Can Someone Please Help Me With Rendezvous?

[starkllr]

I've watched several video tutorials and read a dozen explanations, and I still DO NOT GET IT!!!!!!!!!!!!!!!!!!!!!

I can get my ship to within 2 km of the target craft. Relative velocity is under 10 m/s.

WHAT DO I DO NOW?????????

Nothing I do works. I cannot get closer. No matter what direction I burn, no matter where the Navball is pointed or which icon I'm centered on, it isn't right. I do not understand what's going on at all.

It is maddening, and I am at the point of either tearing my hair out or deleting the whole damn game, which I don't want to do. Can someone walk me through EXACTLY what I have to do, step by step, as though you were talking to a small child with serious learning difficulties?

[Specialist290]

Welcome to the forums!

Once you're that close, you basically want to start flying towards the target with you navball.

First, find the pink dot with the circle around it. Line up the "birdie" in the navball so that you're pointing straight at it. Then give your engines a little throttle.

Notice that, as your engines fire, the yellow circle -- your prograde velocity marker -- starts moving towards the direction your rocket is pointing. Your goal at this point is basically to steer the yellow velocity marker onto the pink target heading; when the two are centered on one another, that means you're heading directly for your target.

If you think you're going too fast, spin your ship around to the crossed-out yellow circle -- your retrograde velocity marker -- and burn in that direction to kill your speed.

Once you're within a few hundred meters of your target, turn on your RCS and switch your camera to Chase Mode with the "V" key. This will ensure that up, down, left, and right on the translation controls are the same as they are on your screen when your view is directly behind the engine. Use the IJKL keys to adjust your course by translating in different directions, and the H and N keys to push your craft "forward" and "backward." Keep that yellow circle centered on the pink target.

Once you're within about 50 or so meters, slow yourself down to about a meter per second and start getting yourself lined up with the docking port you want to dock with. Take it slow; patience is key when docking.

Hope this helps!

[PeteMcCartney]

Set the other craft as the target, kill all your relative velocity and then work to get the yellow prograde marker (circle without cross) towards the pink prograde marker (circle) going at about 15 m/s @ 2 km. Slowly kill your velocity as you get closer. Switch craft and rotate the required docking port toward your oncoming vehicle. Switch back and continue to slow, 1 m/s at 100 m, .5 at 30 m, .3 at docking. Always keeping your yellow prograde marker directly on your pink prograde marker.

Edit - Beat to the punch.

[starkllr]

Thank you! I'll try and see if I can follow this...

[Nibb31]

I've watched several video tutorials and read a dozen explanations, and I still DO NOT GET IT!!!!!!!!!!!!!!!!!!!!!

I can get my ship to within 2 km of the target craft. Relative velocity is under 10 m/s.

WHAT DO I DO NOW?????????

Cut your relative velocity to 0. To do this:

1) Make sure your target is selected and the navball is in Target mode.

2) Point your ship towards the yellow retrograde marker and burn until your relative speed is 0.

3) Then, to approach your target, point your ship towards the pink marker and burn gently. Do not exceed 2 or 3 m/s. Take your time.

4) When your vector (yellow prograde marker) starts moving away from the pink marker, repeat from step 2.

5) When you are within 1 km of the target, forget about the navball, switch on ASAS on both ships, and use only your translational RCS to approach (IJKLHN keys) exactly like you would in EVA.

[Vanamonde]

If you'd like to practice that part of a mission with ships that begin already close to each other, I made this trainer craft: http://forum.kerbalspaceprogram.com/showthread.php/25425-Help-with-Docking-A-Trainer-Ship-for-Newbies

[starkllr]

Thanks for all the advice. Still no luck, though.

I got to within 50M, and then nothing worked. No matter what I do, I can't keep the target lined up with my velocity markers. And I could never totally kill my relative velocity, no matter whether I thrusted forward or back.

I don't know if I just need more practice, or if my brain simply isn't wired correctly to understand this game. Either way, it's driving me crazy.

[Rockhem]

Thanks for all the advice. Still no luck, though.

I got to within 50M, and then nothing worked. No matter what I do, I can't keep the target lined up with my velocity markers. And I could never totally kill my relative velocity, no matter whether I thrusted forward or back.

I don't know if I just need more practice, or if my brain simply isn't wired correctly to understand this game. Either way, it's driving me crazy.

At 50 meters, just using regular rcs mode will not be sufficent, use the translation controls, I, J, K, L. Get lined up and approach the docking port while moving no more than 0.5 m/s.

If you can complete docking, you have completed one of the most difficult things in KSP. It took me hours and hours to do my first docking. But the key is, Don't Rush. Good luck!

Edited May 26, 2013 by Rockhem

[xXRandomUserXx]

Can you show us a picture of your craft?

[relicen]

Like RandomUser said, it would be good to see a picture of your ship. How the ship is designed greatly influences how easy it is to dock.

Edit: although in this case it seems like the problem is that you havent gotten a grip on the techniques yet.

Edited May 26, 2013 by relicen

[Nibb31]

Thanks for all the advice. Still no luck, though.

I got to within 50M, and then nothing worked. No matter what I do, I can't keep the target lined up with my velocity markers. And I could never totally kill my relative velocity, no matter whether I thrusted forward or back.

You really need to get the zero relative velocity thing figured out. When your relative velocity is zero, this means that your orbit matches exactly the orbit of the target.

Are you sure that the target is selected in the map view? Does the navball say Target ?

If so, it's as easy as pointing your ship towards the yellow retrograde marker, and burning gently until it gets to 0. There really isn't anything difficult about it. Maybe you should explain what you are doing wrong. Then you can approach it gently with RCS only. Don't burn too fast, and don't hesitate to zero out your relative velocity when you start going too fast or you are overshooting.

Do you know how to manoeuver a Kerbal in EVA with RCS ? Learn how to do that, go around you ship, align with it, and get back in. The principe is the same with docking a ship, except that you use the translation RCS controls IJKLHN instead of WASD.

I don't know if I just need more practice, or if my brain simply isn't wired correctly to understand this game. Either way, it's driving me crazy.

You just need to be patient and follow the instructions. It takes several days for Soyuz to rendez vous and dock with the ISS.

[starkllr]

I got to within 50M, and my relative velocity was down to about 1.5 m/s. I was in the Chase camera, using the IJKL keys,and H for thrust forward, N to thrust back. At that point, when I kept thrusting to get relative velocity to 0, it started increasing again, regardless of whether I thrusted forward or back. And then the target began drifting away from the yellow velocity marker, and I couldn't keep them centered. And I couldn't react fast enough to keep up with the movement of the navball.

[PeteMcCartney]

When tryin to kill your relative velocity are you pointing at the yellow retrograde marker? If you thrust towards this you should always be killing the rel velocity, as long as you are in target mode on the nav ball.

[starkllr]

OK, checking in again. Another failed and immensely frustrating effort.

How do you keep the target marker lined up with the prograde (or retrograde) marker. I can't keep everything coordinated. Every time I thrust, forward or back, the target and prograde/retrograde markers drift, and by the time I've recovered with the RCS, the relative velocity has changed.

It's also mystifying to me - I'm watching the relative velocity and I get it moving, and I'm pointing at the target, and it goes down from, say, 2 m/s down to 1 m/s, and the distance to the target is decreasing correspondingly. And then suddenly the distance starts increasing again. I feel like I need either Super Idiot mode, or at least a slowdown mode for when I get extremely close and I can't react quickly enough.

I don't know if it's a lack of mastery of the controls, or a lack of understanding of the basic concepts and techniques. I feel as though I'm never going to figure this out.

[relicen]

The best advice I can give you (without actually showing you in person) is to watch

. Watch the part when he's closer than 100 meters a few times and really, really pay attention to which symbols he's burning towards on the navball to adjust his relative speed.

If you don't get it after that, you're going to need someone to show you in person. You could try to get a few friends to play the game and see if one of them learns how to dock, then have them help you out.

[Dragon7722]

I got to within 50M, and my relative velocity was down to about 1.5 m/s. I was in the Chase camera, using the IJKL keys,and H for thrust forward, N to thrust back. At that point, when I kept thrusting to get relative velocity to 0, it started increasing again, regardless of whether I thrusted forward or back. And then the target began drifting away from the yellow velocity marker, and I couldn't keep them centered. And I couldn't react fast enough to keep up with the movement of the navball.

I actually wonder why nobody mentions the docking mode for KSP.

You should switch to it if you are about 100-50m away from your target and your relative velocity is about 0. It's the button in the lower left corner between the map and the staging control or you can hit the "delete"-key on your keyboard.

When you are in docking mode, you can switch between rotation-movement and linear-movement by pressing space. First, you should go to rotation-mode and try to line up your docking ports parallel to each other... you spin your craft with WASD and QE (roll) while in rotation-mode. Then, you switch to linear-control by hitting space again (all in docking mode ofc) and move your non-rotating ship towards the docking port of your target. While in linear-control, use SHIFT and CTRL to move it upwards or downwards, W and S to move forward and backward, A and D to move left and right. If your angle isn't right, just switch back to rotation-control (hit space) and turn your craft around its axis so it's lined up for the "linear-approach".

All these maneuvers are only done with RCS-thrusters. Also, while in linear-control, SAS is activated automatically to avoid spinning of the craft.

If something is unclear, feel free to ask

Edited May 29, 2013 by Dragon7722

[RoboRay]

Docking mode is generally an inferior control arrangement. You're combining two different sets of commands onto a single set of buttons and toggling between them. Which can be usable, sure, but you have to make sure you're in the right setting before doing anything and you can only rotate or translate at any given moment, not both simultaneously. Staying in Staging mode and working the rotational controls with the left hand while the right hand operates the translation controls offers better control over the spacecraft.

The secondary advantage to this two-handed approach is that it forces you to take your hand off the mouse, so you stop working the camera around. The camera view is a distraction and provides less useful data than the NavBall. One hand to rotate, one hand to translate, and both eyes on the NavBall (or the Docking Camera, if you install that mod)... that's how to dock.

Edited May 29, 2013 by RoboRay

[Colonel_Panic]

Hi Starkllr,

I actually made a tutorial video that covers in great detail exactly this stage of rendezvous. You can see it here:

skip ahead a little ways if you already know about configuring your ship for docking and maneuvering.

[studley]

The advise offered above is great. I found it extremely hard the first 20 times I tried it (and failed). After I got it the first time it got easier and easier. Seems like one of those things that once you've done it you can repeat over and over. Good Luck!

[Rickenbacker]

Regarding ship design: Make sure you turn on the center of gravity marker in the VAB, BEFORE you add anything below the orbital stage. Then put your attitude thrusters symmetrically around it. Four at the front and four at the back, at the same distance from the center of gravity, usually does it for me. This way you won't introduce unwanted roll when yawing, etc etc.

[starkllr]

Thank you all for your very patient help! After watching several tutorials, three more attempts and much cursing at my computer, I finally managed an actual docking!

Now I have to do it again!

[Horn Brain]

That is fantastic, starkllr. Good on you for not giving up and learning something new. You'll get the hang of it and before you know it you'll be building these in orbit:

(album: http://imgur.com/a/HYyAY)

[Nibb31]

OK, checking in again. Another failed and immensely frustrating effort.

How do you keep the target marker lined up with the prograde (or retrograde) marker. I can't keep everything coordinated. Every time I thrust, forward or back, the target and prograde/retrograde markers drift, and by the time I've recovered with the RCS, the relative velocity has changed.

Are you using ASAS? During docking, once you have zeroed out your relative velocity, you really shouldn't be changing your position. Align one ship in one direction (normal/antinormal or north-south is usually suggested) and align the second ship in the opposite position. Then activate ASAS on both ships, and don't touch your WASD keys any more (except if you need to correct your attitude: disable ASAS, rotate, and re-enable ASAS). From there, just place your camera behind your ship and ONLY use IJKLHN keys to translate, not rotate.

It's also mystifying to me - I'm watching the relative velocity and I get it moving, and I'm pointing at the target, and it goes down from, say, 2 m/s down to 1 m/s, and the distance to the target is decreasing correspondingly. And then suddenly the distance starts increasing again. I feel like I need either Super Idiot mode, or at least a slowdown mode for when I get extremely close and I can't react quickly enough.

It will drift around a bit, but you just have to bring it back to from time to time. Aim for zero, not 1 or 2 m/s, then thrust gently towards the ship (the pink marker), and watch your distance. When your prograde marker starts moving too far away from your pink marker, stop to 0 m/s again. Once you are within less than 1km, forget about the navball and just translate like I explained above.

[Colonel_Panic]

few more tips: RCS will always cause velocity change when using it for rotation. turn it off before making major rotation adjustments or using SAS, unless you have a very heavy ship.

use precision controls for docking. Hit capslock to turn them on and your crosshair will turn blue. You can make finer adjustments and save more fuel that way.