How do I catch up to my space station in the same orbit?

[Pullarius]

I have 2 parts of a space station stuck on the other side of kerbin one has fuel left and one doesn't have engines on it it is the fuel tanks.

[painking]

If one of them is going faster and they're on the exact same orbit then eventually they will one day intersect and you can use whichever one has fueled engines to slow/increase relative velocity enough to dock. Other wise you'll need to perform rendezvousing maneuvers, which typically involve increasing/decreasing the size of your orbit so you're moving at the same orbital velocity as the other craft by the time you two meet up.

[Enigma179]

Launch a lifter, either something that can dock with the end with fuel and draw that fuel to control it, or which has it's own fuel (or if you like just launch a fuel tank and dock that with the engine-half). Burn prograde till your apoapsis is higher, see intercepts when other half of station is set as target. Play ring around the rosie a few times with timewarp until you get an intercept within 40 or 50 klicks or so, then burn either prograde or retrograde to get that intercept to within 5-10 klicks (use maneuver nodes if you can't figure out which burn to do from sight). Wait till you get within 5-10 klicks, then kill velocity relative to the target before burning towards it. The rest, I assume you know if you're trying to build a space station.

[sojourner]

If one of them is going faster and they're on the exact same orbit then eventually they will one day intersect

It's physically impossible to be in the same orbit and have different speeds.

[mcirish3]

The two answers ahead of mine basically explained how to do this. But perhaps a little further explanation is in order. In KSP as in real life getting two objects close together is rather a challenge. In essence you need both ships on exactly or nearly exactly the same orbit. But that needs to happen only when the two ships are close together. the greater the radial difference between the two orbis the more quickly and more often they will pass each other in their respective orbits. The inner orbital craft will always be the one doing the passing. Incidentally that is why we see Jupiter so often in the sky. There is a large radial difference between Jupiter and Earth. So the greater you can make the radial difference the less time you will have to wait for a close approach. However there is a trade off with this, as with all physics nothing is for free. It takes more energy( think Fuel) to create this difference and then take it away again for rendezvous if the difference is large. Also as the difference between the two orbits gets larger timing the hohmann transfer gets harder to "eye Ball" in other words the timing needs to be more precises to get a decent transfer. Just so I am not throwing out a word you don't understand a Hohmann transfer is just a short way of saying the least possible energy (think fuel) needed to transfer from one orbit to another. THe basic rule of thumb is if going from a low orbit to a higher one you need be behind the target craft you wish to rendezvous with when you start the burn for the transfer. The greater the orbital difference the farther behind you need to be. The reverse is true when going from a high orbit to a lower one. Hope this helps solves your problem feel free to ask if you have more questions.

[mcirish3]

It's physically impossible to be in the same orbit and have different speeds.

Very true Though actually having the same orbit is.... well..... difficult. In physics the saying is "actually measuring 0 is the most difficult thing we do".

Edited August 1, 2013 by mcirish3

[chrischambers]

have a look on Youtube, as there is a lot of videos that cover this very issue.

[krenshala]

I'm also new, but one thing I've found that makes lining up a rendezvous easier is that you can move a node around on your current orbit to see how the intersection changes. This works best if both orbits are of the same shape (e.g., both circular) otherwise the deltaV needed can change quite a bit depending on where in the orbit you put the node.

Now if I can just manage to get the rendezvous to actually happen in my game ...

[Tokay Gris]

I know this is not about mods...

But you could try Mechjeb and see how the autopilot does it. I am not suggesting to use it later on, but you can watch how it can be done.

Personally, I try to do the rendezvous manually. I think I can do it more efficiently, because I try to leave out the phasing orbit.

But Mechjeb can be a usefull teacher.

[Pullarius]

Thanks for all of the tips guys. (I accidently deorbited half the space station trying to slow down enough to get close to the other half :'( )

[TheDarkStar]

Thanks for all of the tips guys. (I accidently deorbited half the space station trying to slow down enough to get close to the other half :'( )

If you can't get it in one orbit, do it in a few or make your apoapsis higher. Also, all navigation except nearby docking and landing should be done in map view so that you can see where you will be easily.