[WIN] Flyby Finder V0.86 [KSP1.3]

[PLAD]

Something that has been weighing on me lately is that Flyby Finder does not find multi-orbit solutions in its searchs. What does this mean and why doesn't it?

I did this little study using FF and Alex Mun's pork chop plotter. The chart below shows what the lowest delta-V path is from Kerbin to Duna on a given day during the first synodic period between Kerbin and Duna. Note that I'm only showing the lowest-dV possibility for each route on a given day- there are lots of higher-dV paths on a given day that can take more or less travel time. We see that sometimes the flybys offer a better choice than a direct flight.

Javascript is disabled. View full album

K-D is a direct path from Kerbin to Duna.The pattern shown with that red line repeats every 227 days with small variations due to the eccentricity and elliptical nature of Duna's orbit. In this path you go less than 1 orbit around the sun during the trip from Kerbin to Duna.

K-E-D flies by Eve on the way to Duna. This repeats roughly every 170 days- the synodic period between Kerbin and Eve. This is because Eve has the gravity to throw your ship to Duna wherever it may be, however the shape and magnitudes of the trip vary a lot from window to window. The windows have finite width, unlike the K-D windows which are continuous. For long periods you can't fly K-E-D for any starting dV. (Well, without a big thrust at Eve, TOT can find those paths for you.)

K-E-K-D flies by Eve and Kerbin on the way to Duna. This repeats very roughly every 170 days and varies a lot from window to window. Same comments as K-E-D.

K-D 2 Orbits flies directly from Kerbin to Duna, but goes around the sun twice during the transfer. So the first time it crosses Duna's orbit Duna is not there then it coasts back to where it left Kerbin's orbit (but Kerbin is not there anymore) and then goes on to intercept Duna. This dark red line repeats every 227 days and has roughly the same shape as the bright red line, it just has a longer minimum travel time, in this case around 240 days instead of the 66 days that a less-than-1-orbit transfer has. I see there are times where it has both a lower dV and a shorter travel time than the other options and so would be the best path by either standard, assuming you had to leave Kerbin on a particular day.

Now on to how this affects Flyby Finder. FF only searches for single orbit solutions, it does not use what is known as a multi-orbit Lambert algorithm, so from one encounter to the next you can't go more than once around the sun. (For a whole flight with many encounters you can end up going many times around the sun.) Why not? First consider this- If you are willing to go 3 orbits around the sun when going from Kerbin directly to Duna then there is another line that would have the same shape as the K-D one orbit line, but its minimum dV would be located at the 177 days departure date and have a value of 1067 m/s and a minimum trip time of 366 days. If you are willing to go 4 orbits then there is yet another line, this one centered around 116 days and around 500 days long. And so on. If you are willing to travel long enough then it is possible to get directly from Kerbin to Duna for less than 1100 m/s when leaving on any day! This sort of defeats the whole purpose of a pork chop plotter.

Now, if FF was to look for multi-orbit paths it would probably be best to do it for every step. So for instance for the Kerbin-Eve leg there are 1 orbit, 2-orbit, 3-orbit etc. solutions, then for the Eve-Duna leg there are another infinite series of solutions. One can decide to look no more than, say, 2 orbits, but then with K-E-D there would still be 4 solutions to pick from, and with K-E-K-D there would be 8 solutions to pick from. It would take much longer to find and check them all for the lowest-dV or shortest one. The total travel times would usually be much longer. So I have elected not to have FF search for multi-orbit solutions at this time, though I bet there are some great ones....

Edited June 18, 2014 by PLAD

[diomedea]

Something that has been weighing on me lately is that Flyby Finder does not find multi-orbit solutions in its searchs. ...

Yes, you explained that very well and I am in agreement with your points. I had not proposed anything like multi-orbit searches, but sure that would be useful if done within some limits. If different orbits have comparable solutions in terms of required Total Delta-V and Total Flight Time, I would certainly like the possibility to have them shown together, would help choosing when and how to make a mission. The best I can do currently is to figure myself what kind of orbits may do the job and have FF or KSPTOT find solutions for each one, than put the best solutions from all different orbits together by hand (in a sort of agenda of launch opportunities).

But, in particular for manned missions, I never like trips that take too long.

I would say that, with reference to the Kerbin-Duna transfer, I want to arrive on Duna using the least DV possible the earliest as possible: as the synodic period is 227days and the best transfer time 66 days, I can't have to wait longer than 227+66= 293 days to arrive; then, any orbit that takes more than 293 days is not of interest. Actually, I would also discard orbits taking longer then the time left to arrive on Duna (taking in account the current day, so to know how long it is before the optimal window for direct transfer).

With other planets, the situation may be somewhat different. If I want to arrive on Eeloo, there may be a lot of different trips to consider, most using less DV (thanks to grav assists) than a direct transfer. And quite possibly some of those trips may also take less time. In that case, I may be fine with waiting that "perfect alignment" so to use Eve, Kerbin and Jool as waypoints, even if it takes years to come (while the direct transfer window, not counting the eccentricity of Eeloo, represents every 113 days).

So, my rule of thumb is to use the most massive planets as waypoints, and see what solutions they give: if the trip duration is acceptable (not too longer than the direct transfer), that trip is useful and the relative windows get into the agenda. Other trips may be even better (e.g. K-E-K-E-K-J-Eeloo ?) but what tool is able to find solutions with 7 different passages? So, there is another limit.

If all those limits are to be observed (let say: no more than 5 passages; no more DV required than a direct transfer; flight time not much greater than direct transfer; and total time to arrival no greater than what would be required for direct transfer, unless of very significant gain in DV) than probably a logic could be built for a tool that implements multi-orbit searches. However, it would be a lot of work and require refinements.

[Arrowstar]

Other trips may be even better (e.g. K-E-K-E-K-J-Eeloo ?) but what tool is able to find solutions with 7 different passages?

This one?

Burn Information to Depart Kerbin
---------------------------------------------
Total Delta-V =                 4.767 km/s
Prograde Delta-V =              4747.481 m/s
Orbit Normal Delta-V =          429.847 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             297.965 deg
---------------------------------------------
Burn Information to Depart Eve
---------------------------------------------
Total Delta-V =                 0.914 km/s
Prograde Delta-V =              -914.363 m/s
Orbit Normal Delta-V =          0.000 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             195.282 deg
---------------------------------------------
Burn Information to Depart Kerbin
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              0.000 m/s
Orbit Normal Delta-V =          0.000 m/s
Radial Delta-V =                -0.000 m/s
---------------------
Burn True Anomaly =             195.282 deg
---------------------------------------------
Burn Information to Depart Eve
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              0.001 m/s
Orbit Normal Delta-V =          0.000 m/s
Radial Delta-V =                -0.000 m/s
---------------------
Burn True Anomaly =             195.282 deg
---------------------------------------------
Burn Information to Depart Kerbin
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              -0.000 m/s
Orbit Normal Delta-V =          0.000 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             195.282 deg
---------------------------------------------
Burn Information to Depart Jool
---------------------------------------------
Total Delta-V =                 0.280 km/s
Prograde Delta-V =              -279.590 m/s
Orbit Normal Delta-V =          0.000 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             195.282 deg
---------------------------------------------

Kerbin Departure Date = 
                Year 9, Day 337 19:53:34.145
                      (281390014.145 sec UT)
Eve Arrival Date = 
                Year 11, Day 33 17:10:44.340
                      (318186644.340 sec UT)
Kerbin Arrival Date = 
                Year 11, Day 84 12:22:22.347
                      (322575742.347 sec UT)
Eve Arrival Date = 
               Year 11, Day 134 12:22:22.349
                      (326895742.349 sec UT)
Kerbin Arrival Date = 
               Year 11, Day 351 01:07:37.525
                      (345604057.525 sec UT)
Jool Arrival Date = 
               Year 12, Day 291 22:14:41.422
                      (372032081.422 sec UT)
Eeloo Arrival Date = 
                Year 16, Day 27 20:35:10.477
                      (475360510.477 sec UT)

It's not great, but it's definitely a start.

Edited June 19, 2014 by Arrowstar

[Arrowstar]

Nope, nevermind, I found it just now:

Phase 1 Transfer Orbit (Kerbin -> Eve)
---------------------------------------------
Semi-major Axis =             14728256.716 km
Eccentricity =                  0.39171
Inclination =                   4.076 deg
Right Ascension of AN =         64.390 deg
Argument of Periapse =          257.737 deg
Period =                    10372451.8729 sec
Departure True Anomaly =        102.263 deg
Arrival True Anomaly =          312.759 deg
---------------------------------------------
Phase 2 Transfer Orbit (Eve -> Kerbin)
---------------------------------------------
Semi-major Axis =             10553387.290 km
Eccentricity =                  0.28986
Inclination =                   2.085 deg
Right Ascension of AN =         12.336 deg
Argument of Periapse =          356.154 deg
Period =                     6291326.5061 sec
Departure True Anomaly =        266.338 deg
Arrival True Anomaly =          183.846 deg
---------------------------------------------
Phase 3 Transfer Orbit (Kerbin -> Eve)
---------------------------------------------
Semi-major Axis =             10583298.318 km
Eccentricity =                  0.28744
Inclination =                   2.112 deg
Right Ascension of AN =         12.336 deg
Argument of Periapse =          5.526 deg
Period =                     6318092.3175 sec
Departure True Anomaly =        174.474 deg
Arrival True Anomaly =          92.681 deg
---------------------------------------------
Phase 4 Transfer Orbit (Eve -> Kerbin)
---------------------------------------------
Semi-major Axis =             22916724.253 km
Eccentricity =                  0.57818
Inclination =                   2.101 deg
Right Ascension of AN =         14.801 deg
Argument of Periapse =          77.843 deg
Period =                    20131828.3586 sec
Departure True Anomaly =        17.900 deg
Arrival True Anomaly =          282.157 deg
---------------------------------------------
Phase 5 Transfer Orbit (Kerbin -> Jool)
---------------------------------------------
Semi-major Axis =             41764918.594 km
Eccentricity =                  0.73284
Inclination =                   0.419 deg
Right Ascension of AN =         14.801 deg
Argument of Periapse =          54.870 deg
Period =                    49530403.8671 sec
Departure True Anomaly =        305.130 deg
Arrival True Anomaly =          176.938 deg
---------------------------------------------
Phase 6 Transfer Orbit (Jool -> Eeloo)
---------------------------------------------
Semi-major Axis =             90707659.517 km
Eccentricity =                  0.26688
Inclination =                   6.546 deg
Right Ascension of AN =         63.740 deg
Argument of Periapse =          233.694 deg
Period =                   158533246.0673 sec
Departure True Anomaly =        309.192 deg
Arrival True Anomaly =          194.945 deg
---------------------------------------------
Kerbin Departure Date = 
               Year 10, Day 303 14:00:33.326
                      (309967233.326 sec UT)
Eve Arrival Date = 
                Year 11, Day 32 23:05:56.410
                      (318121556.410 sec UT)
Kerbin Arrival Date = 
                Year 11, Day 82 23:09:20.217
                      (322441760.217 sec UT)
Eve Arrival Date = 
               Year 11, Day 133 15:17:39.455
                      (326819859.455 sec UT)
Kerbin Arrival Date = 
               Year 11, Day 350 00:00:55.889
                      (345513655.889 sec UT)
Jool Arrival Date = 
               Year 12, Day 260 16:35:02.558
                      (369333302.558 sec UT)
Eeloo Arrival Date = 
               Year 15, Day 361 14:55:53.286
                      (472661753.286 sec UT)

Burn Information to Depart Kerbin
---------------------------------------------
Total Delta-V =                 2.768 km/s
Prograde Delta-V =              2641.943 m/s
Orbit Normal Delta-V =          826.222 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             314.176 deg
---------------------------------------------
Burn Information to Depart Eve
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              0.000 m/s
Orbit Normal Delta-V =          -0.000 m/s
Radial Delta-V =                -0.000 m/s
---------------------
Burn True Anomaly =             213.429 deg
---------------------------------------------
Burn Information to Depart Kerbin
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              0.000 m/s
Orbit Normal Delta-V =          -0.000 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             213.429 deg
---------------------------------------------
Burn Information to Depart Eve
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              0.000 m/s
Orbit Normal Delta-V =          0.000 m/s
Radial Delta-V =                -0.000 m/s
---------------------
Burn True Anomaly =             213.429 deg
---------------------------------------------
Burn Information to Depart Kerbin
---------------------------------------------
Total Delta-V =                 0.000 km/s
Prograde Delta-V =              -0.000 m/s
Orbit Normal Delta-V =          -0.000 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             213.429 deg
---------------------------------------------
Burn Information to Depart Jool
---------------------------------------------
Total Delta-V =                 0.232 km/s
Prograde Delta-V =              -232.321 m/s
Orbit Normal Delta-V =          -0.000 m/s
Radial Delta-V =                0.000 m/s
---------------------
Burn True Anomaly =             213.429 deg
---------------------------------------------

[diomedea]

@ Arrowstar: yes, MFMS does find one best solution (as DV minimum) in the range of dates/Flight Times allowed (never tried MFMS with more than 5 bodies before, excellent). Actually, the K-E-K-E-K-J-Eeloo was just one example of a more complex trip that a multi-orbit searcher could consider. Those different trips are useful to check in case they provide feasible solutions at different dates than the direct transfer window does. Manually finding solutions for all possible multiple-bodies combinations and all possible dates of interest is part of the problem, where a multi-orbit searcher may come to help if feasible. Those solutions you showed are very interesting to demonstrate how good MFMS actually is, but then I have to see if those solutions may come useful instead of using a direct transfer. In this case (sorry but didn't use Flyby finder, as it can't provide solutions for direct transfers) I used KSP TOT to find a very good solution for direct K-Eeloo transfer (not shown, but arrival DV = 1,81 0Km/s, for a total DV of 3,88 Km/s, and Total Flight time of 469 Earth days):

Compared with your first solution, the direct transfer uses less DV and much less time; with the second solution, about 880 m/s more DV but still much less time. The K-E-K-E-K-J-Eeloo was just one example of more complex trips, but in these cases they don't fit my requirements: I would still prefer to use the direct transfer instead (of course, such solutions may still be of interest to find other dates for departures than the windows for direct transfers). What would really be useful (but, I reckon horribly complex) would be a tool able to automatically find those different trips , but show only the ones really useful. I am certainly going to use MFMS to find some of those, though it takes time and I may miss some (as, I must actually state what waypoints to consider, while a multiple-orbit searcher should try all the feasible ones automatically). That is where another tool, showing how different trips compare in Flight Time and DV expended over a wide range of dates, would come useful if it was possible (a very serious problem for what I could see, could be possible but very complex). Was this quest limited to find the single best solution with a specific trip, MFMS is certainly the tool to use. Checking how different trips compare over a wide range of dates, it would require to plot the minimum DV and Flight Time with any trip - a problem you teached me is very difficult to solve.

[PLAD]

An interesting exercise. First let me say that being able to calculate a 7-waypoint mission is impressive. However I've found making more than one K-E-K run is not useful, since to go K-E-K-E you have to lose energy to go back to Eve from Kerbin, since if you go outward after the 2nd K your periapsis will be too high to get back to Eve. In fact on this K-E-K-E-K-J-Ee mission the first K-E is unnecessary, see the pictures below. I assume you started at Kerbin in a 500x500km altitude orbit since that makes the numbers match.

Javascript is disabled. View full album

I want to fly the TOT mission to see if I can do it since thrusting during a flyby can be rather tricky, you have to be at exactly the right altitude to pull it off. Where is the altitude for the 232m/s Jool thrust given? All other needed information is given in a nice format. If it works then that is the lowest-dV mission to Eve I've ever seen.

EDIT-never mind, got it, 17848km. TOT took 51 seconds to run the search. Impressive.

But back to the question at hand, I see TOT also does not do multi-orbit legs, I imagine for the same reasons FF doesn't- much longer calculation times and the missions would have a long travel time. And it also doesn't do double flybys.

A dream flyby finder would do all these things and even allow thrusts at the apoapsis of multiple-orbit-between-flyby paths, but lord would it be complicated and slow!

Edited June 19, 2014 by PLAD

[PLAD]

Well I ran the K-E-K-J-Ee path suggested by TOT and it worked. Total dV from the surface of Kerbin to the surface of Eeloo was 6757m/s, about 300m/s less than anything that doesn't use a periapsis thrust while flying by Jool. The cheapest way to get to Eeloo or Dres is via Jool because it is closer, energy-wise, than any other planet to them. The problem is that if you arrive at Jool from the inner system you have a lot of excess speed relative to Jool, but to get to Eeloo or Dres the lowest-dV way possible you need to leave Jool with a lot less speed. So the best way to get to them is to slow down at Jool. FF does not do that and TOT does so TOT is clearly superior for those situations.

I figured out that TOT gives the V infinity and not the start V at a given altitude, so my 500km-orbit assumption earlier was wrong.

Now I'm trying to decide whether to post a mission report or a challenge on this lowest-dV-to-Eeloo mission!

[Arrowstar]

Now I'm trying to decide whether to post a mission report or a challenge on this lowest-dV-to-Eeloo mission!

Oh man, I would be up for a challenge like that!

[Kerbal01]

any plans for an ingame version?

[PLAD]

any plans for an ingame version?

Nope, not at this time. You can copy and save the detail box's contents to a text file though, giving something relatively small and quick to alt-tab to during a mission.

[PLAD]

FF V0.50 is out. There are several new features:

-Up to 5 bodies can now be entered.

-Added a time converter. You can now take the Y D H M that Kerbal displays and convert it to the UT Earth-style days that FF requires in its input fields.

-You don't have to hit 'clear' anymore. If there is any data from a previous search in the output table it will automatically be cleared. If there is no data then the clear will be skipped for speed. I left the clear button in just in case, if I find I never use it then version 0.60 will get rid of it.

-I added a field for minimum V infinity right next to the 'max v at SOI' field. This is to allow you to 'daisy chain' one set of flybys to another. You do this by taking the last two encounters in a chain of flybys and entering their data in the first two fields ('start' and '1st encounter'). By restricting the start energy to a tight range, and making a tight start search period and 1st encounter search period you force FF to start with a specific path. I will prepare a primer to show how to do this.

Javascript is disabled. View full album

V0.60 is going to take a while because adding double flybys is a big step up in complexity. I might also add the ability to make a standard 2-body porkchop plot since that helps find good places to start searches in.

[AppleDavidJeans]

Can you make a version for Mac please?

[PLAD]

Can you make a version for Mac please?

Sorry, no, I don't have the software or the hardware to do that right now.

[AppleDavidJeans]

Sorry, no, I don't have the software or the hardware to do that right now.

I searched the Internet and found a program that can run .exe files on a Mac. It's called Wine. Wine relies on X11 and thus will also require that X11 be installed since Macs don't carry that natively anymore.

Here's a screenshot of it in action:

A testament that the Internet can be your best friend.

WARNING: Before you go out like Rambo on your Mac with this solution, at least be aware that there are inherent risks in running .exe files on Macs. They were never designed to work together at all. I'd prefer using actual Windows for this, but hey, you can use this at your own risk.

Bugs:

-If you minimize the window (the yellow button), the next time you click on it to pull it back up to the screen, it'll be blank. You'll need to close and boot the .exe again to use it again.

Oh, by the way, what does Vz mean? Does that mean that I need to have a radial or normal component to my burn? And is it just one burn in total that will give me a slingshot through all the waypoints?

Edited July 13, 2014 by AppleDavidJeans

[PLAD]

Oh, by the way, what does Vz mean? Does that mean that I need to have a radial or normal component to my burn? And is it just one burn in total that will give me a slingshot through all the waypoints?

That is an excellent discovery on using Wine to run FF on a Mac. Thank you for posting that!

Vz is the normal component of your velocity when leaving the start planet. If you start from an orbit with the right inclination you will not need to use a z component in the burn (relative to your orbital velocity). It's a bit hairy to describe, check out this challenge where I use the Vz and start inclination numbers that the FF detail box would give me (though here I put them in LambertE) to leave Kerbin in the most optimal way possible.

FF finds paths where you only have to do one big boost right at the beginning. If KSP had 30-digit accuracy in everything you probably could do the whole flight with only the start boost in Kerbin orbit, but in practice rounding errors force you to correct your path every now and then on the way.

[Iron4venger]

V0.60 is going to take a while because adding double flybys is a big step up in complexity. I might also add the ability to make a standard 2-body porkchop plot since that helps find good places to start searches in.

Any progress on that double flyby feature?

[PLAD]

A good question. I've hit a wall in writing something that works AND is still reasonably fast. The problem is that there are many possible ways to do a double flyby. There are 2 key parameters- how many orbits does the planet make between the flybys, and how many orbits does the ship make between flybys. In doing experiments with the Lambert spreadsheet I found that useful flights could be found where those numbers were as high as 5 and 5, and the algorithm I have in mind needs to search 19 of those 25 possibilities, where for a standard flyby it would only search one. Ugh! So I've been playing the game a while and using v0.50 to see what is most useful and what needs to be improved, and hoping for a revelation. Then I got to noticing that it would be really nice to allow multi-orbit flybys with at least 2 orbits in between since this would double the stuff you would find, and deep-space maneuvers dramatically improve your solution field but I can't think of an algorithm for that!

So I'm in a bit of a funk right now.

I should release version 6 soon, but it won't have double-flyby. It will do a 2-body porkchop, increase from an 80x80 to a 100x100 search, increase solution limit from 3000 to 10000, and make it a little easier to find the departure orbit. But these are small things. I need to work on double-flyby. Doh!

[PLAD]

I've just released version 0.60, it's in the first post in this thread, along with an all-new primer on using it. No double flybys yet. It's going to be a while on that. It does do a 2-body porkchop for the first two bodies now, and I increased the search grid to 100x100 from the earlier 80x80, the maximum flybys found to 4500 from 3000, and a few other small changes.

You still pretty much have to have a maneuver node editor in order to do flybys well, I recommend Mechjeb.

-PLAD

[diomedea]

Tried version 0.60, however can't find the new features, 2-body porkchop plot option and Equatorial Prograde Velocity field. Where those just be visible? (It appears to me like a version 0.50 under a new version name, running both versions side by side can't spot a difference).

[PLAD]

Doh!

I just downloaded it from the link in the first post and I got the latest version, 0.60 (and ran it to be sure). It is possible you downloaded it in the time between when I started changing the post and the time I set the link. The new version is named Flyby060.exe. I'm going to delete the 0.50 links and remove them from the dropbox folder to be sure they aren't getting mixed up. Please let me know if it works. Sorry about this!

Edited October 8, 2014 by PLAD

[diomedea]

Re-downloaded version 0.60, re-did the comparison with version 0.50. Still can't find about 2-body porkchop plot option and Equatorial Prograde Velocity field. Only changes I notice are the different default search window and (with graph) adjusted Travel Time scale. I'm not saying those other improvements don't exist, but rather they are very well hidden so I can't use them.

Javascript is disabled. View full album

[PLAD]

Thanks for the pictures, now I'm sure it's the right version.

Pick the planet selection drop-down for the "2nd encounter". The bottom-most choice should be "none". Pick that and now hit "begin search". You should get the pork-chop for the first two planets (in this case Kerbin to Eve).

I completely re-did the 'slide show' introducing the features of FF 0.60 in the first post. If you are already an expert with the program (and I know you are!) you might not have reread that. It covers the new tricks.

You're right, if you're looking at the interface it is not obvious what to do.

[PLAD]

Oh jeesum, now I noticed that the box in the lower right says 1901 "Flybys found" even though they aren't flybys when it's a 2-body porkchop plot. Maybe it should say "paths found" or "solutions found" instead.

Something I might also not make sufficiently clear for all is that is still only works with 24 hour days/ 365 day years, like KSP v0.22 and earlier, but now KSP has the option for 6 hour days/ 426 day years. Does anyone have a feel for what percentage of users use each format? I stuck with 24/365 because I memorized the orbital and synodic periods for most of the bodies in that format and switching would confuse my sometimes-overwhelmed mind, but if a lot of people go 6/426 then I can add the option. We'll have endless confusion in discussions of flight windows though.

[diomedea]

... you might not have reread that. It covers the new tricks.

You're right, I haven't gone throught the slides, didn't notice those were updated. Just thought the interface would have made it clear. Thanks.

...Does anyone have a feel for what percentage of users use each format? ...

I like to use 6/426, but can't say a majority of users do. It may be a worthy case for a poll with this thread?

[immelman]

I've been really impressed with the efficient mission plans you have worked out from Kerbin using this tool and was wondering what I would have to do to adapt this for use with Real Solar System? Would this be possible at all?