Moderate Docking Skill - Improvements, Tips, or Suggestions?

[Turnip]

Hello All, I am able to dock fine currently but I can't help but wonder if there isn't a better way. Usually after 3 hours late one night I'll be doing some mundane task and realize 'Eureka! Why didn't I just do this instead!' So here are some scenarios where I know some of you veterans have developed easy tricks to make things like hauling station fuel a little less tedious. (I run bone stock, no MechJeb or anything).

1) When I currently rendezvous with my target for docking, I use a slightly eccentric orbit with an apoapsis above my target's apoapsis and a periapsis just below or at the targets. Then near my periapsis I just burn retrograde near an intersect to match orbits. The problem; It takes many time-sped orbits to get a close intersect, and the more eccentric the orbit, the greater dV needed. I have seen tutorials that recommend something along these lines: First set your orbit concentric and slightly 'lower' than the target's orbit. Time warp a few orbits until you are close. Use a manuever node to burn prograde and then move this node along your orbit until you get a close intersect. Is this a better way? I find that when the orbits are only 10 km apart, say you're in LKO (70km) and the target is 80km, it takes a very long time for the two objects to intersect if you were sloppy with your launch time.

Anyone have any tricks? I've recently started moving my parking orbits higher and higher to give me more wiggle room. Are two concentric orbits best to burn up to the target orbit, or better to burn down to the orbit? Eccentric orbits work? I understand there is no one best case, just some chatter on the subject would be helpful.

2) When I am in the same orbit, and am closing with RCS thrusters is there a way to orientate the ship so that the WASD keys correlate to up, down, left, right translation on the screen? With unmanned control modules there is no cockpit view or is there? I find myself, as I close in on the docking point, moving the camera to the "Chase view" (which doesn't get the rotation right?) and using Q or E to rotate the ship so that W, up, translation is up on screen. If I get this right, I can usually dock in 5 minutes from say 70m out. Is there something easy I'm overlooking here? perhaps using the navball horizon? (I just thought of that as I sit at work dreaming about KSP). Also say for whatever reason you can't have a cockpit view (unmanned), and you can't orient your camera so that up correlates to W (station is tilted and you are trying to match alignments), is there an easier way than tilting your head at crazy angles or chanting "up is left, up is left, up is left" as you attempt to close the last 10 meters.

3) Lastly, what are the best methods for building in space? For example, I am currently building a fuel depot in a high orbit. My course of action is to build the light weight girders with nothing more than docking ports, lights, batteries, panels and some RCS. I'll blast this giant, oversized, but lightweight rigging into space. Then I'll drag a large fuel tank up one at a time and dock them into a docking port on the rig. Is there a way to join multiple assemblies together using a method other than docking ports? Can a Kerbal get out and 'fasten' items? I guess my question is simply, are docking ports the only way to join parts outside of the vehicle hangars?

Thanks!

Edited October 10, 2013 by Turnip

[Mr Shifty]

1) The amount of time it takes you to orbit once depends on the semi-major axis (1/2 of the long axis) of your orbit. Doesn't matter if the orbit is circular or not; if two orbits have the same sma, they'll have the same period. If you've matched orbits and your target is behind you, you want to orbit slower so it can catch up, so you raise one side of your orbit. The farther you raise it, the slower you go and the more quickly it'll catch up. Likewise, if your target is in front of you, you want to lower your orbit so you'll orbit faster and catch up. This is a good reason not to put your station at 70km.

2) I know you said you're bone stock, but stock doesn't give you the right tools for docking. You need the Docking Port Alignment Indicator. It doesn't do docking for you, but does give you displays for your alignment and velocity in 3 dimensions:

http://forum.kerbalspaceprogram.com/threads/43901-0-21-Docking-Port-Alignment-Indicator-%28Version-2-1-Updated-8-17-13%29%29

3) Again, with stock there is no other way than docking ports to attach two on-orbit vessels. If you're willing to try mods, Kerbal Attachment System has a variety of ways to fix them together in orbit (and on the ground.)

[Scarecrow88]

1) Having an orbit where your peri is lower than your target and your apo is higher is counter productive, as one cancels out the other. If you are behind your target, your overall orbit needs to be lower so that you catch up. The converse is true if you are ahead of your target. When the two are relatively close to each other, at that point you should add a manoeuvre node to your orbit and adjust it so that it intersects your target orbit. Hopefully you should get an encounter marker come up, which you can try and improve by dragging the complete manoeuvre node around your orbit to see where you get the closest encounter.

2) Most people recommend using chase camera view as the view in relation to your craft remains constant.

3) Without using mods the only way to build a structure outside the VAB or SPH is to use docking ports. However, if you use the senior ports you can build quite sturdy structures.

[Silverchain]

For matching orbits:

First match your orbital inclination to 0 degrees with the target.

On one side your orbit should be slightly overlapping with the targets (so you get two intersect points), on the other side it should be either lower or higher.

If the target is orbiting ahead of you, your orbit should be slightly lower (faster, so you will catch them up) than theirs. If they are behind you, your orbit should be slightly higher (slower, so they will catch you up.)

Target in red, your orbit in blue, for a target which is ahead of you:

Wait as you orbit until the intersect points will be fairly close on your next orbit. If the target will be ahead of you at the intersect, lower your orbit slightly; else raise your orbit slightly. As you do so you'll see the intersect distances drop right down to within a kilometre or two (or ten); that's good enough.

Wait until the intersect rolls around; as you get close enough the thingummy will switch to show "velocity relative to target." Kill the relative velocity. You should now be essentially stationary wrt to the other ship and ready to dock.

For docking:

Stay in ordinary flight mode, don't bother with docking mode. Provided your ship has balanced RCS get the two ships to within about fifty metres, kill relative velocity to zero, align the docking ports, use RCS to get to about .5 ms-1, watch as the ships move closer, if needed kill velocity again, realign, repeat-until-docked. Trivial once you get the hang of it.

[Francesco]

- Rendezvous: assuming two circular orbits, with your target in the higher one, you should do your apoapsis-raising burn at a specific distance from your target, which is roughly 12 km for each 5 km in altitude difference. For example, going from 75 to 100 km: burn when you are about 60 km away from the target.

- Matching direction: when thrusting prograde, imagine that you are "pulling" your velocity vector: put the target prograde indicator between the prograde indicator and the level indicator, roughly like this:

When thrusting retrograde, do the opposite by "pushing" the retrograde indicator towards the direction you want.

[Superfluous J]

Regarding docking, here are a few tips I've either seen or figured out myself:

For rendezvous, I like to get my craft under my station (costs less fuel than going over it, assuming you're doing this from launch). Say if my station's at 100km, orbit around 80 or so. Time shift until you're behind it by about a quarter orbit or so, and then make a maneuver node to get you touching the station's orbit. Make sure the station's your target, and you should get a "nearest approach" indicator. It'll probably be far off, so drag the maneuver node around your orbit to see how close you can get. If you get a lock, use that node to burn. If you don't, take another orbit and try again. For all of this, ignore your current periapsis and apoapsis, and those of the station. They are irrelevant to getting a closest approach in this manner.

For docking, don't orientate yourself to the docking port. Orientate it to you. Just get close to what you want to dock to, then switch to that craft. Control its docking port and set your ship as a target, and then get it aimed at you. Turn on SAS and switch back to your ship. Bammo, the port is aligned.

If things start rotating weirdly, hit warp for a second. Warp kills rotation. It's a "cheat", but IMO it's fixing some weird physics thing that caused the rotation in the first place so it's fine.

The closer you are to what you're orbiting (Kerbin, Mun, whatever), the harder docking is. Docking at 75km above Kerbin (or 10km above Mun) is a lot harder than 250km (or say 50km on Mun).

[red7paulbrennan]

So not sure if i should start this in its own thread or not but it seems close to my problem.

I am trying to line up 4 of the 1m docking ports

http://imgur.com/a/phZoX#0

I know it can be done with smaller craft and on the ground.

the docking in the pic was a 10 min line up on my 5th try, not sure if i can do better.

Should i just use the 3m dock or do i have other options.(mods, editing the craft file)

[Starwhip]

A general rule of thumb for me is to match orbit, set up a rendevouz with desired ship/station, wait until within 10 seconds or so of minimal distance, kill velocity, and point toward the ship/station and fire engines. I then repeat until the thing is within 25 meters, and switch to RCS only. I use the H,N,I,J,K,L keys to translate on axes and Q,E,W,A,S,D to rotate. I also play bare-bones stock.

[Kosmo-not]

Though I dislike the narration, this video may be of some use to you. The biggest tip I have when it comes to docking is use your navball.

[Kasuha]

when it comes to docking is use your navball.

Use it but don't trust it. Especially don't rely on the claim that if you put your prograde vector over the target vector you will dock. Even if you control from your docking port and have the target docking port selected as target, it still may lead you to crashing to it from side.

My approach to docking:

- orient target docking port perpendicular to orbit plane (usually north/south)

- orient your own docking port in the opposite direction

- if needed, rotate your ship as needed (may be good e.g. for building interplanetary ships in orbit, you want your RCS ports to be aligned)

- activate SAS on both crafts. Short time warp should ensure they will not rotate away

- if needed, pull your craft so the target docking port is ahead of you

- put your craft into forward motion so you see the prograde vector on navball

- align docking ports horizontally and vertically by keeping the prograde vector behind the target vector until the target vector is in the middle

- watch the situation all the time using chase camera. If anything is wrong, pull back to safe distance and start over from the current position

- when you have the target port ahead of you, in the middle of navball and the prograde vector is over it, check with chase camera looking from above and from the side that they're really aligned. If not, make fine adjustments (navball may be too coarse for this, depends on placement of the port)

- when you're getting too close when not aligned yet, pull back

- if fine rotation alignment is needed, stop at distance of few meters and fine tune rotation and alignment

- dock

Don't hurry, give it time.

[enki]

I am trying to line up 4 of the 1m docking ports ... Should i just use the 3m dock or do i have other options.(mods, editing the craft file)

You can save on 8 parts and a bunch of headache by using the 3m parts. Anytime you can save parts on a station, do it. Especially if you will have an easier time of docking there.

One thing I didn't see mentioned here with docking is that you'll have an easier time lining up docking ports if both vessels' ports are aligned on the normal axis. For equatorial orbits this is simply north/south heading 0/180 and right on the horizon line. For other orbits it will be different, and Kitoban's Enhanced Navball can help you identify where it is. This way the docking ports won't wander away from you as the two crafts orbit.

Edit: I recommend the Docking Port Alignment mod linked earlier in the thread. Docking is a pleasure, and it has a rotation indicator so things can be lined up. I have been docking very very quickly since I got it.

[Tw1]

My method for rendezvous is simple. I make sure one vessels is a higher orbit to than the other, then create a manoeuvre node (anywhere) with an apoapsis or periapsis somewhere somewhere on the target's orbit. Then I drag it around, until the separation makers get close.

If the orbits aren't circular, the node needs to be tweaked as I drag it around to make sure it will pass close to the other orbit.

If I can't get the separation makers close, that means one of the ships needs to do another orbit. If I can get them close-10km or under, I do that burn. Then, I refine the approach using RCS, or tiny bits of thrust from the engines, watching the separation distance to make sure it's going down.

It's possible to do without aligning the orbit first, but that often helps.

It's possible to dock with stock systems alone- the trick is to watch your relative velocity. Keep it zero when you don't want to move. Make sure to rotate or position your ships so the docking ports are facing each other before approaching.

A trick that can help you know which direction your RCS will fire, is to make your ship so it has a "Top" as well as a "Front". The RCS is aligned to the part you're controlling the vessel from. If your vessel is cylinder shaped, like most rockets, you can use small things, like lights or docking ports to mark the sides. Or you can just watch the Navball rather than the ship. It will be aligned there.

[Leberschnitzel]

For your question 2:

Yesterday I docked in less than 5 minutes on my kerbal space station. From Launch.

My tips on how to do it (without mods, I'm also no fan of mods):

If you turn, disable RCS: It won't change your flight direction anymore

Use the Navball: I don't even look at the ships anymore for docking, I just use the navball when I'm close.

How I do it: Target the dockingport you whant to dock to, steer from your own docking port (basic)

align the target (magenta) your trajectory (yellow) and your ship (orange middle horizon thingy) and that's it. If one of this things isn't lined up, you have to correct. If the target is more up, your ship has to get more up. If the trahectory isn't on the target, change your trajectory. if your ship isn't pointing on the target and/or the flight direction: turn it into the right direction

If you start ignoring the screen on docking and focus on the navball, it gets sooo much easier!

Hope that helps

[aeTIos]

The problem is that the navball does not show the target orientation... That's why I use the Docking Alignment Indicator.

[Turnip]

Thank you for all the feedback! There are great tidbits in many of your posts. Thank you very much, I'll try them all out tonight! I will try a few add-ons like the docking alignment. I guess I should elaborate on why I was add-on adverse. Whenever a new version rolls out and you have a collection of add-ons installed, it is very tedious to remember which you have installed, and update them. I have a saved game that wouldn't load because I went a little overboard on the add-ons and updating them all manually is a bit daunting. (This is where someone points out an add-on manager and I facepalm).

Thanks again!

[Superfluous J]

There is an add-on manager but I found it more trouble than it's worth. These days, any mod worth its salt is all self contained in the gamedata folder, so it's going to be pretty easy to make sure you've got them all installed.

Except subassembly manager. That will be a weird one to not install.

[HeadHunter67]

With the DPAI, you don't even have to worry about aligning to normal/anti-normal. Once you learn the best way to use that plugin, you will be able to do high-speed docking from all kinds of crazy angles.

[Kosmo-not]

With the DPAI, you don't even have to worry about aligning to normal/anti-normal. Once you learn the best way to use that plugin, you will be able to do high-speed docking from all kinds of crazy angles.

Let's not get sidetracked. We are talking about the stock game here.

[HeadHunter67]

Let's not get sidetracked. We are talking about the stock game here.

Let's take our own advice and follow the conversation.

I will try a few add-ons like the docking alignment.

[Guest]

I always dock using stock tools, it's so much eaiser that way. Once I've matched speeds with the target I approach. When within 50m or so I stop and orient the docking craft (I never bother switching to the other). Then I move in for docking, translating and reorienting as needed. Chase view disorients me, I much prefer free look from the side, and sometimes I'll switch to overhead.