Chronological List Of Transfer Windows?

[Clipperride]

Having just reached Year 1 Day 260 in my Career Mode game, I sent off a small flotilla of craft to explore this new (to me) territory.  It would be really handy to have a list of the launch windows as they open up, rather than fast forwarding when I want to go somewhere specific.

Does such a list exist?  Starting at Year 1 Day1 and listing the transfer windows in date order for the first few years?  If so, please add a link.  Otherwise I may have to start work on one

Cheers

Edited November 30, 2016 by Clipperride
Pesky autocorrect

[Chiron0224]

There's this mod

But a master list of transfer windows would be cool since I assume they fall on the same days on the same years in every career mode.

[bigcalm]

There's a very early "nice" window for Moho extremely early on (like day 23 or something) - however, in a career game you're unlikely to be able to generate the required delta-v in time, and when I say "nice", Moho is never nice.  There's also ok windows for Jool mid first year and Eeloo as well, around the same time as you'd launch for Duna, though naturally the transit times will be much greater.

I love this tool that shows not just ejection delta v, but insertion delta v as well: https://alexmoon.github.io/ksp/ - and you can use this to create your chart (more accurately than using MechJeb at least).

That said, for relatively distant objects (Jool ; Moho; Eeloo) transfer windows come around roughly every 6 months.  This is because they're either practically stationary compared to Kerbin (Jool; Eeloo) or moving much faster (Moho) - so the only planets that are a bit different to this are Duna, Eve and Dres where the windows tend to come a bit further apart.

[Clipperride]

Thanks for the answers.  Now you mention it @bigcalm it's obvious that launch windows will open up fairly regularly, as their apparent motion is so slow.  

I've not really spent much time outside the Kerbin SOI so far in my KSP adventures.  I did have a very close approach with Moho a couple of versions ago (ok, the probe smashed into the planet at great speed - but it did finish sending back its science data, with at least 3 seconds to spare before impact!), so I'm looking to change that now I've finally fallen in love with Career Mode.

[FancyMouse]

Or if you use KAC it can give you the list of the next transfer window for each body. It's a different algorithm, though - it was a precomputed list instead of Lambert solver (what TWP and alexmoon's site use). But it gives a list!

 

5 hours ago, bigcalm said:

That said, for relatively distant objects (Jool ; Moho; Eeloo) transfer windows come around roughly every 6 months.

um... months... months?? What is a Kerbin month??

Jokes aside, it's actually not correct for both cases. For Moho it's half a year because you want to transfer at AN/DN. If Moho had zero inclination, your transfer window would be actually 1/4 year apart (Moho's orbital period). For outer planets it's one full year, not half a year - being at opposite side of the orbit doesn't give you a transfer window to outer planets.

[bigcalm]

Yes sorry Mouse - you're right.

>  um... months... months?? What is a Kerbin month??

My favourites are Jebuary and Jooly

 

[diomedea]

Somebody already hinted at the regularity transfer windows occur. That's because the relative position of two bodies (same phase angle from the common mainbody, like Sun) repeats at regular time intervals. The interval between any two such positions is the synodic period. There's a very simple equation giving synodic known the sidereal (orbital) period of the two bodies (below, S = synodic period; A = sidereal period of the inner body (lower orbital SMA); B = sidereal period of the outer body (higher orbital SMA) ):

 1/S = 1/A - 1/B

Therefore, once known the time T0 when the first window comes for any couple of bodies, all subsequent windows for those same bodies will be at T1 = T0 + S; T2 = T0 + 2*S and so on. Scheduling all such events for any couple of bodies within a system then becomes almost trivial.

BTW, this wouldn't be complete without a way to compute the phase angle, as it determines when T0 is (though using the earliest window provided by AlexMoon's Launch Window Planner would be simplest). Best one was provided in this old thread, implemented with this online tool.