In game docking tutorial

[Silverwood]

Hello

I am having real issues with the in-game tutorial on docking. I click the man node and then adjust the orbit with the up/down markers, but I can never get anywhere near the zero required. 

Has anyone completed it and if so am I doing something wrong? I follow the instructions - but just can't get the zero required.

Keith

[Cpt Kerbalkrunch]

Are you talking about zero inclination? Or are you trying to get the rendezvous down to zero meters? I suspect you're talking about the inclination. If so, once it's down to around 0.1 or 0.2 it will register as complete and you'll be able to move on with the tutorial. But getting to zero will give you a better rendezvous. If you can't get it with the man node, just get as close to zero as you can, then delete the node altogether. Now right-click the ascending or descending node (whichever is on the far side of your orbit) so it will stay visible. Now warp up to the nearer node (An or Dn) and use SAS hold on either normal or antinormal (depending which direction you need to go obviously). Now tap the shift key to accelerate slowly. Without a man node, you can actually watch the inclination change, and can therefore kill your engine right when it reaches zero.

[bewing]

Well, there are 8 ways to adjust a maneuver node. Forward and back in 3 dimensions, plus you can slide the maneuver node around your orbit, forward and back.

Yes, probably everyone who has played the game for 6 months can complete the tutorial. But adjusting that maneuver node is really tricky. Experienced players also know that you do not really need to get the intercept to zero. You just need to get your ship out to the destination a bit before the other ship arrives. Once you do that, you have plenty of time for adjusting the intercept to get it really close.

Once you have gotten your orbit coplanar (to 0.0 degrees), the only maneuver node adjustments you want to do are prograde/retrograde and sliding. You adjust prograde so that your orbit is big enough to slightly intersect the destination orbit. Then you watch the intercept distance while you slide the maneuver node forward around your orbit. When you get it close, you start tweaking the adjustments as carefully as you can.

[Regor]

1 hour ago, Silverwood said:

Hello

I am having real issues with the in-game tutorial on docking. I click the man node and then adjust the orbit with the up/down markers, but I can never get anywhere near the zero required. 

Has anyone completed it and if so am I doing something wrong? I follow the instructions - but just can't get the zero required.

Keith

That one time, I docked with a spacecraft that was on 10 degree inclination difference from me

[Cpt Kerbalkrunch]

56 minutes ago, bewing said:

Well, there are 8 ways to adjust a maneuver node. Forward and back in 3 dimensions, plus you can slide the maneuver node around your orbit, forward and back.

Yes, probably everyone who has played the game for 6 months can complete the tutorial. But adjusting that maneuver node is really tricky. Experienced players also know that you do not really need to get the intercept to zero. You just need to get your ship out to the destination a bit before the other ship arrives. Once you do that, you have plenty of time for adjusting the intercept to get it really close.

Once you have gotten your orbit coplanar (to 0.0 degrees), the only maneuver node adjustments you want to do are prograde/retrograde and sliding. You adjust prograde so that your orbit is big enough to slightly intersect the destination orbit. Then you watch the intercept distance while you slide the maneuver node forward around your orbit. When you get it close, you start tweaking the adjustments as carefully as you can.

Every experienced player can dock, but not every experienced player has done the tutorial. I got frustrated like @Silverwood and just moved on. I did my first docking in-game a few months later, then came back and did the tutorial after just to compete it for the satisfaction.

If you read the OP (and have done the tutorial), you'll gather that he's most likely talking about the inclination. You only need to get your rendezvous down to within 5km to move on in the tutorial. However, you have to get the inclination down to zero (or .1 or .2, as I said) to move on. He also said "up/down", which I take to mean normal/anti-normal. Though perhaps you're right and I'm the one who's mistaken. I've only been playing for six months after all. 

[Silverwood]

Yes it is the inclination that I can't get to zero. And yes I am using the normal/ anti normal nodes.

I will try again now.

 

[Cpt Kerbalkrunch]

14 minutes ago, Silverwood said:

Yes it is the inclination that I can't get to zero. And yes I am using the normal/ anti normal nodes.

I will try again now.

 

And I know they tell you in the tutorials, but rather than pulling on the dials on your maneuver nodes, it's often easier to just spin the mouse wheel. It gives you much finer control. I've gotten so used to doing it, I even use it for very long burns. It's become a habit now, but a useful one.

[Human Person]

34 minutes ago, Silverwood said:

Yes it is the inclination that I can't get to zero. And yes I am using the normal/ anti normal nodes.

You have to make the maneuver exactly on your ascending/descending node.

however: Adjusting your Inclination can easily be done without maneuver nodes: 

When approaching the ascending node, point Antinormal and vice versa.

Make a careful burn just before you reach the node, you can now "push" the node infront of you until it reads zero.

[Silverwood]

Ok - I think I have it now. I was using the normal node, but it required the anti node. So have got past that hurdle, even got as far as 500 m from the ship to be docked. Ran out of fuel then! The tutorials are not for the faint hearted.

At least I have managed to get the first bit done. Shame you can't save as I have to start from the very beginning again.

I dont suppose the actual instructions are available anywhere? Would be good to have all the steps to hand.

[bewing]

What Physics Student said was right. To reduce inclination to zero, forget about maneuver nodes. Wait until you are very close to the node and then burn antinormal or normal until the node value goes to zero. For the last little bit of it, you need to be very careful -- but it's a million times easier just to do it than to set a maneuver node. I know the tutorial suggests that you make one -- but I don't.

 

[Spricigo]

3 hours ago, bewing said:

Yes, probably everyone who has played the game for 6 months can complete the tutorial. 

I take your word,  since I didn't touched the in game tutorials yet.    But,  based on what people say,  seems pretty effective. Still,  who need a tutorial,  by definition,  didn't grasped the subject yet. How a more experienced player manages to complete a tutorial, unfortunately, is not really relevant. 

 

1 hour ago, Silverwood said:

Yes it is the inclination that I can't get to zero. And yes I am using the normal/ anti normal nodes.

I will try again now.

 

You probably know (and 'everyone tell' )  to match inclination you need to be at AN/DN,  where the trajectories crosses.  Well,  that is technically correct, for the same reason many things we say about orbital mechanics also are technically correct : maneuvers take time. 

Now you probably think 'no problem,  I need to do a x s burn.  I start x/2 s before the node.  Half before,  half after,  should work' . Well it may work,  except that while you did half of your maneuver the AN moved further ahead,  maybe more than the time you need to finish your burn or even far enough that you are closer to your DN and your inclination is increasing. 

My advice(also kinda TL:DR version):

-Don't use maneuver nodes, it hides the actual AN/DN. Be in map mode with the mouse over AN/DN marker (or use KER/MechJeb/SomeOtherMod time to AN readout) 

-start the maneuver just before the AN/DN.  As close as possible without passing that point. 

-control the throttle so time to AN/DN decrease as inclination decrease.  Ideally reach AN/DN when inclination reach 0.0°.*

-Practice. Practice  Practice. 

 

 

 

 

-And practice even more. 

[bewing]

1 minute ago, Spricigo said:

Still,  who need a tutorial,  by definition,  didn't grasped the subject yet. How a more experienced player manages to complete a tutorial, unfortunately, is not really relevant. 

Yes, that was a joke.

But still, docking really is one of the hardest things in the game to do, and it does take time to learn.

 

[Spricigo]

1 minute ago, bewing said:

Yes, that was a joke.

But still, docking really is one of the hardest things in the game to do, and it does take time to learn.

 

I still need to accept your word since I have no experience whatsoever with the tutorials. And for the same reason I had little chance to get the joke.

In any case good joke have some dose of truth. In that case the fact that experienced player, used to do [insert task here], may forget how difficult it was to learn that task, let alone the difference from person to person. Something people that offer help should always keep in mind.

[felcas]

4 hours ago, mabdi36 said:

That one time, I docked with a spacecraft that was on 10 degree inclination difference from me

You got the DOCKED DRUNK achievements. Congratulations

 

[felcas]

52 minutes ago, bewing said:

Yes, that was a joke.

But still, docking really is one of the hardest things in the game to do, and it does take time to learn.

 

I second on that, but I have to add that, poor ship design on how to place the RCS thrusters may dictate how  hard or f#$%^@ing hard docking becomes latter on. 

The secret for an easier docking is to study very carefull the placement of RCSs in relation to the CoM. I am still learning about it and I can few inprovements. It may sound simple, but change in fuel quantity in the tanks will move the CoM back and forth and soo you need to think ahead how much fuel you will have when you will need to use the RCS. And to make things even more challenging, the CoM may be just aligned with a surface that you can't put the RCS.

 

[Cpt Kerbalkrunch]

2 hours ago, Silverwood said:

Ok - I think I have it now. I was using the normal node, but it required the anti node. So have got past that hurdle, even got as far as 500 m from the ship to be docked. Ran out of fuel then! The tutorials are not for the faint hearted.

At least I have managed to get the first bit done. Shame you can't save as I have to start from the very beginning again.

I dont suppose the actual instructions are available anywhere? Would be good to have all the steps to hand.

I'm gonna assume that means you want the entire docking rundown, which will make for a long post. I'm stuck at work on the 4th of July with nothing much to do, so I'll give you my take on it. This will go on for a bit, though. So...

 

Now you're actually at the good part. Five hundred meters is actually a great rendezvous. What matters at that point, is your relative velocity. Click on your Navball 'til it's set to Target, then hit Retrograde hold on your SAS. You're now pointing "away" from the other ship. Now you need to burn retrograde to get your relative velocity down to zero, but you want to time it so that it hits zero (or very close to zero) at your rendezvous point. This can be tough to get the timing right. A good trick is, when you're about a minute or so away from you rendezvous, burn retrograde for just a second to see how quickly your relative velocity goes down. This should give you a good idea of when you'll need to burn. You can also burn in stages. Burn a little, check your rendezvous (it will be further away, time-wise), then burn some more.

Once you're at your rendezvous, and close to zero relative velocity, kill your engine and turn on RCS. Hit H (which moves you forward, but since your ship is pointing retrograde, this will actually be pushing you backwards; in essence, slowing you down). When you hit zero, disable your RCS. You are now floating in space, hopefully within a few hundred meters of your target vessel, and the two of you are "not moving" in relation to each other. This isn't exactly right, but it's close enough.

Now right-click your docking port and select Control From Here. The game will now measure distance and heading from this point. Just makes your Navball a bit more accurate. Hit Target hold on your SAS. Your ship is now facing the target vessel, docking port-first. Now switch control to the target vessel.

In command of the target vessel, move the camera around and locate your original ship. Double-click it to target it (it can be tough to spot another ship sometimes: if you have trouble, just switch to map mode and target it from there). Now right-click your docking port and select Control From Here. Turn on SAS and set it to Target hold. Both of your ships are now "stopped" in relation to one another, and are floating in space with their docking ports lined up and pointed at one another.

Now switch back to your original ship. Turn on SAS, but without selecting any direction. You just want it to hold you steady. Engage RCS and press H to move forward. Watch your relative velocity and your Prograde marker. You want your Prograde marker centered on your Target marker. You'll usually accomplish this, not by burning directly at the Target marker, but by burning off to one side or the other. Watch how your Prograde marker moves and adjust course accordingly. You can press N to slow down, and you'll see you need to be on the other side of the Prograde marker to move it towards the Target marker (sounds confusing, but play around with it and you'll see what I mean). When you're new at docking, keep your speed slow. Really slow. Less than a meter per second. Around .2 to .4 is good. Just use time warp to speed up and, again, watch your markers. If you see the Prograde marker begin drifting off to one side, stop time warp and adjust course. Keep moving to within 100 meters of the target vessel. Turn the camera until you get a good look at the other vessel's docking port. Try to click on it (this used to be really easy before 1.2; you just needed to be within 200 meters and click on the other ship near the docking port). It may be tough. Just keep trying to click on it if you can, and select Set as Target. If you can't, it's not the end of the world. Just makes lining up a bit more exact. Just keeping easing forward, with your markers lined up, until the docking ports kiss one another. You might need to wiggle a bit to get them to connect. They're magnetic, though, so once you're close enough to being lined up they'll come together. And when they do, congratulations. You just accomplished one of the toughest things to learn in the game. The solar system is yours. 

As an alternative, there are about a million videos online. If you can find a good one, they can be helpful. I don't much like them personally, cuz I'm always trying to move the camera angle. It's irritating.

[Tyko]

1 hour ago, felcas said:

I second on that, but I have to add that, poor ship design on how to place the RCS thrusters may dictate how  hard or f#$%^@ing hard docking becomes latter on. 

The secret for an easier docking is to study very carefull the placement of RCSs in relation to the CoM. I am still learning about it and I can few inprovements. It may sound simple, but change in fuel quantity in the tanks will move the CoM back and forth and soo you need to think ahead how much fuel you will have when you will need to use the RCS. And to make things even more challenging, the CoM may be just aligned with a surface that you can't put the RCS.

 

This is spot on. I normally try to estimate how much fuel this ship is likely to have when docking and lower the fuel level to that in the VAB to see how it affects you COM

anothrt useful trick is to enable fine controls mode (caps lock by default) and put sets of RCS ahead of and behind your COM. The benefit here is the fine control mode tries to adjust the power if different RCS based on the changing COM. If expending fuel makes you a big nose-heavy, for example, it will adjust the thrust so the back end doesn't try to swing around the nose when you translate

[Cpt Kerbalkrunch]

1 hour ago, felcas said:

I second on that, but I have to add that, poor ship design on how to place the RCS thrusters may dictate how  hard or f#$%^@ing hard docking becomes latter on. 

The secret for an easier docking is to study very carefull the placement of RCSs in relation to the CoM. I am still learning about it and I can few inprovements. It may sound simple, but change in fuel quantity in the tanks will move the CoM back and forth and soo you need to think ahead how much fuel you will have when you will need to use the RCS. And to make things even more challenging, the CoM may be just aligned with a surface that you can't put the RCS.

 

 

25 minutes ago, Tyko said:

This is spot on. I normally try to estimate how much fuel this ship is likely to have when docking and lower the fuel level to that in the VAB to see how it affects you COM

anothrt useful trick is to enable fine controls mode (caps lock by default) and put sets of RCS ahead of and behind your COM. The benefit here is the fine control mode tries to adjust the power if different RCS based on the changing COM. If expending fuel makes you a big nose-heavy, for example, it will adjust the thrust so the back end doesn't try to swing around the nose when you translate

I guess I can understand wanting finer control (though personally, 4 thrusters reasonably close to the middle of the ship is good enough for me; I don't bother checking the COM for RCS anymore: if  I'm gonna dock, I only need to move toward the other ship or slow myself down; I don't see the need to be more precise than that), but for the purposes of this thread, the OP is talking about the docking tutorial. In the tutorials, your ship is already built. You can't make any changes to it. You have to deal with what you're given.

[felcas]

42 minutes ago, Tyko said:

This is spot on. I normally try to estimate how much fuel this ship is likely to have when docking and lower the fuel level to that in the VAB to see how it affects you COM

anothrt useful trick is to enable fine controls mode (caps lock by default) and put sets of RCS ahead of and behind your COM. The benefit here is the fine control mode tries to adjust the power if different RCS based on the changing COM. If expending fuel makes you a big nose-heavy, for example, it will adjust the thrust so the back end doesn't try to swing around the nose when you translate

Yes I use that trick on the VAB too, playing with the fuel quantity helps visualize where the CoM will be when the RCS are needed.

I also like to use 2 sets of RCS but in this case I place them as far as I can from the CoM as possible. This strategy seems to aleviate the unbalance a lot. This aleviate any unbalance that may exist when the time comes, but it need to follow another rule, that is to place the RCSs EQUIDISTANTS to the CoM, starting from the fartest if you can place it at 3m from CoM the other also need to be at 3m and soo on. This strategy seems to give much better control then just trying to find one placement for a single set of RCS. 

Another trick is to place the tank where the CoM will be or equidistant, this way as fuel get lower it will keep the CoM stabilized.

 

[Tyko]

1 minute ago, felcas said:

Another trick is to place the tank where the CoM will be or equidistant, this way as fuel get lower it will keep the CoM stabilized.

 

Good call. If you can get your fuel centered on the COM you don't have to worry about how full the tanks are

[felcas]

24 minutes ago, Cpt Kerbalkrunch said:

 

 I don't bother checking the COM for RCS anymore: if  I'm gonna dock, I only need to move toward the other ship or slow myself down; I don't see the need to be more precise than that)

LOL I would like to know how you do that. Docking is still the most complicated thing for me. I am still strugling with it.
 

 

25 minutes ago, Cpt Kerbalkrunch said:

but for the purposes of this thread, the OP is talking about the docking tutorial. In the tutorials, your ship is already built. You can't make any changes to it. You have to deal with what you're given.

Yes, but what is the problem of evolving the answer? This is a community, the OP purpose is to clarify but paralel discussions on the same subject may rise, it is healthy for both the OP poster and for those that are talking about it. Generally speaking.

Specifically speaking the OP is about the tutorial, which implies the poster is still learning and I just tried to help him with more information to avoid a lot of headaches in the future and give hints to improve his playing. 

[Cpt Kerbalkrunch]

14 minutes ago, felcas said:

LOL I would like to know how you do that. Docking is still the most complicated thing for me. I am still strugling with it.
 

 

Yes, but what is the problem of evolving the answer? This is a community, the OP purpose is to clarify but paralel discussions on the same subject may rise, it is healthy for both the OP poster and for those that are talking about it. Generally speaking.

Specifically speaking the OP is about the tutorial, which implies the poster is still learning and I just tried to help him with more information to avoid a lot of headaches in the future and give hints to improve his playing. 

Good point.

As for docking; for a long time I had know idea what I was doing. I refueled everything at Minmus. I literally spent (wasted) hundreds of hours doing it. I've docked more times than I care to think about. As a consequence, I simultaneously became pretty good at it and tired of it. I try to dock only when I have to now. 

[Silverwood]

Wow..as always you are great at replies and I thank you all. Especially the guy at work on your 'special' holiday. By the way how are you getting on without us? (??)

Now back to docking. I am almost there, the issue now is running out of fuel, I am afraid I have decided for this to use the cheat menu for unlimited fuel. Not good, but otherwise its back to square one each time.

If I ever manage it I will post here to prove to other newcomers you can do it!!!

Keith

[Spricigo]

Basically what @Cpt Kerbalkrunch say but in this link there is pictures:

I also as a rule of thumbs: [velocity(m/s)]=k.[distance(m)].  Start with k=1/20 and increase it as you get more practice/confidence.

About RCS, setting it for rotation only and let the reaction wheels deal with rotations make a huge difference. Also limit the thrust of RCS thrusters for more fine control. (Advanced Tweakables required for both tricks). 

Another way to deal with CoM issues (also provides some other nice features, like RCS deltaV budget):

 

[Silverwood]

Ok thanks for that.

Just tried again, before your post, got as far as the 100m away bit, but just could not get the ship aligned. Either shot off too far or the wrong way round! I can see this is going to take several hours/ days to complete. Oh and clicking on te target ship you do not get an option to select that docking port. You can select your own, just not the target craft.