Node markers

[Ron Devu]

   I have a probe in equatorial orbit around the Mun. It has fuel and I'd like to make the orbit as polar as I can. Trouble is, it's the only thing I have out there, and I can't figure out how to get ascending and descending node markers to show up. Is there a way to do this?

[Superfluous J]

There are two a couple ways I can think of.

Use alt-f12 to put something else in an equatorial orbit of Mun. Then target it, do your thing, and then delete the other craft.

Take a satellite contract for an equatorial orbit, and then adjust your satellite 90 degrees to it.

Accept that if you were not sure if your orbit is polar or not, it's good enough.

that last one is what I do.

Edited April 5, 2019 by 5thHorseman
fixed a swypeo

[Ron Devu]

11 minutes ago, 5thHorseman said:

There are two a couple ways I can think of.

Use alt-f12 to put something else in an equatorial orbit of Mun. Then target it, do your thing, and then delete the other craft.

Take a satellite contract for an equatorial orbit, and then adjust your satellite 90 degrees to it.

Accept that if you were not sure if your orbit is polar or not, it's good enough.

that last once it's what I do.

What is alt f12 all about? And why didn't Werner von Kerman tell me about it?

Oh and completely off topic, have you seen Scott Manley's perpetual thrust machine? It's hilarious, it really looks like some crackpot garage project and it delivers 1 m/sec^2 forever without engines or fuel. Trouble is, to operate it you have to issue commands very fast, so you need to write a script to make it work.

[Superfluous J]

2 hours ago, Ron Devu said:

What is alt f12 all about? And why didn't Werner von Kerman tell me about it?

It's the cheat debug menu. You can do all sorts of things in it, including place any craft in any orbit of any body, so long as it's a high orbit.

[Rocket In My Pocket]

Just eyeball it till it's relatively straight up and down?

Doesn't have to be perfect, and if it's for a contract, they'll show you the exact orbit it needs to be in.

[Ron Devu]

1 minute ago, Rocket In My Pocket said:

Just eyeball it till it's relatively straight up and down?

Doesn't have to be perfect, and if it's for a contract, they'll show you the exact orbit it needs to be in.

Tried eyeballing, it looks like the orbit expands a lot if you are off the nodes.  And it's not for a contract, I'm just using up a spare ship from a rescue effort.

So i tried eyeballing it anyway and got about a 60 degree tilt and a large enough orbit to avoid annoying eclipses. Good enough.

[bewing]

To get into a polar orbit, you want to start burning when you cross the equator. You can see exactly when you are about to cross the equator by watching the latitude in Kerbnet. So that's when you start burning.

You want to be locked Normal or Antinormal.

As you burn, your Normal/Antinormal icon will rotate around your navball. You stop burning when your heading gets to either 90 or 270, depending on whether you are Normal or Antinormal.

You don't need any markers, and you don't need any reference ship.

 

[Superfluous J]

7 hours ago, Ron Devu said:

Tried eyeballing, it looks like the orbit expands a lot if you are off the nodes.  And it's not for a contract, I'm just using up a spare ship from a rescue effort.

So i tried eyeballing it anyway and got about a 60 degree tilt and a large enough orbit to avoid annoying eclipses. Good enough.

You may have not understood the suggestion, unless I didn't. Assuming @Rocket In My Pocket was furthering my idea from:

12 hours ago, 5thHorseman said:

Accept that if you were not sure if your orbit is polar or not, it's good enough.

I meant to just eyeball when making the maneuver node to create the orbit. Then follow the maneuver node. That way, you don't waste fuel trying to burn perfectly normal or anti-normal (which is inefficient even if you were able to do it perfectly the whole way)

Edited April 5, 2019 by 5thHorseman

[Ron Devu]

3 hours ago, 5thHorseman said:

You may have not understood the suggestion, unless I didn't.

I meant to just eyeball when making the maneuver node to create the orbit. Then follow the maneuver node. That way, you don't waste fuel trying to burn perfectly normal or anti-normal (which is inefficient even if you were able to do it perfectly the whole way)

 

Are you saying there is a better way to tilt an orbit than burning normal? It's the only way I know.

[Superfluous J]

47 minutes ago, Ron Devu said:

 

Are you saying there is a better way to tilt an orbit than burning normal? It's the only way I know.

Yes.

Try it. Hack a ship with plenty of dV and maneuverability into orbit. Use the maneuver node marker to make a 90 degree orbit shift and see how much dV it takes. Then burn it going normal instead of following the node. Note how much dV your ship has before and after the burn.

As to why, as you burn normal, the direction of Normal changes. Therefore, you weren't burning the correct direction originally and are correcting your direction slowly throughout the burn. Any burning you do away from what that maneuver node told you to burn is wasting fuel.

[bewing]

But the deltaV difference doing it that way is only about 40% at the most, and it's a lot less controllable, and it requires a lot of microfiddling with maneuver nodes which is mighty annoying.

 

[Superfluous J]

21 minutes ago, bewing said:

But the deltaV difference doing it that way is only about 40% at the most, and it's a lot less controllable, and it requires a lot of microfiddling with maneuver nodes which is mighty annoying.

 

Weird you say that. I find doing it with maneuver nodes to actually be easier than burning normal, where you're constantly a little off so your Ap goes crazy.

Is the absolute maneuver node a stock thing now? Or is that still from PreciseNode? Where the maneuver node doesn't rotate as you pull on the handles. With that on it's super simple to get the destination orbit correct, because the handles actually change your resultant trajectory the direction you pull them.

[Capt. Hunt]

You don't need the ascending/decending nodes unless you are actually trying to match planes with a target.  The AN/DN are just the points where the two orbits cross.  If you're in an equatorial orbit aren't actually trying to match a target orbit, then any point on the orbit will do.  If you need a specific longitude of AN/DN for a contract orbit, just start your burn as you pass that longitude.  If your orbit is inclined, then the points where your ship passes the equator are effectively the AN/DN.

BTW, it costs an order of magnitude less Delta-v if you make the burn to your planned inclination just after you enter the mun's SOI, rather then waiting until after you decelerate to enter orbit.

Edited April 6, 2019 by Capt. Hunt

[KevinW42]

18 hours ago, Capt. Hunt said:

BTW, it costs an order of magnitude less Delta-v if you make the burn to your planned inclination just after you enter the mun's SOI, rather then waiting until after you decelerate to enter orbit.

And if you’re already in a low orbit, it may be cheaper in some circumstances to go into a highly elliptical orbit, do your plane change at the apoapsis, then re-circularize.