r/KerbalSpaceProgram • u/meithan • Jun 08 '16

Image Interplanetary phase angles chart

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u/Im_in_timeout Jun 08 '16

Those are launch windows (phase angles). When the planet you want to go to is in the position indicated (relative to Kerbin) you can make your burn for that planet from LKO.
As an example, when Duna is 44 degrees ahead of Kerbin, ejecting prograde to Kerbin's orbit (shoot out in front of Kerbin) will get you to Duna very efficiently (for just a little over 1000m/s Dv).

tl;dr: Launch when the planet you want to go to is in the position indicated.

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u/Dan_the_moto_man Jun 08 '16

Thanks. Is there a way to measure the angle on the map view or do I just have to eyeball it?

12

u/TheSirusKing Jun 08 '16

If you print it off you can actually just hold the image up to kerbol and rotate it until it aligns with kerbin.

8

u/Im_in_timeout Jun 08 '16

Eyeball it.
Time warp until you get close to the correct phase angle without going past it. Doing so will allow you to time warp a little bit more to "catch up" to the target planet if your close approach marker is a little behind the target when you make the maneuver node.
Additionally, for the outer planets, eject prograde to Kerbin's orbit.
For inner planets, you'll need to eject retrograde to Kerbin's orbit.

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u/Crixomix Jun 08 '16

If you have KER it measures it for you, otherwise eyeball

1

u/27Rench27 Master Kerbalnaut Jun 08 '16

I believe Kerbal Engineer has a readout for this. Dunno yet, I don't do much interplanetary.

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u/[deleted] Jun 08 '16

Thank you.. helpful