[Beginner] How to dock in 3 easy steps

[Vanamonde]

On 7/18/2017 at 7:48 AM, warlock31415 said:

So I tried the in game tutorial and I looked up yours, here's my problem to get close to the other vessel I need to throttle up (or use RCS) but in doing so I increase my speed, to decrease it I burn anti-target which increases the separation. what am I doing wrong?

Probably just trying to do it too quickly. Try shorter burns. 

[Kerbal101]

@Vanamonde @warlock31415 When navball is locked into Target mode, burning Target is to increase approach speed - as it brings Prograde marker into Target. To slow down, burn strictly Retrograde instead.

Because your vehicle and your target speeds are different (at approaching phase), the orbit geometry is too. And if you are approaching from below, you will soon notice that Prograde will have a tendency to drift Upwards (radial out direction) to the actual target. So this is exactly the error you are investing energy into, if you (incorrectly) burn anti-target to slow down.

Imagine that you are a giant boat in 2d space.
You row towards the target, wait until you notice you start to drift incorrectly - in this moment, you slow down and drop the acceleration in that wrong direction to zero. Then you row again direction your target.

Take a look at this video, it includes multiple rendezvous and docking.

[Goofygoff]

This is so helpful because I was first going from suborbital trajectory to my target's orbit, and all the videos I watched by Scott Manley and Matt Lowne did NOTHING to help me out. THANKS SO MUCH I WILL TEST IT RIGHT NOW

[Tanmay]

I tried the ingame tutorial 5 times, but I couldn't even reach the target. But this tutorial has cleared all my doubts. Thanks

[Ho Lam Kerman]

I do stuff differently. I usually use main bipropellant engines to dock, and I usually dock at 2.3 m/s or a bit more. I don't use chase camera either, and it works fine.

Maybe I'm just trained to do stuff like that.

Edited May 5, 2018 by Ho Lam Kerman

[21kubes]

Everytime I try docking I get quite close (100-200 meters away) but then the capsule I'm trying to dock with just floats away right next to me. Any tips? 

[Vanamonde]

3 hours ago, 21kubes said:

Everytime I try docking I get quite close (100-200 meters away) but then the capsule I'm trying to dock with just floats away right next to me. Any tips? 

If you're that close, you should be able to point your ship target-retrograde, burn to zero relative velocity, and then fly directly to it and dock. Where is that going wrong? 

[21kubes]

Just now, Vanamonde said:

If you're that close, you should be able to point your ship target-retrograde, burn to zero relative velocity, and then fly directly to it and dock. Where is that going wrong? 

Thanks that's what I was doing wrong. I didn't stop I just kept my marker on target. Thanks for the help. =) 

[Sergei Kerman]

Thx for the guidance 

[WillWam]

What if the closest I can get is 400km (docking tutorial)?

[Superfluous J]

3 minutes ago, WillWam said:

What if the closest I can get is 400km (docking tutorial)?

Then you're not docking today.

[WillWam]

21 minutes ago, 5thHorseman said:

Then you're not docking today.

No seriously what can I do? I've been doing this for hours.

[Superfluous J]

53 minutes ago, WillWam said:

No seriously what can I do? I've been doing this for hours.

I don't know what the tutorial tells you to do, but I would suggest my own set of videos for this:
 

Spoiler

 

 

 

[putnamto]

Another  good  tip  is  to  send 2 ships  to  orbit  that  are  already  docked  together(like  two  pods  with  terriers  and  rcs) get  em  in  orbit, undock  them  and  fly  them  around  a bit. Then  redock  them.

 

Also  change  your  camera  mode  to  locked, really  helps  with  lining  the  ports  up, and  making  sure  your  translation  keys  work  the  way  you  think  they  should. (This  was  actually  my  biggest  problem  at  first)

[Vanamonde]

On 1/14/2019 at 3:31 AM, putnamto said:

Another  good  tip  is  to  send 2 ships  to  orbit  that  are  already  docked  together(like  two  pods  with  terriers  and  rcs) get  em  in  orbit, undock  them  and  fly  them  around  a bit. Then  redock  them.

You mean like this? 

https://kerbalx.com/Vanamonde/M131-Docking-Trainer

[putnamto]

1 hour ago, Vanamonde said:

You mean like this? 

https://kerbalx.com/Vanamonde/M131-Docking-Trainer

Yup

[KillSwitchX]

This might be considered a bit late to the party seeing as how most of these comments were made in 2013 and 2014 and I'm posting here in 2019...I have docked successfully before but will add that it can be incredibly frustrating if one step is missed or core concepts are not well understood. Nonetheless, do not lose hope, what you need to be mindful of is that it is an incredibly complex process to match two small ports of spaceships in perfect alignment and get them to meet one another in space, so stay patient. I believe it's good to know that these principles still work years later and many versions of the game since released.

I will not explain docking as that is a procedure in itself but my intention is to fully describe how to get a successful rendezvous (ships well within 1 km distance from each other) which will be needed before reaching the docking phase. First off you will need to ensure your pilot is 3-star level (this provides all SAS capabilities including target and anti-target) autopilot features. Without these rendezvous and docking are much harder if not impossible. I think most people seem to have trouble at a few different critical points, one being if your orbits arent close enough to begin with do not attempt to "chase" the other ship to catch it, it will never work...you can't rendezvous if your orbits arent close enough in shape and inclination and even if there's a meeting point, if they begin to deviate significantly thrusting toward the other ship will hardly be successful as the velocities and relative paths of the ships pull them apart. Just look at your orbital map and make sure the ship you want to target is set as target (right click ship and click "set as target"). Focus first on getting Pe of one orbit to close matching Pe altitude of the target orbit, this will put the two ships into some sort of similar orbit, next focus on getting the Ap close to but not too close to your target ship's orbit (potentially about 10k-15k altitude deviation but this can be any number really...play around with this to get desired results; less deviation between altitudes of current and target is "better" but takes longer to achieve phase and close intercept). Next, look at the two orbits to find the points marked AN and DN; Ascending Node and Descending Node, respectively (you can use either one). Place a maneuver node on one of those two nodes and pull either the normal or anti-normal vectors of the maneuver node to change the inclination of AN and DN, you should get these as close to 0 degrees as possible....0.1 or 0.2 degrees of separation I believe should be acceptable as well...the closer to 0 this is the closer the orbital paths will be in direct alignment so it will help SIGNIFICANTLY in putting your ships on the same orbital path. Now once you've done all of the above you can focus on getting an intercept...create a new maneuver node and place it and use the +/- buttons on the main node selection to align orange or purple intercept indicators to preferably within 10km distance. You may have to wait a significant amount of time to get an intercept using this method so it's a good idea to save at this point and to go to the tracking station and time Warp until you get some what close to your intercept (maybe within an hour or so). Assuming you've done everything else correctly and upon getting close to the intercept both ships should be on near identical paths (with a slight 10km or so deviation at the Ap...the further your intercept is from the initial intersection of these two orbits the better, as your ships begin to drift apart at this point). Now the next key pieces are when getting to this (hopefully close to 10km distance or so between ships). MAKE SURE you have the target ship set on your navball to display relative distance and velocity shown between target and current ship, this will help immensely in getting closer to and matching the velocity of your target ship. First kill any remaining velocity differential between target and current ship by doing a small retrograde burn (DO NOT burn anti-target at any point! Only a series of slight target and retrograde burns)...this shouldn't be much more than 100 or so dV, if that. Next, point your ship direct at your target ship and burn slightly, use shift and ctrl at this point for slight throttle adjustments not z and x as these will be way too much thrust for the slight adjustments required. You will want to close the distance between your ships to at least within 1 km (and arguably even much closer but if you can make it within 1 km there is no reason short of running out of fuel that you cant get the ships to rendezvous). You will want at least several retrograde and target burns with very low thrust to bring your relative velocity within 100 m/s and distance of 1 km...by the time you are within 1 km of intercept and rendezvous you will want to bring your relative velocity way down to about no more than 10 or 20 m/s so do this with another retrograde burn....you can do basically as many of these as possible to get the two ships within 100m or closer at which point it's a good idea to kill most of your relative velocity to within 1/ms or even 0.1 to 0.5m/s...repeat until ships are within 20 or 30m, kill all remaining relative velocity and then switch to docking phase.

Edited January 27, 2019 by KillSwitchX

[21kubes]

If anyone's wondering, I'm still reading every single comment on this, so thanks for the tips! I've gotten better at docking successfully, but it's still fairly difficult. Thanks for the support!