r_rolo1

Yeah, pretty much. But with no engines below The RL space shuttle actually used a big one attached to the return veicule, if you recall ... @ Awaras True, ideally you want all of your engines firing up at launch. Otherwise they are simply dead weight ... And BTW are trying to ram any of the Jool moons out of orbit ? That is quite a rocket there

Yeah, the best way to land fuel wise ( in RL, might not apply in the game ) in a body with no atmosphere is to go as vertical as possible and burn at full power as close of the ground as possible, the so called suicide burn ( suicide because you will spat as a pancake if you don't burn at the exact time and you have no margin for corrections. Hence it is not used in RL ) Other thing you might consider is to rework your landing stage. I'm seeing two SAS there, that you probably need for the full rocket but that might not be needed for the lander itself. You also have a LV sitting inert in the second stage that you could put to use if you redistributed your fuel tanks ( meaning one less ton in the landing stage, because you could take one of the third stage LVs out ). You might also consider to use drop tanks ( less mass in the lander = less fuel needed )

That was not a diss , Your attempt is pretty good, and the 3 parts rocket I shown is actually being piloted by a astrophysicist of formation I am pretty sure I could not do it What I was saying about the parts is that you can transform a 6 part rocket in a 3 part rocket by simply taking a rocket with a capsule, a engine and 4 small tanks and trade those 4 tanks for a half big tank: they weight the same drag the same and carry the same amount of fuel. So the least parts challenges lost a little of it's meaning IMHO ...

For some reason NASA and all the space agencies in the world already dropped full manual piloting since ... well, they never did it , to be honest And to add, if anyone here was making it a full auto mission, they would not do it, simply because Mechjeb does not work for interplanetary trips ( italiziced for emphasis ).

By just eyeing the pics, couldn't you maybe change those lateral LVs for aerospikes? That could probably help a little ...

TBH, since the large tanks came out, this kind of "least parts possible" challenges became quite watered down.... Anyway, I think you can that with 3 parts, based on

You mean the LV-909 ? For the orbit and back it might just work ... The issue is to get a TWR of atleast 1 It also has the issue of underperforming in high atmospheric pressures, unlike the aerospike ... P.S On the fuel needed for a kerbin landing ... well, as I stated in a not so clear fashion above, you need around 130 dV to do it ( or in other words, you need enough dV to cancel your terminal velocity ... supposing that you're falling in oblique enough angle to make the aerobraking matter ) + whatever fuel you need to put you in a low enough Pe to get enough atmosphere for braking ( as you can see , I used about 40 dV for that ). That means a surprisingly small ammount of fuel if your ship is light enough and if your engine does not choke in High atm pressures. You can actually do it on RCS only fairly easy if your comp does not choke near kerbin ( like mine does ), but you'll need more than one nozzle for that ( hence making it unfit for this challenge ) and you will have to that manually ( mechJeb RCS management is simply terrible )

They are tricky to attach but I have two tricks that work relatively well: 1) Put landing legs at the side of the tank you want to attach the aerospike. Does not work always. 2) The more complicated one: mount tanks radially from something, check if any of them will attach the aerospike , reduce the symmetry to 1, attach the aerospike to one of the tanks that greened out before, remove that tank+ aerospike and them put it where you want it. @joshblake I think that real deal here is to know how to do maximize your power landing fuel and I even I jumped the boat on this one and started burning a little early ( otherwise the fuel would had been enough ). I already had done a lot of tests on that for other challenges and I know that the terminal speed in Kerbin for most ships is around 130 m/s. Knowing that, the altitude you were going to land ( I landed a little too high for my taste, but I was only testing out ), the TWR at the time and the aerospike thrust and ISP, it is relatively easy to know exactly when to push the burn button ... in my case it was somewhere around 500 m from the surface. My problem was that I mashed the button at the moment I saw a 5 appearing in the mechjeb altimeter first digit and not when I saw 500 , so the fuel ended up when I was 10-20 m from the surface :/ BTW i do not think that the issue is dropping the dry mass but with dropping the dry mass sooner .That is what makes it worthwhile to use half tanks instead of full ones in this kind of drop tanks configurations: you carry dry mass with you less time thus you save some fuel because of that. OFC there is a limit but IMHO in this small ships the dry mass is such a big contributor to your fuel spendings that the extra initial mass of the decouplers is not enough to shade it up.

As I do not like to lie, here is Suicide I <iframe class="imgur-album" width="100%" height="550" frameborder="0" src="http://imgur.com/a/r4Mze/embed"></iframe> Actually the fuel came short in the landing ( last second possible activation of the Mechjeb land button, just because it is faster to throttle up than my fingers mashing the keyboard ), but I was already pretty close of the floor and the ship did not gained enough speed to smash the engine ( I was already " back into the drawing board in how to save alittle more fuel" when the fuel failed, but as it worked ... ) ... I guess that you can create the "Lucky as hell" category for this one *lol* I used Mechjeb ( duh ) and the protractor mod ( that one was mainly out of force of habit, but also to track the dV I was spending in flight ). I do think you can get slightly more effective in the ascent, circularize a little lower and spend less fuel in the return by aiming at a higher Pe and spend a lot of time aerobraking until coming down, but I'm quite skeptic that you can use less fuel tanks ... Do someone wants the craft file? I think that the staging is self evident from the first pic ( 2 opposite half tanks drop each stage until you get to the central stage, that is only a half-tank, the capsule, a aerospike and Mechjeb + protractor. Fuel lines are similar to my Afrodite series ones, that is, asparagus-like ( not asparagus because I only have a central engine though ) ) , but if someone wants it, I'll post it.

I *think* it might be possible to do with with 2,5 tanks, but it might require manual landing (MechJeb does not burn optimally in landings ) and a carefully crafted ascent. Atleast that is what I'll try ( oh and with a diferent kind of of rocket than joshblake )

Nice, but I'll try to beat it Anyway, good thing to have nerves of steel for a powered landing in Kerbin: I've done it to exaustion as training and it is not easy even with Mechjeb if your fuel budget is short.

In that try I made I actually used 3(!) Ike slingshots when coming down to Duna ( actually that was mostly luck in the first encounter, but the other two were planned ) and that probably saved me 50 dV. IMHO that is far from enough ... I think it is possible, but the real caveat is the Kerbin drag at takeoff. I think it is possible to snag out some extra dV if I do the ascent just right ( I am currently not that happy with the +/- 4900 dV I'm spending to get to a 70*70 km orbit ... if I could just reduce it to , say, 4700 ... ). I think it is possible to also tune up the Duna ascent a little and with some luck also get a nice Duna encounter without spending 100 dV correcting to get there after leaving Kerbin SoI. But I'm pretty sure it will be a "on fumes" trip even if it works On Gilly ... problematic as well, because you would need to get to Gilly and circularize it to be able to to a EVA landing, and you can't rely on a atmosphere to slow you down. With some luck, you might get a slingshot from Eve, but I wonder how much dV you would need to circularize after that ...

I do remember the time they worked backwards

The small parachute in Duna will slow down a capsule enough for a capsule only landing. I've already done it ( I agree that it got a pretty rough landing but it landed OK ). The trick is to get to Duna in a almost horizontal trajectory, to maximize the amount of atmosphere your parachute will get in the way . That is far different from what you can do in Kerbin , where the parachutes will work fine in almost all angles of aproach ...

Your parachutes broke due to the excessive speed relative to the ground. It will happen the same in Kerbin , btw . Next time try to aproach the Duna atmosphere almost horizontally ( that is, with a below 13 km Pe ) and wait until the ship gets to atleast 400 m/s before deploying the chutes

You could minimize the danger of a hill landing if you turn the window towards the planet and do a horizontal burn until it kill your horizontal speed when you spot a big flat area. Then you will drop like a rock and then it is time to give the radar altimeter some use

Freudian slip much ? Anyway, atleast the IVA has a radar altimeter, so landings are surely feasible. The rest ... well the interplanetary burns would need a ridiculously precise stopwatch and that needs a insane sidework to calculate the burn times. I think you could probably at best get to Jool SoI ...

I also got to Duna and Laythe with my Afrodite IV ( I have done it wednesday, but was too tired to post ) ... ( sorry for the Laythe first pic but I got a case of invisible water P.S I also have a slight modified version of Afrodite IV in the Duna case ... I just added two extra parachutes. I wanted to see if I could send this back from Duna, so I needed to save a parachute to the eventual Kerbin return ... unfortunately the ship came short in terms of fuel :/ ) As you can see in my Duna landing pic, I had enough fuel to do a return trip if I wanted to if I had not landed ... On the Duna landing and return ... it is tricky. The best engine for this challenge, the aerospike, can launch about 10 tanks of the 400 l fuel variety from Kerbin surface. That would be sufficient with ease if: a) We had no Atmosphere in Kerbin and Duna launches ( and still have it for the returns ) We didn't had to correct a lot to get into Duna SoI. The biggest issue is the Kerbin atmosphere at launch, since it will eat you more than 2200 dV even if you do as much of a perfect ascent as possible. You will lose also around 150 dV to Duna atmosphere when you get out of there, no matter what. And even if we spend extra 150 dV correcting to Duna and Kerbin SoI after launches ( that , besides being both small, also has the issue of the Duna orbit not being perfectly circular and plane aligned with the Kerbin one ), a very conservative estimate, that makes for at best a very tight fit on the dV 10 tanks and a aerospike can give. I've tried two days ago a 9 1/2 tank version and it came short for about 200 dV ( it lacked 80 dV to get a Pe in the Kerbin orbit in the return from Duna )

I made that experiment ( it was Afrodite VII IIRC ) and it actually was slightly worse than Afrodite IX ( not by much but it got to the parking orbit with less +/- 10 L of fuel ) . The fact that you are dropping unneeded dry mass earlier makes up for the extra initial mass pretty soon ... if you used the 4 400 L tanks you would have to drag the dry mass of two of those tanks until you could ditch them due to symmetry reasons, unlike in the 8*200 L design where you drop the equivalent of a 1 400 L tank dry mass out per stage .

I tend to try to make the less weight possible rocket for what I want to achieve. Besides that, I tend to do bizantine fuel line arrangements for some reason

Thanks for the compliment I must say that I left some details out of the reports that actually make a difference ( well, seasoned pilots will get there without my assistance, though ... ), especially on the Laythe trip. First of all , the orbit I always strived to get around Kerbin while waiting for the interplanetary burn was always the closest of 70*70 km as possible, both to use the less fuel possible to get into orbit and to maximize the gains from the Oberth effect. Second, the corrections to the planetary approach should be done the earliest possible except for the plane alignment, that obviously should be done when your orbit plane and the target planet one cross ), in spite of the fact that the current game UI makes that hard as hell. Earlier corrections = less fuel used. Third, you must strive for a Jool equatorial approach in the Laythe case, because that maximizes the chances of getting a Laythe encounter without having to spend a lot of fuel in corrections searching for it ... And, obviously , get your conics draw limit high enough to actually see the details of the encounters and the exit orbit planes better ( I have it on 7 (!) ). That is pretty useful in Laythe case because Jool equatorial plane is pretty close of his orbital one and the Laythe orbit is also pretty close of the Jool equatorial plane. SO, if your Jool approach orbit and the post Jool orbit are in the same plane, your Jool SoI part of the orbit will be pretty close of the Jool moons one ( except Bop ), a thing that maximizes the number and the length of the encounters with them .

Well, I can give a practical example: my Afrodite line. There is absolutely no way that putting up a nuclear engine in there would make any of those ships to work better than the LV 3 of them have. And note, this is not a matter of artificial restriction or not. I was just stating that IMHO the LV-909 wasn't obsolete because there was still a niche for it that the nuke engine couldn't handle well ( or at all ) due to the weight. In other words , there is a lower limit on rocket size for the usefulness of the nuke engine. It might be low enough to not matter much at this point, though ...

Well, true and all, but you are forgetting that I'm talking of putting a small rocket up there with the nuke engine as part of the "payload" ( like in a interplanetary burn stage ). In those circumstances you can't only count with total dV , but also with the simple fact that your TWR at launch must be enough to leave the ground. You can definitely get more dV out of a nuke engine than of a LV-909 with the same fuel tank, but that comes at the cost of putting a extra 1.75 t in the rocket ( supposing all else equal ). If you're talking about a 20 t rocket that is a significant difference, especially if the TWR at launch with the LV-909 was already low ( as it should be in such a small rocket ). In those conditions you would have to increase the TWR to use the nuke engine in that design, a thing that means surely more engines and more fuel ... or simply use the LV 909 in spite of not being as dV efficient.

Actually , the nuke engine does not make the Lv-909 obsolete ( about the poodle ... it was always too weak as a alternative, even in .16 ). The nuke engine is surely a good engine, but it has the big con of being quite heavy compared with the rest of the 1m engines or even compared with the standard 1m fuel tank + 1m capsule weight. If you're trying to make a small rocket ,that can be enough of a reason to use the Lv-909 instead... If you just want to go to Jool, you can go on liquids only.

Actually, I want to be in the Mun landing category for Afrodite IV ...I made some Mun and Minmus landings and back with it before the Eve burn window opened for testing proposes: And actually I'm sure that this ship can go to Laythe and Duna and land safely there. Might try it today ... P.S I can definitely do the no parachute version