:( Can't land on Mun

[MagnesiumDew]

This isn't a technical issue but I can't seem to land on the Mun. As in, I always run out of fuel . "TAKE MOAR FUEL" you all shout; but that just makes the ship heavier and therefore more fuel is needed- and then we end up with more fuel tanks and... you get the idea. Whats the best way to get to the Mun?

[SoldierHair]

Keep it simple , keep it light.

[DisarmingBaton5]

A good Minmus lander (and by "good" I mean OP) should be ok for a Mun landing, and by your signature, I see you have gone to Minmus. That's what I did for my first successful landing, even if I had to use RCS to get back. Also, it may help to see pics of your launch vehicle and lander.

EDIT: ninja'd!

[Scotius]

You can try what i did on my early landers: Asparagus staging . Just add 2 or 4 smaller droppable tanks, get rid of the dead weight as soon as they are empty and you should arrive in Mun orbit with full main tank. Also, dV map and Engineer Redux help to tailor your design for the mission.

[Mediosthenes]

Basically, you're describing the main problem with the rocket equation: your ability to get to places is determined by the percentage of your rocket, by mass, that MUST be fuel. Most rockets are by necessity more than 80% fuel, and less than 20% rocket. There are some ways to help keep this slightly reasonable, though, especially in KSP, because of the inaccuracy of its physics modeling. Due to how drag is calculated in KSP, the most efficient design is asparagus staging, which is where you have every rocket engine start at the same time, and have a double spiral of fuel tanks, attaching two tanks to the center, and two more tanks attached to those, and so on, with fuel pipes transfering fuel from the outermost two tanks in to the next two in, and so on. After the outer tanks empty, jettison them, and then wait for the next two to empty. Also, if your rocket has trouble lifting off due to the amount of tanks, use solid rocket boosters to help it gain the first few kilometers of height. Mainsail engines provide a lot of thrust relative to wait, allowing them to lift a lot of fuel up, but are not very efficient, so have smaller engines in the center stages, because you only need massive amounts of thrust when you are in low atmosphere, and the big engines will have drained most of your fuel by the time you get into Kerbin orbit. Although more fuel is required by the math, the main skill in the game is figuring out ways to use that fuel more efficiently.

Another thing that helps is burning for the Mun at your periapsis, because burning effects the opposite side of your orbit, which would in this case already be closer to where you want to go.

If you arrive at the Mun with enough fuel, but run out because of the difficulties of doing a soft landing, keep in mind that until about 5km, your main concern is not how fast you are falling, but how fast you are going sideways. First eliminate most of your horizontal movement, and only then worry about how fast the ground is coming. Good landing legs can take about 3-6 m/s of landing speed, but going back up can quickly add up in fuel usage, so keep a close eye on the vertical speed gauge near the altitude meter, and avoid hovering.

Most importantly, don't give up. Experiment with what designs works best, and you should eventually get it! Rockets take practice.

[HockeyToad28]

If you try to bring more fuel and it just makes your ship heavier, I would say look into trying to design new concepts for ships. My most basic ship that can get me to the Mun and back and to Minmus and back involves a heavy launcher to do the main lifting, followed by a middle stage that finishes the orbit and does the burn to get me where I need to be, and the last stage is a lander with two fuel tanks, an engine, and lander legs which can get me back to Kerbin.

[rodion_herrera]

My guess is you're doing a direct ascent, meaning you want your entire vehicle to land on the Mun and then lift off and go back to Kerbin. That will indeed cost you a lot of fuel, and a huge vehicle is much more difficult to land. Try learning how to dock and redock and so you can create a rocket with a detachable lander, and let the lander descend to the surface, and not your entire rocket.

[CalculusWarrior]

While adding MOAR FUEL does indeed make your ship heavier, that's generally not a problem of your engine is powerful enough to counteract the Mun's gravity. What engine are you using, and how much fuel are you carrying? Screenshots would really help. Another reason might be that your descent is inefficient, are you coming to a complete stop at any time above the Mun's surface?

[Flixxbeatz]

This isn't a technical issue but I can't seem to land on the Mun. As in, I always run out of fuel . "TAKE MOAR FUEL" you all shout; but that just makes the ship heavier and therefore more fuel is needed- and then we end up with more fuel tanks and... you get the idea. Whats the best way to get to the Mun?

Don't go for the "MOAR FUEL" approach, since you're just making your lander (and consequently, your lifter) to get heavier and heavier, to the point that your rocket won't be able to lift the lander at all to orbit. Instead, cut down some fuel tanks, stick some docking ports, and do some refuelling missions to top your lander up. Yes it's tedious (time-consuming), but effective.

to have an idea of what you need to do.

Also, some screenies of your lander would be helpful.

[Godot]

Well, aside from more fuel (as percentage of total mass), you can also go for more Isp ... sometimes using the available fuel more efficiently is the best way

[MagnesiumDew]

Kk thanks guys. Ill use asparagus staging to help.

[MagnesiumDew]

That was my original rocket

[MagnesiumDew]

Unfortunately my badge says I landed on Minimus. The black line in the centre means that I lost a Kerbal. Or in my case 3 Kerbals (RIP Bob, Bill and that other one)

That is to say, I landed on Minimus, but with more force than was ideal. So really, bits of my spacecraft probably landed after the explosion (ran out of fuel and couldn't slow my descent )

[Flixxbeatz]

Try not to use tricouplers if possible (but if that same design landed you to Minmus, then for sure you can do it on the Mun). As for the lander, use the smallest 1.25m engine for efficiency and manageable thrust output. Also add an extra stage between the lifter and the lander, which will serve as a buffer. You better want to have much extra fuel for the job than running out in-between.

[Uberick]

In regards to the above ship:

I would change the engine to a 909, and increase the amount of fuel to a 360l tank(especially if you want to get home with it). As it stands, that vehicle has about 1600 d/v. As such, if you want it to do a transfer, landing, reorbit and return you're going to be short of fuel. (That, all told, takes around 2000 including a margin of error)

If you change the engine to a 909, you increase to 2200 d/v, and you will also get much more throttle responsiveness. If you upgrade the fuel tank to a 360l one, you go up to more than 3100 d/v, about double before with just a few small configuration changes. That is plenty of D/v to get there, land, and get back without giving yourself a heart attack every time a mistake costs some D/v.

Here is a picture of the altered vehicle:

To do that, all we're gonna do is toss a couple boosters under it.

Effectively, put a decoupler under your 909, then put three 360l tanks with an LV-45 at the end. Then, put four radial decouplers with two 360l tanks each, and put Lv-30s on the bottom of those(we only need one thrust vectoring engine, and the 30s have better thrust and less weight.) After you've done that, go put four struts from the tank immediately below the 909 decoupler, to the tank above the 909 decoupler.

Like so

Finally, put four fuel lines from the bottom of the outside tanks to the bottom of the inside tank.(If you do it from the top tanks, it will unbalance the craft)

After that, you're all good to go. I managed to get it into LKO and circularized with 700 d/v still left in the launcher, so this will have TONs of dv left over after coming back from the moon

Have fun!

[Flixxbeatz]

In regards to the above ship:

I would change the engine to a 909, and increase the amount of fuel to a 360l tank(especially if you want to get home with it). As it stands, that vehicle has about 1600 d/v. As such, if you want it to do a transfer, landing, reorbit and return you're going to be short of fuel. (That, all told, takes around 2000 including a margin of error)

If you change the engine to a 909, you increase to 2200 d/v, and you will also get much more throttle responsiveness. If you upgrade the fuel tank to a 360l one, you go up to more than 3100 d/v, about double before with just a few small configuration changes. That is plenty of D/v to get there, land, and get back without giving yourself a heart attack every time a mistake costs some D/v.

-snip-

About the lander, there's another problem: it's too tall than it's wide, which means high chance of tipping. Since you're using the biggest landing legs anyway, you could just move them abit higher until the engine is just a few meters from the ground (take advantage of its small size). Nice revision anyway

[Uberick]

About the lander, there's another problem: it's too tall than it's wide, which means high chance of tipping. Since you're using the biggest landing legs anyway, you could just move them abit higher until the engine is just a few meters from the ground (take advantage of its small size). Nice revision anyway

Good call, I hadn't thought to change that around at all! Move them up until they just give you ground clearance enough so that the engine won't hit the ground when landing.

If you find you have a problem with tipping, you can use stuff to increase the base of support your landing gear provide. I find that the structural wings, for some reason, make your landing legs more resistant to high speed impacts without popping off. (also, they give you enough clearance to fit a nuclear engine, which is why I actually started using them)

Downside is that on a vessel this small it costs you a bit of delta V(but this'll still have tons anyways)

[Motokid600]

Use the nuke engines for landing. They just do not run out of fuel. I have a larger skipper engine that I use for navigating munar orbit. That engine deorbits my craft then I use it to kill my horizontal speed down to 0. Jet the stage then float down on nukes. I build OP craft. I design them with every major d/v burn ill have to make. Usually its the last of my ascent stage that puts me on my way to the mun. I ultimately land with overkill amounts of fuel. Which is great... I drop the tanks and use the winch mod to siphonn the fuel out for my jump craft.

[MagnesiumDew]

Thanks for the help guys. I finally got to the Mun last night

^Happy Jebediah on the moon^

[Flixxbeatz]

Congratulations! Now it's time to conquer Minmus