Aegolius13

It might help to post a screenshot of some of the maneuver nodes leading you from Jool to Kerbin. But the short answer is yeah, you can probably reduce the 6,000 m/s with a different approach. Assuming an optimal Hohmann transfer, it takes around 2,000 m/s to transfer from Kerbin to Jool. The same is true in terms of the excess velocity you'll need to shed to capture around Kerbin off of an optimal Jool transfer -- meaning the lowest possible velocity at perikee is something like 4,200m/s. So the extra ~1,800 your experiencing suggests there is something suboptimal about your approach - either your periapsis around the sun is inside Kerbin's orbit, or (more like) you're not coming in perfectly tangent to Kerbin. [EDIT] Or you're coming in at a high inclination, retrograde, or something other than the optimal equatorial orbit. One other thing to keep in mind - once you've captured around Kerbin, you can aerobrake at your leisure to get back to LKO, or capture and reenter. So you really only need your velocity at perikee to be about 3,200 m/s. If fuel is limited, it's most effectively to use it to help capture, then rely on aerobraking for the rest (but save a tiny bit of fuel to adjust your periapsis during aerobraking).

It might help to have a screenshot of your current craft, and/or more detailed description of what you're trying to do. For example, by going to Duna, do you just mean going to Duna orbit, or actually landing on Duna? The latter is going to impose a lot of more requirements than the former. As @Pluscksays, a Duna mission is not that different in terms of total requirements than a trip to the Mun, but due to the extra steps and time requirements, it['s a lot easier for something to go awry. But in a general sense, if you need your rockets to go farther, I think the best framework to work around is the Tsoilkovsy Rocket Equation. (Not sure if you're familiar with this, or with the concept of delta-v). There's quite a bit of math involved, but in general, the Rocket Equation says a rocket's total delta-v (i.e., effective range) is a function of only three things: the dry mass, the wet mass, and the engine's specific impulse. So, to get more delta-v, you can do a few things (these are very general tips, so they might or might not be applicable to your current issue): Reduce dry mass. This means getting rid of any parts you don't absolutely need, including excess engines. Increase wet mass. This simply means adding more fuel. But of course, adding fuel hurts your TWR and adds dry mass in the form of empty tanks, so it can hit diminishing returns pretty quickly. Increase specific impulse. Assuming you're able to get you ship to orbit, this means picking engines with good vacuum specific impulse. For a Duna mission, NERVs, Poodles, Terriers and Sparks are all decent choices, depending on your craft size. Make your staging more efficient. (Technically outside of the Rocket Equation) This is a bit more of a complicated topic, but generally you probably want each stage to have about the same total delta-v. As a general rule of thumb, if a new stage has 1/4 to 1/3 the thrust of the previous stage, you're probably in the right ballpark. For example, it;'s common to have a Poodle powered stage, followed by a Terrier, followed by a Spark. Or, if all else fails, add MOAR stages, starting at the top/end of the rocket and moving downward. One other thing that will help extend range on a Duna mission - on the way in, use Duna's atmosphere to aerobrake (i.e., slow your ship enough to get into Duna orbit without needing an engine burn). You'll probably have to use a little trial and error to figure out the right periapsis to aim for.

For anything smaller than Duna / Tylo, the dv requirements for a round trip are small enough that there's not much point to staging. Plus once a support infrastructure is set up, it's nice to have fully reusable landers, which of course requiers SSTO. However, if I'm doing a direct ascent style mission, sometimes a break between stages will occur during the "lander" phase of the mission. (E.g., one stage might do the munar insertion and injunction burns, land, take off, and then a second stage might complete the ascent and return to Kerbin).

I gave it a quick try. At least for me, the landing gear worked fine, and kept the plane straight on the runway up to like 140 m/s, which should be more than enough speed. The bigger problem seems to be the difficulty taking off. A couple points here: You've got your center of thrust well above the center of mass, due to the engines being placed high on the craft. I think this is causing your nose to torque down. You may want to try extending the forward landing gear down a bit, so the plane sits nose-up on the runway. This helps it want to point up and lift off. You might be light on wing area for a plane this size. You might also try rotating your wings so that they point up a bit when the plane is level (this is called angle of incidence, and helps generate lift). Your control surfaces are probably too small for a plane this size. But the bigger issue is that they're in the middle of the plane, so they generate next to no leverage for pitch. Mounting at the tail or the front (as a canard) will help. One other point - this is not as directly related to taking off, but abrupt changes in form factor (e.g., Mk 3 to 2.5m and the like) generate tons of drag. Your plane will perform much better if you smooth these out. For example, I would get rid of that 2.5m monoprop tank in the middle, and put it in a spot with the same form factors. (Or get rid of it entirely - you may have enough monoprop from just the cockpit). Similarly, I would stick a Mk 3 to 2.5m converter on the back of your plane, before the coupler for the nukes. EDIT - one additional thought. I think once you tweak some of this stuff, you'll find that you have more engines than you need to take off and get to space. So you may be able to trim down further, which can provide a cleaner design, and so forth in a virtuous cycle. At the extreme end, you can check out posts by @GoSlash27, who is a master of making clean, low-drag planes that work with minimal engine power.

Can you post a screenshot of the existing craft? That would help a lot in terms of figuring out what your specific issue is and how to fix it. This is often due to wheels not being set perfectly (the game is insanely picky on this). Click your wheel with the rotate gizmo, choose "snap" mode and "absolute" rotation ("F" key I think), and make sure they stick straight down and face forward. Best to check all three axes of rotation. Other wheel things to try: Turn steering off on the back wheels. Increase friction on the back wheels, and/or decrease it on the front wheels. Try larger wheels if you have a heavier craft. You may be overloading it. This could also be related to your other problem re: taking off. If the plane has to go too fast on the runway, or has unexpected forces pushing it down in front, etc., strange things can happen. That sounds like... a lot of Rapiers. Rapiers are not great at low speeds, but unless your plane is enormous, sounds like something unexpected is going on here. Difficulty taking off could be caused by, among other things: Insufficient wing area for your weight (add more wings, or lighten the plane). Insufficient pitch authority (add more control surfaces, use bigger control surfaces, and/or put them at the very front or back of the plane for better leverage). Center of mass too far forward relative to center of lift (move wings forward, or adjust design to shift mass backward). Rear landing gear too far backward (slide forward, but watch out for tailstrikes if you go too far). Unbalanced thrust making the plane want to pitch down (adjust engines so the center of thrust aligns with the center of mass). The "RCS Build Aid" mod is great for checking engine torque. Again, a screenshot would do wonders for a diagnosis, preferably in the hanger with the Center of Mass and Center of Lift indicators on.

Agree. I think the existing ion engine is a decent compromise between realism and playability. It's wimpy enough that you typically have to mission-plan around it, but powerful enough that burns can happen in a scale that works for the game. Doesn't it have to scale this way, for balance reasons though? If you had an ion engine with more power, but less electricity required, it would kind of destroy the other engines in terms of balance. Unless you turned the specific impulse way down or something... at which point the revamped ion is starting to resemble the NERV. Put another way, an in-game version of a real-life ion engine is not going to be well-suited for heavy lift, or landing, or those kind of tasks. You might want to check out the Near Future series of mods - they have several types of electric propulsion motors (VASIMR, etc) with enough thrust to work in "normal" gameplay. The power consumption is correspondingly huge, but the mod also offers gigantic solar panels or (more practically) nuclear reactors to deal with that.

To answer your first question - yes, aerobraking is absolutely a worthwhile way to lower your orbit. It will always take a little bit of fuel to to raise your periapsis back out of the atmosphere, but this is usually much, much smaller than the amount it would take to lower your orbit without aerobraking. However, I'm a bit confused about the "accelerate out of the atmosphere" part. You should NOT need to burn engines while in the atmosphere -- that kinda defeats the purpose of aerobraking, which is to bleed off speed. You will need to do that final burn to finish into the target orbit, but that burn always happens in space. Perhaps the issue is that you're dipping too low in the atmosphere, which is bleeding off more speed than you want, which is making you burn to compensate. That 10m heat shield generates orders of magnitude more drag than smaller parts. I would suggest trying the aerobrake up higher in the atmosphere, and seeing where that gets you. There's also nothing wrong with doing the brake over a couple orbits (and that's sometimes necessary to avoid burning up).

Are you sure you had all the engines on, and in the same mode (jet vs rocket) both times? I can't see your stats on the image, but 8 rapiers seems like it shouldbe enough to accelerate a plane that size pretty well.

You could also look at using a gravity assist from Ike to help with the inclination change. I have not tried this at Duna but it works great in the Jool system.

I find that if you do a big braking burn from LKO, you reenter steeply, but the parts so not get all that hot- because you've already lowered your orbital speed, and if you keep your plane pitched up you should not regain much speed. But a shallow descent usually works too. Where are you reentering from when youget this issue? If coming from somewhere higher than LKO, you mat want to bring your apoapsis down first, such as by making a few aerobraking passes.

It's not quite the same thing, but you could always set your opening altitude for pretty high, but wait to activate them via staging until you know where you're going to land. I.e., stage them earlier if you're coming down over mountains and later if coming down over water. You could also do a similar thing by creating an action group to disarm / arm them.

I'm not sure I'd call it a "launch" engine without running it at high throttle from the start, but that's just a question of semantics. I've done similar stuff with engines that are mediocre to poor at sea level, like the Swivel and Rhino. But I still don't see why the Wolfhound would NOT be just as good (or better) as a sustainer or vacuum engine. Yeah, its thrust may be overkill for smaller spacecraft, but that's true of the Poodle, or any engine for that matter. Just a matter of fitting the right size engine for the right ship (or clustering Wolfhounds for the really big stuff).

I would prefer things to go in the other direction -- more (and more balanced) differentiation from the existing engines. I bought MH largely for new gameplay features. It's a little lackluster in that department, but reducing new engines to just re-skins would only exacerbate that problem. I don't have a great idea on exactly what I'd like to see, but I think it would involve giving each engine a clearer niche. E.g., maybe the Kodiak should be more efficient than the Reliant, but more expensive and higher tech--or vice versa. I guess some of the problem is that these engines were probably designed to work with replicas of the historical rockets, rather than to mesh well with the existing engines. Kind of the same "realism vs. gameplay" argument pervading the Skiff v. Wolfhound discussions. And while the old engines could potentially be tweaked without upsetting any replica business, that might not sit well with non-MH players. Gotta disagree with that last bit. The Wolfhound doesn't have the TWR or atmospheric ISP to work well as a launch engine. I think it's a vacuum engine, just optimized for bigger craft than a Poodle.

If you have Making History, the engine plates make it much easier to work with clustered engines like this. But then of course there's still the lack of good LF-only tanks...