rendezvous

[wadena]

Hello,
I have a "tiny" problem with my scientist beeing stuck on return from Minmus (I forgot to pack parachutes, lol). So I've launched a rescue vessel with a mechanic to use KIS/KAS to attach the (missing) part. The problem is; I su** at rendezvous. I have matched the planes/inclination with the target. Do I also have to match the targets Ap and Pe (Ap= 7.87166Mm and the Pe= 85.975Km @ 5.989 inclination)?

(I'm playing on the 1.2.1.1604 Windows x64 bit version).

[James Kerman]

I would get the inclination down a little more.  I get it to 0.1deg before worrying about the orbit.

You don't actually match the PE or AP to rendezvous - you make an orbit slightly higher if you are in front of the target or you make an orbit slightly lower to catch up to a target.  It's probably going to take a with those numbers.

@Snark has created a fantastic pictorial tutorial here.

 

[wadena]

Thank you, I'll keep this in mind and read the pictorial tutorial. I can't do much with the inclination on the target ship since it's out of fuel. Hadd to burn it all pro grade when I realized I had forgotten the chutes (I calculated the reentry just after SOI to Kerbin. Had it at a steady 30Km thinking it's all good for aerobraking).

 

Edit;
Ps. I'm also using TAC LS so I "only" have 50 days...

Photo of my problem: https://www.dropbox.com/s/0kwfuw674lgta8j/20161113173109_1.jpg?dl=0

Edited November 13, 2016 by wadena
Info.

[Starhawk]

Hello wadena and welcome to the KSP Forums!

Since this is mostly a gameplay question thread, I've moved it to the Gameplay Questions from Welcome Aboard.

You will probably get more help in this section.  Glad to have you aboard.
 

Happy landings!

[James Kerman]

You can use the rescue vessel to match inclination.

Set a maneuver node at either the An or Dn and use the normal or anti-normal sliders to get the inclination as close to 0 as you can.

[Palaceviking]

Dude!

all is well, you've got a metric butt ton of Dv, you're chasing your target on a slightly lower orbit and inclination don't look too bad.

Get prograde quicksave and give it a little bit of gas until you see your closest approach get <5km (<1km if your feeling savvy), then switch navball to target and get out of map view( you remembered to turn the throttle off right?), get on the retrograde and as you get to closest approach start killing off your relative velocity(to target on navball).

you need more??

[ForScience6686]

Rendezvous becomes easier once you understand the mechanics.   are you behind the target?   then lower your orbit.   in front?   then raise it.   inclination can be a pain,  but if you set your rendezvous at the an  or dn,  then you don't have too worry much, except for the increased speed that will need to be dropped when closing in.

 

Practice,  practice,  practice.   You'll be doing it in your sleep in no time.

[Epox75]

A Rendezvous with a target with such an eccentric orbit is a bit different from a rendezvous with a target in circular orbit. Try this, presuming you are starting from a Kerbin low circular orbit. 

- once you matched the inclination with your target, plan a maneuver and raise your apoapsis until it matches the apoapsis of the target.

- check how long it will take for you to reach the apoapsis and take note of it

- remove the node and plan/execute the same maneuver when the target's time to apoapsis correspond as much as possible to the time you took note earlier. You should intercept the target. 

- once you are nearing the closest approach to the target, you must match its orbital velocity with another maneuver. 

 

Edited November 14, 2016 by Epox75

[WanderingKid]

To directly answer the question: No, you don't exactly match the PE/AP of the target.  What you do is get a little lower than it, or a little higher than it, and they meet up.  If your target is 'behind' you in orbit (chasing you) than you want to be above it as a higher orbit is slower per revolution of the SOI body.  If your target is ahead of you, then you get a little below it.  How far you want to be under/over the target will depend on how far apart you are and how long you are willing to wait.  A 1k difference will *eventually* catch you up together.  Some day.

Once you're within a cycle or two, you can play with your orbital speed and the rendezvous markers to see just how close of an intercept you can reach.  Once you've gotten to the closest point, you'll switch targeting from Orbital to Target (once you mark it as a target, anyway) and retrograde away your speed difference.  Then you aim for the purple dot in a circle and burn towards your target.  Rinse/repeat until you're nice and close.