PLAD

It could in version 0.90. I haven't tried the new Duna atmosphere though, to get the K-X to Duna's surface and back Duna's atmosphere has to do almost all of your braking, and I hear it's a lot thinner now...

The performance of the stock Kerbal-X that comes with KSP has changed quite a bit over the years, as the weight of its parts and the iSp of its engines change from version to version. Here is what Mechjeb has told me are its numbers ready-to-launch: (Note that the numbers may vary a bit depending on what method you use to measuere them and whether you measure in the VAB or on the pad.) Version........total vacuum dV............total weight on launchpad 0.22..............6832 m/s......................131.67 tons 0.23.5...........6818............................131.44 0.24.2...........7333............................131.24 0.25, 0.90......7333............................130.94 1.0x..............6428............................129.22 It was not possible to launch from the KSC, land on Mun, and return to Kerbin before version 24.2. From then through .90 a Mun landing mission was moderately difficult but quite possible. You might think it became impossible again in 1.0x, what with the loss of 905 m/s in dV, but thanks to the new atmosphere model it takes about 1000m/s less to get into orbit than it took in the earlier versions. In fact it can now get to an LKO and have about 135m/s more available than it did in the earlier versions. This makes a mission to take of from Kerbin, land the ship on Mun and Minmus, and return to Kerbin without refueling possible. Barely. Here it is! Note that I was chicken and took the monopropellant out of the command pod before launch, giving the ship and extra 35m/s of dV. I did this in 1.02, the new versions came out while I was doing it but I don't think they change any of the space manuevers at all. I made about 30-40m/s of mistakes in this mission, so the K-X can do this mission in 1.02 and have about 80-90m/s left over. I now have to see if the K-X can get to a 72x72km orbit for no more than about 3430m/s with version 1.04, if so this mission is still possible. EDIT:I just tested it, and the new atmosphere model in 1.0.4 makes it possible to get the Kerbal X to a 72x72km orbit with only 3274m/s, which is 74m/s less than in 1.0.2. So a Kerbin-Mun-Minmus-Kerbin mission can now be done even without my fancy method of getting to Mun.

You can indeed use a gravity assist from Mun to reduce the total dV required to get into a low orbit around Mun from LKO. Since version 0.23.5 or so I have used the stock Kerbal-X to go from Kerbin surface to Mun's surface and back, trying to do it for as little total dV as possible. My best try is here, and another try with a slightly different approach is here. To sum it up, to get from a 72x72km Kerbin orbit to the first Mun flyby is about 846 m/s, tricky manuevers add 15m/s, then decelerating into a very low 6x9km(for efficiency) Munar orbit is 208m/s. LKO to LMO for 1069m/s. A direct flight would normally be about 860m/s (with course corrections) +271m/s or 1131m/s. But it the trip takes 13 days to save those 62m/s! Note that you can use similar methods to get from LMO (8x8km) back to Kerbin for about 230m/s. This sort of stuff has actually been done in the real world! My favorite was a Japanese moon probe that malfunctioned before completing its trans-Lunar burn and was stranded in a too-low ellipse to get to the Moon directly. They thought it was doomed but an astrodynamcist at JPL figured out how to adjust the orbit's period so it would get little tugs from the Moon that eventually pulled it all the way up and into a low-energy capture.

Thanks all, and for the link to that article immelman, that was great. It is a tribute to RO that I was forced to deal with a lot of the issues it brings up. For instance I felt a bit guilty about not installing the engine ignitor mod, which allowed me to use non-throttling motors for the final landing by letting Mechjeb pulse them really fast. The article covers this with "Recent full-scale testing...demonstrated that pulsed-mode engine firing is robust." (Though I wonder what the maximum engine size tested is for that.) And the huge problem I had-slowing the ship down enough with the heat shield to allow the main chutes to open before the ship hit the ground- gets major coverage. For comparison my lander weighed 24,300 kg at Mars atmosphere interface, with a 78.5 m^2 heatshield for a loading of 310kg/m^2. And yes, I flew by Venus to shorten the mission by about 400 days. I figure the first mission to Mars should have a short stay for safety's sake, and the free-return to Earth that you can get with a Venus-first flyby is nice too. The last minute of the Mars landing was the most exciting part of the whole mission. As the article says, "In this very dynamic phase of flight, robust event sequencing and timeline margin are critically important." Though no one asked, here is a detailed breakdown of my landing: L-139 seconds: Activate drogue chutes (to prevent the ship from wobbling as it slows down) L-44 : Activate main chutes (any sooner and the ship is moving too fast to survive the jolt when they open, any later and the ship will hit the ground too soon and fast) L-42 :release the heat shield (keep it on 2 seconds to buffer the main-chute-jolt, then release so it lands well clear of the landing zone) L-41 :open landing gear (as soon as the shield is out of the way) L-40 :Start motors (to assist with slowing down in time, in practice I turn on Mechjeb's 'land anywhere' here) L-23 :release main chutes (they've done most of the slowing they're going to do, and any later and they will land on the ship) (Adjust landing site by ~+/-100 meters if needed) L-0 :Touchdown! A lifting body would allow a lot more control on where the ship would land, but I don't know if the problem of getting slow enough to be able to open a chute big enough to make a difference would change.

This report presents a minimalist piloted mission to Mars and back using the Realism Overhaul mod. I find getting to Mars quite hard-you need a lot of delta-V, so you either need a huge rocket or nuclear rockets (or both), with all their attendant problems (H2 boiloff, launcher size, etc). Here is my analysis, my apologies to all those who've already been through this... I know of 4 general paths for a Mars land-and-return mission (see a NASA review here): 1) Conjunction class. So called because Earth and Mars go through a conjunction during the flight. You take a (roughly) Hohmann path from Earth to Mars, then wait about 18 months at Mars to take the next Hohmann window back to Earth. 2) Sprint class. You take a considerably higher-energy path to Mars, spend a short time at it (A week or two, the longer you want to spend the higher the delta-v requirements) then take a high-energy path straight back to Earth. 3) Opposition class, Venus first. "Opposition" because Earth and Mars go through opposition during the flight to Mars. With this you take a near-Hohmann path to Venus, fly by it and get flung to Mars. After a week or two at Mars you take a near-Hohmann flight back to Earth. 4) Opposition class, Venus last. In this you take a near-Hohmann path to Mars, stay at Mars a week or two, then fly by Venus to get back to Earth. Here are rough delta-V requirements and mission durations for a favorable example of each the 4 types. I am assuming a 10-day stay at Mars for the fast missions. Assumed start and finishes are from a 200x200km circular orbit. This does not include the landing or returning to orbit requirements at either world, which would be the same for all cases. Aerobraking to the final Earth landing is assumed. I used my Flyby Finder to get this data. Type........Leave Earth.......Brake at Mars.......Return from Mars...... Duration 1 ............3640m/s ...........3810m/s.............2000m/s...................925 days 2 ............3990.................4410..................3980.......................416 days 3 ............3920.................4260..................2480.......................538 days 4 ............3640.................3810..................3890.......................456 days These require a lot of fuel that has to be storable for up to a year or more, thus low-isp. But you can save a lot if you aerobrake into orbit at Mars. Let's look at the total dV requirements with and without Martian aerobraking: Type....... Total dv,...... ......Total dV,................. Duration ...............no Mars aero ......Mars aerobrake 1.............9450m/s.............5640m/s....................925 days 2 ............12380................7970........................416 3 ............10660............... 6400.........................538 4 ............11340............... 7530.........................456 Now options 1 and 3 require only a small impulse to return from Mars and the trip can be managed with only low-isp rockets. For comparison, going from LEO to a Lunar orbit and back to re-entry takes about 5000m/s. Here are my mission parameters: -This is a test/plant-a-flag flight more than a science gathering mission. Think Apollo 11. I therefore picked a short Mars stay, with mission option 3 being the best deal for duration (consummables mass) versus dV (fuel mass) required. -I limited my launcher to Saturn-5 size, so launch weights below around 2800 tons. -After lots of testing I found my speed at Martian atmospheric interface cannot exceed 7800m/s for a managable aerobraking. I also wanted to be able to abort the Mars aerobrake and do a free-return to Earth if needed. This tightly constrained my Earth-Venus-Mars leg. -I Settled on a crew of only 2 Kerbalnauts. I don't intend to leave anyone in Martian orbit. The carrier won't do anything while the Kerbals aren't on it. -CG is critical for the aerobraking to work, so all motors and RCS on the carrier/lander use the same fuel, which can be pumped between 3 tanks as needed. -I cheated with H2 boiloff (details below), and fudged the centrifuge and DRE at Earth, but other than that I used the mods as-is. I use all the required mods and most of the difficulty mods except Remote Tech and Engine Ignitor. It's RO version 8.1.1. THE WINDOW Here are the FFRSS readouts for the Earth-Venus-Mars leg and the Mars-Earth leg. This is the best one I found before 1980, the Mars return is fast and relatively low-dv, and the E-V-M leg gets to Mars exceptionally early. Note I limited the E-V-M graph to only show paths that arrive at Mars before day 8175. Most of them had to be rejected because the arrival speed at Mars was way too high. I will depart from Earth on June 3rd, 1972 (Y22 D160 at 0:00, UT day 7825) and arrive at Mars on May 19th, 1973 (Y23 D145, UT day 8175). Spend 10 days on Mars and fly back to Earth from May 29 1973 to Nov 4 1973. THE LAUNCHES The first launch puts the carrier/lander in orbit 8 days before Earth departure (I'll call this D-8). This is followed 1 day later by the crew lifter, which is carrying 6 Kerbalnauts-Jeb and Bob who will go to Mars, and 4 engineers who will test all systems on the ship over the next 5 days. Once they give their OK, the 3rd and final launch, on D-1.5, puts 144 tons of LH/LOX (8 tons can boil off by D-0) and the departure motors in orbit. A spacewalk puts in reinforcing struts and joins the cables between the carrier and the tank. The crew lifter returns to Earth with the 4 engineers on D-1, and the ship is ready to go. Here was my biggest cheat. I have not mastered H2 boiloff yet, and between running out of battery power at night and the 36 hours between the tank launch and D-0 I lost too much and had to Hyperedit 3 tons back in to make the departure. (I have to finish all the orbital insertions manually and didn't have the heart to try another launch of the tank.) EARTH-VENUS-MARS D-0. The departure burn is 3941m/s, plus a 7m/s correction burn after leaving Earth's SOI. The tank is then extended from the carrier via the 4 cables and the assembly is spun up to 2 RPM with RCS. The CG is closer to the carrier than the tank, but I calculate the radius as 35M at the 'lowest' occupied section for about 1 lunar gravity. The Venus flyby is at D+160.4. The assembly would have to be despun for the manuevers 2 days before and 2 days after Venus flyby, then respun for the trip to Mars. It was suprisingly easy to get it safely extended and spun up, but the moment I hit time warp I got a 'cannot warp while under acceleration' message. If I took tension off the cable the 2 parts would fly apart and rip the cable when I hit time warp. So I didn't really spin it the whole way. Despinning was a nightmare anyway. And how would the ship keep an antenna pointed at Earth during spin? I decided next time I will eject an autonomous antenna platform with a large high-gain antenna to talk to Earth, and a small omni antenna to talk to the ship, and keep it about 1 km from the ship for the E-V-M leg. I've also found a 'maintain spin under warp' mod, I'll try that soon. I also need to put clouds on Venus, though I fear the memory hit as I'm running near my limit with so many mods. MARS AEROBRAKING AND LANDING Two days out from Mars the empty tank is released before the Mars periapsis adjustment. This is the last chance to switch to a Mars flyby and direct return to Earth if the aerobraking has to be scrubbed for some reason. To prep for the aerobrake all fuel is moved to the frontmost tanks and the panels are retracted. Periapsis is 45.1 +/-0.15km, too low and the ship breaks apart, too high and it is not captured into orbit. Apoapsis after braking is around 1500-2000km. Peak deceleration is ~4.5 gees. At 1st apoapsis the periapsis is raised to 160km. Fuel is moved back to the carrier and the lander separated. Lander periapsis should be from 65-75km depending on where you want to land. The lander is rock-steady when aerobraking, that huge heat shield makes it easy. Drogue chutes release at 25km and 1500m/s, main chutes at 3km and 350m/s, heat shield then releases, gear out and motors on, release chutes and land on rockets. The first aerobrake is tricky, it's at the edge of possible. RCS is needed to keep it stable, and the ship moved a bit too much and lost 2 rear RCS thrusters, one solar panel array, and the outer TACLS container (that was there for balance). Turns out I forgot to remove the waste tanks from that container and it was heavier than I planned for, (yes, my plans were full of s**t) but after it ripped off the ship was more stable and survived the aerobraking. Final carrier orbit was 160x1500km, well within specs. The landing went well (the result of about 20 test runs when designing the lander) and the guys were on Mars after a 350-day journey! Note: for some reason the landing motor gimbals worked in reverse so I turned them off and used RCS for direction control. MARS EXPLORATION The guys lived in the Itinerant module while on the surface. They spent the first day inside getting used to moving in Martian gravity. Near noon on day 2 they took their first steps on Mars. In later days they unloaded the rover and experiments and did some science. After 10 days on the surface they returned to orbit and docked with the carrier. The only trouble was the rover dynamics, when crossing certain lines the rover would get kicked up in the air. I kept it below 8m/s and it never sunk into the terrain. Communication with Earth would be a trick, a high-gain antenna can communicate directly when Earth is above the horizon, but what do you do after Earth sets? I'd accept being out of comm for 12 hours at night and early morning, the time lag means they are never really in direct communication anyway. RETURN TO EARTH It took about 4200m/s to get the SSTO lander back to the carrier. I debated moving the lander RCS units to the carrier to replace the lost ones but decided that would be too unrealistic. I had 1000m/s more return fuel than needed, I could have kept the lander on during the trans-Earth burn, and even used the lander's motors if the carrier main motor had failed. But I discarded the lander and did a 2519m/s burn to get back to Earth. The lost RCS was a problem- The carrier was unbalanced at this point and needed all the RCS to keep it on course near the end of the return burn. So I had to break the return burn into 4 parts and repoint the ship when it got too far off course. This main motor also gimbaled in reverse so I couldn't use its gimbals either. Maybe a result of flipping the ship around during construction? In any case my huge fuel surplus allowed me to use a faster return to Earth than I had planned- only 159 days instead of 180 in my original plan. My final cheat was on Earth re-entry. I hit the atmosphere at 12.1km/s, about 1.2km/s more than a moon return. This turned out to be utterly impossible with the standard DRE settings, the ship would heat up to 2000C and explode around 82km, even with a periapsis at 80km where the deceleration was trivial. So I changed the DRE settings to allow it to survive. The Stardust mission reentered at 12.4km/s and survived with a PICA shield so I don't feel too bad about this. MISSION SUMMARY Primary crew total time in space: 525 days Total launch weight: 2216+243+2775 = 5234 tonnes Cargo landed on Mars: 3.5 tonnes (The Itinerant container and everything attached to it but not the ascent stage and fuel) Now it's time for me to upgrade to the latest RO and figure out H2 storage and high-speed re-entries.

My entry in the Jool-5 challenge made extensive use of flybys of Jool's moons to reduce the total dv requirements quite a bit. The trick was that I never put the carrier in orbit around any moon, it would drop of the lander during one flyby of a moon, then pick it up at a later flyby. It sounds like you want to flyby all the Jool moons as cheaply as possible, so you want to follow the carrier's path. Note that my carrier's total mission requirement for this was: 1070m/s : Kerbin low orbit to first flyby of a Jool moon (this depends on the Kerbin-Mun-Eve-Kerbin-Kerbin-Jool path I took to get there) 245m/s :total of all maneuvers between the moons 100m/s :last Jool moon flyby to Kerbin atmosphere. Here is my secret- this is much easier to do than you would think! I did not calculate the whole flight ahead of time. (Except for getting from Kerbin to Jool, I had to calculate all of that.) Rule #1- Use a node editor. You have to make little bitty adjustments when setting up a flyby, only a node editor (I use Mechjeb's, but there are others) can do that easily. Rule #2 is to get exactly into the plane of the inner 3 moon's orbits. I did that cheaply by approaching Jool fairly close to that plane and then flying way out after my aerobraking pass. This way I was moving quite slowly when I crossed through the moon's plane and the plane-adjust was cheap. This is the strictest rule-any error in inclination will be multiplied by each flyby. I still had to do small plane corrections every now and then. Rule #3- the first moon flyby is the most important. My first, long orbit around Jool went so far out that it was easy to adjust it so that I swung back in past Laythe's orbit at the right time to encounter Laythe. Once you have that first good encounter with Laythe the rest is searching for the simplest next encounter. Rule #4- Never do one flyby without already knowing what the next flyby will be. The game's accuracy usually prevents you from seeing 3 flybys ahead, but if you keep in the right plane you can always see 2 flybys ahead. You may have to circle Jool several times between flybys, but you will note I never had to do more than 5 Jool orbits between flybys. Place dummy nodes if you have to to see the path after a future flyby. I never had to see more than 2 flybys ahead, the moons are close enough together that there is always something. The rest are rules of thumb. Your Jool orbit ought never be such that it crosses less than 2 moon's orbits, or is entirely outside Tylo's orbit. Patience in looking for the next flyby. Sometimes I would be surprised by a better option that would pop up as I was carefully adjusting a flyby, it was good to search through a wide range before settling on the best path. Flying by the two outer moons is tricky, you have to do it where they cross the plane of the inner moon orbits, check out how I rotated the Jool-orbit apsis to do that. Enough of my yakking. Good luck, and may the force (of gravity) be with you!

Gives you something to aim for? Uh-oh. I'm gonna need a bigger ship. I'm working my way up, here's my new 30kdv ship for the Dres run. Definitely nuclear class. 103 Kerbal days, 0:19:41 to Dres. (25 Earth days, 18:19:41.)

Yah, that was embarrassing. I'd translate the Moho trip but I did a better one, this time in KERBAL days. Here it is. This one got mighty exciting at the end, I cut the dv margin rather fine. Still, 33d, 3:17:08 from launch to when the rolling stopped. He lived and that's what counts, right? My Eve entry should be 11 Kerbal days, 2h 33m 11s. Middle of the pack.

Here's my Eve entry. 2 days 20 hours 33 minutes 11 seconds. And that's with no nukes or ions. !Earth Time! Kerbal time it's 11 days 2:33:11. I've found a better approach to this challenge that should allow my existing ships to beat the previous entries for all planets, including my Moho one. The key is Alex Moon's pork chop plotter. I give a brief explanation in the album. The immense ships I've seen others make should be able to crush this. Now it's a matter of finding the best windows, (some are significantly better than others) and making an immense burn accurately enough. And of course leaving enough to brake with at the airless worlds. !edit! I just realized the numbers don't add up-at the speeds you were going you should have made it much quicker. Are you using 6-hour Kerbal days and I'm using 24-hour Earth days?! Doh!! I believe my planet entries have to be multiplied by 4. At least it doesn't matter for the Mun run.

The whole ship has 33 chemical rockets and one nuke, but it didn't use the nuke until the course correction after the transfer burn.

Woohoo! Now I wanted to try a planet and Moho looked good. I used my Mun ship with its relatively small 22649m/s, but a pork-chop plotter found a great path. 10 days, 14 hours, 2 minutes, Earth time. In Kerbal time it's 42 days 2h:2m. Funny thing, when I was about halfway through the departure burn the path crossed an Eve encounter for a couple seconds, 9 days out. One of the tanks almost hit it. Hmmm...

Foxster, that 60kdv ship is epic! So is the whole mission. I dread to ask how much real-world time it took to use up the ions. OK, I did a new Mun run using 0.90 and those nice new motors. A Mun run is much easier than a planet run since the ships can be smaller- a total dV of more than about 25K is pointless because you will not have time to use it up. High acceleration is more important, my 14m/s^2 (average) ship coasting 10 minutes at 9400m/s makes for the same trip time as a ship that accelerates/decelerates at 10m/s^2 all the way and reaches a peak v of 10600m/s - a savings of 2400m/s. And the aiming is much easier on a Mun run since you can see your target the whole way! I like the mission drama though. Every second counts. 33 minutes and 51 seconds?

There was a speed run to the Mun challenge long ago, I believe my entry from that meets the rules for this challenge. We had to get back, too. My time from launch to flag out on Mun: 43 minutes 33 seconds. All stock except for Mechjeb. I did it in KSP 0.22, back before you whippersnappers had these new-fangled high-TWR rockets, by gum! Scott Manley in 32 minutes and there and back in 58 minutes, but he didn't EVA on Mun. Someone might be able to beat 30 minutes with the new parts?

I got a little 12-ton SSTO from Low Kerbin Orbit to Eeloo landing and back for 2897m/s. In a separate 1-way trip I shaved 21m/s of the K-E leg of the trip, so I'm sure an Eeloo landing and back can be done for 2876m/s. With these new Kerbal-X ascent trajectories it has ..2876m/s available in LKO. Considering the required starting window there just isn't much room for improvement on this (I flew just 200 meters over Mun's surface on its flyby!). So Kerbal-X to Eeloo surface and back would be the most epic trip of all, I agree. I don't think Vector's trick can be used because you would have to do 5 Munar flybys and 13 orbits around the Sun and then arrive at Kerbin in a 12-hour window (to then head on to Eve). Maybe Metaphor could do it. Heh. You know, your resounding victory in Jasonden's old flyby challenge was a big motivation for me to write Flyby Finder. Have you ever used it? I like to use Mechjeb for ascents because it is repeatable, so I can vary one parameter at a time and see the result. Someone would have to go theoretical to do better. I know there are a couple of autopilot scripts out there, has anyone already developed an optimized ascent algorithm? And here's a Kerbal-X to the Mun addendum challenge- is it possible to Launch from Kerbin, land it on both Mun and Minmus, and return it to Kerbin? I think it's about 150m/s short, but just maybe there's a way.

In my LKO to Jool orbit for 1051m/s thread I made it from LKO to Eve on 993m/s. In this thread Vector made it from LKO to Eve for 873m/s! So I bet 7217m/s to Moho can be beaten by more than 300m/s with a but it would be an epic task. I fiddled with the Kerbal-X launch parameters and found that using all the ones you used except for dropping the acceleration limit from 25to 22m/s^2 gets you to a 75x75 orbit for 4344m/s. How low can this go?!?

Von Ziegendorf, that is freaking brilliant. You didn't even need to remove the monopropellant from the ship to make the trip, even with it you would have had about 28m/s left at the end. I had thought it was not quite possible to make the trip without Vector's multi-Mun-flyby trick, but you did it. I see several of my tricks are obsolete. Some observations- -You got into orbit for only 4354m/s. That is the best I've ever seen for the Kerbal-X. Thanks for showing the ascent profile so I can use it from now on! -Your landing about 500m higher than me on Duna cost about 7m/s on the landing (assuming I'd done it as perfectly as you did, which I didn't) but saved about 33m/s on the return to orbit. This suggests there is a perfect altitude to land at that is somewhat higher than 1200m. -Your path took 102m/s more to get from Kerbal's surface to Duna's atmosphere than mine (in 8 years less time!), but 80m/s less to get from there home. This shows it is possible to do the Kerbin-Duna-Kerbin round trip for only 7072m/s. I've dreamed of having a 'Kerbal-X to anywhere' challenge, where entries would try to land the stock Kerbal-X on the various bodies (or land-and-return) with the least dV used or most fuel left. (This to the Mun... and back thread would be a subset of it.) My worry has always been that the next version of KSP would change the X's specs and make comparisons difficult. Well, and that there would be no entries for most bodies. Maybe when KSP 1.0 comes out. Food for thought-Metaphor got from Kerbal's surface to a Moho landing for 7217m/s. The Kerbal-X has 7202m/s of dV available, taking isp losses during ascent into account. Now that would be a challenge...

Hello Carlo, I put a primer on how I searched for the Pluto flights in the FFRSS thread, I'll pick it up there if you could use more advice on it. StoryMusgrave, I think all flights to anywhere past Jupiter have flown past Jupiter first, and after doing the Pluto search I can see why- Jupiter makes it quicker and cheaper to get anywhere out there, and the windows are pretty frequent. Edit-oops, rereading your post I realize you only meant that none of those deep space probes have stopped at their destinations past Saturn, which is true. It looks like one could stop at Pluto for only 4km/s or so though, but only if the flight takes more than 20 years to get there. Now I wonder what the minimum total dV would be for an Earth-Jupiter-Uranus orbiter. Can't use those dinky little moons to slow down like Cassini did with Titan though...

Below is a primer showing how I searched for optimal flights to Pluto. To Carlo and anyone else getting lots of blank screens, it's not easy to find that first window, most of the time there is no path between the selected planets at the selected times. The most important thing though is to set the "V at SOI" "max" number high enough. If you leave it at the default 3500 it will only find windows from Earth to Venus and Earth to Mars, and even then only if you set the "Earliest Search Dates" and "Search Periods" just right. In the following primer I have a set of good numbers to start with, for instance, If you are going from Earth to Jupiter you must set V at SOI max to at least 9500, (10000 would be even safer), the "Earliest Search Date" for Jupiter must be at least 600 days later than the one for Earth, and the "Search Period" for Jupiter should be at least 500 days, (or even 1000 days to be safer). For flybys you often need an even higher V at SOI, for instance Earth-Venus only needs 3500m/s but Earth-Venus-Mars needs at least 5500. I still forget to raise this number high enough sometimes. (If you raise it too high you'll often hit the 'flybys found' limit of 4500 and a big part of the output will be blank) To test that the program is working correctly on your computer pick one of the graphs in the pictures below and copy all of the "V at SOI", "Earliest Search Date", "Search Period", and "Start at", "1st Encounter", "2nd Encounter" (etc) numbers to your program and see if you get the same result I show. If you don't, is it possible to get a screen grab of it?

This is just the sort of problem I wrote Flyby Finder for. I might post some charts and screengrabs of this in the FFRSS thread tomorrow, in the meantime here are what I've found so far... Problem: Get from Earth to Pluto as quickly as possible using as little dV as possible. We need to brake into orbit at Pluto. I checked the direct flight first. Standard porkchops show it's best to arrive at Pluto around October 2018 (when it crosses the ecliptic plane), since then you can use as much of Earth's orbital motion as possible. Lowest dV I found was Depart Earth Dec 30 1988 arrive at Pluto June 27 2018. Total dV expended (assuming you start in a 200km circular orbit around Earth) is 8183 (leave Earth)+3610m/s (brake at Pluto) =11793m/s, trip time 10771 days. The Earth-Pluto synodic period is about 366 days, so there is a window every 366 days before and after this departure date. Next I searched Earth-Jupiter-Pluto. The Pluto-Jupiter synodic period is 4554 days, Earth-Jupiter is 398 days. It turns out that every 4554 days (~12.5 years) there are 4 or five windows (spaced about 400 days apart) for going E-J-P. I feel the best one before 1990 is to leave Earth Jul 16, 1976-Jupiter flyby Aug 26, 1978-Pluto arrival Aug 13, 1996. This is 7333 days for 6495+4803=11299m/s. This saves 9.5 years over direct! Next I searched Earth-Jupiter-Saturn-Pluto. This got really complicated. You can get to Pluto really fast this way, less than 10 years for no greater start thrust than in the cases above, but you will arrive at Pluto at more than 14000m/s. Ouch! It gets to be a judgement call, is adding (for example) 200m/s to your total dV budget worth it to save 200 days on your trip? How about 400? In any case my favorite is: leave Earth Aug 30, 1977-flyby Jupiter Sep 16, 1979-Flyby Saturn Feb 13, 1982-Arrive Pluto Jun 12, 1996. This is 6860 days for 6833+5197=12030m/s. Still almost 19 years in transit. I found only 4 E-J-S-P windows, all in the 1970's, and no others before 1990. I think there might be more starting around 2020 but I haven't checked yet. There are more complications, like the inclination of the optimal Earth starting orbit being less than the latitude of your launch site, but I'll put that aside for now. Lord, I hope I didn't make a typo up there.

I've done a lot of experimenting with this on the Moon. With KSP 0.25 and RSS 8.2.1 I found that if I kept my rover below 8.6m/s it would never fall through the terrain. At 8.6m/s it would eventually fall through, and the faster I went the shorter the distance it would go before it would fall through. I've accepted that as a reasonable speed limit on an alien world with no roads. But here's a trick-I was landing a ship on the Moon's South pole when I discovered the 'jagged' appearance of the surface there, it's a result of the terrain cells not meshing well where a whole bunch of them come together. I read that you could eliminate the jaggies by changing the game's graphics settings, "scenery", "terrain detail" to "high" so I did that and the jaggies disappeared. I then discovered that my rovers would not fall through the scenery anymore, at any speed! (Well, above 30m/s or so I always wipe out quickly so I can't be sure about really high speeds). I switched back to the default terrain detail and they fell through again. At least one mod makes getting rid of the jaggies impossible (active texture management), and then no matter what terrain detail is set at the rovers fall through. Conclusion: Poles are jagged, rovers fall through. Poles smooth, rovers don't fall through. You have to put something on the ground at the pole to see if the terrain is truly smooth, as looking from even a kilometer above the ground can hide the details. I've just upgraded to KSP 0.90 and RSS 8.5, and it's behaving a bit differently. With ATM on (so poles jagged) and terrain detail on high the critical speed is around 9-10m/s but with detail on default it is lower than 5m/s. I'm still experimenting with that. If anyone else has done experiments on this I'd love to hear it. I want to check if any of the other scenery and rendering settings make a difference too. I've only done these tests on the Moon, I wonder if it's the same on other worlds?

This stand-alone program searches for flyby opportunities in KSP when using the Real Solar System mod by Nathan Kell only. It also does pork-chop plots. It only finds ballistic trajectories, that is, ones where you do one major boost when leaving your start planet and then coast past all other planets you encounter (allowing for small course corrections). Real world examples of this are Pioneer 11, Voyager 1&2, and the New Horizons Pluto probe. I also use it for planning opposition-class missions to Mars. It does not handle deep space maneuvers or multiple flybys of one planet, like the Mercury Messenger probe or Galileo or Cassini. I've tested it with up to RSS version 12.0 used on KSP 1.2.2. It works with all RSS versions back to at least 8.2 as well, but note that Earth's SMA changed in version 12.0 so you have to select the right version from the radio buttons when you start FF. Default is set for V12+ so if you are only using older versions of RSS then I would stick with FFRSS V0.83 so you don't have to select the radio button every time. This is a fork of my Flyby Finder for stock KSP. As such the basic operation is the same as FF, and if you've used that then you need only see this quick guide for FFRSS, the new 0.80+ features are shown at the end: If you have never used FF then here is its guide, which you should read for FFRSS as well: Here are the known bugs and suggestions on things to avoid: 1) The program does not accurately do double flybys, that is consecutive encounters with the same body. It doesn't warn you of the error if you do enter a planet twice in a row, and the output will be wrong. 2) There is limited input checking- make sure to only enter decimal numbers in the input fields! The program just refuses to do the search if bad entries are made. 3) If the initial departure orbit shows an inclination of exactly 90 or -90 degrees then the departure equatorial prograde and departure vZ values will be wrong. Okder's addon (mentioned below) gets around this! High-inclination transfer orbits are very tricky to fly in any case, I try to avoid them if I can. 4) Paths that fly by gas giants more than 3 times get clumpy. (See FFRSS guide for example.)My problem is that setting precision parameters good for Mercury makes them bad for the big outer planets. 5) When doing searches with more than 3 bodies the program sometimes stops updating the screen (though it is still working and will finish the search eventually). The problem is that I don't have it update the screen when it is deep in nested loops since it could be a big hit to run time. 6) The new "Search steps per period" (SSPP) feature is handy, but remember that increasing it by a factor of 2 increases the run time by 4x. It is also best to keep (Search Period/SSPP) higher than 12 hours or so or it slows down even more. Here are the links. I'd call 0.85 a beta version. 0.85 has only one change from V0.83- a pair of radio buttons have been added to select between Earth's SMA from RSS Version 12.0+ (default) or Earth's SMA from all older versions. Version 0.84 has been dumped because I did not enter all the changed parameters for Earth's orbit correctly in it, 0.85 corrects those and is now the one to use with RSS V12.0+ I use the MIT license. FFRSS 0.85 Executable and instructions for Real Solar System mod only: https://www.dropbox.com/s/7o5buwpkp9fgj39/Flyby Finder RSS085exe.zip?dl=0 FFRSS 0.85 Source code for Real Solar System mod only: https://www.dropbox.com/s/4p8kgc4lcn8pgk3/Flyby085RSSsource.zip?dl=0 and just in case, here is the previous version. I would stick with this one until you install RSS version 12: FFRSS 0.83 Executable and instructions for Real Solar System mod only: https://www.dropbox.com/s/32pkvymdftvd8al/Flyby%20Finder%20RSS083exe.zip?dl=0 FFRSS 0.83 Source code: https://www.dropbox.com/s/mkk8wyvf8c6t3p9/Flyby083RSSsource.zip?dl=0 Here is an Excel spreadsheet, LambertH.xls, that I use to set up and test FFRSS. It does test double flybys, and it shows you the data and calculations that are used in FFRSS. It is pretty hard core math-wise though, you probably shouldn't mess with it unless you know what you are doing. This is an update that fixes the 'out of order' third double flyby field. It also shows an Earth-Venus-Earth-Earth-Jupiter path with a very low starting dV. Beat that, Galileo mission planners! https://www.dropbox.com/s/58yepcybuoz2ll2/LambertRSSvH.xls?dl=0 Here is a little spreadsheet, "MoonfinderB", I made that gives the next 2 launch times from any high-latitude (higher than 28.4 degrees) launch site to Earth's Moon using a due East launch azimuth (the easiest and most efficient launch azimuth). I fly to the Moon a lot and was getting tired of guessing. Instructions are in page two of this thread, here. and a direct link to the Imgur album here. Check the yellow cell in the spreadsheet to make sure it is set for your version of RSS as Earth's sidereal rotation period has changed. Doh! I need to upgrade it for V12.0 since Earth's SMA and year have changed, that only affects the info on where the Moon's terminator will be though, the best time to launch calculation should still be correct. https://www.dropbox.com/s/rqcb48m43rmh7g6/MoonfinderB.xls?dl=0 Okder has made a Mechjeb addon that eliminates the need to use a test probe for deciding when best to launch into the transfer orbit. It even creates an updated departure burn node after you are in orbit! Now being off by a couple of degrees in inclination or LAN can be instantly accounted for. Check it out! I also find slingshotter by Overengineer1 to be very useful in setting up flybys, it enables you to see if your future path will cross a future target planet's path in the right location. It is only available for KSP 1.05 though.

Kerbal X to Ike and back. Not bad. But you know, the stock Kerbal X can legitimately make it to Duna's surface and back to Kerbin. It just takes a few extra tricks. It is interesting to consider all the bodies that the Kerbal X can get to. I think it can do a land-and-return to Mun, Minmus, Gilly, Duna, Ike, Bop, Pol, and Eeloo. And a safe landing (but no return) on Moho, Eve, Dres, Laythe, and Vall. Only Tylo's surface is beyond its reach.

With the Mk1-2 pod: I set a vacuum periapsis of between 56 and 65km before hitting the atmosphere. I then use descent mode as needed to get an actual first periapsis of 58.5 to 59.9 km. I then try to not skip back up higher than 65km (rotate to the maximum sink position if you have to). After I start back down from 65km I keep the pod rotated for maximum lift until the flames stop. This keeps the g-max to about 4-5. As you found, if you bounce up too high after the first pass you might come down the second time too steeply to survive. Good luck!

47.76, that's pretty good. I did a run with the 24.2 Kerbal X when it first came out and I discovered it could do the Mun-and-return. I had 71.27 units of fuel left just before I ditched the service module on re-entry. (It's the fifth entry in the thread.) Since I didn't land the service module I figure you should get a bonus (or I a penalty) for what you used landing, and I used Mechjeb for guidance and reporting, but I think I still beat that. I was judging mission efficiency by total dV expended which was 6869m/s (I later did it with 6809m/s with the .23.5 Kerbal X and a refuel but that is another story.) I cross your line in the sand, sir! (I can't beat your pose-with-the-flag photo though!)

Thanks Hattivat. That is considerably higher than I was figuring. You bring up a big issue- keeping it stable will be a trick. First I'll try an 'umbrella' with a big shield on one end and a lot of rcs thrusters on the opposite end and hope autopilot control can keep it in line, if that fails I'll try a lifting body approach despite the weight penalty. This is gonna be interesting...