Another idiot who can't dock.

[King_Gus_Man]

Wow, was not expecting this much response that quick.

I have not had time to try any of these things, but there seems to be some new ideas here that I didn't understand the last few times I've tried docking. I'll try this stuff out the next time I'm playing.

I think docking will help me out with my new problem, Jebadiah is stranded in the Mun without enough fuel to even break orbit. If I can establish a refuelling station in Kerbin orbit, i should have the fuel needed to make the rescue mission.

I'm not against mods, i use Kerbal Engineer Redux for all the extra info and I have MechJeb but have no idea how to use most of it. I'm not interested in using any kind of auto pilot, but I'm not against tools that will give me the information I need to make this happen.

[King_Gus_Man]

It sounds like you are doing it just right, but once at a close encounter are never quite getting the relative velocity down.

My bet is also on problems with orbit/target settings on your navball.

Once you get your nice close 1km intercept you want to burn retrograde all the way to 0.0ms. Leave em hanging dead relative to each other. They will try and slowly drift since their orbits wont be perfect matches, but it gives you a nice static frame of reference for the final RCS approach. While burning rcs to approach the target (h), you want to use the strafedrive (ijkl) to bring your green prograde marker over the purple target prograde, otherwise you drift just past him on a relative drift. Remember that once the navball is in target mode the green markers are your speed relative to target, so you want them to sit directly over the purple markers to get a straight approach-vector.

Keep at it, you understand the problem and seem to be doing it 99% right.

This seems to be the thing that makes the most sense after reading through every thing that has been posted. I really feel like that is a method I can follow.

[SuperBigD60]

Once you've figured how to do it once, just design other missions that involve more docking and rendezvous.

Really I suspect this is a sort of skill that you internalize better by doing it A LOT.

[King_Gus_Man]

I would tend to agree, my job has had me doing 24 hour shifts every other day so I haven't had much time to play lately. It makes me mad that my Minimus landing and return went so easily, but after 5 attempts I still have a man stranded on the Mun.

Just a side note, this is in Career mode so I don't have access to all the parts just yet. I have the basics to begin constructing a refuelling station, I just lack the ability to do so right now. With an orbital refuelling station I can redesign my lander to have enough fuel to make the return from the Mun, or just push the station to a Mun orbit then I just have to get the lander into a mun orbit, refuel, then drive back. Either way, I'm not leaving Jebadiah behind.

[catastrophy]

I thought I'd never learn that too, but then I figured out how to use Nav-Ball and the Nodes (they can be moved!!! along the orbit). Once you're close, kill your relative v to target (target mode), point to target and accelerate. Use little amounts of thrust and coast. Go retrograde once you pass the target and kill your v again (all relative to target).

The rest is figuring out how to use RCS (docking mode - remember the space bar) and align the docking ports.

[DrMonte]

Not suggesting to practice this but if your docking ports are not aligned (which happens very often) and ships are rather small you can still dock them. Just collide (aka dock) the ships with docking ports. They wouldn't dock as the ships are not in line but keep pressure and try to gently rotate. Both ships will rotate to the needed side and ports will dock.

That's some desperate maneuver when docking su..ed to the death. But quite effective.

[DaMichel]

When i learned to rendevous, i killed my relative velocity completely several times during the encounter and then just burned toward the target. Approaching with 5m/s from a distance may be too slow because as you noticed you target will run way. When you are 5km to target you might try .. say up to 50m/s relative velocity. Burn relative retrograde and lower you speed as you get closer. At some point you have to switch to RCS. Use lateral thrust to keep your velocity vector on target. It takes a bit of practice but it is actually not hard. For when you are really close i also suggest NavyFishs Docking Alignment Addon. Also while learning make sure that your ship has high TWR and powerful reaction wheels to make the whole thing more responsive.

[deadelitezealot]

it is really not that hard really after a first succesfull try it gets routine

just target make orbit make nodes cross use rcs orbit is getting even and you fall with it in space orbiting

and then rcs

[blizzy78]

@OP: I've made an in-game rendezvous tutorial that should help you getting within docking distance, without zipping by the target vessel. (see signature)

[aimeilian]

Sounds like you're on the right track and getting advice that makes sense to you to help improve -- all wonderful!

One tiny little trick that I learned from some random tutorial (sorry I don't remember whose it was): before making your rendez-vous, rotate the craft with which you'll be docking so the port you want to dock with is pointing at exactly 90° to the plane of its orbit (i.e. along its normal or anti-normal).

Why, do you ask?

Because your target is going to retain its orientation as it orbits Kerbin (or whatever body it's orbiting). That means that, for example, if your target port is pointing prograde at one point of its orbit (say periapsis), it will be pointing RETROGRADE at the opposite point (say apoapsis). Which in turn means that, in the relative frame of your target and the craft you're manœuvering to dock with it, the docking port is spinning around in circles and you have to keep adjusting your vector and orientation to keep up with it. If your target docking port is pointing "straight up or down," then it's going to simply rotate about its axis rather than present a target you're chasing around.

Admittedly, the effects of orientation are small, and as you level up your docking skills this step will become superfluous -- but just starting out, if there's a variable you can eliminate, eliminate it! It lets you focus on the basics and get them down first.

Good luck and safe flying!

[Xiphos]

I still have a man stranded on the Mun. Either way, I'm not leaving Jebadiah behind.

I know how you feel, In my career mode, jeb is in solar orbit from accidental mun slingshot when I warped past it by accident. Ooops. Anyway, to answer your original question, make sure you are canceling your relative velocity to your OWN retrograde marker, not the targets retrograde marker. (The green one with the X inside) If you try and cancel relative velocity by burning to the target retrograde, you'll never reach the target. I have made a docking tutorial back in .19, link in my sig if you're interested. Even though it's a earlier version of the game, the basic principles apply. I wish you luck in your missions!

[King_Gus_Man]

Rescue mission to Mun finally went fairly well, lander had 880 dv left, but I landed a nice piece away from where Jebadiah was stranded. Annnnddd, he was killed during the Eva to the rescue lander.

RIP Jebadiah Kerbal.

Not sure if 880 is enough for the return and I just botched it, or if I need more, but all that got me was back into a Mun orbit.

The only science I have left to get in the Kerbin system is recovering a ship that landed on the Mun. Going interplanetary seems a bit out of my reach given current technology unless I get this docking down.

I'm going to mark this as answered, I'm pretty confident that I can get this docking with the new ideas I got hear. Which leaves me with one question, is there a sub forum that is more of an ongoing mission log? Some place I can post about the mission as a whole and ask questions as they come up, rather than making a new thread here every time I get lost.

[Galileo Kerbonaut]

Yes there is: http://forum.kerbalspaceprogram.com/forums/55-Mission-Reports

[King_Gus_Man]

Awesome, I guess I'll be starting up a thread over there.

Thanks to everyone for all the tips and advice, I'm sure I'll be docking in no time now.

[alkopop79]

Maybe not the most effecient way, but easiest for me.

1. Get to somewhat nearby distance , even 10 km is okay. Kill all relative velocity to <1m/s

2. Aim just at target , get 5-10 m/s (depending on distance) relative vel , velocity vector must just aim at target vector on navball

3. Fly =) Use rss in translation to keep velocity vector on target's vector.

4. Slowdown at 100-50m , killing rel vel to 0 again.

5. Switch camera to chase view , point just behing the ship - this will help a lot with rss translations , they will become intuitive as WASD

6. Slowly coast to the point 10-15m from docking port normal , like on docking trajectory. Stop once there.

7. Point docking port , burn small speed and dock. Use rss to keep on docking trajectory. RSS on low-power (capslock) can help.

... and this is exactly how I just managed my very first docking after months and months or trying. Thank you!!!

[Streetwind]

...Wait, you mean you used the forum search function instead of making a new thread?

Impossibru!

(Congrats on your successful rendezvous btw)

[RW-1]

No you're doing it right.

Only one thing I see missing here for a complete docking,

add step 5.5 (Actually could eb anytime, but easier when you are in range) - click on target docking port and select as target.

[KillSwitchX]

I've learned a lot since I wrote this original post in 2016 so I've made the appropriate edits and reposted. What follows should be a successful docking tutorial from start to finish (minus pictures).

I will say this, it is of utmost importance to do the following things if you want to successfully rendezvous and dock ships:

• Get orbits of the ships you want to dock into close relative orbits (have an Apoapsis and/or Periapsis that is close to that of the other, this allows at least one point where the orbits can have a close intersection to allow the crafts to get close to each other (I suggest within a few Km, the closer the better and the more aligned overal the orbits the better chance for a closer intersect without much work and deltaV cost) Note that difference between the orbits is good as well, getting the orbits too aligned or having too much deviation can actually make getting an intersect to take more time, the idea is to have a bit of deviation in the orbit this will take some practice at first possibly.
• (Optional) Circularize both orbits before attempting other maneuvers, ie: Close Apoapsis and Periapsis for both orbits (this will make sure ships don't have tendency to drift apart on their orbits).
• Make sure you select the ship you want to target for docking (right click and select "Set as Target"): The target orbit will show as yellow.
• Create a maneuver node and check the orange and purple indicators for closest intersects, *KEY* the +/- on the maneuver node will assist with setting the node time which adjusts the orange and purple intersect points, get either one as close as you can to the matching one for that pair (orange to orange and purple to purple, both don't have to match...just pick one and get it close to the other one of the same color (preferably no father than 50km apart though farther can work as well...the main things to watch are the distance apart and the relative velocity a higher difference in relative velocity and distance will require more delta V (fuel) to narrow the difference between each).
• Use the tracking station to cover large time gaps as you can watch your ships and see the maneuver node time in the status on the left (as MNV -X:XX) and warp may allow higher settings, be careful not to overshoot your maneuver node or you need to start over.
• When you get to the proper intersect after the maneuver node has been reached for the time selected you should be relatively close to the other ship and velocity as noted by the intersect indicators, it is now time to zero out your relative velocity with respect to the other ship. Make sure you have TARGET selected on the NAVBALL (as opposed to a setting of Orbit or Surface which will give you incorrect readings for what you're attempting to do), this will ensure you get the target velocity and vectors needed to get close to your target).
• With Target selected on the navball orient your ship towards the retrograde vector and burn to get the relative velocity as close as possible to 0 (doesn't have to be exact, just try to get it within a few or say up to 10 m/s).
• Now point towards the target vector and burn as much as you want to give yourself a nice shot at your target (faster isn't necessarily better as you will tend to waste more delta V with excessive burns), try to keep it say under 50 m/s with respect to the target, as you will need to do a series of burns to correct for movement of the target around its orbit against your current movement.
• Watch as you speed towards the target making sure you are closing the distance and not going farther away from the target. Once your relative velocity and distance to the target starts to slow it's time to again zero out your relative velocity with respect to your target (this is why you don't want to make your initial speed towards the target too high, you will end up wasting delta-V on corrective and slowing maneuvers).
• Point back to retrograde vector again and burn off as much relative velocity to get back to zero (or close).
• Again, point towards the target and burn again as much as you feel comfortable with (each time should require less delta v, say a third or half less than the prior step).
• Continue this process until you are within a comfortable range of 1km or so from your target and again zero out your respective velocity to the target with a retrograde burn.
• You can keep doing the steps above to get ever closer to the target but take care not to overshoot or risk slamming into your target (that's bad mmmkay?)
• At about 100 meters is a good place to switch to RCS thrusters (turn RCS on [r key] ensuring your ship has RCS tanks and thrusters (you included those right?
• When you get within about 100 meters or so to the target again zero velocity with respect to the target and ensure you are moving no more than several m/s with respect to the target at all times, this should make rotational and translational movements easier
• *KEY* It is FAR easier to dock if both vessels have RCS, power, etc...you can position and orient each with respect to the other on the fly by using the [ and ] keys which will cycle between close ships and allow you to position each so that they're oriented and facing direct towards the targeted docking port of the other.
• When close (Under 1Km) use RCS thrust ONLY in Chase cam mode
• Switch out of map mode and find the target ship in your normal ship view.
• Set the target to the individual docking port you want to use when close enough to see it with your normal view.
• Once you're within about 100 meters or so now is a good time to set an individual target piece of the ship you want to dock with (usually a docking port, duh) so select the part you want to dock with (usually the most accessible part directly facing you)...right click and click "Set as Target", if you can't select this you may need to get closer first.
• Now is the time to set the piece you want to control from, this is an important step and done on the ship you are guiding towards the other (keep the other relatively still to make the process a little easier, but can adjust as needed). This will orient the navball so that the vectors are aligned with respect to the port you select on your ship and you will be able to orient with respect to the ship you are targeting, you can spin the ship so that the navball is over the target vector. Switch to the other ship (using [ or ]) and do the same from there setting the same port on your ship as the target and aligning the ports, hopefully the prograde vector should be over or close to the target indicator, if it is not, you need to get it there, the first step is aligning your target with the center of your navball and then watching your relative velocity, if it is 0 or close there sometimes won't be any prograde or retrograde markers so using your RCS thrusters (with Docking mode on) apply a bit of forward thrust (Shift key) until the Target velocity reading is  0.1-0.5 m/s - this can be anything but again faster doesn't equate to better necessarily - Especially when docking.
• Of enormous help to me was someone who mentioned keeping the Prograde vector over top the Target vector. The more aligned you keep the two ships with respect to each other the better, I like to make sure both ships are oriented exactly as close as can be to each other and if you do it right they should "fall together" moving within fractions of 1 m/s.
• Repeat this technique until success!

Edited October 3, 2020 by KillSwitchX
I am editing this after several years and improved my docking technique significantly and want to reflect such in the post.

[ibanix]

On 11/23/2013 at 11:53 AM, Taki117 said:

If you are having trouble lining up your docking ports (And are not adverse to using mods) you could get the Docking port alignment indicator by Navyfish All it is is a little window that pops up when you select your target as a docking port and it shows your relative orientation and speed, as well as distance from the docking port, not the center of the station.

^ What he said. The Docking Port Alignment indicator mod is mandatory for me.

[Waxing_Kibbous]

Just my 2 cents:

Once you get in close, take some time to get everything lined up. Make one port line up on the south facing point on the navball, and the other on the north. Next, on the ship you are controlling, rotate it until it is lined up perfectly with the RCS controls, as square as possible with them so the left/right and up/down are lined up with the X/Y of the screen and the keyboard keys. Don't try to dock while you are thrusting diagonally and the keys are mirrored. Lastly, take your time, it's not a race. Get one dock under your belt and you will be good to go.

Try to make a couple of rovers and dock them together at KSC just so you get a feel for how things lock together.

Edited June 5, 2016 by Waxing_Kibbous

[Warzouz]

A trick to dock even without any alignement issue.

When you have your rendez-vous (around 100m from your target),

• Switch to your target
• Select you own ship
• "Control from" your desired docking port
• Set SAS to "target" and wait for the orientation to match
• Switch back to your vessel
• Switch SAS "Target"
• Move forward until touchdown.

Of course this is possible if both ships have sufficient SAS capacity.

Edit : I don't use this method much, because it's quite crude. I prefer the beauty of translating. But it's very efficient if your ship has no RCS. I usually turn the target ship to avoid translating around a station. It's much quicker that way.

 

Edited June 6, 2016 by Warzouz

[Oafman]

On 23 November 2013 at 10:07 AM, King_Gus_Man said:

That's me, I just cannot make it happen. I've read every post on the forum that I could reasonably find about it. I've read the wiki pages I could find. I watched the Scot Manley tutorial on docking. I still just cannot do it.

Here's my problem, 2 orbits, both are nearly perfect circles. (Less than 1000 m between Ap and Ep). I wait for the ship in the lower orbit to be right behind the one in the higher orbit, burn pro-grade which pushes ap out and gets me an encounter, (usually between 1km and 4km, but I've gotten as close as .1km). Now that I have an encounter I have to kill relative velocity, so I burn retrograde, relative velocity is under 5m/s, but now the other ship is as close as it will get on its own, and if I burn at the other ship to keep it that close my relative velocity goes way up. If I keep relative velocity down to a manageable level, the other ship runs away and I have to wait for another encounter.

Am I missing some key trick? I've tried doing everything with RCS (as one tutorial suggested) I've tried getting to about 100m before I start using RCS (as another suggested), I've tried not using RCS at all (just to see if I could do it, I can't). I hate to lose, but this docking thing is making me think about giving KSP up.

Being a little pedantic, it's rendezvous that's your problem, rather than docking. Once you've matched velocities at close range, you have a bunch of new problems to look forward to! But you need to RV first. 

Any mention of the nav ball is conspicuously absent from your post. It sounds like you're doing this in the map screen. Early on that's fine, but when you get close to your target (within a few km) you really need to use the nav ball markers. You can still do that in the map screen of course, but the point is you need to be focusing on the nav ball rather than the orbits on the map screen. 

You want your retrograde (yellow) to sit directly on top of the target retrograde (pink). If your yellow marker starts to move away, which it will, then you need to 'push' it back onto the pink marker. Move your heading away from it, so the yellow marker is directly between your heading and the pink marker, and burn gently. Your yellow retrograde marker will move back towards the target marker, and you'll also slow your relative speed down a little. 

If you over do it, and find yourself going too slowly, then spin your ship around and point to the target prograde. Except this time, you need to pull your prograde marker onto the target, instead of the way you pushed your retrograde marker. 

Reading this back, it seems kind of confusing. But honestly, it does make sense.....

Good luck. It took me ages to learn to RV and dock. Weeks. But it's a great feeling when you finally crack it. 

[Stoney3K]

On 26-11-2013 at 5:45 PM, aimeilian said:

Sounds like you're on the right track and getting advice that makes sense to you to help improve -- all wonderful!

One tiny little trick that I learned from some random tutorial (sorry I don't remember whose it was): before making your rendez-vous, rotate the craft with which you'll be docking so the port you want to dock with is pointing at exactly 90° to the plane of its orbit (i.e. along its normal or anti-normal).

Why, do you ask?

Because your target is going to retain its orientation as it orbits Kerbin (or whatever body it's orbiting). That means that, for example, if your target port is pointing prograde at one point of its orbit (say periapsis), it will be pointing RETROGRADE at the opposite point (say apoapsis). Which in turn means that, in the relative frame of your target and the craft you're manœuvering to dock with it, the docking port is spinning around in circles and you have to keep adjusting your vector and orientation to keep up with it. If your target docking port is pointing "straight up or down," then it's going to simply rotate about its axis rather than present a target you're chasing around.

Admittedly, the effects of orientation are small, and as you level up your docking skills this step will become superfluous -- but just starting out, if there's a variable you can eliminate, eliminate it! It lets you focus on the basics and get them down first.

Good luck and safe flying!

This is especially useful if you're building a station since you don't want to re-orient it every time a visiting craft wants to dock.

MechJeb's Smart ASS can re-adjust the orientation of a ship if it is in physics range, but the stock SAS can't control any craft except the active vessel.

[Mr Shifty]

On 6/4/2016 at 11:36 AM, KillSwitchX said:

• Get orbits of the ships you want to dock into close relative orbits (Several Km of one another).
• Circularize both orbits before attempting other maneuvers, ie: Close Apoapsis and Periapsis for both orbits (this will make sure ships don't have tendency to drift apart on their orbits).
• Get Target Nodes close to the other ship using a manuever node to put you on path with the other orbit (Within 5KM).
• The real key to successful docking for me was learning how to properly burn toward target and away from target to control velocity [NOTE: USE YOUR RETROGRADE NOT ANTI-TARGET]
• When within several hundred meters of target you should get relative velocity to around 5 m/s or less give or take using above technique (Again the two vectors to use are TARGET and RETROGRADE vector when set to Target mode...It is easy to confuse these vectors with Prograde and Anti-Target, DO NOT use these vectors.)
• When close (Under 1Km) use RCS thrust ONLY in Chase cam mode
• Switch out of map mode and find the target ship in your normal ship view.
• Set the target to the individual docking port you want to use when close enough to see it with your normal view.
• Of enormous help to me was someone who mentioned keeping the Prograde vector over top the Target vector, you will have to "chase" the target vector around the nav ball using Forward RCS thrusters while maneuvering to keep the prograde on top of the Target vector, [Your relative velocity should be no more than 1m/s].
• Repeat this technique until success!

• You don't need to match orbits, you just need an intercept that passes closer than about 20km. I usually am for 1km or less, but it's not necessary.
• Once you're within about 20km, it's all velocity control. You should be able to see the target and a readout of its distance. I tend to keep closing velocity at about 20x the distance e.g. at 20km I try to be closing at 400 m/s. 10x is probably more reasonable if you're starting out.
• You're wrong about vectors, you want your prograde marker on top of the target marker, and your retrograde marker on top of the anti-target. Another way of saying this is that you want to be moving toward the target. If your relative velocity is too high, point your vessel toward retrograde; if it's too low, point your vessel toward prograde.
• When you fire your engines, it will "pull" the prograde marker in the direction you're pointing and conversely will "push" the retrograde marker away from the direction you're pointing. You can use this to position the pro/retrograde markers over their respective target markers. If you keep the markers aligned and continuously slow down as you approach the target, your obit will align with the target's automatically.
• Once within 50m or so, dock using RCS. Note the tricky part of this is orienting your vessel properly, since there's no indication of this on the Navball. Using a helper mod like the Docking Port Alignment Indicator or the NavBall Alignment Indicator can help.
• On non-north/south docking ports, you really have to dock quickly. The relative vessel orientation will rotate through 60° every 5 minutes in LKO.

[Spaceception]

Anyone else noticed that the last post not from a couple days ago was in 2014, and that it was made in 2013?