Moho lander designs?

[ammonia_ocean]

Hi, guys! This is kind of a lame question, but even though I've been playing KSP for almost a year now, I've never actually gone to Moho. I'm making a giant overengineered Apollo-style mission to rectify that, but before I start, I want to make sure that the lander (planned to be an extremely minimal design with one Mk1 Lander-Can and no more science than 2 goo canisters) works well. Basically, how much more powerful should it be than a Mün one? What fuel tank sizes and engines have worked best for you? Have you been successful with multiple stages?

(Also, I'm not using LV-Ns. My long-term mission is to land and recover something from every body in the system with chemical engines only.)

Edited January 18, 2014 by ammonia_ocean

[Captain Sierra]

A standard Mun lander will work on Moho. Landing is not hard. It's getting there that demands an over-engineered hundred ton drive stage.

EDIT: No LV-Ns? Make it a 200 ton drive stage.

[Guest]

Rough guess, you'll want about twice the fuel of a Mun lander and about half again the TWR. That might be a bit overkill, but it'll do the job.

[ammonia_ocean]

200t drive stage? Check.

Okay, great, thanks. I'll just mess around with one of my minimalist lander designs and go from there.

[Captain Sierra]

200t drive stage? Check.

Okay, great, thanks. I'll just mess around with one of my minimalist lander designs and go from there.

In all seriousness though, you're going to start hitting the point of diminishing returns for chemical rockets going to places like Eeloo and Moho. I can make Jool work on chemical, but only one way unless I can refuel on site (which I usually do).

[ammonia_ocean]

Okay, I'll keep that in mind. I did do an Eeloo mission, but with nuclear engines only, so this is a total first for me. If I can't return I may as well use what science I get from the mission to research nuclear engines, then build a more logical rescue craft in true KSP tradition.

[maccollo]

Going to Moho is actually the about the same as going to Eeloo in terms of delta V requirements, providing that you do it the right way.

http://forum.kerbalspaceprogram.com/threads/61478-Oh-bugger-Injection-burn-at-Moho?p=835667&viewfull=1#post835667

It's a bit more difficult because any mistake will cost you more delta V. As for the lander, just put a 2.25 ton fuel tank, a Rockomax 48-7S and some small lander legs on you lander can. That will get you over 3000 m/s of delta V.

Edited January 18, 2014 by maccollo

[Silverchain]

For a fair lander payload with lots of room for error (Moho is about 2400ms‾¹ δv really; this is the sort of margin I allow for my incompetence):

Vacuum landing and ascent.
Checking fuel at 21:08:14 for planet Moho Plus.
Completed at 21:08:14

Payload mass 2 tons.
Desired TMR: 2.7 and desired δv: 3000

LV-909 with 7 tanks gives 7.77 TMR ( 288.0 %) and 3001 ms‾¹ δv ( 100.0 %); mass 6.438 tons.

48-7S with 8 tanks gives 4.55 TMR ( 168.0 %) and 3198 ms‾¹ δv ( 107.0 %); mass 6.6 tons.

48-7S, 48-7S with 8 tanks gives 8.96 TMR ( 332.0 %) and 3120 ms‾¹ δv ( 104.0 %); mass 6.7 tons.

48-7S, 48-7S, 48-7S with 8 tanks gives 13.24 TMR ( 490.0 %) and 3046 ms‾¹ δv ( 102.0 %); mass 6.8 tons.

48-7S, LV-909 with 8 tanks gives 11.27 TMR ( 417.0 %) and 3040 ms‾¹ δv ( 101.0 %); mass 7.1 tons.

48-7S, 48-7S, 48-7S, 48-7S with 9 tanks gives 16.08 TMR ( 596.0 %) and 3172 ms‾¹ δv ( 106.0 %); mass 7.463 tons.

And for what it's worth, an LV-N design isn't a better option, especially given the extra difficulty of fitting the engine:

LV-N with 5 tanks gives 8.5 TMR ( 315.0 %) and 3429 ms‾¹ δv ( 114.0 %); mass 7.062 tons.

Edited January 18, 2014 by Silverchain

[Taki117]

Going to Moho is actually the about the same as going to Moho in terms of delta V requirements...SNIP

You don't say? But I agree, getting to Moho isn't hard, just dV intensive. If you are not adverse to mods I would get Kerbal Engineer for it's dV readout at different locations. This is useful for landers as you can have a TWR of slightly over 1 at your location, even though it might only be a .32 on Kerbin (Duna I'm looking at you!)

[maccollo]

Eeeh... I meant going to Moho is about the same as going to Eeloo. Moho is a bit more expensive, but the optimal transfer comes around pretty often, every year in fact. With Eeloo you just have to take what you get.