Eve Sundiving

[dharak1]

So a few minutes ago in my career save I decider after Duna I would go to Eve. A logical step considering a transfer window was only a couple weeks away. I had no problem doing a complex double probe deployment on my Duna mission but decided to keep it simple as I had never been to Gilly. I began my launch and waited until I got to my ejection angle then burnt for roughly 1km/s until my orbit was dipping through Eve's. That's funny I thought, I had Eve selected as a target and didn't even get a closest encounter marker. I played around with some maneuver nodes until I got an encounter. I had a 350km encounter, perfect for aerobraking and I would need to as my orbit had me nearly hit the sun after the Eve encounter. This happens nearly every time I try to get to Eve, I either have to sundive or just wait until I get captured. I have no problem getting to Jool or Duna or even any other inclined bodies like Minmus. Does anyone else always have trouble with Eve? Does anyone else seem to always have to sundive to get to the inner solar system?

[95tiger59]

you must be doing a killer gravity assist to do that, any chance you could post a picture of the encounter/sundive? I know you wrote it down but it will be clearer if I can see it.

[RocketPilot573]

you must be doing a killer gravity assist to do that, any chance you could post a picture of the encounter/sundive? I know you wrote it down but it will be clearer if I can see it.

Indeed, going to eve from pretty much anyways shouldn't produce such a gravity assist... Pictures would be nice

[*Aqua*]

Doesn't sound like you tried an efficient Hohmann transfer orbit.

You have to wait for the right time spot (when the phase angle is right) or time window (time spot +/- a few days) and then lower the periapsis until it hits the orbit of your target.

Picture is misleading. Kerbin should be 54° ahead not behind Eve.

You can calculate the phase angle with tools like this one: http://ksp.olex.biz/

Or ignore all this crap, take enough fuel und burn straight there.

[Pecan]

...I began my launch and waited until I got to my ejection angle then burnt for roughly 1km/s until my orbit was dipping through Eve's....

Well if you say so, but how did you calculate your ejection angle? How did you calculate the planetary alignment?

[CalculusWarrior]

Eve is freaking massive, so it's not surprising that it would be able to affect your orbit to such a degree. I believe it is one of the favoured targets for gravitational assists, since it is so close to Kerbin, and so heavy.

[dharak1]

http://ksp.olex.biz/

I used that and had my origin as Kerbin and my destination as Eve. Waited until i got just past kerbin prograde and burned my entire node for 1km/s deltav with no closest approach. I set up another nod that got me an intercept but it took 6km/s deltav so I made another one that I could actually do. It still took more deltav than necessary.

[SpaceSphereOfDeath]

http://ksp.olex.biz/

I used that and had my origin as Kerbin and my destination as Eve. Waited until i got just past kerbin prograde and burned my entire node for 1km/s deltav with no closest approach. I set up another nod that got me an intercept but it took 6km/s deltav so I made another one that I could actually do. It still took more deltav than necessary.

Can you post a picture of you encounter?

[Pecan]

http://ksp.olex.biz/

I used that and had my origin as Kerbin and my destination as Eve. Waited until i got just past kerbin prograde and burned my entire node for 1km/s deltav with no closest approach. I set up another nod that got me an intercept but it took 6km/s deltav so I made another one that I could actually do. It still took more deltav than necessary.

Ok, good - so did you go at the right date and time? If you're going the right way at the right time it's very strange that you didn't get an encounter.

http://alexmoon.github.io/ksp/ is favourite for telling you when to go as well as which way.

[KingPhantom]

Doesn't sound like you tried an efficient Hohmann transfer orbit.

You have to wait for the right time spot (when the phase angle is right) or time window (time spot +/- a few days) and then lower the periapsis until it hits the orbit of your target.

http://i.imgur.com/pNLk0hg.png

Picture is misleading. Kerbin should be 54° ahead not behind Eve.

You can calculate the phase angle with tools like this one: http://ksp.olex.biz/

Or ignore all this crap, take enough fuel und burn straight there.

do you have those pictures for all the bodys in the solar system?

i never wait for the window. i shoot mi out of kerbin and adjust the hohmann there

EDIT: Ignore it! i have everything on the site you posted!

Edited July 25, 2014 by KingPhantom

[Pecan]

Lol, since the picture's "misleading" you can just use that one for every encounter - it'll still be wrong for them too ^^.

[dharak1]

I don't have a picture of the encounter I already landed the probe and got plenty of sciences.

[magnemoe]

Eve is freaking massive, so it's not surprising that it would be able to affect your orbit to such a degree. I believe it is one of the favoured targets for gravitational assists, since it is so close to Kerbin, and so heavy.

If you areobrake but don't get an orbital capture its possible that you get both an aerobrake and a gravity turn and exit close to 180 degree of your incomming trajectory, this should drop you close to sun.

Another possibility is the singularity gravity turn bug. you can get this at Mun too, do an impact trajectory to the mun and try to hit it dead center. You will see some crazy exit trajectories, This is because the node system treat gravity as an singularity at core of the body, if you fly close enough gravity is infinite

[Richy teh space man]

Most of my Eve missions require two burns, one around Kerbin to get into the neighbourhood of Eve and the second in Kerbol orbit to match the inclination of Eve's orbit.

[SkyRender]

The problem is that Eve's first really "good" encounter happens a LONG ways out from the other planets. It happens around year 2 day 175 in Kerbal time, in fact, while all of the other planets get a decent alignment somewhere between 200 and 265 days into the first Kerbal year (except Dres; its first good launch window is about day 375 or so). It's just the case that Eve starts out in a position that doesn't lend itself to efficient encounters for a really, really long time.

[PoorYorick]

The reason the first perfect window is so far out is because there's another one about 20ish days before day 1. While it's not great, you can get a ship there for about 1500 m/s of dv, not THAT much more expensive than the optimal window if you launch within a couple days of the beginning of the game.

[KerbMav]

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Please enlighten me as to how I would aquire such indepth knowledge?

I am only using KAC or Protractor to get (obviously semi-)good encounters.

[PoorYorick]

Using http://alexmoon.github.io/ksp/ you can plug in your destination, the time of flight you want, and the earliest and latest launch dates. So if you set it up going to Eve, with the earliest date on y1d1 and the last on y1d5, it'll calculate the cheapest transfer, its flight time, and where to do your ejection burn. It's also really nice for going to the inclined planets and moons since it'll tell you how to minimise the inclination change by doing some of it during the ejection. For actually setting up the manoeuvre it gives you, PreciseNode or MechJeb's node editors are nice, although it's pretty easy to eyeball it.