Help for a new guy..

[Rocketman1994]

Hi guys, first let me go off by saying I love this game, it plays right to a lot of my interests and being able to run my own space program is awesome.

Let me also add, I do have some basic things under my belt. My program has slowly been progressing to where I want it to go. At first getting into orbit or even sub-orbit resulted with explosions and tears (although over time I have grown numb from the amount of Kerban's i've killed), when I did my orbits were weird looking and could rarely be reproduced. Throw in that my rocket tech was widely inconsistent, not stable and really primitive.

Over time though, my little Kerbal program has been advancing. We are now able to send the little guys into orbit consistently, giving them nice, flat, circular orbits. I even have gotten my rocket tech down somewhat, with my KHL series (Kerbal Heavy Lifter) being able to send fairly heavy loads into orbit.

My current goal is to build what I'll call Station 1, a space station in orbit (at about 150k-200k km above kerbal. Its mission being to provide fuel to interplanetary missions, giving Kerbal a consistent space presence and to give me experience docking.

That last part is where my difficultly comes in. To make my station, I need to perform about three docking operations to complete it. Even though the KHL series has made huge strides, it is not powerful enough to launch an entire space station. I have watched tutorials by Scott Manley, I am pretty good at getting it close enough to being able to see it on screen and seeing the little speed tracker change from Orbit to target. My problem is I can never get close enough to start using RCS to perform final docking procedure. So I was wondering if anyone had and tips or tricks, I am going to go back to the Scott Manly video again and see if I can get anything, but any suggestions would be much appreciated.

TL:DR

I need help docking, I can never get close enough to perform the final approach with RCS, how do I do it?

[Nibb31]

There are dozens of tutorials on YouTube and on this forum that explain how to rendezvous and dock, as well as at least one or two threads everyday from people asking how to dock. Reading up on answers that have already been posted will be more useful than asking for people to answer the same thing for the 36th time this month.

[capi3101]

Short answer: practice with something a bit smaller than a space station first. -- http://wiki.kerbalspaceprogram.com/wiki/Tutorial:_Gemini_6A_and_7

The main trick is to get the orbits of the two objects you want to do close to one another first; that means having apoapsis/periapsis as close as possible and killing any declination in the orbits (ascending/descending node = 0). If the target's ahead, lower your orbit and vice versa. Watch the intercepts; when they get pretty close to one another, begin tinkering with your orbit to get it the intercept as close as possible. Once you get that to within 500 meters or so, you should be close enough to attempt the rendezvous. From there it's killing your thrust relative to the target (yellow retrograde), then thrusting towards the target (pink prograde) until you get within ten meters or so. Align the docking ports on both craft (preferably on torque thrust, not RCS), thrust forward and off you go.

[Rocketman1994]

Awesome thank you! I will give it a try!

[Uberick]

Short answer: practice with something a bit smaller than a space station first. -- http://wiki.kerbalspaceprogram.com/wiki/Tutorial:_Gemini_6A_and_7

The main trick is to get the orbits of the two objects you want to do close to one another first; that means having apoapsis/periapsis as close as possible and killing any declination in the orbits (ascending/descending node = 0). If the target's ahead, lower your orbit and vice versa. Watch the intercepts; when they get pretty close to one another, begin tinkering with your orbit to get it the intercept as close as possible. Once you get that to within 500 meters or so, you should be close enough to attempt the rendezvous. From there it's killing your thrust relative to the target (yellow retrograde), then thrusting towards the target (pink prograde) until you get within ten meters or so. Align the docking ports on both craft (preferably on torque thrust, not RCS), thrust forward and off you go.

I highly recommend these Gemini missions to practice docking, thats what got me started.

Pretty much the only thing it doesn't teach you how to do is what always caused me trouble; stopping my ships "tumbling" end over end when I get to the final stage of docking them. (within 100m or so) Adopting a higher orbit is one way of making this less of an issue, but the real solution is well placed thrusters(around your CG) and using the i j k l keys to re-orient your ship as it's coming in.

[capi3101]

If that gets too bad, I usually just time warp. That's probably cheating, of course...

[Tobmaster]

OK, since you are able to get close enough for the switch from orbit to target, then you are already stepping in the right direction. Now when it switches to target, your speed switches as well to m/s relative to your target. The prograde and retrograde (green indicators) switch as well so you know which way to apply thrust.

This quick and dirty Tutorial will not be easy on fuel, but once you've gotten it down, you can change the inefficient parts:

Usually I come in at the switch (orbit to target) at about 150m/s relative to target and when I get within 10k, or nearing as close to the target as possible, I will burn on the yellow/green retrograde to bleed off the speed. Here is where it isn't efficient, but easy to do: Burn off all the speed until you are at as close to 0m/s as you can. Now turn to the pink prograde (you should be pointed roughly in the direction of your target but use the navball for alignment) and accelerate towards the target to about 20 to 30 m/s (or slower depending on how close your initial encounter was. Of course since you are in orbit, the course will change over time and you will just have to repeat the above action over again once the distance to target tapers off). Once you make it within 1-2k from the target, keep the m/s much lower. Ideally you would want to keep your green prograde circle aligned over the pink indicator which will bring you to your target.

Once you figure out the rough mechanics of it it become much easier and you can throw out some of the unnecessary burns as you progress, but the above guarantees you will get close to your target, just won't guarantee how much fuel you have left or how much time it would take, but you will get there.

One thing to help you out, if you have unbalanced RCS thrust where you try to translate and it started to rotate your ship, you can use the asas with the rcs and it will keep your attitude and rotation constant and you can still manually adjust the translation, but this will burn quite a bit of RCS propellant...

Edited May 15, 2013 by Tobmaster

[Tobmaster]

And you don't "have to" start small... This was my first docking project:

Edited May 15, 2013 by Tobmaster

[Rocketman1994]

Mother of god....thats huge.

Awesome, thanks for the advice guys. I'm gonna practice me some docking!

[Merinsan]

And you don't "have to" start small... This was my first docking project:

<Cool pictures removed>

What in Kod's name is that thing?! And how many Kerbals can live there?

As for docking, What Tobmaster said is pretty much it. Scott Manly actually did a specific video saying the same thing.

One thing I do is try to get my initial rendezvous down to below 1km using the maneuver nodes. After the burn, I set up a new maneuver node to match orbits, at the rendezvous. This gives me 4 things:

1. approximate time of closest approach.

2. Approximate delta v required to match orbit

3. Approximate time I need to burn

4. Approximate direction of the retrograde vector

Since you're typically going to be having a relative velocity that is over 100 m/s, it's very useful (especially when you are using nukes). I've done rendezvous to within a few kilometers when I have had to start my burns from 100km out using this method.