Making a node for interplanetary ejection.

[Motokid600]

I understand and know how to use the interplanetary ejection planner/calculator. But its utilizing this information is what's hard for me. Using EngRedux i wait and see until my ships at the right angle to prograde ( in this case I'm going to Dres with a 108 degrees to prograde burn ).

So I make the node at this angle and from here on i.. wing it. Using the advanced manouver node mod I just mess with the values until I get myself a nice ballistic ejection burn. Im usually able to get it right on the ball, but it takes me 20min to a half hour. Longer then a full orbit at 1x timewarp and this is a problem because if the ship goes around and passes my node all my work is lost. ( however I may be able to copy-paste the values in the node mod into a new node if this happens )

So is there a better, faster way to do this?

Edited September 25, 2013 by Motokid600

[Cranium]

if you're missing your maneuver nodes, try using Kerbal Alarm Clock. It's really nice for that.

[SRV Ron]

I think that his problem is that his ship passes the node before he has the settings completed for the most efficient burn he can find. Believe me, you learn to work fast when you are setting one up and find that the most efficient launch window is only a minute away.

[Guest]

I understand and know how to use the interplanetary ejection planner/calculator. But its utilizing this information is what's hard for me. Using EngRedux i wait and see until my ships at the right angle to prograde ( in this case I'm going to Dres with a 108 degrees to prograde burn ).

Wait until you're about one orbit away from the desired burn time, then start checking to see if your ship is at the right angle in its orbit. Once your ship is in the right spot, go into map view, zoom all the way in, and create a node immediately behind your ship. That should give you a good fifteen minutes or more to setup the node for transfer on the next orbit and it'll be in roughly the correct spot.

[Van Disaster]

In addition to that, if you're using a node editor ( it's a really good idea if you're going to be doing long-distance nodes ) you can step the node around an entire orbit again easily.

[Motokid600]

I am using a node editor. Pretty much the main problem is the fact that it takes me too long to make the node. Last night it took me 20mins to make a Dres ejection burn. Id like to think the planner could help me make one easier, but the only useful information I can utilize is the prograde angle, phase, year and day. Other then that I just guess.

[Eskarina]

Dude, 20min for an ejection node is way too much. I recommend to set up that nodes without the node adjustement plugin. They are way too sensitive and you can spend +15min on it easily.

I had this problem also. Remember that is more important to have an encounter that anything else. Is just not possible to set up a perfect 1-node encounter 100.000.000.000 meters away. The game uses a lot of reference windows, and scale transitions from map view to ship view. So I finally realized that, unless you are aiming for a moon, or something in the neiborhood, the precission for such a long trip, is so low that you will need to make course correction along the way from planet to planet.

Also, remember that Moho, Dres and Eeloo are the only bodies that have a sightly inclination and eccentricity orbits. Maybe you want to use my method if you are doing a classic Hozltman:

- from the map view, zoom out until you see the planet and you orbit at the same time.

- locate the face of the planet is facing the sun and the one that is in the shadow

- trace an imaginary line that comes from the sun and crosses the planet, and trace other at 90' angle, so you put an + in top of the planet.

-Your ejection node will be almost always, in top of one of the lines of that cross, so when you burn, you will follow the planet orbit path, prograde or retrograde.

- burn around 1000m/s and them zoom out again to check how close you are to the destination planet.

- Fine-tune the burn to get an encounter at the apo. WARNING be sure you know WHEN is the correct date to do the burn and not fail your target miserably. Any encounter out of the apo. is 100% harder to tune.

But a node planner plugin have its uses, for a precise aerobraking / slingshot maneuvers, I find it indispensable. I'm not a plugins advocate and certainly I do whatever it takes to archieve goals 100% stock, but I cannot recommend 'better nodes' plugin and similar ones enough.

Hope this helps.

[SRV Ron]

Where setting up a node gets really critical; Note the burn time for the slingshot that made this major change in orbital plane and closer orbit around Duna.

And a better then expected result;

This was done without the node planner plugin.

[SRV Ron]

For an intercept of Eeloo Dres or Moho, if you can get the intercept as their orbital planes crosses yours, you will do so most efficiently. Otherwise, you have to make the best guess of where to do the intercept and later do a course correction that alters your plane to intercept. Those three are tough due to their eccentric orbits and small sphere of influence.

[Kasuha]

You don't have to set up your maneuver perfectly. First, it's very hard to do perfect match with it, the controls are not sensitive enough. And second, the execution is never perfect as the maneuver node assumes applying the dv at single moment while your burn takes a while. It takes way less time and only very little more fuel to set up the maneuver "close enough", then perform the burn "close enough" and finish it using a few m/s of corrections after the main burn. For interplanetary burns there is usually plenty of time to do these tiny corrections about anywhere on the course.

[Monkeh]

To match inclination set up a maneuver node on the ascending or descending node. This is where you're on the same plane as your target. From there you can use the pink things to adjust adjust your inclination to match. I just move my POV so the green orbit line of my target is a single thin line and then tweak the pink things of my maneuver node until they perfectly line up. Then you can go for the burn to intercept, safe in the knowledge you're on the right 'vertical' trajectory.

[mellojoe]

Just start creating the node earlier?

Why wait until you are AT the point before setting up the node? I create my node when I'm half an orbit away from it. And then, yes, it doens't have to be perfect. Once you leave the sphere of influence of the planet you are leaving (ie: Kerbin) then you can make changes very effeciently. You can move the periapsis a million meters using just small amounts of RCS even.

[Eric S]

Just start creating the node earlier?

Very much this. Planetary transfer windows are significantly wider than the time it takes for a single orbit in LKO. Never feel like you have to transfer THIS ORBIT. If you don't get it set up in time, start setting one up for the next orbit. Seriously, Even Moho windows are several days long if you're willing to adjust your travel time. For a Duna transfer, you can launch 5 days early or late for a cost of about 40 m/s delta-v. I usually spend that much just fine tuning my transfer once I'm out of Kerbin's SoI.

http://alexmoon.github.io/ksp/ gives a nice visualization of the increased delta-v it takes to launch early or late. Well worth playing around with even if you don't use it to plan your transfer, just to give you a feel for how early/late launches affect the budget.

[Specialist290]

Another tip: If you're in danger of losing your node due to your ship bypassing the point where it was plotted, pick it up and drag it along the path of your orbit in the direction your ship is orbiting until it's almost directly behind the ship. This will allow you to keep the information you plotted and give you another whole orbit to fine-tune it, if you need that much time.

[Kulebron]

Very much this. Planetary transfer windows are significantly wider than the time it takes for a single orbit in LKO. Never feel like you have to transfer THIS ORBIT. If you don't get it set up in time, start setting one up for the next orbit. Seriously, Even Moho windows are several days long if you're willing to adjust your travel time. For a Duna transfer, you can launch 5 days early or late for a cost of about 40 m/s delta-v. I usually spend that much just fine tuning my transfer once I'm out of Kerbin's SoI.

http://alexmoon.github.io/ksp/ gives a nice visualization of the increased delta-v it takes to launch early or late. Well worth playing around with even if you don't use it to plan your transfer, just to give you a feel for how early/late launches affect the budget.

I used this initially, but figured out that most of this means that you should shoot when Kerbin is on the opposite side. The periapsis/apoapsis of the planet does not matter much: it can add about 50 m/s of launch speed. The is some difference in speeds on approach, but aerobraking can cancel it out.