Docking with rotating "wheel" stations

[eveningsky339]

I'm playing with my World of 2001 addon. Everything is smooth as a pearl except for one thing: docking with Station V, the big wheel in the sky. I line up with my linear thrusters as best I can and when I get within 100 meters, I try to match the station's rotation. That's where things get hairy. It seems like no matter what I do, I absolutely cannot match the rotation of this station and use my linear thrusters in a "normal" manner.

Are there any tricks to doing this? As I speak, my Orion is sitting about 100 meters out from the dock, waiting for advice...

 

[pattersoncr]

You're on the right track.
Make sure you're dead on with you're linear thruster before you start to match rotation. I also would recommend waiting until you get closer than 100m. I wait until I'm just about crossing the threshold of the outer "door" before I start my roll. That gives less opportunity for things to get gooned up.

 

[eveningsky339]

Thanks chuck.

 

[ar81]

You also can use default Luna-OB1 station to practice.
I made a replacement mesh just in case.
[ame="http://www.orbithangar.com/searchid.php?ID=2737"]LUNA-OB1 replacement (DARK VERSION)[/ame]
and this
[ame="http://www.orbithangar.com/searchid.php?ID=2856"]Luna-OB1 Dark version (texture replacement)[/ame]

 

[joeybigO]

There was once an addon that used to have a x, y, and z position and velocity indication. Chris Kinestrick wrote it long ago, I don't know if it is still available.

If you had that you could do some quick Chloessy-Wiltshire equations to get the time and rotation to exact match velocity and hook up.

 

[Cornflake]

I've been trying to get better at docking with rotating stations myself. I would line-up with the docking MFD, and then start rotating way out, like over 500m but that always had very... messy results. I'll try waiting until I'm closer than 100m as you guys suggest and then give it a go

That addon with x, y, and z velocity indicators would be very handy if you happen to find it.

You also can use default Luna-OB1 station to practice.
I made a replacement mesh just in case.
http://www.orbithangar.com/searchid.php?ID=2737
and this
http://www.orbithangar.com/searchid.php?ID=2856

You're replacement models are excellent btw, I downloaded them some months ago

 

[silent_protagonist]

That addon with x, y, and z velocity indicators would be very handy if you happen to find it.

I'm not sure if this is what joeybigO was referring too, but [ame="http://www.orbithangar.com/searchid.php?ID=3165"]Attitude MFD[/ame] might do the trick.

 

[sputnik]

I find as a technique, I use the Docking HUD and Docking MFD at the same time. The MFD tells me how far off I am from centerline, but the HUD is a lot easier to watch to fix it; just put the velocity vector opposite what the green arrows on the MFD are showing.
Doing it that way, I find that spinning to match rotation doesn't affect my solution much. Corrections come more often, but it's not too hard to use the two displays to predict when you've got the right correction in.

I hope that helps, and that was a coherent explanation. It works for me, anyway....and I've certainly done quite a few!

 

[unussapiens]

I believe absolute kill-rot had an option to kill relative velocity and rotation, which was very useful for docking to rotating stations.

 

[Thunder Chicken]

Even if you null out all of the relative rotation, the linear thrusters won't properly translate your ship relative to the wheel due to the rotating reference frame. The centripetal and centrifugal 'forces' need to get canceled as well, which is hard to do on the fly. Might be an interesting idea for an autopilot - one that would fire the thrusters in such a manner that it would null out the rotating acceleration terms and would let you translate 'intuitively' relative to a rotating object.

 

[Kieran]

One Year Later

I agree with Thunder Chicken's suggestion - allow the pilot's manual approach using translation thrusters with an autopilot compensating automatically for rotation forces. Otherwise, how can we simulate the approach to Station V as seen in the film.

 

[Tommy]

One of the difficulties lies in that on many vessels, the docking port isn't perfectly in line with the vessels COG. This is especially the case with vessels that have there docks someplace other than the nose, such as the Shuttle or XR-5. The easiest way is to wait until you're pretty close to the port, then get the rotation. It does take quite a bit of practice, though. Like many tasks in Orbiter, it takes a bit before you get the hang of something. Once you "get it", skill begins to build much more quickly. Practice enough, and the 2001 type approach becomes attainable. The most common mistake is overcorrecting. Once you begin the spin, some translational variation is normal, and often will correct itself if you let it. You'll go out of alignment a bit, then drift back in to alignment as you complete a rotation - try to correct this and you just end up chasing your tail.

Axial Velocity HUD can help you adjust your rotations and helps prevent you from being fooled into thinking you are rotating on the pitch and yaw axis when you aren't - and vica versa.

[ame="http://www.orbithangar.com/searchid.php?ID=3595"]Axial Velocity HUD v1.0 RC2[/ame]

 

[kevinvr]

One of the difficulties lies in that on many vessels, the docking port isn't perfectly in line with the vessels COG. The most common mistake is overcorrecting. Once you begin the spin, some translational variation is normal, and often will correct itself if you let it. You'll go out of alignment a bit, then drift back in to alignment as you complete a rotation - try to correct this and you just end up chasing your tail.

Axial Velocity HUD can help you adjust your rotations and helps prevent you from being fooled into thinking you are rotating on the pitch and yaw axis when you aren't - and vica versa.

Axial Velocity HUD v1.0 RC2

He he, yes I have just started playing 2001 scenarios and I have yet to dock correctly with stationv. A great and difficult challenge!

 

[fort]

It will be interesting to see if navMFD ( the 2.5 vers ) still works for that. I remember have used that function ( when all the others was, now, unaivaible ) some months ago ( with a problem nevertheless with the DG cone/noze/docking part, whose not in the good axis for it ) but that can help with some others flying machine.

NavMFD 2.3&2.5 (with Docking Assistance)
made by David Canard:

http://www.orbithangar.com/advsearc...ult&text=default&search=default&submit=Search

 

[liber]

Heh,anyone try to dock with LEM,that was a nightmare...

 

[othoudt]

It Makes Sense Now!

I could dock 2001 style back in the day with the old "Elilte" game but in Orbiter docking a DG with Luna-OB1 has been impossible and now thanks to Orbinaut Ford I now know why; the DG's docking port is off center of it's longitudnal axis! I can close with Luna-OB1's docking port right on it's axis just fine up until I begin rotation, then the off-center mass of the DG pulls it away from the station's docking axis in an ever-widening spiral that seems to be unrecoverable. I even try matching rotation with the station only in the last 5 meters or to and it still goes all "gooned up". Has anyone docked a DG to a wheel station successfully? Or are you using another type of vessel; one with a docking port centered on it's longitudinal axis?

 

[PhantomCruiser]

It just takes practice... The default LunaObj1 (hereafterknown as Wheel) isn't easy to line up on. Get the update that ar81 put on OrbitHanger. It has a docking port that you can put the crosshairs on. Now the "carrot" in the center off your screen in the docking HUD will actually be aimed at a space about halfway between the docking port and the window.

You can also cheat a little, you should be able to use the scenario editor to slow down the rotation of the wheel, this will let you get the hang of it. BTW Station V isn't selectable IIRC. But if you want to stick with the WO2001 stuff, Station III and IV can be added via scenario editor as well.

Practice, practice, practice. And before long you'll be able to line up, match rotation and dock just like the scene in 2001 (humming Danube Waltz).

 

[Interceptor]

Lots, and, Lots of practice but you'll get there. good luck

 

[JamesG]

Use an autopilot. Thats what they did in 2001 (notice the cockpit shots).