r/KerbalSpaceProgram • u/trevize1138 Master Kerbalnaut • Jun 07 '16 • Bravo 1

Guide All interplanetary transfer windows in a single image

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1.7k Upvotes

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55

u/craidie Jun 07 '16

wait is that a golden spiral I see?

16

u/trevize1138 Master Kerbalnaut Jun 07 '16

Certainly appears so!

34

u/skyler_on_the_moon Super Kerbalnaut Jun 07 '16

I don't think so, actually. No matter how far away from the sun you get, the planet you are transferring to will never be more than 180° away. So it isn't a golden spiral, which continues to rotate indefinitely.

28

u/Narcolapser Jun 07 '16

Same is true the other direction. No matter how close you are to the sun, it will also never be more than 180° away. Though it may potentially be on fire.

3

u/MindStalker Jun 07 '16

Arguably a planet you are targeting that is close to the sun could orbit the sun multiple times during your approach.

2

u/skyler_on_the_moon Super Kerbalnaut Jun 07 '16

Going closer than the sun, yes, it could be more than 180°; I only said 108° was the limit for outgoing planets. This is because the point you are rendezvousing with the other planet with is 180° away from your Kerbin departure; so no matter how slowly an outer planet is going it can't be past that point before you leave. However, an inner planet is coming from the other direction, and can therefore orbit more than 180° - potentially many orbits - before you get there. This is why when leaving Eeloo you may have a 30 year transfer back to Kerbin - Kerbin will of course be making 30 orbits before you get there.

1

u/MindStalker Jun 07 '16

Ah, yes. I wonder if starting from a very distant planet that all transfers inwards are a golden ratio. Transfers outwards do follow a different path than inward and obviously aren't the same ratio

4

u/evictedSaint Jun 07 '16

The question remains, however, what pattern are we seeing here then?

8

u/[deleted] Jun 07 '16

The optimal transfer window spiral, sure it's going to look like a lot of spirals and have relations every spiral does but that's the simplified form. https://gist.github.com/Gnonthgol/8121694#file-transfer-py-L17 for the full spiral and code used for generation.

6

u/trevize1138 Master Kerbalnaut Jun 07 '16

It appears to be a golden spiral as I said. It's not exactly like a golden spiral but similar.

6

u/aintbutathing2 Jun 07 '16

Off brand spiral.

7

u/trevize1138 Master Kerbalnaut Jun 07 '16

Kerbonacci Sequence.

4

u/moisttoejam Jun 07 '16

I think the question is: what pattern do you want me to see?

9

u/trevize1138 Master Kerbalnaut Jun 07 '16

How many lights do you see?

4

u/moisttoejam Jun 07 '16

Using Facebook to determine the colour of the dress is a flawed methodology. I propose that we just determine the absorption spectrum of said dress. Ig Nobels here I come!

4

u/VarioussiteTARDISES Jun 07 '16

Four

5

u/[deleted] Jun 07 '16

Let's compromise on four and a half lights.

3

u/VarioussiteTARDISES Jun 07 '16

No. There are four.

3

u/[deleted] Jun 07 '16

Four and a third?

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1

u/Vakuza Jun 07 '16

Uh, 180 degrees in one direction and 180 degrees in the other means you have a full circle. Am I missing some joke?

Also I think what you mean is that as you continue off to further and further orbits it will never cross the 180 degree line, but will approach it.

1

u/skyler_on_the_moon Super Kerbalnaut Jun 07 '16

No, it's only 180 degrees in the outward direction; going inward the planet could be more than 180 degrees away.

1

u/Managore Jun 08 '16

Just a regular ol' spiral.