Need help with docking

[baarnold]

Hey guys, I've had KSP for almost a month now and a few days ago I decided to make a forums account because I thought it would be a good idea to connect with the community. Back to the subject, I've been having troubles docking in space and was just wondering if somebody could give me some tips on how to rondevous with another spacecraft without colliding or sweeping by it. Thanks.

[Sovek]

Ahhh yes, one of my most frustrating things to learn and favorite past times with KSP...

The tutorials available dont explain it too well, but lemme see if I can give it a go.

First step: Get the Docking Camera mod found here. This will give you a much better idea of whats going on on your final approach and get your orientation correct. I've done picture perfect captures because of this mod. I know this isnt really helpful on getting close to it... but hey. Another mod to look at is Mechanical Jeb 2 AKA MechJeb AKA MJ2. This can make the node planning take a second instead of minutes trying to get it right. Anyways... on to the meat and gravy.

Step 1. Place something in orbit to dock with. Place it about 120Km or so up. Have it face in a Normal or Anti-Normal position (facing north/south). This helps prevent confusion and even give you impression that its spinning when in fact, its not. More often than not, if you see Kerbin, you will try to use that as a point of reference instead of the target. I speak from experience on this.

Step 2. Launch your ship that you are going to use for the docking procedure. Launch when you have a phase angle of about 45-60°. I'm not entirely sure since I'm used to something in a 300km orbit, and I had to launch with a PA of about 85° or I'd shoot past my transfer window before I got other stuff done. Try to get a near circular orbit, this will help in keeping your separation distance down at time of closest approach. Set you're initial orbit lower than your targets, as this allows you to catch up to the target.

Step 3. Align planes to match. MJ2 helps greatly with this, I always aim for an inclination difference of .01° or better. Burn at the AN and DN, If not using MJ, set up a node to plan it out, get it 0.0°.

Step 4. Transfer burn.... have MJ2 setup this as well, or try to plan it with a 6km separation or better. Try to get the burn right and start cutting back on the throttle when it approaches 0 ÃŽâ€V for the node. you want a .1 m/s difference, otherwise your separation is going to suffer. You'll also want to be ahead of the target and not behind it on closest approach.

Step 5. Fine tuning and final approach. When your target is about 10km start slowing down your relative velocity. I'm assuming you have an idea of what the markers mean... you'll want to burn facing the retro-marker of the target. During this stage you can fine tune your closest approach so a 4.4km separation becomes a 0.0km separation. As you start getting closer to the target (and as your relative velocity drops) you'll see the retro marker shift. You want this marker on the pink triangle at all times. To make this happen, note the angle and distances at which retro marker is to where the triangle is (or the direction of your target). Point your ship along the same angle and direction and past the Retro Marker (or RM), and set SAS. Burn until the RM is back on the triangle, cut engines move back to the RM. Start slowing down even further. As you slow down, the RM will shift, do the same thing as it shifts. When you're within 1km of the target, slow down to about 10m/s relative velocity, and then 5 at 300m and so on. When you are slow enough (3m/s or so) you can start using your RCS translation controls (IJKL, much like WASD, H/N to thrust forward backward) to move the RM back on the target. at about 50m, use RCS to kill your velocity, then start guiding it in. Its really simple once you get the hang of it.

And remember, slow adjustments with RCS, and an direction you thrust in, you'll have to thrust the opposite direction to kill your movement.

Edited April 29, 2013 by Sovek

[EmanonP]

Try these out. Really helped me to get the hang of it.

There are a lot of docking tutorials on youtube besides the ones in this link as well.

http://forum.kerbalspaceprogram.com/showthread.php/15652-Orbital-Mechanics-101-A-Kerbal-Space-Program-Tutorial

[vencaslac]

Docking is a tough one for most people... and I subscribe to everything Sovek here mentioned except the use of MJ for learning purposes. MJ is great for making things easier but it has a learning curve of its' own. Have a look at my tutorial, I hear it's pretty good... There's also

vid on "how to make the dock" funny AND informative

[Sovek]

Docking is a tough one for most people... and I subscribe to everything Sovek here mentioned except the use of MJ for learning purposes. MJ is great for making things easier but it has a learning curve of its' own. Have a look at my tutorial, I hear it's pretty good... There's also

vid on "how to make the dock" funny AND informative

Sorry but I have to disagree. This game doesn't provide the presicion nor the information needed to make docking as easy as it is stock. MJ2 provides this, even if you dont use the auto-pilot, its great for proving lots of other useful (and much needed stuff). Heck, a .09 inclination difference could put your ship farther from the target than it should be, Depending on the altitude difference of your ship and the target. Phase angles are useful too. Trust me, MJ2 helps, alot.

And this video here http://youtu.be/O-y5w28vY2w?t=9m40s explains by moving your Retro marker better than I can by showing you.

[vencaslac]

Yes, MJ does provide a lot of useful information on the fly and in one place... it does help - provided one is familiar with the terminology and with exactly what makes that information useful, so the question really is, is the new player ready to handle that information right away - if they're not familiar with orbital mechanics from prior experience with say orbiter or from just general knowledge i submit that they are not.

[capi3101]

I'd try out the Gemini 6A and 7 tutorial from the wiki; that's how I learned how to do docking. Only other advice I can give you is to take it slow. Consider adding lights near your docking ports if, like me, you constantly wind up having to do docking procedures in planetary shadow...

Really, docking sounds scarier than it is. I've done it a couple dozen times now; I've only botched it badly once (and that wasn't on the first go, believe it or not).

[Kosmo-not]

Docking is easy for me. Of course, I had a plan set up for it before docking became an official part of KSP from knowing about the new marker that would be available to us (the pink target marker). If you play flight sims and like doing instrument approaches, it's similar to that.

This method assumes the axis of your docking port passes through your command pod. (I don't know if this problem has been fixed yet)

1) Maneuver your ship into a position where you would want to go straight in to the docking port from.

2) Select the other vessel's docking port as your target. Right click and select "control from here" on your own docking port.

3) Using the navball, point the "nose" (the dot) of your artificial wings onto the dot of the pink "to target" marker.

4) Use RCS to start moving towards the docking port.

5) Use translational thrust to keep the dot of the pink marker on the dot of your artificial wings.

6) ???

7) Profit, and docked.

Is using MechJeb, things become even easier. You can use the "PAR -" (I think that's the correct one) command on the SmartA.S.S. to point the axis of your docking port parallel with the axis of the other vessel's docking port. It takes the guessing out of lining things up. Fly it in like an ILS approach.

If you have the docking cam... well, that's almost cheating. Docking cam is very helpful for if you have a docking port that doesn't have its axis pass through your command pod.

Once you dock a few times using this method, you will be able to do it in your sleep.

One tip I have for you is to switch the 'I' and 'K' assignments for RCS control.

[ThatBum]

Try the Docking Cam mod.

[Alistone]

My short guide with some tips:

1) launch your target and get it into as perfect a circular orbit as possible. Preferably at a round number. if you can get it at exactly 120km up at both periapsis and apoapsis then it makes your intercept easier. You know exacly what orbit you are trying to match.

2) design your docking vessel. It should include: RCS thrusters that can turn/move the ship in all 3 axis. Plenty of RCS fuel. ASAS. Plenty of fuel for a rocket engine to achieve a close approach/intercept. Also it should have lights and a power source to illuminate the docking port.

3) launch your docking vessel; and set your target as your target using a right click in the map view.

4) At either the ascending or descending node burn south or north to "align" your orbit with the target. Just click on them to set a maneuver nod and adjust the pink triangle orbit accordingly. You'll know you're aligned when you see the AN/DN quickly flip sides.

5) Generally I start in a lower orbit and "catch up" to your target. As you get closer, speed up at apoapsis (or sooner if necessary) into a slightly higher orbit getting closer and closer to the targets orbit. The closer you are to your targets orbit the slower your relative speed will change. If I overshoot then speed up to a higher orbit (higher than the target orbit). Burns are often imperfect; you may need to repeat step 4 to ensure the orbits are aligned.

6) When you get to within 5km of the target click on the velocity display and toggle it from "orbit" to "target". Then point your nose at the target Purple circle using the nav-ball and accelerate toward it at 10-50 m/s. As you close turn and prepare to burn opposite your relative velocity (they yellow circle with an x in it)

7) When you notice that you are no longer getting closer to your target burn toward the yellow circle with an x in it until you reach zero relative velocity (with the target).

8) Repeat 6 & 7, but as you get closer you will need to reduce your speed to just a few m/s. If you find yourself within 100 meters of your target you should burn to zero relative velocity and move to RCS power and "docking mode"

9) Disable your rocket engines. When you are trying to maneuver for docking you will probably accidentally throttle up your engines. Just disable them to avoid a problem.

10) Point yourself at your target and use RCS thrusters to move closer. I usually leave SAS on, but wait until in "docking" mode to turn on the RCS. Just be prepared to turn off RCS as you are "coasting" in so that SAS doesn't use all your RCS gas just keeping it stable.

11) When you get really close (less than 30 meters) don't move toward the target but instead move toward the empty space along the side/end where you intend to dock. Once you reach that space near the docking port, then zero your relative speed, go back to the "normal" maneuver mode to turn your craft to directly align your docking port with the target docking port. Then switch back to docking mode and close the last 30 meters with very careful RCS maneuvers.

12) If you bump the target and it begins spinning then time accelerate briefly to stabilize it and then repeat step 11 to try again.

Edited April 29, 2013 by Alistone

[brienne]

Watch tuto... http://forum.kerbalspaceprogram.com/showthread.php/15652-Orbital-Mechanics-101-A-Kerbal-Space-Program-Tutorial

One thing to really understand: while you re close to the vesssel you re aiming for, switch to "Target" mod with your Navball.

Pro/retrograde marks are now related to the Target. Retrograde: you diminish/stop your movement from target POView. Use Engine until you re 50m from target, then swith to RCS.

Take your time, no hurry!

[joppiesaus]

Sorry but I have to disagree. This game doesn't provide the presicion nor the information needed to make docking as easy as it is stock. MJ2 provides this, even if you dont use the auto-pilot, its great for proving lots of other useful (and much needed stuff). Heck, a .09 inclination difference could put your ship farther from the target than it should be, Depending on the altitude difference of your ship and the target. Phase angles are useful too. Trust me, MJ2 helps, alot.

And this video here http://youtu.be/O-y5w28vY2w?t=9m40s explains by moving your Retro marker better than I can by showing you.

I disagree with you. Everyone docks different, some do it automatic, some don't, some use docking mode, some just do normal controls(like me)

[brienne]

I like to learn and to do it by myslef (no mods, no "help"). Once I'll be bored, I use mods to dock auto.

Docking: hard to understand what to do, step by step. Once you get it, a bit tricky but not difficult.

Edited April 30, 2013 by brienne

[MappleTree]

Hi there, here is a good video that helped me very much on how to manually dock.

hope it helps!

Scott Manly

[Peenvogel]

This one really helped me:

[baarnold]

Thanks allot for all of the help. I'm having troubles installing mechjeb 2 and I'm very unsure of what to do with the files because by themselves they do nothing...

[Kosmo-not]

I really should make a new video on how to dock like a pro.

[kajoman]

I just started a post with my and some other people's tips on docking. Maybe it'll help:

http://forum.kerbalspaceprogram.com/showthread.php/26886-Docking-With-Ease

[Sovek]

Thanks allot for all of the help. I'm having troubles installing mechjeb 2 and I'm very unsure of what to do with the files because by themselves they do nothing...

Just need to copy the "Parts" and "Plugin" folders into the main folder of your KSP installation, place a MJ AR202 module on your craft (found under the control tab) and get get all the mechjeb features .