Trying to orbit the Mun

[JackBush]

I have a beautiful circular orbit around Kerbin. My ship should have enough fuel left to get me to the Mun. But my problem is I have no idea what any of the explanations of how-to-get-into-Mun's-orbit are telling me. I've seen Scott Manley's but he loses me at some point. So I've come back to the in-game tut. But I'm not understanding this explanation:

Pick any spot on your orbit and set a maneuver. (Fine.) With handles showing, pull the Prograde handle until your theoretical orbit intersects that of the Mun. (Fine.) It has to be an interjectory trajectory to the Mun however, (not fine.) so move the node itself as necessary (how do I do that?) to get one. I've moved every handle every which way and created all kinds of messes, but none of them is right. I can tell this because I'm not able to click "Continue" to move to the next stage in the tutorial. The professor is not happy, but I don't know why.

Edited October 16, 2015 by JackBush

[Starhawk]

You can grab the node by the circle in the middle and slide it around on the orbit line.

Happy landings!

[Monsterlunch]

Hi Jack,

interjectory trajectory just means, that at the time your orbit passes the Muns circular orbit, the mun has to be near your vessel. You do not have to use the handles on the manouever node itself for that. An intersection between your ship an the mun will show up in map view as soon as you have plotted an intersectory trajectory.

Ill have some pictures up for you shortly.

Edit:

Javascript is disabled. View full album

Cheers

Edited October 13, 2015 by Monsterlunch

[MaxL_1023]

Try setting it so that your Apoapsis is about 90 degrees ahead of the Mun's current position, then slide it around from there.

When you get a trajectory which will encounter the Mun (you see a circular symbol on your projected path, then a color change and probably another "Pe" icon) stop burning. Try using RCS or low-throttle to fine tune to get the approach distance you want.

The most foolproof way to enter Mun orbit from your encounter is to wait until you are at closest approach, then just burn retrograde until you close an orbit. You can then circularize later on - you won't lose your orbit once you close one.

[JackBush]

Hi Jack,

interjectory trajectory just means, that at the time your orbit passes the Muns circular orbit, the mun has to be near your vessel. You do not have to use the handles on the manouever node itself for that. An intersection between your ship an the mun will show up in map view as soon as you have plotted an intersectory trajectory.

Ill have some pictures up for you shortly.

Edit:

http://imgur.com/a/a8TFw

Cheers

Thanks Monsterlunch. But I don't know what makes the one picture Good and the other one Bad. I can create the Bad one easily but don't know where to take it from there or how.

[Alshain]

Drag your prograde till it just barely touches the Mun's orbit. That is good. Now grab the center circle and drag it around your orbit till you find an intercept. That is very good. Dragging prograde increases your cost in fuel. Dragging the white circle, merely changes the time of your burn without increasing the length of your burn and that costs nothing but time. In a game with timewarp and immortal Kerbals, time is meaningless.

So, to get a 'good' maneuver you want to spend as little fuel as possible. The alternative is to keep pulling prograde till eventually you hit the Mun (assuming you are already in the ballpark), but that costs fuel. Ideally you want to burn just enough to get you out there and let the Mun's gravity take over.

Edited October 13, 2015 by Alshain

[The Aziz]

It's late 2015 and I just learned that I can actually move the node. Oh well. Fuelsave maneuvers, here I come!

[Alshain]

It's late 2015 and I just learned that I can actually move the node. Oh well. Fuelsave maneuvers, here I come!

Yes, I know. The things hidden in this game that shouldn't be...

[Monsterlunch]

Thanks Monsterlunch. But I don't know what makes the one picture Good and the other one Bad. I can create the Bad one easily but don't know where to take it from there or how.

Ok, so the difference between the good and the bad picture simply is that in the good picture, you get this mysterious "interjectory trajectory to the Mun" whereas in the bad picture you don't. The only differnce in the manouever node however is its location in the current Orbit.

In the BAD picture, the moon is too far away from your vessel, when its planned orbit crosses the orbit of the Mun.

Point is that you want to get pulled in by the muns gravity so you can land there. You can achieve this by departing from your circular orbit around kerbin at a different time. (Dragging the manouever Node around.)

Cheers

[Snark]

It's late 2015 and I just learned that I can actually move the node. Oh well. Fuelsave maneuvers, here I come!

Yeah, don't feel bad. I was playing the game for more than a year before I discovered that. (And even then, I didn't discover it for myself-- I read about it in the forums). The hell of it is, I spent that year grumbling about the lack of the feature, and kept wishing "Dang, I wish I could drag the node back and forth along the trajectory." Never occurred to me to try to grab the center of the thing; it just doesn't have a visual style that says "grabbable" to me. Maybe if they could change the visual appearance so that it matches the other grab handles (e.g. draw with a thin line and make it some vivid primary color).

KSP has a fair number of extremely non-discoverable features in it. The draggability of maneuver nodes is perhaps the worst offender, but there are others. Proportional RCS thrust in fine-control mode is one of my favorites.

[JackBush]

I appreciate the answers but am still not there. Here's a screenshot of what I have so far. What's good or what's bad and what should I be doing with it?

http://imgur.com/rd9JZzi Sorry, still not seeing the editor button that lets me automatically put around it.

[ElWanderer]

I appreciate the answers but am still not there. Here's a screenshot of what I have so far. What's good or what's bad and what should I be doing with it?

http://imgur.com/rd9JZzi Sorry, still not seeing the editor button that lets me automatically put around it.

Good: you have an encounter with the Mun

Bad: I don't see a periapsis at the Mun, implying you would be on a collision course if you burn accurately.

Bad: You have two manoeuvres plotted (not necessarily a bad thing), the second of which alters your course a lot more than your typical mid-course correction. This will use up more fuel than a single manoeuvre in low Kerbin orbit. It is also more awkward - small inaccuracies in your first burn can have a big effect on your orbital track by the time you reach the second node.

Fixes: Right-click on the second node and delete it.

Select the first node and add more prograde until your apoapsis is about 12Mm. Then click-hold on the middle of the node and drag it back and forth around your orbit until you get an encounter.

Alternatively, adjust your second node until your orbital track near the Mun shows a periapsis. I don't know what adjustments you need, but try more prograde first.

[JackBush]

I think I've done what you suggested. At least there's a Mun periapsis in it. What do you think?

http://imgur.com/oufEnkO

And now what? Burn?

[Empiro]

Yes, you just need to execute the maneuver. You can probably tweak it slightly to get a closer encounter (a combination of going more or less prograde, and burning earlier or later). Generally speaking, the closer the encounter (without crashing) the better.

[Clipperride]

It took me several 100 hours of play before I discovered manoeuvre nodes were manoeuvrable. For me the other late discovery that makes life sooo much easier was, focusing on the target Moon/planet let's you see your path through its SOI. Before that I was forever moving and zooming the map whilst still focused on my ship.

Moral of the story? Don't feel bad, you do have to put some work in to get the most out of KSP, but it sure is worth it

[Alshain]

You can always make a correction burn once you get to the Mun's SOI if you don't have a Pe. It's not the most efficient way, but you will get better in time.

[Waxing_Kibbous]

I'm pretty new, but when I get into the situation where there is an encounter (like you have above) I put a new maneuver node about halfway along the blue path, then click on the Mun and set the focus to it- you will see where your Munar Pe is then, and using the node on the blue path you can adjust it, the benefit is very little dV is needed. After that node is executed, again with the Mun in focus I put a node on it's Pe and pull the retrograde marker to make the orbit happen. Hitting backspace will center focus back on your ship, fly into the Mun's influence (where the blue path turns brown) and you will see everything come together, execute the retro burn you set up and you are in orbit. At this point it's perfectly OK to raise your hands in triumph

Edit: I see you haven't done the initial burn yet, when you do be careful not to over shoot, your trajectory will start accelerating really fast as it gets close, throttle down and have a finger on the "x" key ready to stop. I am usually set up so that a little overshoot gets me a bit closer, but it can really get out of control fast.

Edited October 14, 2015 by Waxing_Kibbous

[TheSpaceManiac]

Without maneuver nodes, you can get to the Mun by burning prograde when you see the mun rise... Although it's not fuel efficient

[Kryxal]

Also note that being in node-following SAS mode is a recipe for disaster at the end of a burn. Go ahead and use it for most of a burn if you have it, but always just hold heading at the end.

[Vanamonde]

May I suggest the guide I made? Has pictures of the paths you'll need to take, and the guide does not use manuever nodes for the sake of simplicity.

[JackBush]

focusing on the target Moon/planet let's you see your path through its SOI.

This sounds interesting and valuable. How do I do that?

- - - Updated - - -

This is all great stuff, folks. Thanks so much. I'll be back to let you know how I make out.

[Scarecrow88]

If you click on a planet you will get the option to set it as target or to focus view. Select focus view and then zoom in. If you have set a manoeuvre node to cross the SOI, the path will be shown in focus view mode. This can make it easier to tweak the manoeuvre node to get a better encounter.

[JackBush]

Happy to report that I finally am orbiting the Mun. Am very excited, but the best my wife could come up with was the typical "That's nice for you, dear." So I had to tell someone who would appreciate it. Now on to gather science. Thanks to everyone who gave advice and help. This forum has a terrific group of people willing to help newbies. We appreciate it.