Achieving Munar orbit: Do you first need to set the Munar orbit as a target?

[MetricKerbalist]

Hi KSP colleagues,

I am having a really difficult time getting a spacecraft to orbit around Mun.

Let me begin with this one question, please.  I understand that, from Kerbin, you have to set up a maneuver that intersects Mun's orbit around Kerbin.  Prior to doing that, however, do you first have to click on the Munar orbit around Kerbin and set that Munar orbit as a target?  Or should you not do that?  Or doesn't it make a difference?

Thank you.

Stanley

[FleshJeb]

It's much easier to set the Mün as a target. It's not necessary, but it's super-handy.

The other easy method is to just burn prograde as the Mün is coming up over Kerbin's horizon (from around 80km). No maneuver nodes needed.

[MetricKerbalist]

Hi FleshJeb,

OK.  Thanks.  I will work on what you are saying.

Stanley

[MetricKerbalist]

So FleshJeb,

What are you saying?  I wait until I see the Mun appear over Kerbin's horizon.  Then I head straight to the Mun, and I will intercept the Mun's sphere of influence?  Do I have it right?

Thanks.

Stanley

[FleshJeb]

12 minutes ago, MetricKerbalist said:

What are you saying?  I wait until I see the Mun appear over Kerbin's horizon.  Then I head straight to the Mun, and I will intercept the Mun's sphere of influence?  Do I have it right?

Yes. It's not an overly precise method, but it works. It's just a coincidence of physics, BTW--I don't know any other planet/moon combo this works for.

Also, quoting or pinging people is how you get them to notice you responded:

• To quote, you can use the button at the bottom, or highlight selected text and a "Quote Selection" menu will pop up.
• To ping, you type "@" followed by the username. It has some autofill capability. @MetricKerbalist

Feel free to use my name or text here if you want to experiment with the features.

[Streetwind]

1 hour ago, MetricKerbalist said:

I wait until I see the Mun appear over Kerbin's horizon.  Then I head straight to the Mun, and I will intercept the Mun's sphere of influence?  Do I have it right?

No, that's not quite it. You wait until you see the Mun rise, and then you burn straight prograde. Not at the horizon/the Mun. In general, never burn directly at the destination you want to go - that's not how orbital mechanics works Only when you're trying to meet up with another spacecraft and have managed to get within 10 kilometers of it. Then, and only then, you can go straight towards it.

When you look for the Mun rising, feel free to start burning immediately as soon as you see it. The perfect moment would actually be slightly before it becomes visible, but of course you can't see that moment. So you simply wait for it to peek over.

 

EDIT: And if you still want to practice with maneuver nodes as well - here's a post I once made with a step-by-step guide about how to get a good Mun maneuver node. Not sure if it's what you're looking for, but I did include a video that shows the process in practice.

 

Edited June 16, 2021 by Streetwind

[18Watt]

Here’s another way to visualize approximately when to burn prograde to reach Mun-

• Let’s say you are in LKO (low Kerbin orbit), roughly 100 km, roughly circular.
• Burn prograde when Mun is about 100 degrees ahead of your position.
• You can ‘eyeball’ that by rotating your view to be looking ‘down’ at your orbits.  (Looking ‘down’ at the North Pole of Kerbin)
• If you rotate the view so Mun is at 12 o-clock, your ship should be at 3 to 4 o-clock.

Burn until you achieve an intercept.

Note- I’m assuming you are playing in Sandbox mode, or that in Career you have upgraded your Tracking Station. If you’re playing in career and haven’t upgraded your Tracking Station, you won’t get advanced orbital information, and intercepts won’t appear.

[MetricKerbalist]

Hi @FleshJeb, @Streetwind, and @18Watt,

I thank all of you for your suggestions.

18Watt, you have been constantly helpful to me.

FleshJeb, you can see that I am using your method to ping people.  I didn't know about that.

6 hours ago, Streetwind said:

And if you still want to practice with maneuver nodes as well - here's a post I once made with a step-by-step guide about how to get a good Mun maneuver node. Not sure if it's what you're looking for, but I did include a video that shows the process in practice.

 

Streetwind, I have now taken a preliminary look at your old post and your video.  Later today, I will go through it very carefully.  It seems that it will be very instructive.

I am so grateful to everyone on the KSP Forum for helping me learn this amazing program.

Stanley

[king of nowhere]

of course, you don't have to reach mun without manuever node. you can do it easily with a manuever node. Mun is an easy target: burn prograde from low kerbin orbit for 850 m/s, and sooner or later your orbit will intersect mun. it has a large sphere of influence. and that's why it can be reached without planning manuevers.

planning manuevers makes for more precision, and i recommend it to anyone. the only reason to not plan a manuever is if you are playing the caveman challenge, which is not your case

[Zhetaan]

13 hours ago, MetricKerbalist said:

Let me begin with this one question, please.  I understand that, from Kerbin, you have to set up a maneuver that intersects Mun's orbit around Kerbin.  Prior to doing that, however, do you first have to click on the Munar orbit around Kerbin and set that Munar orbit as a target?  Or should you not do that?  Or doesn't it make a difference?

The short answer is no, you don't have to do that.  Should you?  It helps.  It makes a difference in that by setting the Mun as a target, the game knows what you're trying to do when you set up a manoeuvre node, so it can provide helpful information such as your predicted closest approach, relative inclination, and other data that can assist you in getting the encounter.

There are relatively easy ways to get a Mun encounter without needing to set it as a target.  Some ways, as others have mentioned, allow you to get the encounter without needing to set up a manoeuvre node, either.  However, some of these techniques take advantage of unique circumstances particular to the Mun and are not broadly applicable.

I don't know whether you've worked on rendezvous yet, but the principles are similar.  For an encounter, you want to reach the Mun's orbit at the same time that the Mun will be at that point in its orbit.  Doing this is complicated in real life but relatively easy for the Mun because the Mun happens to be in a perfectly circular, equatorial orbit.  The Mun was designed this way deliberately in order to give you a good chance to practise the technique before going on to more interesting (meaning complicated and difficult) transfers and encounters later on.

There's nothing wrong with eyeballing a transfer, or setting up a node without setting the Mun as a target.  I would advise you, though, to play with the node planning controls a little.  Try dragging the node around on your orbit (you can click and drag the node) to see how that shapes your encounter.  Or, if you don't have one yet, so long as you have an orbit that reaches high enough to cross the Mun (and it's equatorial), then you'll get an encounter at some point by dragging the node around your orbit.  See how changing the planned burn changes the predicted encounter.  Don't be afraid to delete it and start over.  At some point, you'll start to get a feeling for how you should plan your burns in order to go to the Mun.

[MetricKerbalist]

5 hours ago, king of nowhere said:

Mun is an easy target: burn prograde from low kerbin orbit for 850 m/s, and sooner or later your orbit will intersect mun.

Hi @king of nowhere and anyone else,

So I began a flight from a fairly circular Kerbin orbit from an altitude of about 125'000 metres.  I clicked on prograde, and I tried to go 850 m/s.  But even with the slightest amount of burn -- one click out of the 15 clicks possible -- it says in the Navball well over 2000 m/s.  That is my delta-V, right.  My first point, therefore, is that I could not do a burn as low as 850 m/s.

I am flying my spacecraft right now as I compose this message.  My altitude is somewhat more than 3 million metres and I don't have a lot of fuel available.  I don't see how I am possibly going to reach the Mun's orbit, even if I were set to encounter the Mun's sphere of influence.  Maybe I am doing something wrong.

Stanley

 

Hi everyone,

Well, since I have now run out of fuel, I time-warped forward.  It looks like I will intersect the Mun orbital path around Kerbin.  But now, how do I intersect with the Mun's sphere of influence?

Stanley

[king of nowhere]

30 minutes ago, MetricKerbalist said:

Hi @king of nowhere and anyone else,

So I began a flight from a fairly circular Kerbin orbit from an altitude of about 125'000 metres.  I clicked on prograde, and I tried to go 850 m/s.  But even with the slightest amount of burn -- one click out of the 15 clicks possible -- it says in the Navball well over 2000 m/s.  That is my delta-V, right.  My first point, therefore, is that I could not do a burn as low as 850 m/s.

I am flying my spacecraft right now as I compose this message.  My altitude is somewhat more than 3 million metres and I don't have a lot of fuel available.  I don't see how I am possibly going to reach the Mun's orbit, even if I were set to encounter the Mun's sphere of influence.  Maybe I am doing something wrong.

yes, you are. unfortunately, without pictures, we can't know for sure.

Did you execute the manuever correctly? was your ship correctly holding prograde?  Were your engines correctly aligned?

which part of your navball said 2000 m/s? was that your speed, or the manuever? when did it start to change? how much fuel you had in the first place?
 

Quote

 

Hi everyone,

Well, since I have now run out of fuel, I time-warped forward.  It looks like I will intersect the Mun orbital path around Kerbin.  But now, how do I intersect with the Mun's sphere of influence?

Stanley

 

you'll have to reach apoapsis right when the mun is passing there. which, unless your orbits are perfectly syncronized, will eventually happen.

 

again, if you posted some pictures we could help you better

[Rhomphaia]

1 hour ago, MetricKerbalist said:

Hi @king of nowhere and anyone else,

So I began a flight from a fairly circular Kerbin orbit from an altitude of about 125'000 metres.  I clicked on prograde, and I tried to go 850 m/s.  But even with the slightest amount of burn -- one click out of the 15 clicks possible -- it says in the Navball well over 2000 m/s.  That is my delta-V, right.  My first point, therefore, is that I could not do a burn as low as 850 m/s.

I am flying my spacecraft right now as I compose this message.  My altitude is somewhat more than 3 million metres and I don't have a lot of fuel available.  I don't see how I am possibly going to reach the Mun's orbit, even if I were set to encounter the Mun's sphere of influence.  Maybe I am doing something wrong.

Stanley

 

Hi everyone,

Well, since I have now run out of fuel, I time-warped forward.  It looks like I will intersect the Mun orbital path around Kerbin.  But now, how do I intersect with the Mun's sphere of influence?

Stanley

Delta means change, delta v is change in velocity. The speed shown on top of the nav ball is your current speed. (in orbital reference it is your instantaneous velocity tangential to your orbit

Burning 850 m/s prograde means increasing your orbital speed by 850 m/s.  the Delta V your spacecraft is capable of is shown in the staging.

 

When you burn prograde you push up your apoapsis on the opposite side of your orbit, the idea is to push it up enough that it just reaches the altitude of the mun, and time it so you arrive at apoapsis at the same time as the mun arrives at the same place.  typically it will take about 6h to get there, and in 6h the mun will travel a bit less than 60 degrees around its orbit on that time.

 

When you get there,  kerbins gravity will have slowed you down alot and you will be travelling much slower relative to kerbin than the mun, and would need to speed up to match its orbit. but as you cross into the muns SOI, from the muns point of view you are going faster than escape velocity, so then you need to burn retrogade to slow down enough to orbit the mun.

 

[herbal space program]

2 hours ago, MetricKerbalist said:

Hi @king of nowhere and anyone else,

So I began a flight from a fairly circular Kerbin orbit from an altitude of about 125'000 metres.  I clicked on prograde, and I tried to go 850 m/s.  But even with the slightest amount of burn -- one click out of the 15 clicks possible -- it says in the Navball well over 2000 m/s.  That is my delta-V, right.  My first point, therefore, is that I could not do a burn as low as 850 m/s.

I am flying my spacecraft right now as I compose this message.  My altitude is somewhat more than 3 million metres and I don't have a lot of fuel available.  I don't see how I am possibly going to reach the Mun's orbit, even if I were set to encounter the Mun's sphere of influence.  Maybe I am doing something wrong.

Stanley....

Hi everyone,

Well, since I have now run out of fuel, I time-warped forward.  It looks like I will intersect the Mun orbital path around Kerbin.  But now, how do I intersect with the Mun's sphere of influence?

Stanley

There seems to be some confusion here. What it says on the top of your navball is your speed relative to the ground below you (surface), whatever you may have selected as your target (target), or the center of the body you are orbiting (orbit). You can toggle between those modes by clicking on the window where it says that, and for this purpose it should say "orbit".  Low Kerbin orbit is a little over 2200 m/s in "orbit" navball mode, so you were probably looking there.  If you make a maneuver node by clicking somewhere on your orbital path, the amount of deltaV associated with that will appear just to the right side of your navball.  Anyway, to boost so you intersect Mun's orbit, you'll need to burn prograde to add another 850 m/s or so to your LKO orbital velocity of ~2200 m/s, so you'll be going a bit over 3000 m/s after you do that. I don't know how much dV you had left when you reached LKO, but if it was more than 900 m/s and now you're out of fuel, then you've overshot significantly, which means that your orbit goes well beyond Mun's, and although you may enter Mun's SOI at some point, you will need to do a significant amount of boosting with fuel you don't have to actually get into Munar orbit. So I would recommend that you revert that mission to the ground and try again, this time either placing a 850 m/s prograde maneuver node about 100 degrees behind the point in your orbit that is directly below Mun, or by just boosting prograde from that spot with the map view open and stopping as soon as you see yourself encountering Mun. To actuall make Munar orbit from there as cheaply as possible, you should set up your encounter so that your Munar PE is around 20 km and then boost retrograde when you reach it until you no longer see yourself escaping Mun's influence.

[MetricKerbalist]

Hi KSP colleagues,

I am getting really confused.  I just want to learn how to do a visual intercept with Mun so that I can get into Munar orbit.

Would anyone be willing to do a Zoom session with me?  If anyone would be willing to do that, then please send me a private message.  You would need to give me your e-mail address, and then I would send you an invitation.

Thank you for your consideration.

Stanley

[MetricKerbalist]

Hi KSP colleagues,

Here is a screenshot.

Stanley

Edited June 16, 2021 by MetricKerbalist
I changed the link to an image.

[MetricKerbalist]

Hi KSP colleagues,

With the background of everything that you helpful and knowledgeable Kerbalists have taught me, let me start over.

I want to get into Munar orbit.  I want to do a visual intercept with Mun.  I am in a fairly low, and roughly circular, orbit around Kerbin.

Here are my questions, please:

• Should I click Mun as a target?
• I should wait until Mun is at approximately 12 o'clock, right?
• I should click on Kerbin at roughly 7 o'clock and initiate a maneuver, right?
• I should set the prograde value to be about 850 m/s, right?  That sets the dotted brown line to just about touch Mun's orbit around Kerbin.
• Before I initiate the maneuver, do I click on the button that says "maneuver" or "target"?
• Then, please, what do I do?

Thank you.

Stanley

[Rhomphaia]

Here is how I would do it.

1 . get into roughly circular orbit

2. enter map view set mun as target, double click kerbin to focus map on it. rotate and zoom so you are looking straight down on the north pole and the mun is at the 2 o'clock position.

3. click the point on your orbit at the 6 o'clock position, and place a maneuver there. I prefer the draggy handles to the numerical inputs for manuevers, it is easier to see what is happening,  drag the prograde handle out until the brown dotted line touches the muns orbit.

If you will encounter the mun then half of the brown dotted line should disappear and a purple dotted line should appear around mun

If you have not got an encounter then the pale blue markers will tell you how far off you are, if you click and drag the central circle of the maneuver node  you can move the node around your orbit until you see the encounter

4. set SAS mode to the left of the nav ball to maneuver. To the right of the nav ball you should see time to maneuver and estimated burn time, start the burn when time to manuever is half of the estimated burn time. EG from your screenshot above, with a burn time of 52s you should start at t-26s

[herbal space program]

39 minutes ago, MetricKerbalist said:

Hi KSP colleagues,

Here is a screenshot.

Stanley

You are doing that maneuver  too early and in the wrong direction. You should be boosting entirely prograde, and from that screenshot it's obvious that you're boosting a lot radial-out as well.  Delete that maneuver node and place another one right at your PE, then carefully pull on the prograde handle to extend your existing AP to just short of Mun's orbit.  If as I suspect that puts you ahead of Mun at your intersect, then wait one more orbit of your craft and try again.

[MetricKerbalist]

Hi Rhomphaia,

OK.  I will do it as you suggest.  I just want to get into Munar orbit one time.  Then I will be satisfied and move onto something else in KSP.

Thank you.

Stanley

Well, wait a moment, please, @Rhomphaiaand @herbal space program.  If Mun were at 2 o'clock, then my brown dotted line needs to be at 12 o'clock, right?  Don't you both agree with that?

Stanley

Edited June 17, 2021 by MetricKerbalist

[herbal space program]

4 minutes ago, MetricKerbalist said:

 

Well, wait a moment, please, @Rhomphaiaand @herbal space program.  If Mun were at 2 o'clock, then my brown dotted line needs to be a 12 o'clock, right?  Don't you both agree with that?

Stanley

Roughly.  My guess is if you extend the AP of the orbit you're on now by boosting purely prograde  around your PE, you will hit Mun's orbit just a little before it gets there, but you should just try placing that maneuver node and sliding it back and forth a little along the orbit. If it does show you coming in ahead of Mun, then just right click on the node and push the little white "next orbit" button that's on the lower right.  If that gets you (i.e. the arrows) closer, keep doing it until you see an encounter.

[king of nowhere]

by the way, there is a tutorial - in the game - that covers going to the mun. you should definitely give it a try, because it guides you step by step.

[MetricKerbalist]

Hi @king of nowhere,

Thanks.  I know there is a tutorial.  I have had trouble with that too.

One thing that I don't get is that I have gotten close enough to Mun that its gravitational pull should have captured my spacecraft.  But it didn't.

Stanley

[Zhetaan]

14 hours ago, MetricKerbalist said:

One thing that I don't get is that I have gotten close enough to Mun that its gravitational pull should have captured my spacecraft.  But it didn't.

It won't unless you get the actual encounter.  Gravitational influence is an all-or-nothing thing in KSP:  you're either in the Mun's gravity or you're not.  Where the game thinks that will happen, the blue line of your vessel's trajectory will turn brown for the portion that falls inside the Mun's sphere of influence (and where it comes back out again, it will change again to purple).

I should let you know that there is an art to moving things around in space that simply is not intuitive for people who are used to moving things around on the ground.  Reading the navball is a technical skill all in itself.  To help you, I'll go with your description of the burn that you gave just after my last post:

19 hours ago, MetricKerbalist said:

So I began a flight from a fairly circular Kerbin orbit from an altitude of about 125'000 metres.

So far, so good.

19 hours ago, MetricKerbalist said:

I clicked on prograde,

Clicking prograde is the right thing to do.  It's not the very best thing, but that's okay; you're learning.  For now, it works just fine.  I will say that you may want to consider node hold () instead of prograde hold () since you have a manoeuvre node set up, but for this manoeuvre, the right time to burn is about when they point in the same direction anyway.

19 hours ago, MetricKerbalist said:

and I tried to go 850 m/s.

So far, so good.  What I want to make certain that you understand is that the 850 m/s is not meant to be your final orbital speed.  The 850 m/s here is the change from your starting velocity at the point of the burn, but this is one of the things that is not intuitive about rocketry:  the starting velocity is not zero.  Generally, it is never zero.  It isn't even zero when you're on the pad; that's why it's to your advantage to launch to the east, for example.

To illustrate, imagine that you're driving down a highway at a typical, albeit slightly slow 25 m/s.  You would like to go a bit faster, so your intuition is to say that you will, for example, increase speed to 30 m/s.  For a rocket, the same manoeuvre is 5 m/s.  You can see where we get that 5 m/s, but the part that is not intuitive is that we drop all reference to the initial and final velocities when we do so.  There are lots of good reasons to do this that make sense for rockets, but the important part is to remember that rocketry manoeuvres are changes and that they are measured as amounts of change, not target velocity values.

The 850 m/s does not add directly to your orbital speed, either.  The reality is much more complicated, because once you change your orbit, you change your velocity, and of course your position on the orbit is changing, as well, plus there are errors and losses that factor, so you generally should not treat the burn velocity as being strictly additive.

19 hours ago, MetricKerbalist said:

But even with the slightest amount of burn -- one click out of the 15 clicks possible

The clicks are simply visual markers; you should have finer thrust control than that.

19 hours ago, MetricKerbalist said:

it says in the Navball well over 2000 m/s.  That is my delta-V, right.

The only thing in your navball that would read that high at that point is your orbital speed.  That's the little panel with green text at the top of the navball.  That is not your delta-V.  Delta-V needed for a burn is the bright green text in a grey box to the right of the navball.

19 hours ago, MetricKerbalist said:

My first point, therefore, is that I could not do a burn as low as 850 m/s.

I covered this above:  850 m/s is not your target final velocity; it is your change in velocity from the burn.  Actually, since you're going prograde, you'll want your final velocity to be higher than your initial.

19 hours ago, MetricKerbalist said:

My altitude is somewhat more than 3 million metres and I don't have a lot of fuel available.  I don't see how I am possibly going to reach the Mun's orbit, even if I were set to encounter the Mun's sphere of influence.  Maybe I am doing something wrong.

You are, but this one is easy to correct.  If you're going from 125,000 metres to 11,000,000 metres or so, then at 3,000,000 metres, you shouldn't be burning at all.

One of the first principles of moving around in rockets is to conserve propellant.  What that usually means is that you burn hard where it will do the most good, and then you coast the rest of the way to a point where you burn hard again, again where it will do the most good.  The essence is that you have long, languorous journeys doing nothing at all, and these are punctuated by rare and sporadic fits of extreme activity.  At 3 million metres, there might be a case to make a minor correction burn for inclination or to refine the encounter at the Mun.  Burning prograde there, though, will not help and may hinder you.

15 hours ago, MetricKerbalist said:

Here are my questions, please:

• Should I click Mun as a target?

Should you?  Yes.  It will make learning easier because it will give you additional helpful information.

15 hours ago, MetricKerbalist said:

• I should wait until Mun is at approximately 12 o'clock, right?

You don't need to wait; you can click and drag the map view to orient the Mun where you like it.

15 hours ago, MetricKerbalist said:

• I should click on Kerbin at roughly 7 o'clock and initiate a maneuver, right?

Kerbin should be the vertex of this angle.  I assume that you meant that your vessel should be at the 7 o'clock position.  That is backwards.  The transfer angle for a Mun transfer from 125,000 metres is 110.5°, so wherever your manoeuvre node is, you want the Mun to be 110.5° anticlockwise from there.  If the Mun is at the 12 o'clock position, then you want your rocket (or at least your manoeuvre node) to be roughly at the 4 o'clock position (it's actually a little less than that; put it between 3:30 and 4:00).

Alternatively, if you put the Mun at a bit more than 45° clockwise from the top (roughly 2 o'clock), then you want to put your manoeuvre node at the 6 o'clock position.  Choose whichever visual orientation is easier for you.  You can afford to be less than precise here because the Mun is big, close, and very forgiving for people who are learning this.  You'll need to be more exact literally everywhere else, but the idea is to learn the basics before we move on to refinements.

15 hours ago, MetricKerbalist said:

• I should set the prograde value to be about 850 m/s, right?  That sets the dotted brown line to just about touch Mun's orbit around Kerbin.

Yes.  You want it to touch.  The number is less important--it could be a bit higher or lower depending on a lot of things--but that's a good value.   However, you don't stop there.  You will also want to adjust the line for an encounter.  That means that, after pulling on the little green prograde handle to get the line to touch the Mun's orbit, you click the greyish circle that those handles come out of and move the node around on the orbit.  Watch the point where the line touches the Mun's orbit; when you get the encounter, you'll see it change.  Part will turn purple, there will be new icons that show up, and it may look a little weird--that's just KSP calculating what the encounter with the Mun will do to your predicted orbit.  That's something that you'll need to deal with, but the important part is that you only need to deal with it because you've successfully gotten a Mun encounter.

15 hours ago, MetricKerbalist said:

• Before I initiate the maneuver, do I click on the button that says "maneuver" or "target"?

Manoeuvre.  Even when you're flying towards a target, don't click on Target.  There is a specific case that requires it, and you'd be forgiven for thinking that this is it, but oddly enough, flying to a target is just about the worst possible time to use Target.  That's because Target points to where the Mun currently is, as in right now--so if you fly there, then you'll arrive after the Mun has moved on in its orbit.  You'll end up constantly chasing it, only to arrive at where the Mun used to be.  Much like throwing a ball to someone who is running, you need to lead the target and throw your rocket, not to where the Mun is, but to where the Mun will be when it gets there.

15 hours ago, MetricKerbalist said:

• Then, please, what do I do?

Burn at the right time.  Burn time depends on your rocket, because rockets all have different masses.  KSP tries to predict the burn time for you; it displays this calculation near the bottom right of the navball along with the node countdown clock.  It is best to split the burn in half, putting one half before the node and one half after, so you should start a little early, but for a burn this short and close to Kerbin, it's okay to start on the bell rather than trying to be technically perfect just yet.

When you burn, burn at full thrust.  This is Z on the standard keyboard layout, though you may want to check if you're not using a US English keyboard.  The most efficient burns are the shortest burns, and for dumping a lot of energy into your orbit in as short a time as possible, there's really no reason to do anything less than full power.  Lower thrust is good for landing and fine corrections.  Nuts to that; we're going to the Mun.

Press X to shut the engine off when the burn is done.

When is the burn done?  Watch your orbit--this means staying in map view.  You can switch back to flight view for staging and such but map view shows you everything that you need to see.  When you see your blue orbit trajectory line jump and add extra icons and do all the weird things that the manoeuvre node prediction did when you planned it before, you've gotten the encounter.  You can fine-tune the trajectory (this is a time when low thrust is useful) but you've got the encounter.

After that, it all depends on what you want to do.  I suggest that you do flybys and not worry about orbit and capture until you can get Mun encounters and transfers predictably, but if you want to do capture and orbit of the Mun, then we can help you there, too.

Edited June 17, 2021 by Zhetaan

[modus]

The Mun will never 'just' capture your spacecraft. You have to slow down (burn retrograde, ideally at Mun periapsis) first in order to be captured.