10 year launch window calendar

[Dkmdlb]

I couldn't find one so I made one.

http://i.imgur.com/qvmUhBn.jpg

EDIT Jan 21 '15: the days are in earth days because this was made before Kerbin days were in the game.

Edited January 21, 2015 by Dkmdlb
clarification

[TJ_Tas]

Brilliant idea. I would love to see some sort of built in way to calculate these.

[StrandedonEarth]

Great idea. Now how about the return trips? Kerbal Alarm Clock has a transfer window calculator which I use for everything

[Westo454]

Eh... You left out Moho? I know it's not a popular destination but you know, somebody might want to go their.

Otherwise I'm thinking this is going to see some use for my interplanetary missions.

[metl]

Huh. My flight to Gilly and back took over 300 days. Clearly i need to work on my transfer window timing.

[MalfunctionM1Ke]

Nice Job, receive Rrrrrrrrrrrrrrrrrrrrrrrrreputation

[patrickcanttype]

I couldn't find one so I made one.

http://i.imgur.com/qvmUhBn.jpg

Awesome. I've always wanted to see a list like this. Thanks for making it!

As StrandedonEarth said, a list of return dates would also be outstanding.

Eh... You left out Moho? I know it's not a popular destination but you know, somebody might want to go their.

True, but also keep in mind Moho windows come up often and will be very abundent on the list. I've read that some people don't even time their Moho launches, and they just head there at any time. Moho's orbital period is around 30 days IIRC; so it doesn't take too long to rendzvous with it (on a planetary scale).

I usually don't go there personally becuase the trip is very delta-V heavy, and thus takes a long time to perform the maneuvers.

.

[Dkmdlb]

a list of return dates would also be outstanding.

I didn't want to do that because it took me all day to come up with just the outbound dates. But here I am now almost done with all the return windows from Eve. Poop.

Moho windows come up often and will be very abundent on the list. I've read that some people don't even time their Moho launches, and they just head there at any time. Moho's orbital period is around 30 days IIRC; so it doesn't take too long to rendzvous with it (on a planetary scale).

This is exactly the reason why I didn't include it. There are a dozen windows a year. Think of the clutter. Also, the dv estimates are unlikely to be accurate to the actual performance in game because of how fast and bizarre Moho's orbit is.

Even if I only included the very low dv launch windows to Moho, there would still be 4 per year. The point of this calendar is to help with planning, and the truth is there are so many launch windows to Moho you can pretty much go whenever you want.

[Dkmdlb]

In regard to return windows I need help.

Pull up http://alexmoon.github.io/ksp/

Input these settings:

Origin: Jool

Initial orbit: 500km

Destination: Kerbin

Final orbit: 100km

Check "no insertion burn"

Earliest departure: year 1 day 1

Transfer type: ballistic

Show advanced settings

Latest departure: Year 11 day 1

Time of flight 150 to 450 days

Plot it.

Now - it's possible to do a transfer from Jool to Kerbin at any point in those first ten years for about 2,900 m/s. There are no specific windows.

Should I just leave Jool out of it completely when I'm making my return chart and make a note at the bottom?

Do the same thing for Eeloo, but change initial orbit to 100km and time of flight to 200-800 days. There are large swaths where it's possible to transfer home from Eeloo for about 1,200 m/s. This can be done at any time in years 1, 5, 6, and 10. How should I denote that?

Should I just leave Jool and Eeloo out of the return chart altogether?

[Amaroq]

Either consider them to be very large windows -- or elect a shorter time of flight. E.g., if you set up the Jool returns at 160-320 days, thats a different chart with some distinct windows; similarly, if your Eeloo returns are 275 to 650 days and you aim for a delta-V under 1,100 m/s, then you pick up some real transfer windows again. Just add a note at the bottom that you the return transfer windows from Jool and Eeloo are "soft", and that there's almost always a decently cheap departure for a craft willing to take a slow transfer in.

Alternately, un-check "No insertion burn" and run with THOSE windows, which are a lot more strict. (And more expensive)

[kroysemaj]

Does this calendar still work with the 0.90 release of the game? I tried hitting several of these windows in a sandbox game and ended up with 20 million km closest approaches. Is there a process to this I'm missing? I'm not a complete newbie, but interplanetary transfers are still challenging for me. Maybe this is a little above my pay grade and I should stick to ideal phase angles? Send help or snacks.

[Pecan]

Ahh, Duck Soup, "If you can't send help, send two more women!"

I never really had much luck with this - use a mod; transfer window planner or MJ will both give you plots in-game or, if you want to keep your install clean, look up all the details on http://alexmoon.github.io/ksp/

[kroysemaj]

Good, then it's not just me. I've used Alarm Clock to notify me of the ideal launch windows. That seemed to work pretty well. Thanks!

[Dkmdlb]

Does this calendar still work with the 0.90 release of the game?

Should work, but note that the dates are in *earth days* because this chart was made before Kerbin days were in the game.

[kroysemaj]

...the dates are in *earth days* ...

OHHHHHHH..... That explains everything. That's why I'm derping on the launches. Thanks!

[smartech]

I think this is a very useful chart for the atmospheric planets: Eve, Duna and Jool. Unless we are we have a massive delta-v budget, for the rest it is almost always better to aerobrake into a highly elliptical orbit with a periapsis barely above the atmosphere and apoapsis as close the edge of the SOI as possible around the closest atmospheric planet and wait for a good transfer from that orbit.

Edited January 22, 2015 by smartech

[WuphonsReach]

I'd like to see a table on the KSP wiki with launch windows defined not as exact dates but as "between these two days, delta V is within 5% of optimal DV of the perfect date".

For example, Kerbin -> Moho, the optimal DV is about 5030 m/s (Ballistic). You can leave as early as Y1D251 or as late as Y1D284.

[Thrain]

Should work, but note that the dates are in *earth days* because this chart was made before Kerbin days were in the game.

Does this means it is calculating 1 day as 24 hours? So if it said year 1 day 2 it would actually mean Kerbin day 5? If that is the case, how were years calculated?