r_rolo1

@ Apotheosist What is your TWR at liftoff? And could you also provide a save of the ship? I am pretty sure you can shave some fuel load out of that with the same performance by using smaller tanks and jetissoning them as they get empty ...

With 12 fuel tanks it is definitely possible to do a fly-by and back . Well, on the rocket, it is a nice one ( good call on the canards as supports for the legs ) but I'm reticent on the use of the nuke engine on a such small ship, since it is probably between 1/3 and 1/4 of the mass of the landing stage ( I'm eye balling it via screenshot ). I wonder if replacing it for a small LV or a aerospike would not increase performance ...

I like the design, but I definitely dislike those 3 big engines in the 3rd stage ... don't get me wrong, but they are just ( very heavy ) payload until you jettison out the first two stages ... that could definitely be optimized. You could also probably gain some efficiency replacing the LVs in the 4th stage for aerospikes ( +/- same weight, more thrust and better fuel efficiency ( same for the 1st stage small LVs... with the add that aerospikes work better in dense atmospheres than LVs ). But the general staging is quite ok and it shows quite a bunch of work On the video ... well you lost a LOT of fuel by going straight up to the 200 km. Injection burns, as a matter of principle , should always be done in the lowest orbit possible, due to the Oberth effect ( I know that controlling a mammoth of that size in the atmosphere is hard, but starting to turn at 10-15 km would had saved you a lot of fuel ). And your landing on the Mun, as you say yourself , was far from optimal Anyway, you landed in one piece and that is all it counts

That is what I did I only got mechjeb after flying dozens of Munar landings ( I basically pinpointed a crater in the limit of the visible from Kerbin area and landed there mission after mission until i could land safely in a place within 100ish m of the intended target ) and after some serious training in powered kerbin landings ( that are quite a challenge if your computer gives you 6 fps at best in kerbin surface ). That said ... I do think that, being this a space program game, the automated missions should be the norm , simply because that is what happened ( and happens ) in RL, and with good reasons. Even V2 was automated ( within the limits of the 1940s tech ) and the first human astro/cosmonauts were pretty much excess weight in automated ICBM ( OFC you would want to have the best human possible in there if you decide to actually put one , just in case the automated devices go berserk ). More, and even if we discount the fully automated missions ( that are by itself a big majority ), all of the missions involving humans since Gemini and Soyuz have a big degree of automation atleast on takeoff. So, I'm pretty much expecting to see more and more automation inserted in the game as the game approaches beta stage. I would even say that .17, with the need of bigger precision for the interplanetary burns than the one needed to go anywhere that currently exists in the game will only make the need more automation more visible ... not necessarily MechJeb autopilot style ( that are clearly the less performant parts of the mod , btw ) though.

Eagerly waiting for the craft files Just a question ... how do they hold in terms of autonomy ? Amusing, OFC, no debug RCS

Have you tried to use the EVA RCS to try to put the ship straight ?

I had to do some slight modifications to the ship, but I managed to solve your issue. See it here. I also changed some of the staging ( just to make it more compact ) and of the fuel lines in the lower stages to increase the efficiency BTW, and as a opinion, the ship has clearly the dV needed for a trip to Eve or duna ( I tried to burn to the supposed Eve orbit and and it ended with almost a full tank big tank of fuel left ), but I do not understand why you are ejecting the four lateral engines out at that time ... IMHO you should do that after jettisoning the lateral upper tanks ( that would need other fuel line work, though )

The game does not like fuel line systems that come from the center to the outside, and then back to the center. That is your issue and it can be prevented using other fuel line arrangement ...

@ Thobewill10 Cool, another Eve project contributor I see that you got some good ideas out of there and of Scott Manley, but the 8 engines in the outside are a cool idea. BTW I tried a home made version of your Gemstone II ( with the fuel bug fix , mind that ) and the ship alone would be enough to go to Eve with a half FL-T400 tank to burn. And to be honest I don't think you need a much bigger rocket than my Eve I for this Your massive rocket could get some cuts

May I ask you why your calculator assumes that you are doing a clockwise orbit for a burn to get to the interior bodies, instead of the much more natural ( atleast from a Kerbin launch ) anti-clockwise one ? I assume that from a purely injection burn PoV it is more effective that way, but given the extra fuel costs to launch for a clockwise Kerbin orbit, choosing between a clockwise and a anti-clockwise starting orbit should probably be a option

Well, I do not know the best places to burn I am pretty much eyeballing the issue here , but there are some guides in the "How to" area to get more precise answers ( like here and here ). The basics is quite simple: you want to burn in the lowest orbit possible ( makes the burn more efficient ) and, in the case of wanting to go to interior planets, you want to burn to the inside side of the planet in a way that your trajectory inside the body SoI is hyperbolic ( duh ) and the closest possible to a antiparallel from the orbit the body you're leaving is doing around the center of the system. If you want to train that kind on manouvers you can just do it from the Mun to return to a arbitrary Kerbin orbit ...

I told you didn't needed the legs Well, on Eve this is , as far as I know, the last input from the devs ( correct me if wrong ): I've been developing my Eve going rockets based on this intel.

Yup, that video. I hadn't noticed you had not posted it already in here

All I can remember from heart is that you need +/- 840 m/s of dV to do a munar injection from a 100*100 km orbit and that you need +/- 1300 dV from a 70*70 orbit to get a Kerbol orbit Pe consistent with the Eve orbit Nova posted in page 1 if you burn near the right place ( that is, +/- 40º from the daylight line into the sunny side ). So I assume that a rocket with 2200+ dV can deliver something to Eve... that means that in theory a rocket that can do the munar injection twice will be enough for Eve ( that is, liftoff, munar injection (, circularize around the mun? ), burn to Kerbin (, circularize ? ) and do a munar injection again ) ... it might be even a little too much, but as you need some extra fuel to do corrections ( and to put the ship in Eve orbit ? ) it probably fits well enough On Scott Manley ... well, I steal ( er... borrow, I mean ) a lot of him for a long time and he actually seems to have seen some of my designs, given his new heavy lander design ( or atleast has got there independently ). Even today I gave him a suggestion on a fuel lines issue he had

I took some interest in your fuel lines drainage issue in the last video and, in the interest of science, decided to give you a hand Unfortunately, due to what I already hinted you in the youtube comments ( rrolo1 there , in the slim chance you haven't noticed already ), it is pretty much impossible to get what you want in terms of fuel flow with the ship you have there. I have devised 2 solutions, working in a barebone structure of the stages that were giving you issues ( both are bolted to the ground for testing proposes in the saves ): Solution 1 ( named 3 in zip file ): It is the least radical one. I noticed that it would be indifferent stage wise ( well, almost ) to switch between the bottom tank and the two lateral ones in terms of rocket performance, so I did exactly that. I also put the fuel lines to the engine coming from the upper decoupler, but you could probaly do that from the central tank and save a fuel line ... Solution 2 ( solution 2 in zip file ): Instead of using the bottom tank, I divided it in 2 and putted them in the side. As you can see in the staging, the lateral tanks are grouped in 2 groups of two and they are connected and staged in "aspargus" fashion. To be honest, I like the design, but, besides not being really equal to yours ( thus, with possible problems in terms of center of mass and space impediments in the real rocket ), this type of design needs more struts ( I haven't put any, but you would most likely need atleast 4 ) and, due to the small struting provided by the fuel lines added to the non-radial symmetry of the fuel lines display, it tends to rotate and being less stable in general. I know this will not save your kerbals that are in the iminence of trying to land a borked lander with a erroneous fuel line work and a Kraken eaten MechJeb but hopefully it will help you in .17 or even before. Zip with both saves here . Oh, and fly safe

I definitely like your leaner lander ... aerospikes really are the best engine in game ( most likely they will get the nerf hammer sooner or later though ) and you can even engineer the delivery rocket in a way that allows those aerospikes to do lifting work since takeoff, making things more efficient. BTW you could probably be more liberal with the landing legs in terms of touchdown speed ... to be honest, you don't even need landing legs if you use the MechJeb "land" button and if the land below is not too tilted, but even if you use the legs, they can hold a little more that 1 m/s . I routinely do 3 m/s landings in Kerbin and I've done some science long ago about the legs and even the smaller ones can withstand up to 16 m/s if the impact is pretty in the normal direction ( to reference that impact speed is enough to detach capsules from fuel tanks attached to those same legs ... without breaking the legs ). BTW I'm 100% sure you can even make a Eve lander that does not need burns to land ( since I already made Kerbin ones in pre .16 ) if you use enough chutes and time their opening right ...

The Crossbow is a cool design, but those 27 mass units of rocket engines sitting in stage 6 make me cringe I'll probably do some kind of work like I did in Eve I to cut them out.... Other thing you might consider is to use the smaller 1m LVs instead of those you have. I do not recall the Murs g , but even on kerbin 3 of those + the aerospike would be more than enough to take off.

@Apotheosist I think he means that the first stage has to carry a lot of empty fuel tanks for a lot of time and that you could probably optimize that with ease. And your lander is nice. I would probably replace the 2 big chutes for 4 small ones ( for balance reasons ) and would find a way of not having those SRBs ( I really don't like SRBs ) but I like the design.

First of all, some questions: a) Your orbit was circular ? Did you used "land" or land on target" ? For the first, mechjeb assumes a lot of stuff regarding your orbit and , in case of the landing algos, it assume that you're either using a circular orbit or that you are using one that crosses the body surface. If you are not in neither of them, it will do wacky stuff. For the second, if you used, "land on target" with the target being on the other side of the world at the time it is expected you will land without intervention or at Pe, Mechjeb will try to do a bi-elliptical or atleast to circularize ....

Well as the youtube comments are quite short, better to do it here You could probably do it with more/bigger parachutes. Your lander is way too heavy for those 3 small ones you used resulting in them snapping explosively ( you know, this is KSP, where everything is made out of TNT and structurally fails via explosions ) when opening, taking out your ship as well. If you had added more parachutes ( by eyeballing I would say 5 big ones would do the trick for your lander in Kerbin ), even if the capsule would roll out, after the opening of the chutes you would have time to use the capsule SAS to turn it ( or even the "land" command of the mechjeb landing window ). Not saying that part editing is not OK, especially in a case like this, though.... BTW, waiting for your new lander. I agree that the one you have there has margin for improvement

Well, I tried to make a video of me operating the Eve I, but it ended in a 1 fps slideshow that was barely watch able. SO, I ended giving some written explanations and some pics in the dedicated thread + a refined version ( basically some stage rearrangement and more parachutes ). See it here

Ok, as there were some issues with the staging and the number of parachutes, I decided to make a slightly refined version of this called Eve I a. You can find it in the opening post, both in stock and MechJeb versions. And as there were some doubts about the flight plan and staging, I guess, I will just explain it a little ... First of all staging. Before all, it might be useful to point out that stages 0-3 are the ones that constitute the lander ( except for the engines , that fire all at start except for one ), while stages 4-8 ( in the revised version ) are the ones used to put the ship in orbit and to make the interplanetary injection burn. Anyway from bottom up: - stage 8 fires all engines except the smaller LV - stage 7 drops the solid boosters out. The fuel in it should be half spent in the time the SRB light out - the next 3 stages drop the outer tanks, starting by the lowest ones and then climbing. Activate the next as soon as the fuel dries out - stage 3 separates the central big tanks and 3 of the aerospike engines out also firing the small LV. In other words it separates the lander out. It is recommended that you do this with the engines out, but it is not such a big deal. - stage two are the parachutes. In the revised version I increased their number to 6, due to some cases of parachute breakup . - stage 1 separates the tanks that have the lander legs. thus it should not be activated before landing. - stage 0 separates the lateral tanks and the aerospike engines. Now on flight plan ... well, due to the absolute need of using Mechjeb in my comp to launch this ( I tried to record a video to put here and ended with a 1 fps mess until it got out of the atmosphere ... ), I used the regular flight plan of mechjeb with the max altitude set on 72 km. This is by far not optimal, but at this point I can not be bothered to refine it. Then i circularized the orbit at 70 or 71 km. As the rest for the push to Eve "orbit" is already posted, I'll just add something for the lander tester. I normally start in a 70*70 km Kerbin orbit and then burn to lower the Pe to 30 km ( it could easily be less , but I play safe in kerbin landings ). Then I either put the Mechjeb in retrograde or do the the retrograde positioning manually until you hit +/- 22 km, where you can deploy the chutes. Then you can take the mechjeb or the SAS out, because the chutes will keep the ship aligned ... and will open at little more than 400 m above ground. At that time you should deploy the legs and prepare to burn a little to decrease the velocity to 3 m/s or less on impact ( you can let that to mechjeb "Land" command in the Landing window if your comp lags badly like mine ). By this time you should have a almost full ship, so it is time to fly again Put the ship in full throttle and activate stages 1 and 0 as soon as the tanks get dry in the bottom stage. I used again the same flight plan for mechjeb ( i know, lazy ). The lander needs to be kept at low throttle ( the good ol' Goddard problem ), so there are certainly issues with the fuel bug ... so I reserve the right of putting more fuel in the lander stages. If this explanation is not enough, see pics here ( P.S : start from the bottom )

Oh, I see ... the issue you have with stage 3 is because I forgot to say that is preferably done with the engines off :/ That stage is pretty much only a separation stage of the lander. Then you can burn or activate stage 2 ( the chutes ) , or both. Then on liftoff, you activate 1 when you depleted the small tanks and 0 when you depleted the aerospike connected tanks. Anyway, I will try to do a video on this ( if my comp does not melt ). A image is worth a 1000 words don't they say ?

I'm facing the same difficulties ... the game really does not like complex fuel line systems, especially ones that go from the center and come back. This will need some extra engineering...

Even then it is most likely too much ( I assume this is a Mars analogue lander, right ? ) I have serious doubts about the ability of those tanks that have the chutes to stay attached to the ship as it is now ... IMHO the ship needs far more struting. Oh and how about replacing those fixed stairs by adding another extendible ladder ( check the weights ) ? BTW, and for my own convenience for my delivery rocket, I worked up the lander staging and fuel lines a little... The ship lost in stability ( due to the small strutting force of the fuel lines, my non radially symmetric fuel line placement tends to make the ship spin ), but it gained in efficiency ( in my tests it made to a Kerbin 70*70 km orbit with 30% more fuel than your lander while using the same flight plan ). If you want to use it get it here ... @cardgame Other alternative is to use those engines in the launch ( thus, they are not simply payload ). That is what I intend to do.