How to warp into Eve-Gravity-Influence in the correct angle?

[blizzy78]

2nd. Mid-course ascending/descending node. = NaN...already tested. And it won't work.

The only thing I can think of here is that even though you do manage to get "NaN" at the AN/DN, the relative inclination is not perfectly zero because of the long distances (and rounding errors) involved. If that is the case, there is nothing more you can do but to wait for the next AN/DN (most possibly only after you've achieved a stable orbit around the target body.)

3rd. 5-10 days before encounter. That is impossible, if you using manual-all-the-way, you will know why. Because there is no more ascending/descending node for you to refer anymore. It just a line to the destination.

He was trying to guide you through the trajectory. Of course the "5-10 days before encounter" mark comes after the mid-flight inclination change at AN/DN, and he pointed that out before that correctly.

And the 10m/s? make adjustment 1000-2000km from surface? what surface? Mid-course correction? I just make the ascending/descending to be NaN. other correction 0-10 m/s? huh what? other correction? orbital geometries of planets? Ok. How to tell? what it refer to? How do I adjust? According to what?

Again, he was trying to guide you through the trajectory, advising you to make additional course corrections as you get nearer to the target.

[Johnno]

I've followed this thread trying to grasp why Sirine isn't understanding course corrections, and I think this last post revealed it.

You don't need to be at ascending/descending node to do a course correction. You don't even have to refer to it. I don't use mechjeb either and fly entirely manually, often not even using manouver nodes. You can change your trajectory/course just by looking at where you're heading, then burn in the appropriate direction.

For example, if you're heading for say Eve and you place your ship so that you're facing your prograde you can alter where you'll end up by turning and burning (or even just using RCS). If you have Eve straight ahead on your prograde, turn left and burn, your trajectory will change and you'll end up flying left of Eve. Turn right instead and burn, your trajectory will take you on the right side of Eve. Up/down is the same.

You can compare your mapview of where you'll end up compared to your target, then look at your navball and burn the appropriate direction compared to your prograde, depending on where you want to end up. It really isn't all that hard. And you can do this at any time. This is why I early on in the thread said to do so when you enter the SOI, because at that point it's cheaper in delta-v than when you're closer.

You can do course correction during your route, just as I mentioned (although briefly in my first post) and as Hannu now pointed out. After you leave Kerbin SOI do a correction burn so you have the encounter, then halfway do another to get the encounter closer, then another a few days before getting to the SOI, and then yet again after entering the SOI.

Your orbit/trajectory is entirely dependent on you.

[Apollo13]

Do yourself a great favor and get kerbal alarm clock for starters. It automaticly kills warp at a set time. ( I set it to kill warp 5 seconds before SoI change ). Takes all the guess work out of having to stop in time.

Alarm Clock should be in the basic vanilla KSP. I consider it essential for warping.

[Sirine]

So far, only "Vector" understand my problem, and get close enough to solving it.

"blizzy78" is saying something but means nothing.

"Johnno" when you enter Eve SOI it is already too late.

"Apollo13" please go somewhere else.

"Hannu" sorry I do not understand.

" SRV Ron" thanks for sharing the image.

Thanks above people for helping. Appreciated it much. If I did found the answer, I will sure to post it here.

Edited September 3, 2013 by Sirine

[Sirine]

Simple. Please show me an "image" at the edge of Eve SOI that you are near the equatorial angle of Eve.

And tell me how you do it with-out mech-jeb or any plug-in/mob, and by referring to what. (don't tell me eyeballing).

Then you got the answer!

[blizzy78]

"blizzy78" is saying something but means nothing.

Well, have my apologies for trying to help.

[Johnno]

"Johnno" when you enter Eve SOI it is already too late.

Too late for what? It's never too late for a course correction. What exact part do you not understand about course corrections? I explained, or I thought I did, quite simply that you don't need to be at AN/DN, you don't need to refer to them. You can change your course/trajectory/orbit any time you want by applying thrust, be it by engine or RCS.

I'll go make a few screenshots.

[Vector]

I will post some screen shots later tonight showing the regular inclination-adjustment (expensive) method and also the double-encounter method, which I tried out recently.

I've uninstalled MechJeb because I was encountering some bugs (orbits drifting under no thrust and even when game is paused) and it turned out the bug went away when I removed MechJeb!

[Johnno]

Ok I intentionally set up an encounter where I'd end up in a highly inclined orbit if I simply burned retrograde at periapsis.

Pull the purple thingie.

Pull the blue thingie.

Manouver node done, burn at it...

3.6° inclination, easy enough to sort once you get to the planet. 55m/s delta-v correction burn, inside SOI, from 68.8° inclination approach to 3.6° inclination approach.

Is that good enough or is it another problem, Sirine?

[Sirine]

Is that good enough or is it another problem, Sirine?

The "Normal" 4~8 LV-N engine going into Eve SOI is about "Less" then 1000m/s. Mine show 824.7m/s. I have no ideal how you go into Eve SOI with 2342m/s ALL the Way!

So, for just pulling the Purple things..pulling from 824.7m/s to 2342m/s...is estimated about 3000++ Delta-V. (68.8° to 3.6°).

Perhaps you should explain how you get the 2342m/s into Eve's SOI. And your correction burn only .2m/s? 55m/s delta-v correction burn?

the regular inclination-adjustment (expensive) method

As per "Vector" said. inclination-adjustment is suppose to be EXPENSIVE. Please do it the normal way. Off all mod, plugin, do it manually.

[Vector]

Ok I intentionally set up an encounter where I'd end up in a highly inclined orbit if I simply burned retrograde at periapsis.

...

In this scenario your position is already near the equatorial plane. In this case there will be a cheap inclination burn that will level out your inclination, yes. But if you are approaching Eve "from above" then the pink normal burns do not give you a cheap equatorial orbit. They just let you pick which polar orbit you want.

Off to take pictures...

[Johnno]

The "Normal" 4~8 LV-N engine going into Eve SOI is about "Less" then 1000m/s. Mine show 824.7m/s. I have no ideal how you go into Eve SOI with 2342m/s ALL the Way!

That's irrelevant, it was not the speed I was showing you it was the way to change your approach by a simple manouver node and adjusting your "purple things" (vertical adjustment of orbit), "blue things" (horizontal adjustment of orbit). No need to even touch the prograde/retrograde markers since you'll either aerobrake or burn at PE.

So, for just pulling the Purple things..pulling from 824.7m/s to 2342m/s...is estimated about 3000++ Delta-V. (68.8° to 3.6°).

Are you being ridicilous on purpose? My prograde speed compared to yours doesn't matter whatsoever since your initial issue was to change from a "always polar approach" to a "equatorial approach". Why would speed have anything to do with it? If you had the identical orbit of what I had in my screenshots, with 824m/s instead of 2342m/s, you'd have a similarly low delta-v manouver from 68.8° to 3.6° since all you're doing is pushing your trajectory sideways or up/down.

Perhaps you should explain how you get the 2342m/s into Eve's SOI. And your correction burn only .2m/s? 55m/s delta-v correction burn?

I got to that speed because I didn't bother timewarping for an optimal window, I toggled infinite fuel, burned into a low Kerbol orbit and then went for Eve when it lined up better for me. This is irrelevant. I was showing you how to change your approach inclination, the question you asked at the beginning of this 4 page thread. How to do a correction burn... something you still don't seem to understand.

And if you spend 55m/s delta-v sideways your prograde speed won't change, you're just altering your orbit. Do you seriously not understand anything about how trajectories work? I'm really losing my patience here, you've had replies from so many people, for 4 pages, yet you seem dead set on refusing to understand any of this.

What is it honestly going to take, a step by step approach of Eve in particular, with a screenshot before every single manouver?

How can you not understand that if you're heading prograde and burn perpendicular to your trajectory (90° angle compared to path) you change your trajectory in the direction you burn?

Going straight for Eve, turn 90° left and burn, you will fly left of Eve. Turn 90° right instead and burn, you go on the right side. Or up if you burn up compared to your trajectory, down if you etc..... how is that so hard to understand?

[Johnno]

In this scenario your position is already near the equatorial plane. In this case there will be a cheap inclination burn that will level out your inclination, yes. But if you are approaching Eve "from above" then the pink normal burns do not give you a cheap equatorial orbit. They just let you pick which polar orbit you want.

I know I was near the equatorial plane, I was merely demonstrating how to adjust your approach once inside SOI. But I guess I misunderstood. I'd done a correction burn, as one should do, and Sirine has said they'd gotten to 0° AN/DN or whatever. That's what course correction burns before entering a SOI are for, something we've been saying since the beginning of the thread.

[Johnno]

Please do it the normal way. Off all mod, plugin, do it manually.

Here you go, did a quick trip, no mods apart from engineer, no aerobraking, ballistic trajectory without plane change, wasted some delta-v on sloppy manouver nodes, didn't wait for a very good transfer window either.

So roughly 3000m/s delta-v from Kerbin orbit to a 0.13° inclination 147/165km orbit without aerobraking. Couldn't be bothered making the final orbit any prettier, plenty of fuel and monoprop left for that though. Initial trajectory on the 'wrong' side of the planet, so moved it to the other side after entering SOI, then fixed my 14° inclination after initial capture burn. And as you can tell I could've saved a lot with aerobraking.

Enjoy.

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[Sirine]

Thanks "Johnno" for the effort. Very much appreciated.

Below are mine version, the process of entering Eve's SOI. I'm using the Tiny craft to test it out.

Once again: I repeat my question. How do I go in to Eve's SOI in near the equatorial angle (90 Degree), left or right. And not from TOP-DOWN.

Changing inclination angle inside the Eve's SOI is a no-no solution. It is Delta-V expensive. My Tiny craft already cause over 700D-V, If I'm using my full craft which Mass over 150tons, it cause more than 3k delta-v.

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[Vector]

1. Start off in LKO with full fuel.

2. Leave Kerbin SOI in retrograde direction (relative to Kerbin's orbit around Kerbol)

3. Inclination is 2.1 degrees relative to Eve. Luckily I don't have to wait long to reach AN/DN

4. Adjust normal (pink arrows) until AN/DN nodes get "wobbly". The dashed trajectory will be parallel to Eve's plane. The AN/DN indicators going wobbly are much more accurate than eyeballing the plane.

5. After burning, inclination is zero (pic is actually before I finished matching inclination)

6. With inclination matched, you don't have to aim for AN/DN, you can do Hohmann Transfer anywhere. In this case it's 1 and 2/3 trips around Kerbol and I can get an intercept.

7. After starting Hohmann Transfer

8. Fine-tuning intercept to get periapsis down to 100 km or so. Maneuver node closer to intercept helps me know which side of the planet I'm arriving on. By tweaking radial and normal I can arrive on the right side (prograde) and level with the planet. Tweak pink arrows until periapsis is at a minimum, and you'll be sure to arrive in the plane of orbit. You can lower your periapsis down to 10 km and then fine-tune with the pink normal arrows very accurately, then raise your periapsis back up. In this case I'm aiming for 70km periapsis. If the adjustments are too sensitive, move the maneuver node closer to the intercept. If you are farther away it's more efficient but can be touchy to make small adjustments.

9. Manuever node costs only 0.2 m/s for the fine adjustment

10. I did my burn early. It's not a problem because you can watch the actual periapsis to guide you.

11. Approaching Eve SOI

12. Crossing SOI boundary at warp

13. Periapsis changed from 70km to 46km!

14. Even with warp disturbance, my orbit (hyperbolic) is still precisely in the orbital plane.

Cost about 330 m/s to match inclination and 665 for Hohmann transfer. Fine-tune corrections were very very small.

Double-intercept (or a slingshot around a moon, if there were a suitable one) can greatly reduce the inclination cost. Without some sort of gravitational help, you are going to have to pay the 330 m/s one way or another, either in deep space by matching Eve's inclination, or pay a lot more once you arrive in Eve's SOI.

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[Vector]

Sirine, in your 6th image it shows your inclination matches well and you have a nearly equatorial position relative to eve. Your inclination matching in the first image is accurate.

If you are heading straight toward Eve, you don't usually want to use the pink nodes. In these situations I fly manually without maneuver nodes. Your prograde indicator will be straight toward Eve, very near the center of the brown area on the nav ball. Orient yourself so that you are aiming prograde and north is up. Then yaw 90 degrees to the right. You should be pointing near the horizon on the nav ball and the nav ball should be telling you 90 degrees "longitude" or whatever. Then slowly burn.

This will push you to the right of the planet and the direction of your exit will naturally swing around to point to the left after you pass eve. Since you are lined up straight toward Eve, it should not take much, and this will bring you to be equatorial. Once your orbit is more rounded and not so severely hyperbolic, then the pink nodes are more useful to adjust your inclination.

[Sirine]

2nd image I'm referring from here...http://forum.kerbalspaceprogram.com/showthread.php/27236-Tutorial-Step-by-step-Interplanetary-Hohmann-transfer-guide-and-tips

3rd image same as mine...2.1 inclination. (that is 0 degree with the Mun)

4~5th image same adjust to 0 degree.

Image 7,8,9,10... I'm lost...

I'm digesting the info... trying to understand...give me some time.

Your prograde indicator will be straight toward Eve, very near the center of the brown area on the nav ball. Orient yourself so that you are aiming prograde and north is up. Then yaw 90 degrees to the right. You should be pointing near the horizon on the nav ball and the nav ball should be telling you 90 degrees "longitude" or whatever. Then slowly burn.

[Sirine]

Thanks for above all the reader/writer who was trying to help. And I'm very much appreciated.

I've finally got it... Later I will post the picture and DETAIL explanation on how to get it to Eve's SOI in the equatorial angle. Here.

Especially Vector and Johnno. Thank you very much.

[Sirine]

Should any forum administrant see this thread. Please move it to the Tutorial sub-forum. I believe there will be some help for the newbie like me.

[Vector]

Here's the double-encounter method, with the goal of minimizing fuel to get roughly equatorial around Eve. It's hard to explain but maybe someone will be able to decipher it.

Note that the fuel in the final shot is only very slightly less than after the burn to encounter Eve (slide 8). The slingshot inclination correction is very nearly free if you don't mind a extra trip around Kerbol.

The slideshow doesn't show circularizing around Eve, but with the inclination already close to equatorial and the periapsis near the aerobrake range, it should take very little fuel to capture and circularize around Eve.

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[Sirine]

Vector...please check the 1st post in this thread...The answer is there!

[blizzy78]

Vector...please check the 1st post in this thread...The answer is there!

Your "solution" is exactly what I described earlier:

The only thing I can think of here is that even though you do manage to get "NaN" at the AN/DN, the relative inclination is not perfectly zero because of the long distances (and rounding errors) involved.

Pardon my saying this, but I think you only see what you want to see.