I can't dock

[Zerro]

Greetings,

I've watched many rendezvousing and docking tutorials. I've read a couple of written tutorials. I understand the concept of leveling the inclination planes, getting an encounter as close as possible, and just slowly creeping in. Whenever I try in real-time though, I always fail miserably. For instance, last time I managed to get within 100m of target with some assistance from MechJeb(yeah...). It was going okay, I was using RCS and translation keys to edge in with the assistance of LazorDocking. For some reason, even though my ship was aimed on the docking port, it was still wobbling around off course. I don't know if that's just the physics of space or me being horrible. I eventually touch my target but I missed and everything just went bad. I couldn't figure out how to get the module back to the station and after an hour of attempting, I just gave up.

So I'm wondering, am I just horribly bad at docking or is docking the most difficult thing to do in this game? I wouldn't really consider myself to be a patient person; maybe that's my problem. It just seems like there's very little room for error.

I have been thinking about trying to put reverse engines on my ship so I don't always have to be flipping around from prograde to retrograde to adjust my velocity. Any other tips or suggestions on how I could improve my docking skills that might not have been laid out in a tutorial? Also I was wondering, when is the best time to launch to rendezvous with something in orbit?

Thanks for the advice

[DChurchill]

You have to watch what you use for attitude hold with MJ. Ideally, your target should be free floating. SAS will make it stable enough. SAS on the ship you're flying should be good enough, too if you don't care about rotational alignment.

Ideally, use MJ to set up your alignment, then switch to SAS. You'll find yourself to be less wobbly. That being said, if your ship has poor balance, you'll be better off with MJ. It holds attitude better when using RCS thrusters than SAS on an unbalanced ship, at the expense of it being wobbly. Keep in mind that if you're using Smart A.S.S. in target mode to hold attitude, if your target is wobbly, then that's only going to get amplified and make your ship more wobbly. Nothing or SAS only for the target ship.

If you've got sufficient RCS, that should be all you need to adjust your forward velocity once you get close enough to begin to dock. Anything closer that 100m means engine off until you get good at docking.

[Tex_NL]

Next to reaching a stable orbit rendezvous and docking is one of the major milestones one can reach in the entire game. Either you get it or you don't. Until the pieces fall into place it all seems like some weird kind of magic, after that it's child-play.

The only advice I can give you is practice practice practice. No matter what others might say it is not a shame to use mods to make your life a bit easier.

That nasty wobble you encounter when docking (for me it's often oscillating left and right roll) is probably RCS related. The thrust is too high to counter the roll resulting in an opposite roll.

Best rendezvous is on the day side of a planet/moon. Docking is much easier when you can actually see what you're doing.

[Johnno]

So I'm wondering, am I just horribly bad at docking or is docking the most difficult thing to do in this game?

It is one of the more difficult things to master in this game, but even then with a bit of practice it's not that hard to get the hang of.

I wouldn't really consider myself to be a patient person; maybe that's my problem.

Um, yeah. Probably is.

It just seems like there's very little room for error.

There's plenty. If you creep up to your target at 0.2 m/s then two pulses with your RCS should stop you. I'd say practice with lighter ships, easier to control their speed.

Also I was wondering, when is the best time to launch to rendezvous with something in orbit?

Anytime really, just takes longer to reach your target. But it's good for practicing orbit adjustments and aligning orbits, so I'd say just launch and get to orbit, then take it from there.

[LameLefty]

Best rendezvous is on the day side of a planet/moon. Docking is much easier when you can actually see what you're doing.

Agreed, but that's not always possible, especially if one or the other object's orbit isn't precisely circular and you have a pair of close approaches to work with; and sometimes the process takes you into orbital night because of Kerbin's small scale. In any case, that's why EVERY ship I design for docking has a ring of three lights right around the docking port, and now also has a set of red and green beacon lights from the Aviation Lights mod. In the real world, docking and berthing spacecraft have and use lights. Kerbals should too.

[Zerro]

Ideally, use MJ to set up your alignment, then switch to SAS. You'll find yourself to be less wobbly. That being said, if your ship has poor balance, you'll be better off with MJ. It holds attitude better when using RCS thrusters than SAS on an unbalanced ship, at the expense of it being wobbly. Keep in mind that if you're using Smart A.S.S. in target mode to hold attitude, if your target is wobbly, then that's only going to get amplified and make your ship more wobbly. Nothing or SAS only for the target ship.

MechJeb auto docking was kind of acting dumb last time I tried to dock to a Multi-Point Connector. It seemed a bit confused as to what it was doing.

Next to reaching a stable orbit rendezvous and docking is one of the major milestones one can reach in the entire game. Either you get it or you don't. Until the pieces fall into place it all seems like some weird kind of magic, after that it's child-play.

The only advice I can give you is practice practice practice. No matter what others might say it is not a shame to use mods to make your life a bit easier.

That nasty wobble you encounter when docking (for me it's often oscillating left and right roll) is probably RCS related. The thrust is too high to counter the roll resulting in an opposite roll.

Best rendezvous is on the day side of a planet/moon. Docking is much easier when you can actually see what you're doing.

wierd magic like that mythical stuff called Delta-V?

I don't use RCS when I try turning the ship to align with a target. I heard the RCS would just throw the ship off course.

My problem is, I'd probably be coming in at a 30deg angle instead of coming in straight to the target. I think to myself that it's possible to just turn the aft section of the ship but I doubt space physics works that way.

There's plenty. If you creep up to your target at 0.2 m/s then two pulses with your RCS should stop you. I'd say practice with lighter ships, easier to control their speed.

That's another thing that throws me off. My relative velocity may say 0.2 m/s but I'm actually getting further away. Would be nice if it say -0.2 m/s to let me know that I need to RCS forward to catch up instead of playing a guessing game as to what is happening with my velocity

Agreed, but that's not always possible, especially if one or the other object's orbit isn't precisely circular and you have a pair of close approaches to work with; and sometimes the process takes you into orbital night because of Kerbin's small scale. In any case, that's why EVERY ship I design for docking has a ring of three lights right around the docking port, and now also has a set of red and green beacon lights from the Aviation Lights mod. In the real world, docking and berthing spacecraft have and use lights. Kerbals should too.

I like lights too but I found they made docking with Lazor Docking Cam to be much more difficult because the target would be lit up bright in the cam. Of course when I turned off the lights, the target got much darker in the cam :\

Edited August 9, 2013 by Zerro

[annallia]

Agreed, but that's not always possible, especially if one or the other object's orbit isn't precisely circular and you have a pair of close approaches to work with; and sometimes the process takes you into orbital night because of Kerbin's small scale. In any case, that's why EVERY ship I design for docking has a ring of three lights right around the docking port, and now also has a set of red and green beacon lights from the Aviation Lights mod. In the real world, docking and berthing spacecraft have and use lights. Kerbals should too.

Install lights near your docking port. Hold shift and use your qweasd keys to rotate it so it points out at the port you would be docking with and a little bit inward. If done right it lights up the other port like a christmas tree when you get within 20 or so meters.

[Tex_NL]

MechJeb auto-dock has been flawed from day one. It CAN dock but it's incredibly inefficient, it wastes RCS by the bucket load. If you want an autodocker I've read good reviews on ORDA.

[shand]

my key contribution here would be to say this:

balance your RCS in the VAB before launch. this will help reduce wobble - you want the forces on one side of the rocket to equal those on the other use symetry and try to place the rcs thrusters at equal distances from the CoM (important note, this will change as you burn fuel ect, so try to anticipate this)

[blizzy78]

You might want to check out my in-game docking tutorial plugin, of which I have incidentally released an update just a few minutes ago. (see signature)

[Zerro]

my key contribution here would be to say this:

balance your RCS in the VAB before launch. this will help reduce wobble - you want the forces on one side of the rocket to equal those on the other use symetry and try to place the rcs thrusters at equal distances from the CoM (important note, this will change as you burn fuel ect, so try to anticipate this)

I usually try to have 4 RCS at the top and bottom of my tug. One problem though is once in space, I kind lose track as to which way is up and which way is down on translation controls. I've been thinking about putting a marker on the ship in the VAB just so that I can orient myself better.

[Tex_NL]

... One problem though is once in space, I kind lose track as to which way is up and which way is down on translation controls. ...

Switch to chase mode. (Use [V] to cycle through all available viewing modes.) Once in chase mode up will always stay up and down will stay down no matter how you turn or roll.

[blizzy78]

One problem though is once in space, I kind lose track as to which way is up and which way is down on translation controls. I've been thinking about putting a marker on the ship in the VAB just so that I can orient myself better.

There's an easier way: Activate RCS, then press H to go forwards. Just tap the key shortly, you only want to see which way it thrusts. The way the smoke comes out is the rear end

[Zerro]

There's an easier way: Activate RCS, then press H to go forwards. Just tap the key shortly, you only want to see which way it thrusts. The way the smoke comes out is the rear end

I like Tex_NL's suggestion. Seems easier I actually have my translation controls mapped to 8,4,8,2 (7,1 Fwd/Bwd)

One other thing that complicated things for me when trying to dock is when I set the docking clamp as target, the distance marker didn't switch to it. The distance marker seemed to stay on the command module.

[Captain Sierra]

Use Chase mode. Up will then always be up if you look at the ship from behind. Again, I recommend Lazor Docking Cam to help you learn the lineup. There is also a docking alignment plugin available but it does a bit less. Your RCS sounds balanced. As a newbie at docking, I suggest bringing a fair bit of RCS fuel. Most more experienced dockers can dock a tug with under 50 units of monopropellant. I can do it in about 60 on a good day. make sure you have plenty (150 should be plenty). Once in orbit, you won't need much fuel for orbital stuff so don't bring much. It really depends on the engine you use as to how much you should carry. The smallest 2.5m tank should be okay if you use a poodle or an LV 909.

[Captain Sierra]

It does change, but the marker does not move. The distance readout is in relation to the docking port. Do not let KSP's quirks fool you.

[Zerro]

It does change, but the marker does not move. The distance readout is in relation to the docking port. Do not let KSP's quirks fool you.

Damn KSP trying to trick me!