Anyone have some good tips for building a Mun landing module?

[The Joker]

Yeah. Looking to expand on my landing design.

[Nibb31]

Make it low and wide for stability. Make it light so that it lands with just enough fuel to get you home. Don't forget a ladder.

I suggest using the "crasher stage" concept, which is probably the most efficient method and was planned to be used by the Russians. Basically, you burn off most of your speed with the large upper stage of your rocket, that you jettison just before the final descent, so that your spacecraft lands with its tanks practically full.

Edited September 6, 2012 by Nibb31

[The Joker]

That's great, actually. Also, do you have any tips for building a (stock) rover?

[KAO]

Make it low and wide for stability. Make it light so that it lands with just enough fuel to get you home. Don't forget a ladder.

I suggest using the "crasher stage" concept, which is probably the most efficient method and was planned to be used by the Russians. Basically, you burn off most of your speed with the large upper stage of your rocket, that you jettison just before the final descent, so that your spacecraft lands with its tanks practically full.

if you get the Kosmos packs you can recreate all of that pretty well actually

[j516mt]

I've been experimenting with different lander designs recently and I think this is my favorite so far.

It's pretty damn heavy, but now that I've got a ship that'll get it to Mun or Minimus, I love it.

The main part of the lander actually functions to finalize the transfer into Mun or Minumus orbit, retroburn, and land. There's usually a bit of fuel left over, but not enough to get back to Kerbin, and probably not enough to get into orbit around the Mun.

Usually what I do when it's time to leave is disable fuel flow to the lower section, begin the burn for the ascent module and decouple. You could also probably use the lower section to begin your return and just break off when it runs out of fuel, though I personally like leaving part of the ship behind.

[spikeyhat09]

always use the telescoping legs. they extend further, and won't snap off as easily. also use three landing legs. they will sit flat on any surface. there's a reason they make "tripods" and not "quadpods". If you're using the smaller capsule, try to make it as light as possible, and have more than 1/2 a tank of fuel left to return home (depending on the engine.

try to make use of the tiny engine (not the white radial ones, those are terrible). they are the most efficient in a vacuum (with an impulse of 400!). they're fairly useless on kerbin, but in space and on the moon they save a lot of fuel. if your using the three man lander, use the bigger version of that engine.

[MaxMurder]

I always put 4 legs on my landers as 3 tends to be too unstable. They say a tripod is the most stable structure... id like them to say that after my lander touched down with 1ms horizontal velocity then immediately tips over and breaks in half.

[spikeyhat09]

I always put 4 legs on my landers as 3 tends to be too unstable. They say a tripod is the most stable structure... id like them to say that after my lander touched down with 1ms horizontal velocity then immediately tips over and breaks in half.

perhaps you landed on the side of a hill

[maltesh]

I usually go with three-footed landers, but I tend to spread the legs very widely.

Probably could have raised the legs a bit higher on that one, for even more stability.

[EndlessWaves]

I always put 4 legs on my landers as 3 tends to be too unstable. They say a tripod is the most stable structure... id like them to say that after my lander touched down with 1ms horizontal velocity then immediately tips over and breaks in half.

It depends on the type of stability required. Three is good for preventing rocking but a circle would seem better for mostly flat surfaces that are tilted.

[softweir]

Three won't rock, but a tripod can be pretty easy to tip over unless it is very widely spaced. Also, three legs have absolutely no redundancy in the case of a leg failing!

Five legs are vastly less likely to tip over, and can remain stable even if one fails. This is why swivel-chairs these days have five legs - it's just that bit safer.

NASA wanted to put five legs on the moon landers, but had to compromise with four due to weight considerations.

[ElJugador]

@softweir

But you should know we don't have a 5x symmetry option. AND there's no place to manually put such an amount without defeating the purpose of having five legs.

[Vanamonde]

I've tried a lot of layouts, but I keep coming back to this one.

By putting the fuel tanks to the side of the core, you keep the height down while also providing wide mounting points for the legs, and as others have noted, that leaves you more stable on uneven ground. Then the problem is that anything you put on one side needs to be balanced, so which symmetry to use? Both bilateral and trilateral symmetries will tend to wobble around one or both of the vertical axes while you're manuvering, so quadrilateral is the most stable. And putting the ASAS and RCS tank below the final stage means they aren't competing for space with the parachutes.

[nhnifong]

But c'mon that's boring. Build the largest, most extravagant pile of folding gadgets you can bolt together and land that sucker at the capital of the Mun!

[softweir]

Indeed, and I am well aware of that. I should have made it plain I was talking generally, not making suggestions for KSP landers! What I forgot to say (because I started considering making a suggestion that 5x symmetry be added as an option) was that 6 legs is as close to 5 as we can get.

[plumsink]

The problem with landing legs is that they are great for absorbing vertical impact and bite at absorbing horizontal impact. Of course careful landing can mitigate that some, but I have had some of those smaller legs snap off even in gentle landings. Also it can be a challenge to have your base wide enough. I counteract that by putting the telescoping legs on the most sharply inclined type of wing.

(This is my kethane rover.) The wings weigh very little, and this directs the strength of the legs outwards. As someone also said, it helps to keep your center of balance low. Also, I usually don't go for the weaker landing engines because I like to play chicken with the Munar surface. That allows you to waste less fuel killing velocity at higher altitudes. Larger engines weigh more, but it is weight well spent. Also as someone said, the radial engines that you tack onto the sides of your spacecraft are just about the least efficient you can use.