can't make a rendevous

[alfrank]

My problem, is with getting the two shield icons to converge. They merrily chase each other around their orbits, sometimes getting nearer other times jumping to opposite hemispheres. The few times I achieved a close encounter (within 5 km), I have no idea what I did right  Suggestions, tips. ideas anyone?

[king of nowhere]

the main thing to realize is that bodies in higher orbit move more slowly, and you can therefore changing your orbital time by making your orbit higher or lower.

so, you have your two ships in orbits touching each other. the one in the llower orbit will move faster, so it will gradually catch up with the other.

at some point it will overtake the other entirely; then you will need to raise its orbit to slow it down. or you can lower orbit for the ship in a faster orbit. in both cases you should see the markers converge and overlap.

be careful with the acceleration, a single m/s will throw you off by many km. sometimes it's better to manually reduce an engine's power.

[fulgur]

It's usually easier to have one ship in a much lower / higher orbit than the other one, so that they have different orbital periods and can catch up quickly.

Then, make a manoeuvre node with whichever ship you are in control of. Make it prograde / retrograde so your orbit crosses the other orbit. Move the manoeuvre around the orbit until you get a close enough encounter.

If you can't get a close enough encounter this orbit, right-click on the manoeuvre node. You will see a red "delete manoeuvre" button and two blue "increase/decrease orbit" buttons. Click the blue "increase orbit" button. This will move it onto the next orbit (i.e. one full orbit in the future). You can keep doing this to get a close encounter. 0.0km is obviously ideal but 2-3km is perfectly fine.

Once you are at the encounter, make sure you are in "target" mode on your navball and burn retrograde to cancel your relative velocity. If you are a few kilometers away, you can just point towards the other craft and burn directly at them to get closer.

 

Edited June 17, 2023 by fulgur

[alfrank]

i"m getting he hang of setting up a close encounter. Two things though - once I do get within 5 km of stranded the tutorial doesn't give me a "next" button; and when I go to map view to see the target there's nothing there. No target ship in sight.

One more thing. How do you reduce the speed relative to target?  It takes all my fuel to do a retrograde burn and even then I'm still too fast.

[Vanamonde]

9 hours ago, alfrank said:

How do you reduce the speed relative to target?  It takes all my fuel to do a retrograde burn and even then I'm still too fast.

The speed at closure is just a matter of how the ships are coming together. Their speeds are determined by their orbits. The closer the orbits are to each other the lower the final speed will be, but also the longer it will take for the ships to come together. As others have suggested, try putting the two ships in matching orbits with one a bit higher than the other, then wait for time to bring them close. 

[BechMeister]

13 hours ago, alfrank said:

i"m getting he hang of setting up a close encounter. Two things though - once I do get within 5 km of stranded the tutorial doesn't give me a "next" button; and when I go to map view to see the target there's nothing there. No target ship in sight.

One more thing. How do you reduce the speed relative to target?  It takes all my fuel to do a retrograde burn and even then I'm still too fast.

I had a lot of trouble doing rendezvous until I found out you can click the velocity meter and change it from Orbit/Ground/Target - Once in target it shows you the relativly velocity to your target... and you get a "local" prograde and retrograde that shows you direction in relation to the target. - I remember not knowing this.. and not knowing your relative speed to the target makes docking really hard... since you have to eye ball it all.

Any way... once you setup your 1A and your 1B to intersect close enough (I usually aim for <1000m) you just point to your target retrograde and burn until your relative velocity is around 0. - then you use the RCS thrusters to go the final distance 

If you want I can try make a simple picture guide in KSP2 on my next run? - The guide Fulgur sendt is very good.. but I myself has found the UI differences can make it a little difficult to translate when you're already going through figuring it out.  

[king of nowhere]

22 hours ago, alfrank said:

i"m getting he hang of setting up a close encounter. Two things though - once I do get within 5 km of stranded the tutorial doesn't give me a "next" button; and when I go to map view to see the target there's nothing there. No target ship in sight.

 

I suspect you need to hit f4. it highlights close targets, if it's toggled off you won't see the ship

[BechMeister]

Here is my step by step guide on how to Rendevous:

First some context - I am currently updating parts to my station that has glitched. I am flying an docking arm for fuel tanks to my station.

Now Step by step with pictures and Gifs:

1.  Get your rocket into space and set the vehicle you want to rendezvous with as target:
   
2. Make a Orbit slightly higher than your target orbit - to ensure you will cross your targets path at some point.. and not just endlessly chase each other.
   
    
3. Adjust for inclination - This is done by going Normal/Anti-Normal on the AN point (the place you can see your inclination error)
   
    
4. Wait for an optimal window where I:a and I:b is close.
   
    
5. Use a maneuver node to figure where to Raidal In / Out:
   
    
6. Once at the point close the maneuver node (the game is not that precise now.. so its better to do it manual) - hold your mouse over the 1:A while burning Radial out/in - Burn until your 1000 ish m from target.
   
    
7. Set your speedometer to "Target" by pressing on it and press on "Go retrograde" - In target, your prograde/retrograde is your movement in relation to the target.
   
8.  Kill your relative speed by burning retrograde when your near your target - REMEMBER TO PRESS THE LOCK (Stability on) ONCE THE VEHICLE POINTS RETROGRADE - This locks your current direction. In my experience if you burn retrograde while in target, your rocket will chase it and start spinning. - Stop boosting when your relative speed is 0-10 m/s
   
9. Use a combination of RCS thrusters and main engine to get your prograde ontop of target and move the last bit of way to target:
   
   Here you can see the prograde is 40° off.
   
   Now its corrected - take not of the time it takes to accelerate to the relative speed to target on approach - It takes the same time (depending on how you make your crafts) to de-accelerate.
   
   Hotkeys for RCS thrusters:
   A: Jaw left
   S: Pitch Down
   D: Jaw Right
   A: Pitch Up
   Q: Roll counter clock
   E: Roll clockwise
   H: Move forward
   N: Move Backwards
   J: Move Left
   K: Move Down
   L: Move Right
   O: Move up
    
10. Make sure the docking port you want to dock with is the point your controling the craft from:
    
    And the specific docking port you want to dock at is target:
    
     
11. Position your craft so it can reach the docking port, and burn towards it:
    
    Here I have moved my craft down so its outside the docking port I want to dock at - and I have killed all relative speed.
    
    I turn off the RCS thrusters and click "Point at target" - The reason I turn of the RCS thrusters is that I find that the craft start dancing around because it keeps adjusting to point at target - which means it just spirals into a spin/dance around target. - So I always have RCS off when pointing at target. 
    
    I then click the lock and turns on "Stability" and then i make sure my local prograde is on target.  Now the angle may be off, So the closer you get to target your vehicle will start moving up down, left right. You correct this by putting your prograde uppersit the target like this:
    
    Your prograde location will drag your vehicle in that direction - So by making sure your prograde is uppersit the target, you will drag your vehicle on top of it. The distance to the target translate to the speed. If your prograde is on target, your vehicle will not get closer.. if its far away it will be dragged into your vehicle quick, but you may not have time to get the prograde on target - and will have to reverse. 
    
    It will most likely end up looking like this:
    
    
    If you do it correct - the two docking ports will meet and you are docked.

 

 

I hope this helps you mate.

Edited June 21, 2023 by BechMeister

[Zhetaan]

On 6/16/2023 at 10:18 PM, alfrank said:

Suggestions, tips. ideas anyone?

Others have covered the basics of rendezvous, but one thing that I wanted to bring up is that sometimes, the shield icons will go wild when you're very closely matched with your target.  If you're in nearly the same orbit, then your distance from the target is nearly constant, and something as simple as rotating in place can affect what the game thinks is your closest approach.  The shield icons can only give you a general idea and are no good for final approach and rendezvous.

There comes a point in any rendezvous when you need to get out of Map View, for the same reason that you don't use Map View when landing a plane:  you need to see details that Map View can't show you.

Another issue, which I suspect is closer to what you're experiencing, is that the shield icons represent the next two closest approaches only.  It is possible to have two close approaches on one orbit and then have a third closest approach (which is not shown at first) on the opposite side of the planet.  Once you pass the first point, the game doesn't have the subtlety or nuance to understand that you're still fairly close--it jumps to the next prediction and if that prediction is for a closest approach on the other side of the planet, then so be it.  The solution for this is, again, to ignore Map View once you're close and use other tools for final approach and rendezvous.