Docking without the map

[rpayne88]

I already know how to dock using the map screen and maneuver nodes. I have two questions about how it can be done manually.

1. Is this possible with only an understanding of algebra and trigonometry? (I suck at math)

2. How do you do it if it can be done with such a limited understanding of math.

[capi3101]

I don't think it'd be possible without referring to the map at least once for some details. You'd need to know the initial spherical coordinates of both the source and target crafts (i.e. latitude, longitude, altitude) as well as their initial velocity. I suppose once you had that you could then determine at what point you'd need to make your rendezvous burns; how much delta-V and when. There's some pretty nasty rotational kinematics involved in all that, of course.

Of course, I usually perform the actual docking visually. That starts at 500 meters, I close to 100, zero out relative velocity, re-aim at the target, thrust ahead and do the same thing again at 50, 20 and 10 meters.

Maybe I'm not understanding the question...

[blizzy78]

Is this question about docking or rather about setting up a rendezvous course?

[air805ronin]

Is this question about docking or rather about setting up a rendezvous course?

Since he said manuever nodes I think he's including the rendezvous in with the docking.

To which I say, it certainly is possible, but it isn't easy. It will involve math. There used to be a table on here showing the kinds of burns needed to transfer between different orbits. Basically you'd wait till you're X kilometers apart and execute a specific burn. Even that involved checking the map to see where you were in relation to the other spacecraft.

[rpayne88]

Since he said manuever nodes I think he's including the rendezvous in with the docking.

To which I say, it certainly is possible, but it isn't easy. It will involve math. There used to be a table on here showing the kinds of burns needed to transfer between different orbits. Basically you'd wait till you're X kilometers apart and execute a specific burn. Even that involved checking the map to see where you were in relation to the other spacecraft.

That is exactly what I'm asking.

[metaphor]

You can switch the navball to target mode and cancel your relative velocity with respect to the target, then burn towards it. Repeat this several times. It works even from many tens of kilometers away. It wouldn't be as fuel-efficient as using the map though.