Mun Lander Design

[Nik75]

Hi all, just registered here!

Would like some suggestions on how to design a small Mun lander and return craft.
Is this good or bad design? Any suggestions?

32 tonnes. 52 parts. - It reaches 20 km circular Mun orbit and then lands, does the
science possible, plants flag etc. Then reaches 20 km circular orbit again. Returns
to Kerbin with about 300-400 dV left.

[Majorjim!]

Immediately I can tell you it is too tall. Oh, and welcome to the forum! You will find that a tall lander will be very hard to land upright. Have you landed on Mun yet?

Edited January 13, 2016 by Majorjim

[pTrevTrevs]

I think you may want to replace those jet engines with some SRBs. They should be cheaper, more powerful, and slightly lower the part count. I would also ditch the find on the lander itself, they seem pretty superfluous to me, and they won't do much to stabilize the rocket. If you can, you should replace that giant SAS with a smaller one on the second stage. It will be cheaper, lighter, and stay with you longer.

Hope this helps. 

[Ten Key]

53 minutes ago, Nik75 said:

 Any suggestions?

Yes, as Majorjim already mentioned, that lander is too tall. Low and wide is the way to go.

Visualize it like this: Draw an imaginary line perpendicular to the ground that runs through your landing leg. Then, find your lander's center of mass. Any horizontal velocity you have left at touchdown (and you will have some) is going to want to make your lander tip up on its legs. And landing on anything short of perfectly flat ground will make your lander want to tip. If your lander's center of mass ever crosses that imaginary line, it is going to tip over. A tall, thin lander with a high center of mass only has to tip a few degrees off vertical before it is doomed. Conversely, a short, wide lander with a low center of mass can tip to a ridiculous degree and still be okay. 

https://www.youtube.com/watch?v=vTt1PLVTIAs

Edited January 14, 2016 by Ten Key
Video link doesn't want to embed?

[Raptor9]

On another note, I assume the OP is posting an older screenshot, or not using the current version of KSP.  Judging by the model of the Whiplash turbo-ramjets.

[swjr-swis]

1 hour ago, Raptor9 said:

On another note, I assume the OP is posting an older screenshot, or not using the current version of KSP.  Judging by the model of the Whiplash turbo-ramjets.

It could be the demo.

[selfish_meme]

You should not need any fins at all, if it does, then either you are going too fast through atmosphere, so TWR too high, or you have a very light un-aerodynamic nose. Your using a poodle on your first stage which is a poor rocket for in Atmosphere work, which is probably why you need the jet boosters to conserve fuel and get the TWR up. A mainsail and more fuel would be a better mix.

[Foxster]

Looks good to me. 

You have all the ingredients for a working lander and I like the use of jets to save weight. Sure there are some tweaks that might make it better but I'm sure you'll spot them during your mission. 

About the only thing I would add is some solar panels as you are reliant on that battery lasting the whole mission. 

[Nik75]

Thanks alot for all the feedback!

Yes, I have made a few trips to Mun with that ship. It is quite tall so I have to
find flat places to land or make a few tries. Have a good amount of spare fuel
so if it's not flat enough i just burn a little  .On this one maybe it's the
Science Lab Jr. that makes it look extra tall. It also have solar panels on
the other side of the craft maybe not to easy to see in that screenshot .

I'm using KSP 1.0.4 , have a feeling I will wait a while for 1.0.5. Or is it
safe to update? Is there any new bugs in 1.0.5 that can be annoying?

Anyway, would be really fun if some of you could post some info/screens of
a "as simple and cheap" as possible for a manned Mun landing and return.
Have seen some old examples of rockets, would be interesting to see some
1.0.4 or 1.0.5 Mun rockets!

[Rune]

That looks fine, but a tad... inefficient? I mean, I get the minimalistic approach, and I approve, but with those expensive jets thrown away, you ain't really saving money. I did mostly all my career sciencing using these:

Not exactly 1.05, but close enough. The booster is a SSTO recoverable rocket, and on top of that I get a ~3.4km/s, bottom-heavy, 2.5m diameter lander with science equipment, a seat for the scientist, and a probe. All the rest, minus recovery stuff in the booster, is fuel and/or engines. The only two engines are a Twin-Boar and a a Poodle, so even if I screw everything and burn them both on reentry, the cost ain't that bad... 60k√ to put on the ramp. And Mun is not even the most scientifically productive trip, even tough you can squeeze a couple extra biomes there thanks to the generous dV allowance: go to Minmus, and you can milk that tiny moon dry with just one or two of these!

 

Rune. I hadn't developed the SpaceX-style legs yet.

Edited January 14, 2016 by Rune

[Kerbalmann]

Hi im new as well. Tall lander is just fine for me (1.05 build). I just have to increase the legs to create more landing surface plus some good landing technique that Ive learned from this vid. https://www.youtube.com/watch?v=cmAMGJm-bwU

 

http://imgur.com/RcdWEja

Edited January 15, 2016 by Kerbalmann