, and point at it. Switch back and reset the docking port as a target and it should literally be a straight shot. Don't be afraid to go more than 2 m/s to close the distance.

Also, I re bound my RCS translation controls to the arrow keys and Left Ctrl and Shift. I find this easier than the default keys and still allows you to use rotation controls.

[Kasuha]

When you have your encounter, you wait until ~30 to the encounter to cut out your relative velocity.

The time you need in advance depends heavily on your relative velocity, i.e. on how different your orbits are. Definitely place a maneuver there, set it up to match the two orbits and start killing the velocity at T minus whatever the maneuver tells you is needed. As soon as you start burning, delete the maneuver (right-click on it, then click on (X)). Then close map and switch to navball, get the velocity to reasonable dimensions and finish the rendezvous without looking at map, just using the navball and checking the distance of the ship in normal view.

[Vanamonde]

Rather than advice, let me suggest this. It's a docking trainer ship which sends up 2 small orbital maneuvering ships in one launch. You can separate them, and then practice bringing them back together from longer and longer distances.

[cr055H41rz]

Maybe not the most effecient way, but easiest for me.

1. Get to somewhat nearby distance , even 10 km is okay. Kill all relative velocity to <1m/s

2. Aim just at target , get 5-10 m/s (depending on distance) relative vel , velocity vector must just aim at target vector on navball

3. Fly =) Use rss in translation to keep velocity vector on target's vector.

4. Slowdown at 100-50m , killing rel vel to 0 again.

5. Switch camera to chase view , point just behing the ship - this will help a lot with rss translations , they will become intuitive as WASD

6. Slowly coast to the point 10-15m from docking port normal , like on docking trajectory. Stop once there.

7. Point docking port , burn small speed and dock. Use rss to keep on docking trajectory. RSS on low-power (capslock) can help.

No you're doing it right.

[HeadHunter67]

Learning to pull and push the marker isn't easy - I didn't understand it at first, myself - but once you learn that, cancelling relative velocity becomes so much easier.