Docking Port Orientation

[Scarecrow71]

So, I apologize for all of the questions over the last 2 days.  I'm going through some new stuff that I've never done in KSP before, thanks in large part to the Kerpollo Challenge.  I mean, what's the point of playing if you don't get better, right?  And, at least for me, I can't get better if I don't push myself.

Anyhow, I've come to the part about using docking ports.  And my question isn't how to dock; I've gone through the in-game tutorial, and I've got MJ installed to help me.  No, my question is about the orientation of the docking port as it relates to both the lander and the main ship.  As an example, let's use the Clamp-o-Tron Docking Port Jr., primarily because this is the one I have access to:

Ok, so what you see there is the part as it looks when you click on it in the VAB.  This will be easy for me to describe because this is how I see the part when I go to use it.  I know I need 2 of these, one on the lander and one on the main ship.  So that's not the issue.  What I'm having trouble identifying is how to orient this on each piece.  If we make the assumption that the lander is above the current image, what is the correct orientation for the port?  Does it go into the lander the way it shows there, or do I need to rotate it so the shiny ring that is currently on top is pointed to the bottom?  And then that feeds into orientation for the second port that sits on the main ship.  Is the shiny ring pointing up at the lander, or pointing down towards the main ship?

I know that this must seem like a basic question, and again I apologize if it is.  But I can't seem to figure this out on my own, and I can't seem to find the answer anywhere else.  Of course, once I get the answer it'll be all "Well, that was so simple I should have known it".  But this community is great at helping people out, so I come to you all with this question.

Thanks in advance!

[Vanamonde]

In your picture, the port should attach to its own ship on the bottom and the upper side should mate with the port on the other craft. If you're assuming that the lander you're making is above it, then you need to invert the port before attaching it. 

Quote

 I apologize for all of the questions 

That's what the forum is for.

[Zhetaan]

2 hours ago, Scarecrow71 said:

So, I apologize for all of the questions over the last 2 days. 

Well, don't apologise for asking questions.  That is the literal point of this forum, and besides, if you ask certain questions frequently enough then we can put it in a special place for questions that people ask frequently.  We can call it 'Things People Ask About a Lot', or the TPAAL--something catchy like that.

Anyway:

2 hours ago, Scarecrow71 said:

If we make the assumption that the lander is above the current image, what is the correct orientation for the port?  Does it go into the lander the way it shows there, or do I need to rotate it so the shiny ring that is currently on top is pointed to the bottom?  And then that feeds into orientation for the second port that sits on the main ship.  Is the shiny ring pointing up at the lander, or pointing down towards the main ship?

For the Clamp-O-Tron Jr., you get two such to mate by having the shiny rings touch.  This means that, assuming that you're going for an Apollo-style configuration, you will want the assembled Command-Service Module to have the shiny ring pointed up (assuming that the main engine is pointed down and for the Lunar (Munar?) Excursion Module's shiny ring to point down onto that of the CSM.

However, I do feel compelled to point out that if you want authenticity, then you should have the LEM (MEM?) in a fairing under the CSM, which is at the tip of the rocket.  Then, once you've achieved trans-Munar injection, you blow the fairing, release the CSM, and then turn around to dock with and extract the lander.

For the other docking ports, the one that routinely gives people trouble is the Clamp-O-Tron Sr.  The general rule is that you want to see a short slot on the docking face, and no plus sign.  That's the mating face.  Have a look at the part in the VAB (start a sandbox save or look at the wiki) and you'll see what I mean.

Edited November 2, 2021 by Zhetaan

[Scarecrow71]

2 minutes ago, Zhetaan said:

 

For the Clamp-O-Tron Jr., you get two such to mate by having the shiny rings touch.  This means that, assuming that you're going for an Apollo-style configuration, you will want the assembled Command-Service Module to have the shiny ring pointed up (assuming that the main engine is pointed down and for the Lunar (Munar?) Excursion Module's shiny ring to point down onto that of the CSM.

However, I do feel compelled to point out that if you want authenticity, then you should have the LEM (MEM?) in a fairing under the CSM, which is at the tip of the rocket.  Then, once you've achieved trans-Munar injection, you blow the fairing, release the CSM, and then turn around to dock with and extract the lander.

That is what I needed to know.  Point the shiny rings at each other.

And I've got the return stage, complete with the command module and lander, in a fairing that gets blown as soon as I'm in orbit about 240km over Kerbin.

[jimmymcgoochie]

On 11/2/2021 at 7:03 PM, Scarecrow71 said:

That is what I needed to know.  Point the shiny rings at each other.

And I've got the return stage, complete with the command module and lander, in a fairing that gets blown as soon as I'm in orbit about 240km over Kerbin.

240km is unnecessarily high, both for orbiting and for deploying a fairing.

You should aim for an orbital altitude of about 100km which will save you a significant amount of fuel, and deploy your fairings as soon as you’re out of the thick part of the atmosphere where drag doesn’t matter any more- about 50km is usually a good benchmark, though keeping the fairing is a good idea if you’re getting heating effects.

[Scarecrow71]

5 hours ago, jimmymcgoochie said:

240km is unnecessarily high, both for orbiting and for deploying a fairing.

You should aim for an orbital altitude of about 100km which will save you a significant amount of fuel, and deploy your fairings as soon as you’re out of the thick part of the atmosphere where drag doesn’t matter any more- about 50km is usually a good benchmark, though keeping the fairing is a good idea if you’re getting heating effects.

All the videos I've seen indicate to orbit at about 240km when transferring to another planet.  If I can just get away with 100km, that will truly save some dV with the transfer.