can't achieve final docking

[Endoric]

No its not a problem with my docking ports its a problem with me.

I have no idea how to close those last 30 meters!

I am just a bit off and i have no idea how to line it up.

Help please i just cant get the lateral motion correct. Is it my RCS placement? Its like trying to touch the tip of my nose with my finger but i keep missing my head!

[mushroomman]

Could we get a closer shot of the docking ship? I can't see anything exactly wrong with it. At least not from this far.

Do you have ASAS turned on during docking?

[DaPizzaman]

I can't see your RCS placement, so I can't help you there. Make sure you have selected the other ship as your target. Then, burn retrograde until you are basically at 0 m/s. Then point toward the target (the pink-ish looking icon on the navball) and burn very slowly towards it. Make sure you have RCS on to do this so you don't smash the ships into each other.

After that, I find that pointing the two ships in opposite directions really helps. I line one up facing North and the other facing South. Then, using the RCS translation mode (or the translation keys, whichever you prefer), very slowly push the ships closer to each other. Once you get a hang of the directions, it is a bit easier. After you line up in the x and y directions, it's just a matter of coasting in to the docking port.

Here's a video by Scott Manley. He's really good at explaining things, so maybe he will be able to help you out better than I can.

http://youtu.be/AHkY3FusJIQ?t=9m49s

[NeoMorph]

[Endoric]

i watched that video a dozen times. Its that very last part i just cant get right.

I did bump my docking ports once but i think i came in too fast and they bounced off each other.

Is ASAS being on the same as hitting 't' to turn on SAS? Will ships not dock unless that SAS is locked on? The one time i touched docking ports i cant recall if it was on or not.

Problem is i just can not get that last fine tuning that connects the ships correct, i keep missing by a fraction mostly laterally.

And i cant really get another screen shot as it is too late since both ships are out of RCS fuel... i am telling you i just cant steer the things.

[Brofessional]

Set the other ship's port as your target, switch the camera to chase mode, and use RCS translation (IJKLHN) to close the distance.

[TheDarkStar]

Did you make sure that both docking ports are the same size?

[Vanamonde]

If it's only the final docking that is giving you trouble, you might try my docking trainer.

It carries two smaller ships with it, so that you start the manuever already docked, and then can detach and re-dock again for practice. You can download it here: http://forum.kerbalspaceprogram.com/showthread.php/25425-Help-with-Docking-A-Trainer-Ship-for-Newbies

[NeoMorph]

Sounds a good idea having a docking trainer but you seem to have wayyyyyyy too many RCS pods for such small vehicles. A single ring of quads offset and then toggleable via action groups would be better and then a single ring of the place-anywhere pods around the center of mass that aren't toggleable would be better.

That way, when you want to rotate the ship you turn on the RCS pods, and when you are aligned you turn them off and use the place-anywhere pods to move you as they are just pushing against the centre of mass will stop you turning. If you have it done right you can even leave the SAS on too and not have it firing all over the place.

[Vanamonde]

It's a newbie trainer. I don't want them to have to figure out action groups and whatnot when they're still just figuring out how the basic game works.

[Brofessional]

It would be easier to just have two ships with the docking ports on the noses, that way you can point them normal/antinormal and you don't have to worry about rotation.

[CalculusWarrior]

First, get pointed in the same direction as the other docking port, lock ASAS, then all you have to do is use the RCS keys (I, J, K, L, H & N) to maneuver your target velocity vector so that it lines up with the purple target vector. If you do that, you don't even have to look at the other ship; you will dock successfully every time!*

*Exceptions to this rule apply if you are behind the vessel, not lined up with the docking port, drift out of alignment, reenter the atmosphere unexpectedly, or run out of RCS fuel.

[Dictator Dan]

1) Make sure the docking ports are the same size, and if you are using a shielded one, that the cover is off.

2) Select the docking port of the ship you are flying, and go 'Control from here' and on the target ship, select its docking port and click 'Set as target'

3) Turn navball to 'Target' that will show your relative velocities.

4) You want to make contact at a fairly low speed, and turn SAS (yes, pressing 't' will turn your sas on/off) off.

If you are trying to dock with SAS on, it attempts to hold your ship on its current heading, which can be an issue, as it wont be let the ships be 'pulled' into docking position easily.

[Endoric]

2) Select the docking port of the ship you are flying, and go 'Control from here' and on the target ship, select its docking port and click 'Set as target'

thats news to me... will try it. time to send up a third ship with enough liquid and RCS fuel for the other two and hope i dont have to send a forth.

[Deadpangod3]

I can see the RCS thrusters in the pic, there's s some at the bottom of the fuel tank near the engine, and some on the decoupler

[dr_jt]

Consider Kerbals

Edited June 6, 2013 by dr_jt

[Sathurn]

Ok, here my 2 cents worth.

Once your close and using nose docking for learning at least, point your ship at the target and turn on sas.

Switch ships and repeat.

Now using whichever ship you want translate towards your target 'h', at a speed that makes you comfortable.

DO NOT ROTATE YOUR CRAFT, leave SAS on. As your approach use the 'i','k','l','j' keys to keep the TARGET marker in the middle of your nav ball. Use the prograde marker to figure out which way you moving.

Use 'n' to slow down, and if your bumping with out docking turn off sas.

Edited May 9, 2013 by Sathurn

[leax256]

thrust toward-ish the target ship then kill relative, rinse wash repeat, i hate docking the "correct" way, too much worry about staying alligned.

[Tach]

Yeah, I use the "kill relative" approach once I'm close too. The H and N key are awesome for just realigning your approach vector. No one mentioned actual speed of docking. For me, I find 0.3-0.4 m/s relative velocity works well.

[Kerba Fett]

2 addons that will make the job go a lot easier are Mechjeb and the Lazor docking camera.

In the Smart ass panel of Mechjeb use target+ till you get to 10 to 20 meters then switch to Par + for the last bit.

Make sure that the docking port on your target ship is set as the target.

Use docking mod in the linear setting and Mechjeb will keep the ship pointed where it needs to be while you handle lateral movement.

The docking camera is good because it gives you more info on how well you're aligned and how fast your alignment is shifting.

Once the docking ports touch (or just before) you need to turn off the Smartass and SAS so the magnet can pull the ship into final alignment.

When building the ship I like to use 4 linear RCS ports lined up with the COG for lateral movement and 2 on the front and back for linear movement. If you can get the front and back ports close enough to the centerline of the ship the ASAS doesnt seem to waste much fuel trying to turn the ship with them and just uses capsule torque instead.

[Endoric]

ok getting the hang of it thanks to all the advice. i docked twice successfully. i get better as it goes. i have three ships docked, one of them has a docking port at the front and back since i have side mountd engines on it and i have two ships docked on it.

i even went as far to load all but one of my kerbals onto the hitch hicker can and briefly start a deorbit path so i could launch the kerbal still in the capsule and send him back to Kerbal safely.. it worked, i even used the oportunity to decouple some spent engines and eir empty fuel tanks i had radially mounted and send those back into the planet as i hate space junk.

was pretty cool how i could momentarally deorbit, release the pod and reorbit, thus allowing the pod to reenter and the 'space station' to remain in orbit.

now i have to build a recovery craft as my kerbal is floating in the ocean off the west coast of the contintent that looks like africa where the space center is. you you guys should really give these places names....

Edited May 10, 2013 by Endoric

[yithpistol]

When doing the recreation of the Gemini mission per the Wiki I ran into the problem of using lateral movement and my movement always having too much rotation in it. Then I remembered what I learned from the game and physics class and remembered 'center of mass'. I realized that the way the gemini was designed in the game (not sure if they did this IRL) places the two sets of RCS blocks where they are not equidistant from the capsule's center of mass. So when the top ones are firing, they may be firing at the same time as the bottom ones, but they're too far away from CoM and impart rotation. What did was place the two closer and equidistant from the center of mass and the rotation nearly disappeared. I still had to make minor corrections, but it was enough to think "This is lateral movement" rather than "this is poorly designed rotatational movement". Still, somehow, even with the original thruster placement I got those puppies docked. I shouted and cheered. I had been working at getting those two joined up for hours (counting previous attempts to get their orbits matched and failing... and one entirely aborted mission). Anyway, if you're getting too much rotation, try making sure your RCS blocks are equidistant from the center of mass. There's a button in the VAB (assembly building) that shows a big dot where it is. once you do that and you're not rotating like crazy, you should be able to get to the other capsule easier. Definitely check out the Gemini mission setup in the wiki and read the docking instructions there. I learned on those. The above video certainly can't hurt to check out as well. You may have to keep switching back and forth from lateral and rotational movement or just use rotational movement entirely with H and N to go 'foward' and 'reverse' respectively to control your approach.

Good luck. I know my hands were shaking at one point. That's one docking down a million to go... especially if I ever want a space station.

Edited May 13, 2013 by yithpistol
new info

[yithpistol]

OH! Congrats! Now I gotta catch up with you!