Help with orbital rendezvous

[MrUberGr]

Ok, so I've started constructing my first orbital station, and I need some help to fit the first part there, as well as some general questions.

First of all, on what altitude should I position my space station? It's going to be a refueling station. (so I don't get stuck in Mun's orbit again ) Secondly, at what point does it become a "station" in the space center? Cause all I got now is a ship and a probe. Third question is, should I get everything up there, and then move it to it's final orbit, or move it and bring the parts there? Finally, I believe that the Rockomax Skipper is enough to move the station around, even with some extra pieces on it, right? (used that by mistake, instead of the Poodle)

Meet Ananke (Greek for Need - Necessity), or at least the core:

Now, this is the power module I want to install:

And this is their position in orbit:

The Core's points are Ap 185.271km Pe 184.545km

The P.M.'s points are Ap 190.390km Pe 185.328km

As you can see they are almost excactly the same altitude (first try, wooohooo) and are pretty close to each other. The problem is that the intersect points are almost opposite.

What do you suggest I do, just timewarp and wait many days untill they get close, or...?

Thanks in advance!

[Traches]

Lots of questions here, I'll take 'em one by one.

Ok, so I've started constructing my first orbital station, and I need some help to fit the first part there, as well as some general questions.

First of all, on what altitude should I position my space station?

Wherever you want, really. I usually put mine at a round 100km, cause it's easy to remember. No lower than 75, obviously. Wherever it's convenient to launch to.

Secondly, at what point does it become a "station" in the space center?

When you make it one. Right click on that cupola command pod and pick "rename" - then click the icon you want.

Third question is, should I get everything up there, and then move it to it's final orbit, or move it and bring the parts there?

Moving a station with stuff on it is hard, because you usually lose all your symmetry. Why do you need to move it?

Finally, I believe that the Rockomax Skipper is enough to move the station around, even with some extra pieces on it, right? (used that by mistake, instead of the Poodle)

It'll certainly have enough thrust, but it's a poor engine for orbital operations because it's very inefficient. I'd use one of the smaller engines with a higher ISP. But again, why do you need to move it?

What do you suggest I do, just timewarp and wait many days untill they get close, or...?

For that, I would search for "KSP rendezvous tutorial" on youtube. I could attempt to explain it here, but a video will do a better job. Basically, you'll set up either a faster or a slower orbit to bring your two ships together sooner!

[MrUberGr]

When you make it one. Right click on that cupola command pod and pick "rename" - then click the icon you want.

Moving a station with stuff on it is hard, because you usually lose all your symmetry. Why do you need to move it? It'll certainly have enough thrust, but it's a poor engine for orbital operations because it's very inefficient. I'd use one of the smaller engines with a higher ISP. But again, why do you need to move it?

Hehe, cool! Didn't know that was the way. Never tried it tbh.

I'd like to move it to an optimal orbit. I guess that depends on my rocket designs though and on how much fuel they can carry. As I said, the engine was a mistake But, the fuel tank is full and I will move it either to 150km or to 200km so it will do. Does the symmetry matter in space? I mean, in first thought I'd say no, cause there isn't any air to create drag, and make the movement of the station hard.

So basically raise the ap of the PM or pe of the SS.

[Traches]

Symmetry matters - if your engines don't push straight through your center of mass, your ship will want to turn whenever you use them! And the skipper will work fine, it's just not ideal.

[thecoshman]

Whilst the station is small, moving it around will be rather easy and safe, but as it get's larger, it will take more and more thrust to get the same effect. You also run the risk of ripping your station apart, so I would strongly advise you get everything into it's final position as you build it.

Symmetry is not a huge concern for a station, as you will not be 'driving' it around. If you have a normal ship, then yes, the engine must be thrusting through the CoM else it will spin the ship.

[Kasuha]

If you want to move the station with last stage of your lifter, use anything that comes. If you need to design something specific to move the station, I'd recommend using single nuclear engine. In orbit, thrust does matter much less than ISP.

My own construction/refuelling station is at 650 km orbit and I highly recommend it. You can use maximum time warp at this height and it's not that hard to reach from surface (or rather that much harder than LKO). Also it gives you plenty of space for synchronizing before rendezvous.

When adding parts, do not send the new part blindly on the same orbit. Put it on lower orbit first and then match orbits during rendezvous, i.e. match orbits and position at the same time. When on the same orbit, your ships keep their distance because their orbital period is the same. Only when on different orbits, one runs faster than another and can catch up.

[Markus Reese]

Remember, the higher your orbit, the less fuel your ship needs when leaving the station. Personally, I like 1/2 to 3/4 of way between Mun and Kerbin for mine. This is far enough out that any orbit escape or capture is pretty low fuel consuming but you don't end up in slingshot.

I also have made low orbit ones just for fun. Either way, the best concept for capturing the station is I like to get to about half the altitude of the station abouts. When at lower altitude, you will travel faster. Just find what position in your burn will capture. If you are 1/2 or less your station's orbit, you should have an intercept somewhere on your current orbit.

If you are on the orbit and find yourself behind/ahead, the easy way to cut inside is find out how much burn towards orbit body you need to meet up with your station. When you do this, you will make your orbit more eliptical. If you make it so you start going inside the orbit of your station, you will catch up on first part, then meet up where you cross orbital paths again. Burn away, and it will catch up to you. Once you meet up, just do opposite of previous to circularize your orbit again.

This latter tactic is also a good way to planet rendevous if you are one of those peeps like me who don't like messing around with optimal launch windows.

Edited November 27, 2013 by Markus Reese

[KvickFlygarn87]

Ok, so I've started constructing my first orbital station, and I need some help to fit the first part there, as well as some general questions.

First of all, on what altitude should I position my space station?

I usually put my stations at geosynch orbit, 500, 200, or 1000.

[MrUberGr]

Is there anyway to change the Skipper with a Poodle, through editing files etc? I mean the one that's already in space. Is there any chance things might explode if I do that?

[Sirrobert]

It's possible, you'll need to edit the persistance, or quicksave file for it. That stores the exact makeup of each ship in the game. You'd have to replace the skipper part with a Poodle part.

Open the save file in notebook, and look for the ship you want. Than look for the part you want, and replace it with the part you want instead of that.

Don't forget to backup your saves though, as I have no idea if that actually works.

[MrUberGr]

After a few quicksave loads due to running out of electricity here we are. Gonna be docking later tonight. Unfortunately gonna have to use infinite RCS for the docking cause I'm gonna run out, and I wanted to refuel the station.

[Kasuha]

1.2 km is kinda too far away. Use low thrust, kill the remaining 2.9 m/s, (by burning against the green marker) then burn again towards the target (purple marker), get some 10 m/s and get a bit closer before you switch to RCS. While drifting closer turn your ship around to be ready to burn at the green retrograde marker when you're close enough. Switch to RCS when you're below 100 m and after you killed your relative velocity to below 1 m/s.

And that RCS you have is more than enough. You don't need to go any fast or even burn all the time. Just give your ship small impulses to get it moving in the direction you need.