PLAD

Yup, I fired up 0.60 and those parameters I give 4 posts up are identified just as it says. You have to double-click on an entry in the table to bring up the detail box. Note that FF cannot do double flybys, though LambertE can. That is the second huge difference between them. (The first being that FF does all the searching for you while with Lambert you have to enter every planet date by hand and check the flyby heights and energies.)

Argh, sorry about that, I am using my development version here which is not ready to release. You're right, on the last release Boost Vz is the z speed when leaving the SOI, not the z when leaving LKO. And prograde boost and inclination are missing. You can see why that's fairly useless and got replaced with the FF data. This means I have to release a new Lambert as well. I'll have to clean it up first, this could take a week or two.

I don't give the ejection angle the way Alex Mun's porkchop plotter does. Here is an example of the information FF (and LamberE) gives: Start Orbit Inclination: 3 degrees (called 'Start orbit inc' in LambertE) Start Boost: 1502 m/s (called 'departure dV over circ' in LambertE) Start Equatorial Z velocity: 203 m/s (called 'eq boost vZ' in LambertE) Start Equat. Prograde velocity: 1497 m/s (called 'Eq boost prog.' in LambertE) The guide I put on the top of the first page of this thread shows how these are used to set up your Kerbin departure boost, sheets 24 to 34 in particular. They have text but for some reason now you have to click on them to see it.

The five solar orbits of your ship is between the first double-K's, K932.4-(dbl.96) K1358.5. That's 1358.5-932.4=426.1 days, 4 Kerbin years. Anything that is not a double flyby can't be more than one orbit of the sun because LambertE.exe and FF don't use a multi-orbit Lambert algorithm. You are correct, LambertE can't do more than 5 encounters. I get around this by taking the last two encounters and entering them as the first two encounters in a 2nd LambertE. So for instance here I would take the K1358.5-E1394.9 that end the first 5 encounters and use them as the first two encounters in a 2nd instance of LambertE. Here's how I search for monstrosities like this. First, the V SOI when leaving Kerbin must be at least 2750m/s to make it to Jool under the best conditions. In practice Jool will be a little further away, or out of Kerbins orbital plane, or your path won't leave Kerbin in exactly the direction of Kerbin's solar orbit, so something higher than 2750m/s would be better. 2750m/s at Kerbin's SOI is about 1950m/s from a 75x75km orbit. This means you can search for K-E-K paths using Flyby Finder and eliminate all of the ones that have a 'braking dV' of less than 1950m/s. This limits the windows in which the K-E-K-K can start, though it's still a lot of possibilities. Second, I find the windows where you can go K-J for less than, say, V inf 3100m/s. For instance the first window departs Kerbin from about day 40 to 80. Now I look for a good K-E-K that ends an integer multiple of Kerbin years before a good K-J. For a direct KEKKJ it seems to me that there should be 2 Kerbin years between the two K's, though I am not positive that three years won't work, I just haven't found it. So I search for a mission with the parameters of K(a)-E(-K©-K(c+213)-J(d). I enter the numbers into LambertE and tweak the dates and 'dbl' flyby parameter until I find something that works. It takes a long time. The Kerbin departure windows are very thin, maybe 2 or 3 days, and the Eve flyby window is even thinner, so you have to look carefully to find a good path. In the spreadsheet I set the 2nd Kerbin double flyby date to equal the first one plus 213 so I don't have to change that number constantly, but that's still 5 parameters to tweak. I often find a path where the incoming-outgoing V SOIs match but it will fail because one of the Kerbin flybys would have to be below its surface. As for the KEKKEKKJ path I have still never actually flown it, that many flybys would be a real chore and I think the course corrections would overwhelm the start dV savings, so I never searched for another one. If you pull it off I would love to see it. My coming-soon version of FF allows you to sort the graph by braking dV which will help at bit at identifying good start windows. (ETA about 2 weeks) Still no double flyby finder though. Making a general double flyby finder proves to be quite unwieldy, lately I'm toying wth the idea of making one that only does KEKKJ as that would be far simpler. That's many months off though.

I'm assuming that you want to start in a Kerbin orbit, coast to a flyby of Duna and Ike, and coast from there to Eve. This is tricky because Duna is not massive enough to alter your path much. To go Kerbin-Duna-Eve you will need to leave Kerbin and get into a Solar orbit that already has a perihelion close to Eve's orbit and an aphelion close to Duna's orbit. An orbit like that will cross Kerbin's orbit at a sharp angle, and as such when you leave Kerbin you will be at a high angle to Kerbin's direction of motion around the Sun, which means it will take a lot of dV to leave Kerbin and get into this orbit. But it is possible! Here is the first window I could find (Using Flyby Finder, Earth time): Leave Kerbin Y1 day 97 12H (Earth time, From a 75x75km orbit an 1883m/s boost will be required, start orbit inclination is 0.1 degrees). Flyby Duna Y1 day 193 at about a 45 km periapsis. Arrive Eve Y1 day 242. (It would cost about 1950m/s to brake into a circular 100km orbit at Eve). The windows are pretty tight. Arriving at Duna even 6 hours after the target time will cost about 50m/s, increasing rapidly after that. You can't leave Kerbin before day 97, 6H, or after day 100. If you search this using FF, raise the V at SOI max to at least 3000m/s. Note that the start boost is almost what it would take to get to Jool. You could knock maybe 40m/s off of this by using a flyby of Mun at the start, but it would be nasty tricky. Since you fly by Duna lower than Ike's orbit, and your window is more than 1 Ike day wide, you can work an Ike flyby into the Duna flyby by adjusting your start time a bit. Note that tiny Ike will add almost nothing to your energy since you will be flying by it very fast. Flying a Kerbin-Mun-Duna-Ike-Eve path would be quite cool, though. If you go the other way, Kerbin-Eve-Duna, you can start with a much smaller start boost because heavy Eve can alter you orbit a lot. I should have a version of FF that uses both Earth and Kerbin time released in about 2 weeks if you prefer to work in Kerbin time. I'm debugging it now, this problem was a fine test case!

OK, I've just posted links to the new version in the OP. The visible changes are all to the graph display, you can now set the colors that used to only show the start boost dV to show Total dV, Braking dV, Start vZ, and 1st flyby altitude as well. The most powerful addition is a new parameter "Search steps per period" (I abbreviate this as SSPP). See the primer below (which I will tack on to the end of the main primer as well). Watch out, if you double the SSPP you increase the run time by 4x, it is best to keep SSPP at 100 until you've found a good area to make a fancier graph of. Also remember the 'flybys found' limit of 4500, ideally you set SSPP so that you will be just below this limit. I found good uses for all the new features when searching for flights, except for graphing by 1st flyby altitude, I put that in there just to see what it looks like. If someone can think of a use for it when setting up a flight I'd like to hear it. That's why there is no graphing by second or third flyby, I didn't want to clutter up the display (or the code) with experiments. My next plan is a new release for FF for stock KSP. Besides the new graphing features it needs to handle the two time systems and I wish to put in a way to easily add mod systems, starting with the OPM. I figure 4 weeks for this. I also plan to make a primer on setting up the departure boost, Alex Mun's pork chop plotter and my FF use two different ways to help set it up and neither one is perfect (IMHO). It's a complex problem but I've got some ideas... After that I will attack double flybys again and maybe a way to search for Juno-style missions to Jupiter. Time scale for these things is several months though.

You may be right, it must be nice to not have to worry about memory when a lot of mods are loaded. I've never used Linux, so I don't know what it would take to run this in Linux. Windows 10 might be the thing that finally pushes me to find out, but I have no plans for it at this time.

Thanks! I am a week or so away from releasing a new version of FF for RSS, it will have more graphing options and catches up with the slight changes that RSS made to gas giant diameters and atmosphere heights. None of the orbits or masses have changed so the current version is still accurate. I will attack FF for stock next, the giant improvement needed is to be able to use both time systems (6/426 and 24/365). I'll also add the option for the OPM system (Sarnus, Urlum, etc.). I have no plans to add any moons because of the way I wrote FF- it uses linked conics for speed rather than patched conics, so it becomes too inaccurate if the SOI's are large relative to the distance between the bodies (like in Jool's moon system). I think TOT can handle that stuff.

Nefrums, that is a really superb Jool-5 mission! Masterful use of flybys, I've never had the guts to use a multi-orbit build up to the K-E-K-K-J departure because of the tight Eve flyby window, but you did it! Clever design too, I especially like how the wings for that great-looking Laythe lander are functional for the Kerbin take-off as well. (And thanks for the cred:))

I have looked and looked for a flight that would go Kerbin-Duna-Dres-Jool-Eeloo, but have never found one. I think the problem is that Duna and especially Dres are too small to have much effect on your flight path, if that flight path has enough energy to continue on to Jool. I essence you are looking for a flight that goes to Jool and on the way happens to cross the orbits of Duna and Dres while they are there, and that is a very unlikely arrangement. (Once you are at big heavy Jool it can throw you anywhere in the system, so the Jool-Eeloo leg is easy.) If you use my Flyby Finder here is a sample flight that goes Kerbin-Duna-Dres, enter the following numbers in the input fields like so: ....................................Start at...........1st encounter............2nd encounter ....................................Kerbin..............Duna........................Dres Earliest Search Date.........50...................65...........................100 Search period..................50...................400.........................1000 V at SOI max: 3000m/s Note that FF still uses Earth time (24hours/365 days) to define dates. If you study this flight you will see that you are in an orbit around the sun that crosses Kerbin, Duna and Dres' orbits, by luck they are there when you cross their orbits. Note you go out to solar apoapsis and then back in to the Duna encounter, then back out to Dres. Hardly a Voyager-type path! You could try and find an encounter with Kerbin after the Dres flyby that would pump up your orbit. Or you could go straight to Jool first, Jool can send you just about anywhere if you can get to it, so you could maybe go Kerbin-Jool-Eeloo-Jool-Dres-Jool-Duna, if you allow a couple of coasting orbits between the encounters, but none of this is remotely like what Voyager 2 did. (And Flyby Finder can't handle multiple orbits between encounters so you'd have to wing it.) Note that if you use the Real Solar System mod you can simulate Voyager's path quite nicely, since the real Solar System has 4 big heavy gas giants that can dramatically affect your ship's path. Flyby Finder for RSS shows this path in its tutorial. PS- executing multiple flybys is not easy, you will need a node editor like Mechjeb's to set them up, and even then they are unforgiving of travel-time errors. But as you observe, they are a powerful way to reduce the delta-V required for a mission. I'd love to see a solution if you find one!

Val, that is impressively light for 4000m/s dV left in orbit. I think you've reached a practical limit! Is that thing landable on Laythe? Thanks again for including the craft files, those are useful. I think the limit for an SSTO with 2 jets and an LV-N is 20.5 tons for a Laythe-and-return with no flybys, and around 16.5 tons with full flybys. I show my concept craft below along with the numbers I figure. Using Val's 1 Rapier and 1 LV-N ships strongly suggests 15 tons can be beaten with full flybys, but it might be a couple hundred kg short for no flybys. Here's a link to the craft file and the spreadsheet. The plane is pretty boring compared to other planes here, but if you try it set the nose up 30 degrees right after takeoff and keep it there until the apoapsis reaches 72km. (Switch to the Nuke the moment the jets flameout.) Then lower the nose as much as possible without letting the rate of climb drop below 0. The Laythe page of the spreadsheet should be self-explanatory, the 2nd page was just hacking around with the rocket equation. https://www.dropbox.com/sh/375iamx4d94y954/AABR8mjRFaVMhtCIXDZH9nKJa?dl=0

The 2nd part of the OP mentioned an Eeloo SSTO round trip. I think a single-stage flight to Eeloo landing and back to Kerbin is clearly possible using some of the ships from the SST-Laythe challenge. It is possible to go from LKO to Eeloo's surface and back to Kerbin for 3050m/s. I did it here using the old aerodynamics for 2897m/s, modern aerodynamics would prevent that 142m/s braking pass through Jool's atmosphere but doing it just outside the atmosphere would work for 150m/s. This uses the K-Mu-E-K-K-J path to get to Jool, if you wanted to use a simpler K-E-K-J path you could do it for only 300m/s more, so 3350m/s. Or you could go straight to Jool and fly on to Eeloo with the greatly reduced arrival speed that Jool allows for 4000m/ round trip total. (And as always using a Jool flyby on the return to Kerbin.) With no flybys at all it takes about 2100 (LKO to Eeloo)+1400(brake into orbit)+620(land)+620(takeoff)+1100(LEO to Kerbin)=5840m/s, which I agree would be roughly impossible for an SSTO. Regarding the SS-to Laythe and return, with no flybys I think it's flatly impossible for anything under 15 tons with more than 1 LV-N and 1 Rapier ("1L/1R"), and barely impossible for even that. With flybys it should be possible for the 1L/1R design. I'm not counting ion ships, the ultra-low TWR for a Rapier-ion only ship would be too brutal to contemplate. Now I have to prove it...

Sorry for the delay in answering. I've got to figure out how to be auto-notified when something is posted here. Earth-Venus-Jupiter is a very difficult trajectory. To get from Venus to Jupiter requires a V infinity at Venus of about 11500m/s, which is about 17000m/s at 200km above Venus. At this speed Venus can only bend your path a few degrees, in essence you are making a high-speed shot from Earth to Jupiter that passes close by Venus on the way. Because of orbital inclinations there are only some very small points in their orbits that all three planets have to be at where this will work. Here's a sample of this rare alignment: Planet Earliest Search Date Search Period Earth 2250 150 Venus 2315 200 Jupiter 2800 2000 V at SOI max: 16000 m/s (!) The V at SOI is so high because you are shooting at a high angle inward from Earth's direction of orbital motion to pass by Venus in the right spot. Notice the two arrival times, in one you hit Jupiter flying outward from the Sun, in the other you go way out pass Jupiter and then catch it coming back in towards the Sun. In real life this path would never be used but paths that fly by either Earth twice or Venus twice could be used. I've looked for Earth-Venus-Earth-Jupiter paths, but those are almost as rare as E-V-J. It's the same problem, flying from Earth to Jupiter requires a V inf at Earth of around 8800m/s, and Earth can't change your flight path much at that speed, so the alignments have to be very precise and thus rare. E-V-E-E-J is more possible since the two passes of Earth double it's ability to turn your path, but FF can't do double flybys. The Galileo and Cassini missions had to use double flybys and significant deep space maneuvers to get out to Jupiter and Saturn. Finding these types of paths would require using double flybys, deep space maneuvers, and multiple orbits between encounters to really find all possibilities, but I get the shakes just thinking about what that code would look like.

Wow, you did it backwards. And you figured the whole thing out on the fly. Superb. You should get 'Master Astrodynamacist' now. I can't quite read the remaining dV number at landing, it looks astoundingly low (22m/s?!?). That must have been dramatic! That low Tylo pass must have been impressive to watch live. I wonder what the fastest speed your ship can aerocapture at Kerbin is?

Executing KEKKJ for something around 1200m/s is really good, especially if it's a window you found yourself. Randomly selected windows seem to cost in the 1100s, add 50m/s or so minimum for course corrections and you are around 1200. My 1011m/s was a result of finding one particular window that is exceptionally good, and practicing it many times with variations to figure out the tricks. That second pass of Kerbin and the deep-space correction around Duna's orbit are particularly tricky, the first path I find often needs 100m/s or more of adjustments, but extensive tweaking (30-60 real-world minutes!) ultimately finds one around 5-10m/s if I timed the earlier flybys right. In any case it sounds like you are doing it right. I'd enjoy seeing any good windows you find if you ever choose to show them! -PLAD

Doh! I see you're in a good direct return window right now, AlexMun's porkchop plotter tells me that you can leave in the next few weeks and arrive at Kerbin in 968 Kerbin days or so and hit the atmosphere at about 2050-2100m/s (above circular v at that altitude). FF tells me you can leave Jool on Y9 D285, go K-E-K and arrive on Y14 D155 at about 1910m/s. Not much gain for doubling the travel time and adding two flybys. The arrival speed drops to around 1410m/s if you are willing to wait until Y11 D405 to depart. (Jool Y11 D405-Kerbin Y14 D123 -Eve Y16 D141 -Kerbin Y16 D318). Red Iron Crown's advice was more useful, I think.

Val, nice exploration mission there. Being able to explore multiple islands during your stay is superb. What UT year and day is it in your mission right now? We could search for routes that flyby Eve on the way back to Kerbin, though that will add complexity and it sounds like you can safely aerobrake from a direct flight. The problem is that a Jool-Eve-Kerbin route will have you hit Kerbin's atmosphere faster than you would with just a direct Jool-Kerbin flight. However if you are willing to go Jool-Kerbin-Eve-Kerbin then there is a route that will allow you to arrive at Kerbin at less than the Jool-Kerbin value (about 2000m/s at 70km) about half the time.

Using Eve to get to Jool can save you a lot of dV, but it is tricky. The simplest way, going from Kerbin to a flyby of Eve and then directly from Eve to Jool, is not practical. Eve does not have the gravity to throw you to Jool all by itself. You can flyby Eve really fast (leave Kerbin at over 2900m/s from a 75x75km orbit, way more than the ~1950m/s that would get you straight to Jool) and if you time it right you will continue on to Jool from Eve. Or as you point out, you can do a huge thrust at Eve to turn your orbit more than Eve can do by itself and add energy. Either way is more expensive than a direct Kerbin-Jool route. I know of two cheap ways to get to Jool: 1) K-E-K-J. You flyby Eve and then flyby Kerbin before heading on to Jool. There is always a K-E-K-J path available in any given 350-(Earth)day period. The required start boost varies from about 1230m/s to about 1530m/s depending on the window. Using a flyby of Mun would save another 50-70 m/s. Read this post here for some examples. 2) K-E-K-K-J. Using two flybys of Kerbin allows Kerbin to point your solar orbit in just the right direction to get to Jool with a minimum of starting dV. I fly this path with lots of pictures and explanation of what I'm doing here. Note that on my second try (further down in that post) I got from the 75x75km orbit around Kerbin to an orbit around Jool for 1011m/s by using a Mun flyby as well. Without the Mun flyby it would be about 1070m/s. This path is not unique either, but the only other one I've found costs about 1160m/s. I don't know of a great tool for finding double flybys so these are quite hard to find. There may be ways that involve a double flyby of Eve out there, but I haven't found one. I only know of two programs that search for flybys in KSP, my Flyby Finder and Arrowstar's TOT. Neither one searches for double flybys. And regarding your other question, the Kerbol planets have had the same orbits and masses since at least version 0.22 so anything that worked back then would work now. The big change is that time used to be kept in 'Earth style' with 24-hour days and 365-day years, nowadays Kerbin time is used with 6-hour days and 426-day years, be careful to figure out which time style is being used when someone describes a departure or flyby date. I always used to use Earth time, but recently I redid the K-E-K-K-J mission using Kerbol time here. Also, it is very, very hard to fly multi-flyby missions without a node editor, if you're not using one and you want to try these paths then you should probably try one. I use Mechjeb.

Val, that's an impressive packing job, a rover and a jet in the cargo bay of a really good SSTL. If I see it right you have about 3100m/s left in the tank after unloading the cargo? Excellent data taking too. It looks like the low TWR made the Mun flyby route cost about 60-70m/s more than a high (~>2)TWR ship could have done it in, due to less Oberth effect and the larger correction burn required. Low TWR makes the whole mission possible so it's certainly worth it. I'm looking forward to the rest of the mission, especially seeing that tiny jet fly around.

Nefrums, that is superb. A Jool-3 with a single stage! That would be phenomenally hard to beat.

Red Iron Crown-thanks, notice I used your Tylo capture method almost exactly, it is superb. By getting flung outward after the Tylo flyby you can tune your Jool apoapsis and thereby your arrival time at Laythe's orbit to whenever Laythe will be there. It's pretty universal as long as your Jool approach isn't too far out of Tylo's orbital plane. I tried paths that get flung inward but they make getting a future encounter much harder. I'm also going to try your suggestion of taking off with the Rapier in closed mode, in open cycle it sits there for about 10 seconds spooling up before it even moves. Nefrums- Very nice mission so far, that is a lot of dV still in the tank after returning to orbit from Laythe. It'll be interesting to see what you do with it. selfish_meme- I'll try that too. I want to find the limit of the dV I can get to orbit with a single Rapier using a vertical ascent, I suspect the maximum possible is around 1600m/s but it would take about 2300m/s to do a Laythe-and-return. It looks to me like the fastest you can get in air-breathing mode with the Rapier is about 1500m/s on Kerbal (without exploding, anyway). Has anyone substantially beaten that? Next step up is one Rapier and 1 nuke, I see Val has already made some high-dV ones of those with the Dart Mk5 and 6.

These SSTO spaceplanes have been superb examples of form and function. So until I get better at spaceplanes here is a minimalist entry for a 1-way SSTO to Laythe. 9 parts and 7.7 tons at launch. I used my trusty KEKKJ route, this time using Kerbal time instead of Earth time. Some notes on that path: -On the Kerbin-Eve leg KSP's path predicter keeps switching between showing an Eve closest approach before and after solar periapsis. You need to use the post-periapsis encounter (at UT Year 2 D353.6 +/-1, 198.6 +/-1 K-days after leaving Kerbin on Y2 D155). So sometimes it won't show the right Eve encounter but you can figure out where it should be. -Using Mun is much harder than a direct to Eve flight. No matter how well you set up the TMI burn there will be a big error you have to correct right after the burn. -I needed 3 tiny course adjusts between the 2 Kerbin flybys. It is tricky to get the right Jool approach without having to fly by Kerbin too low the 2nd time. -I always adjust to the 1/100th of a m/s even though the rocket can't be nearly this accurate. This way I confirm that the right path is there somewhere even if I can't get on it just yet. -KSP's path predictor can't see more than 2 flybys ahead (usually) so you should use a flyby tool (Flyby Finder or Arrowstar's TOT) to plan a route with more than 2 flybys in it. I can see some advantages to using a plane instead of a rocket are that a plane can have TWR lower than 1, and you don't have the brutal gravity losses while going up. On the other hand I like the high TWR for the ejection boost. I do not think my Rapier-only approach will be able to get to Laythe and back because its ISP and TWR are not high enough though. On the other hand getting from Laythe orbit back to Kerbin shouldn't cost more than about 900m/s. Maybe.

Aanker, you have a point that just a one-time low-dV path isn't too useful, but there are a lot more ways to get from Kerbin to Jool cheaply. The trick is that 3 Kerbin-Jool synodic periods =350 (Earth)days, and 5 Eve-Jool synodic periods = 346 days, so any path involving Kerbin, Eve, and Jool will often repeat (roughly) in about 350 days. For example, the best way I've ever found to get to Jool is that K146-E195.65-K296.2-K509.25-J821 method I used for the 1011m/s mission (and a few others). It costs 1068m/s (or 990 if you use Mun). There is another one 352 days later: K498-E546.9-K639-K852.05-J1062 (but the cost is 1163m/s). This path is very finicky so there are only a few repeats before it fades away, though I'm sure it reappears someday. A much better path for repeatability is K-E-K-J. I have found there is always one of these at least every 350 (Earth) days. A given 'cycle' of paths will run for a while and then fade out, but another cycle will arise before it does. Here are examples for the first 1200 (Earth) days of the game, which is about 11 Kerbin years: K1-E46.4-K263-J454.5 : start boost (from a 75x75km orbit) is 1288m/s. K344.5-E391.6-K608.95-J834 : 1336m/s. that's the last in that particular chain but another has started: K132-E197.4-K406.5-J1046 : 1515m/s. K505.5-E544-K757.5-J1376.6 : 1493m/s. K843-E892.4-K1108-J1742.4 : 1228m/s. K1186-E1235.1-K1452.2-J2038 : 1256m/s. and so on. These windows are more forgiving than the KEKKJ routes, but you still should have your Eve periapsis be within about 12 hours of the time given. I do not think it is possible to do these multiple flybys without a node editor. You have to adjust a, say, 1300ms burn by +/- 0.1 m/s and +/- 1 second until you get the desired flyby time and I go crazy almost immediately when trying that by dragging the little node arrows. Red Iron Crown is way better than me at flying by hand, and it sounds like he couldn't do it either. I found these flybys by using my Flyby Finder for the KEKJ routes and my Lambert spreadsheet (available in the same post with FF) for the KEKKJ routes. Another user here (winged, look a couple of posts up) came up with a way to find KEKKJ routes with just Flyby Finder, though sometimes that might give a route that has to do too low a 2nd flyby of Kerbin. Note all my dates are given in Earth time (24h/365d) and not Kerbin time (6h/426d). I've been too lazy to update FF to do both time formats, arrgh.

The node editor is indispensable for multiple flyby missions. And when I'm trying to optimize a takeoff or landing profile the repeatability of software is extremely useful. I enjoy KSP more with Mechjeb.

Impressive SSTO's. I'm the one who came up with the way to get to Jool from LKO for about 1020 m/s, and it is interesting to see whether it is better to add 1km/s to your ship's dV or to take a convoluted route to Jool. The K-E-K-K-J route should be easier than it sounds here though. There might be a problem with the two time systems available in KSP- I used the 24/365 system for those flights and I think almost everyone uses the 6/426 system now. In 6/426 time you would leave LKO on Year 2 day 155 (with a normal V of -443m/s and a prograde v of 1039m/s from a 75x75km orbit) and flyby Eve on year 2 day 353.8. Then 2 Kerbin flybys on Y3 D330.2 and Y5 D330.4 and arriving at Jool around Y8 D217. You can leave Kerbin over a 48-hour window but you have to flyby Eve within about +/-6 hours of Y2 D353.8 for the final Kerbin flyby to work. I find it impossible to pull it all off without a node editor. I once took an SSTO to Eeloo's surface and back but like everybody I've discovered that all my old jet ships don't work in 1.0x. Now I want to try this. Thanks Val for that album showing your craft development, that's gonna help.