High inclination orbit

[Spaps]

Hello, fellow kerbonauts. I have a problem with one of my contracts, and this one is extremely well paid...

The contract:

-Enter and maintain proper orbit around the Sun for 300 days:

-Orbit with at least 0.50 eccentricity ✓

-Orbit of at least 75.0° inclination

-Magnetometer Scan data from low orbit above the Sun

-Magnetometer Scan data from high orbit above the Sun ✓

-Radio Plasma Wave Scan data from low orbit above the Sun

-Radio Plasma Wave Scan data from high orbit above the Sun ✓

I'm waiting to get to the low orbits to do the two last scans, but I need to know how to get into an inclined orbit like this. Could somebody tell me how that orbit looks? I'll manage to get there myself.

[steve_v]

Can one not see the target orbit in the map / tracking station view?

[lincourtl]

It'll cost you much, much less delta-v if you change orbital planes (inclination) from high orbit. You can then drop down to low orbit. All you really need to do is burn anti-normal on the ascending node, or normal on the descending node. You can pretty much eyeball the angle.

[Taki117]

Because Kerbin orbits at 0° inclination you can set it as you target and do a plane change at the AN or DN while keeping an eye on your inclination. Once you hit 75° you are done.

[Anquietas314]

I'm waiting to get to the low orbits to do the two last scans, but I need to know how to get into an inclined orbit like this. Could somebody tell me how that orbit looks? I'll manage to get there myself.

There should be some sort of preview in the map view of how the orbit should look. As long as you match that, you should be fine. As for how, burn normal/antinormal (these are the dark blue/purple markers on the navball (I'm colourblind, sorry)).

[Kryxal]

It basically comes near the "poles" of the sun ... easiest way I can think to get there is pulling a gravity-assist plane change off Jool (bonus marks if you can get a moon into it).

[Spaps]

Ah so I'll leave the probe I have now, will build a new one and put it properly in orbit. Thanks!

[Anquietas314]

It basically comes near the "poles" of the sun ... easiest way I can think to get there is pulling a gravity-assist plane change off Jool (bonus marks if you can get a moon into it).

That has the added complication of getting an intercept with jool though, which could cost more than a direct plane change depending on the current orbit.

[GoSlash27]

*scratch that*

Totally bad advice

Edited December 20, 2014 by GoSlash27

[Anquietas314]

The easy way to do this would be to launch heading north (+/- 20*) from KSC at either high noon or midnight and do an immediate escape burn for solar orbit.

Actually that doesn't work very effectively at all - it helps but remember the majority of your orbital momentum comes from Kerbin's orbit, not your escape trajectory.

Unless you're leaving Kerbin's SOI at about 10-14km/s in a roughly north(or south)/retrograde direction, that will have very little impact on the inclination.

[GoSlash27]

Actually that doesn't work very effectively at all - it helps but remember the majority of your orbital momentum comes from Kerbin's orbit, not your escape trajectory.

Unless you're leaving Kerbin's SOI at about 10-14km/s in a roughly north(or south)/retrograde direction, that will have very little impact on the inclination.

Yeah, you're right. Brain-fart on my part. Disregard that; it's a bad idea.

Best plan (without slingshots) I can propose would be to:

launch prograde from KSC ,

Escape burn while pointed at the sun to set your solar periapsis

Once at periapsis, extend your apoapsis

and finally

once at apoapsis, do your inclination change.

You really want to be going as slow as possible when doing inclination changes. They hurt.

Now... if you don't mind gravity assists, you can aim for the trailing edge of Eve to help speed you up on your way to periapsis, and if you can, try to grab the leading edge of another planet on your way up to help slow you down. Just a thought. I'll model that real quick and make sure it'd work...

Sorry!

-Slashy

Edited December 20, 2014 by GoSlash27

[Anquietas314]

Yeah, you're right. Brain-fart on my part.

Happens to us all, don't worry

[Spaps]

Well, if only I could aim that well... I didn't even go to Duna yet! (well, I did fly by Duna about 1500km...)

[Anquietas314]

Well, if only I could aim that well... I didn't even go to Duna yet! (well, I did fly by Duna about 1500km...)

You know maneuver nodes are a thing, right?

[Kryxal]

I'd probably set solar apoapsis high, then plane-change there and drop periapsis, to set up this whole thing without gravity assists. As-is, with periapsis in the needed range, just plan a plane-change at apoapsis, see if you have the delta-v ... if not, see what happens if you raise your apoapsis then plane-change. How much time do you have anyway?

[LethalDose]

If you are going to recommend gravity assists for inclination changes around the sun, Jool is much better option than Eve. NASA used this method for the Ulysses mission.

Addendum: Check the expiration on the contract. Kerbin-Jool transfers usually take a few years.

Edited December 21, 2014 by LethalDose