How to rendezvous with a kerbal stuck in a semi polar-horizontal orbit around the mun?

[Bungthebadger]

So, I wanted to land on the Mun so I can get a huge amount of science... Well, the spaceship landed with very little fuel and took off in a orbit, and has no way to transmit the science. So, how do I redvous with a kerbal who's stuck in a orbit around the Mun so I can refuel him?

Edited November 20, 2016 by Bungthebadger

[DD_bwest]

well, you would send your ship to the mun, match inclinations and get in a neat circular orbit.  then create a manuever to intercept, and match speeds at closest approach.  this is followed by edging yourself closer by pointing at your target, followed by cancelling your velocity at your new closest approach.    have you done such a manuever around kerbin before?

 

one tip of matching inclinations, when you get to the mun, dont circulize your entire orbit.  just capture yourself with an AP that is as far out as possible. changing inclinations is cheapest when your at your slowest, so if your ap is really far out there, itll be easier to match inclinations.

[Vanamonde]

You will need to connect the rescue ship to the first ship with docking rings or the claw part in order to transfer fuel. If you do not have a claw on the rescue ship or docking rings on both ships, there is no way in the stock game to transfer fuel. However, you could have the kerbals take the science from the first ship and transfer it to the rescue ship, and then bring the pilot of the first ship back. Of course, you'd need an empty seat on the rescue ship to do that. 

As for bringing the ships together, that depends on the orbit, and I'm afraid I don't know what you mean by "semi-polar horizontal." How about a screenshot of the situation? 

[Bungthebadger]

I have never done a rendvous before so I really am clueless on how it works which is my biggest problem.

[DD_bwest]

25 minutes ago, Bungthebadger said:

I have never done a rendvous before so I really am clueless on how it works which is my biggest problem.

well its a good thing  to learn and practice. its a multi step process.   your first step would be to get there and match your inclinations.  the ascending and descending nodes are when yours are the targets orbital plane cross.  so its the spot you burn to match your inclinatio. this is done by pointing to either your normal or anti normal.  at the descending node you are going below it, so burning normal  will what you want.  at the ascending node, you want anti normal.   right click on the orbital location marker so that it keeps the text of your angle showing.

ince youve done this, circulize about 30km above your target

so once here we need tto plan the intercept burn. sine you are above your target, it will be catching up to you so wait until it is about a quarter orbit away from passing you and create a manuever node.  add retro grade to it until your orbits cross and it woll show closest approach markers. click on the center of your manuever and slide the timing of it around tour orbit to bring it closer.  if you cant get one on that orbit, go around once more and try again.  youll be shooting for an intercept smaller than a km.

next, make sure you navball is set to target and aim retrograde. when you get to yor closest approach burn until your relative velocity  is zero.  once yiu do this, you are essentially in the same orbit but stopped compared to your target.

now you point at the targrt to push yourself towards it, which will make a new closest approach. when you get to that point, stop yourself again and repeatthe process until you are right next to it

Edited November 20, 2016 by DD_bwest

[Bungthebadger]

29 minutes ago, Vanamonde said:

You will need to connect the rescue ship to the first ship with docking rings or the claw part in order to transfer fuel. If you do not have a claw on the rescue ship or docking rings on both ships, there is no way in the stock game to transfer fuel. However, you could have the kerbals take the science from the first ship and transfer it to the rescue ship, and then bring the pilot of the first ship back. Of course, you'd need an empty seat on the rescue ship to do that. 

As for bringing the ships together, that depends on the orbit, and I'm afraid I don't know what you mean by "semi-polar horizontal." How about a screenshot of the situation? 

 

I don't have the Klaw or docking ports. Does external fuel feeders work? ( The yellow tape looking thing )

[Streetwind]

55 minutes ago, Bungthebadger said:

I have never done a rendvous before so I really am clueless on how it works which is my biggest problem.

You could try the rendezvous tutorial scenario that is included in the game. It guides you through the process step by step.

You access it by choosing "Start Game" in the main menu, then "Training", then scroll down and pick the scenario named "Docking".

[bewing]

Rendezvous and docking are two of the more advanced and important techniques that KSP tries to teach you. Having an example to try them on may give you some extra incentive to learn them.

Snark created a docking tutorial that might be helpful in learning the techniques: https://web.archive.org/web/20151126132127/http://forum.kerbalspaceprogram.com/entries/3770-Illustrated-guide-to-docking

 

But as Vanamonde said, there is some equipment necessary before you can dock. If you don't have it, then you need EVA capability (Upg Astronaut Complex to Tier 2). Then you "just" need to rendezvous and EVA your Kerbonauts + data over to the rescue ship, as he said. But flying through space on an EVA is really exactly the same thing as doing a docking -- so you still need all the techniques.

Edited November 20, 2016 by bewing

[Vanamonde]

1 hour ago, Bungthebadger said:

I don't have the Klaw or docking ports. Does external fuel feeders work? ( The yellow tape looking thing )

Sorry, no. The fuel lines can only be placed during ship construction in the assembly buildings. 

[ForScience6686]

1 hour ago, Bungthebadger said:

I don't have the Klaw or docking ports. Does external fuel feeders work? ( The yellow tape looking thing )

No they will not.   You will be stuck transferring kerbal and science.   alternatively you could use kas/kis  to attach connection ports and then link the ships manually.   But you'll still have to learn rendezvous.   But I think you're close than you think.   You done the basics by reaching the moon.   The only difference is at the closest approach you kill relative velocity.   switch your nav ball to target to see how much speed to bleed off.   then enjoy your accomplishment.

[Magzimum]

Follow these steps:

1. Do the tutorials. They are great to teach rendezvous and docking.
2. Install KER. It gives you information on how far your ship can go, so you avoid running out of fuel halfway (or bringing too much).
3. Make a rescue ship. Get your Kerbal home. Abandon that science. The Kerbal(s) can just EVA (leave the ship, to do a spacewalk towards the rescue ship).
4. Make a new lander with more fuel. Land on the Mun. Get the science. Go home.

[bewing]

If you can rescue the Kerbal, you can always rescue the science, too. A kerbal can always carry an infinite amount of science experiments with them.

[Sharpy]

2 hours ago, bewing said:

If you can rescue the Kerbal, you can always rescue the science, too. A kerbal can always carry an infinite amount of science experiments with them.

Let's spell it out.

1. Put kerbal on EVA from the craft that carries the science. Don't let go of the ladder yet.

2. rightclick the cabin.

3. Pick "Take data".

Now your kerbal carries all the science that was in that cabin. If it was elsewhere (science container) you need to fly up to it and do the same thing.

 

Also note: Kerbal's jetpack carries over 600m/s of delta-V. So instead of your rescue craft meeting up with the kerbal, you can just do a flyby, and have the kerbal rendezvous the rescue craft.

Edited November 21, 2016 by Sharpy

[bewing]

27 minutes ago, Sharpy said:

 

Also note: Kerbal's jetpack carries over 600m/s of delta-V. So instead of your rescue craft meeting up with the kerbal, you can just do a flyby, and have the kerbal rendezvous the rescue craft.

Heh. A dangerous thing to try for an OP who is just getting started on the concept of rendezvous.

[Bungthebadger]

Okay, well here's my biggest question. What happens if the kerbal was orbiting counter-clockwise, and the rescue ship was orbiting clockwise? Also, how do I change my inclination without affecting altitude?

[bewing]

46 minutes ago, Bungthebadger said:

Okay, well here's my biggest question. What happens if the kerbal was orbiting counter-clockwise, and the rescue ship was orbiting clockwise?

Ouch. You try to avoid that. The best fix for that is to raise the Ap of the rescue ship really high. Then at the Ap you burn west (retrograde) until you are orbiting in the opposite direction.

46 minutes ago, Bungthebadger said:

 

Also, how do I change my inclination without affecting altitude?

You lock in either Normal or Anti-Normal SAS, and burn gently.

[DD_bwest]

44 minutes ago, Bungthebadger said:

Okay, well here's my biggest question. What happens if the kerbal was orbiting counter-clockwise, and the rescue ship was orbiting clockwise? Also, how do I change my inclination without affecting altitude?

then if you even able to get an intercept, the velocity they will be passing each other at will be roughly double your orbital speed,  so its no good. It also means to turn around where you are, you need to essentially stop then head backwards, this is very fuel taxing.  your going to want to do your best to get a mun encounter that will have you orbiting the right direction, or to  change it at the edge of mun's sphere of influence.

[IWanttobeEVA]

On 11/20/2016 at 1:02 PM, Bungthebadger said:

Okay, well here's my biggest question. What happens if the kerbal was orbiting counter-clockwise, and the rescue ship was orbiting clockwise?

Your best bet might be to break your orbit and plot a return to Kerbin orbit, and as you swing around Kerbin plot an trajectory so you orbit Mun the opposite way. I think this might be cheaper in dV then to try to flip the orbit 180'.

Example: to flip your orbit from a 50Km orbit on Mun 180' is about 1000 dV, but swinging around Kerbin and orbiting the other way can be done for about 1/2 that amount.

[pincushionman]

The only time you can enter a target's orbital plane is at the ascending or descending nodes (AN/DN) between your orbits, since those times are the only times you're already in-plane. "Set as target" on your target and these nodes will magically appear in map view.

If you set up your transfer burn such that your Mun periapsis is roughly at one of the nodes, it's easy to close your orbit around the Mun with AP just inside the SOI and aligned with the node, and do the  plane change at AP when large changes are cheap. Alternatively, you could combine your capture and plane change burns into one, which makes small changes very cheap. Or a combination of both.

But best would be to add normal or antinormal to your transfer burn such that when you enter Mun SOI you're already in-plane with your target or close to it. The amount of normal/antinormal you have to add if you do this is a spit in the bucket compared to the transfer burn itself. Then you've done most of the hard work up front, and only have to deal with small changes to effect the rendezvous.

But all of these suggestions assume you're not time-constrained by life support or contract deadlines, because it can take some time for Mun to move into a favorable position for this. If you choose a bad time and come in on a trajectory perpendicular to the target orbit, it's gonna be very, very expensive. Planning ahead is very much your friend here.

Edited November 22, 2016 by pincushionman