KSP's HARDEST THING (to me) : DOCKING

[Kerbal Nerd123]

Can someone help here how to dock other ships I even can't dock ships THAT ARE ONLY 10 meters-20 meters CLOSE! I don't get the rendevorze thing I tried many  tutorials but it didn't help me at all I tried to dock ships that are really close like the apollo 11's lander,I target it's docking port and tried to dock the lander I came in slowly but I can't still dock it I bang the lander every time AND CAN SOMEONE HELP ME HERE HOW TO DOCK?? 

[Streetwind]

Docking and rendezvous are two different things. It seems like you are having problems with the former.

In order to dock comfortably, you should ensure that a number of factors are given:
- You have sunlight. (It's incredibly annoying to try docking at night.)
- The target vessel has SAS attitude hold enabled. (If the target vessel tumbles uncontrolled, you're setting yourself up for frustration.)
- You are controlling your own vessel from your own docking port. (Don't just target the other port; rightclick yours and select 'control from here'.)
- You have selected a helpful camera mode. (With a fixed camera, you can steer much more easily while also keeping your target in view at the same time.)
- Your vessel is built from the ground up to be comfortably dockable.

To expand on the last point: It is possible to dock with just your main engine and reaction wheels for turning, but that is an advanced technique. Instead, you should bring RCS thrusters. If you stay in staging mode (don't bother with docking mode, it's useless), you can control attitude with WASD and at the same time control RCS translation with the keys around the J and K area.

However, you can do all of that right and still have a hard time docking, because the spacecraft is poorly designed. In order for RCS to be useful, the thrusters need to be balanced around the center of mass... and not the CoM in the editor, but the CoM in flight at the time you are docking, which can be significantly different because you have already burned some fuel. With misaligned RCS thrusters, trying to translate will induce rotation in your spacecraft - and when you try to fix the rotation, you will induce unwanted translation. In effect, you will be drifting all over the place, unable to even get back to standing still, much less approach your target.

That's why it's incredibly important the docking spacecraft has properly placed RCS thrusters. And getting that right requires either experience, or a mod.

Edited August 3, 2016 by Streetwind

[Foxster]

I think that when you have managed to do it once then that's enough. After that use MechJeb like they would on a real spacecraft.   

[Hodari]

Getting that close to the target is really the hardest part of docking(unless you started out close to it in the first place).  Once you are close to the other vessel:

1.  If you haven't already done so, in map mode, set the other vessel as target.

2.  Click on the Navball and set it to Target mode.

3.  Use your engines and/or RCS to kill all relative velocity between the two ships.

4.  Right click on your docking port and select Control from here

5  Right click on the other vessel's docking port and Set as Target.

6.  Rotate your vessel so it is pointing directly at the Target marker on your navball

7.  If possible, switch control to the target vessel for a moment and repeat steps 4 and 5 from there, then rotate that vessel so the docking port is facing directly towards your other vessel.  This will make the final approach MUCH easier, but if you can't do this for some reason, you'll just have to maneuver your vessel around to the correct side of the target vessel first and then point towards the docking port.

8.  Once you're lined up with the two docking ports facing towards each other, use your RCS thrusters to VERY slowly move toward the target again.  For the last 10m or so, you should probably only be going about 0.3 m/s.  Also use the RCS translate controls (HNJKLI) to keep your target and prograde markers on the navball EXACTLY aligned with each other and rotate so you're pointing the ship towards them.

9.  Once the docking ports actually come into contact, they should connect immediately if everything is lined up correctly,.  If the ships are still at a slight angle to each other or not perfectly aligned, you might need to maneuver around a little to get them to connect.  Also, at this point it might help to turn SAS off for a moment and let the magnets on the docking ports pull them together.

[Tyko]

3 hours ago, Foxster said:

I think that when you have managed to do it once then that's enough. After that use MechJeb like they would on a real spacecraft.   

after you've done it once, celebrate because it's one of the toughest things to get right...then do it again and again until you no longer find it interesting. After that you may choose MJ, or you might find it so easy you don't have to use MJ. It's like a perfect baseball or golf swing. Do Baseball or Golf players quit playing once they've mastered it? When you do it right it's a great feeling because you're doing something easily that only a handful of people on the whole planet can do 

Edited August 3, 2016 by tjt

[Alshain]

The biggest problem with docking is unbalanced RCS.  Unfortunately the stock game doesn't help you much there.  RCS Build Aid mod is useful (assuming this is a PC version) to balance the RCS forces.  Unbalanced RCS doesn't mean you can't dock, but it's a lot harder when your craft won't stay pointed at the target because of induced torque.

Edited August 3, 2016 by Alshain

[DD_bwest]

are you playing console or pc?  just so we can help with mentioning proper controls

also i find alot of success with rcs placement on simple vessels by placing it as close to Center of mass.

to expand upon steps 4 thru 6 menioned by hodari,  if you have good enough sas on both vessels, switching to the target and setting it to target your other ship can make things even easier.  with SAS doing the leg work of aiming, all you nees to do is nudge yourself towards it anduse rcs to keep your prograde marker directly over top he target marker.  in pc h will nudge your rcs forward, I J K L will provide linear directional control so that whwn you look at your navball,  you can move your prograde marker around and center it over your target marker.  just keep is center as you close in on your target.

turn rcs off for the last 3 meters if you can.  if rcs are poorly placed, the sas will get messy trying to focus on the docking port and fling itself around.  with it off, the docking ports and so the work and pull them together

infact you can even dock without looking at your target, once you learn to fly with the navball.

 

if your playing on console the nudge and rcs adjustments have to be done in docking mode with linear control.

[Spricigo]

If the problem is "banging the other vessel every time"  maybe you are going too  fast. Keep in mind that you have a lot of time and do it slowly,  after get the hang of it you may try to speed up the process (if possible/convenient) 

Also try do your maneuvers using the navball,  the navball tells everything you need to know about your ship attitude and movement learn how to understand. The only 'missing' information about the target it's the distance and that you can pretty much ignore if you are heading in the right direction. 

[Blaarkies]

Right click the RCS ports of your craft -> click "Show actuation toggles" -> click yaw,pitch,roll(to disable them). This should leave you with ONLY translation control on your RCS controls, so that automatic SAS will not use your RCS thrusters. (do it to EVERY thruster, since those settings are independent)

Now press CAPSLOCK...this will activate "precise control" mode(allows you to press keys longer before the RCS ports thrust at full throttle). Just take it slow, as in 0.5m/s slow.

The tips here about the "lock camera" is also very, very useful(then hold down your mouse WHEEL button/middle button and drag the mouse around...it is like "looking upwards without tilting your body upwards")

Good luck and keep at it, docking is a really valuable skill in KSP 

Edited August 4, 2016 by Blaarkies

[EliasDanger]

Look up a video tutorial on youtube. A lot easier to understand when you see it done.

[Magzimum]

My 2 cents:

The [ ] keys are used for switching quickly between ships that are near each other (*). I think it can switch to anything within a 2 km range.

Use those keys to switch to the target ship, rotate the docking port of the target ship towards that of the approaching ship, then press [ (or ]) again, and continue flying with the ship that approaches. Or alternatively, rotate the docking port into bright sunlight, so that it is easier to see... Either way, use that to make your life easier. It's a really easy trick (worth only 2 cents)... but it is a pain to do if you do not know the keys, and have to go through the Tracking Station or map to switch between ships.

(*) It will also switch to an EVA Kerbal, and back to a ship, if you have a Kerbal jetpacking around in space.

[PT]

Docking Ports have 90 degree limit on roll tolerance. If one of crafts is "upside down" ports will not lock. 

Here are values exposed by some mod (Tweakable Everything I think):

Control from docking port, target far end. In both crafts. For long crafts it keeps rendezvous angle in check. Helped me a lot when docking that thing together.

If docking takes long time crafts will rotate out of prograde/retrograde alignement. To mitigate it you can align them to normal/anti-normal (pink markers, north-south for equatorial orbit). Normal/anti-normal is same in every spot of orbit, so target docking port will not "run away". Approach, however, will be a bit more complicated.

Do not forget to switch NavBall to "Target" mode. (Click on speed display on top of ball).

MechJeb Smart S.A.S. function is able of controlling inactive vessel. Set it to "target" on both crafts then just go gently forward.

Whether you are using MJ or not, here is list of maneuvers you need to do:

1. Match inclination
2. Plot collision course (Some call it Hohmann transfer to target)
3. Fine tune rendezvous to separation of few kilometers at most.
4. Match orbital speed.
5. Slooowly approach target.

[swjr-swis]

19 hours ago, Alshain said:

The biggest problem with docking is unbalanced RCS.  Unfortunately the stock game doesn't help you much there.

Precise control (caps lock on PC) also auto-balances RCS. A little not-very-advertised stock feature.

 

23 hours ago, Streetwind said:

- The target vessel has SAS attitude hold enabled.

If you're not controlling a vessel, any SAS hold of any kind it might've had is no longer applied. The slightest sneeze will start it tumbling.

[wumpus]

1 hour ago, Magzimum said:

My 2 cents:

The [ ] keys are used for switching quickly between ships that are near each other (*). I think it can switch to anything within a 2 km range.

Don't underestimate how important this is.  I've seen a few videos that suggest doing complicated maneuvers to line up the spacecraft, when all you have to do is flip to the "target" and point you docking port at the ship that wants to dock.  Make sure both vessels are going as slowly as possible, or otherwise can be left alone for as long as it takes (KSP tends to "forget" your target, forcing you back on the navigation screen to painfully click on a target you are nearly on top of).

5 minutes ago, swjr-swis said:

Precise control (caps lock on PC) also auto-balances RCS. A little not-very-advertised stock feature.

If you're not controlling a vessel, any SAS hold of any kind it might've had is no longer applied. The slightest sneeze will start it tumbling.

Did not know about the autobalancer.

Note that "the slightest sneeze" includes a blast from any non-RCS thruster.  RCS have the magical property of having physicsless reaction mass, so are the only ones you can safely use in close.  Also SAS is critical for anything with buggy torques.  I've returned to a spinning craft because of landing wheels (for a contract) that magically applied torque.  It really is important to have the time to correct for that when coming in.

And above all else SLOW DOWN.  In real life, the rendezvous takes multiple days between whatever and the ISS.  The final approach is cm/s.  While KSP simplifies things by a few orders of magnitude thus lets you go faster, those last final meters should be SLOW.

[Montag]

If you are on PC, get the Docking Port Alignment Indicator mod by Navyfish.  This does not require any parts.  It is a very awesome visual indicator on how your orientation and speed is relative to your target.

I also recommend RCS Build Aid mod.  This will help in RCS thruster placement.  It will show you what torque would be exerted on your craft when you translate in the different axis.  Ideally, you would have zero torque when translating.  Do keep in mind what your expected fuel state is.

If you have sufficient RCS thrust to adequately maneuver your craft, then hit the caps lock key to get to refined controls.  This also balances the RCS thrust somewhat. 

For final approach, I would recommend relative velocity speeds of 0.3 m/s or less. 

At the very last moment, you want to turn SAS off for the craft you are controlling.  The stability assist may fight the "magnetic" pull of the docking ports and you may get a chatter / wobble state and they never get it done.

[ZooNamedGames]

8 hours ago, PT said:

Docking Ports have 90 degree limit on roll tolerance. If one of crafts is "upside down" ports will not lock. 

Ok, I just popped in here- but what? I've never heard of that and definitely never seen it in practice. Unless your referring to a mod.

Docking ports work as long as your aligned so they press together within a 2D plane, it will work perfectly fine. As to which craft is upside down or not has always been irrelevant.

Again, if your referring to a mod, then I admit to being wrong.