Problems Landing on Minmus and Mun

[Sirrobert]

Change "nice margin for error" to "reserve to cope with poor piloting skills" and you're spot on. I've landed that configuration on Mun twice now and both times used aerobraking to get back down to Kerbin as I've been worried I wouldn't have enough fuel to deorbit

Having just read the first bit of the "science bomb" thread linked above I've now got a better idea how the science works and will go for a quad materials bay/goo lander next time. Thanks to the science from the last trip I've now unlocked the mainsail and big orange tank so I reckon I should be able to launch a big mission with 2 or 3 landers on it which separate in mun orbit and return independently.

Actually when we talk about how much fuel you need to go to Mun/Minmus, we usually asume that you aerobreak to land.

So it only takes like 200m/s deltaV to get from Mun orbit to landed

[Wanderfound]

You might get some use from having a poke through this thread: http://forum.kerbalspaceprogram.com/threads/91365-I-need-a-simple-lander-design!

[capi3101]

Thanks to the science from the last trip I've now unlocked the mainsail and big orange tank so I reckon I should be able to launch a big mission with 2 or 3 landers on it which separate in mun orbit and return independently.

That's definitely doable; two of your landers would wind up minus a chute (the one on top of the command pod) but that shouldn't be an insurmountable problem; they'll just come in a little faster than they would ordinarily but should still impact at a survivable speed. Geschosskopf's sci pack landers as they appear in the second post of his thread (in the pictures) have a mass of about 10.786 tonnes; three of them together with a transfer stage big enough to shoot them to the Mun would weigh 77.19 tonnes (assuming a single LV-909 is used for the transfer stage and that you pack 22.8 tonnes of fuel tanks - an X200-32 and an X200-8 would come close to that; if you have nukes, so much the better). You oughta be able to get that into Kerbin orbit with a classic 4-stage asparagus setup with a Mainsail and three radial engines in the core and mainsails on the boosters, with each stack containing an orange tank, an X200-32 and an FL-T400 (or an X200-8 with 40-45% of the fuel removed). Each lander would arrive with enough delta-V available to it to make the transfer to Mun, land, launch and get back to Kerbin; since they'd get to Munar orbit fully fueled, you should have plenty for inclination changes. Price might be the limiting factor on that mission; I haven't calculated that...

[Wanderfound]

Change "nice margin for error" to "reserve to cope with poor piloting skills" and you're spot on. I've landed that configuration on Mun twice now and both times used aerobraking to get back down to Kerbin as I've been worried I wouldn't have enough fuel to deorbit

Having just read the first bit of the "science bomb" thread linked above I've now got a better idea how the science works and will go for a quad materials bay/goo lander next time. Thanks to the science from the last trip I've now unlocked the mainsail and big orange tank so I reckon I should be able to launch a big mission with 2 or 3 landers on it which separate in mun orbit and return independently.

How far are you from the orbital lab? A lab/tanker to leave in Munar orbit, one purely spacegoing lightweight lander and a return capsule will get the same job done with a much lighter launch. Clean out every biome on the Mun, if you want to.

That's the sort of setup I usually base these at:

Edited September 30, 2014 by Wanderfound

[Vanamonde]

If you are looking for example/trainer ships, here's one I made. The lander is indeed, low and wide, as people are advising.

[RizzoTheRat]

How far are you from the orbital lab? A lab/tanker to leave in Munar orbit, one purely spacegoing lightweight lander and a return capsule will get the same job done with a much lighter launch. Clean out every biome on the Mun, if you want to.

That's what I was going to do but I'm now slightly confused, I'd read that linked post as meaning you can only ever achieve 40ish% of the total science by using the lab, can you keep going back several times to end up with the same amount of science as if you'd returned all the experiments?

Here's my original Minimus lander. It's evolved slightly as it's done 2 Mun shots since then so I've researched some new parts. The next iteration will be wider as it was tricky landing last time as I hit a slope

Edited September 30, 2014 by RizzoTheRat

[Sirrobert]

That's what I was going to do but I'm now slightly confused, I'd read that linked post as meaning you can only ever achieve 40ish% of the total science by using the lab, can you keep going back several times to end up with the same amount of science as if you'd returned all the experiments?

Here's my original Minimus lander. It's evolved slightly as it's done 2 Mun shots since then so I've researched some new parts. The next iteration will be wider as it was tricky landing last time as I hit a slope

https://dl.dropboxusercontent.com/u/12134283/KSP/Minimus%201.jpg

If you transmit through the lab, only a limited amount yes.

But you can also use the lab to store all experiments, collecting all possible science, and than landing the lab. That way you get 100%.

You'd only need 1 set of experiments, because, while with the lab you can't use the Material's Bay/Ooze more than once, you can clean them out with the lab and use again.

So you land, collect science, dock with the Lab. Store all experiments in the lab, clean all science parts, and repeat until you got all biomes.

Than you land the lab.

Note that this also requires alot of docking and EVA, which is pritty difficult.

Also note that doing this will result in WAY more science than you could ever use. So it's really only worth it for if you want to grind out every last drop

[bdito]

Watch this Scott Manley video, specifically how much throttle he uses and how he points the lander. You might want to fast forward to about 10:30 of the vid.

[Wanderfound]

What Sirrobert said is mostly right, but: you don't have to land the lab.

Orbital labs do three things:

1) They allow you to "process" science data, greatly increasing the % of the total returned if the data is transmitted.

2) They can clean out goo pods and materials bays, allowing them to be reused.

3) They can store an infinite amount of science reports and samples.

It's features 2 & 3 that are relevant here, although 1 isn't useless. Sure, you'll always get more science for returning a sample (although the transmit percentage isn't always as bad as 45%), but it may not be worth the bother if you're sitting on a rich science mine. You can always come back and do a physical return mission later if you're desperate for those last few points.

Anyway, how to get the science back without returning the lab. Labs aren't the only things that can carry science reports: so can capsules and cockpits. However, you'll need to go EVA, right click the lab to "take experiments" and right click the capsule to "store experiments". There are limits on how much science is stored in a capsule, but it's done on a per-biome basis. So, one capsule can hold one surface sample from every biome on the Mun, one Goo Pod result for every biome on the Mun, etc.

See http://forum.kerbalspaceprogram.com/threads/66773-How-much-science-can-you-store-in-modules

The orbital lab/lander arrangement does imply one rendezvous and dock per landing, yes. However, rendezvous and docking is trivially simple once you get good at it, and I can't think of a simpler way to get good at it than to do a dozen quick Munhops.

I use my lab/landers for on-tap science, not grinding. I get one up early in the game, and then ignore it except for when I want some science points. When I do, I'll quickly pop down to a Munar biome or two, process the data in the lab and then transmit for 60% recovery or so. That generally provides enough science for whatever tech node I feel like unlocking. There's no reason to immediately scrape the mine bare, unless you're trying to knock off the entire tech tree in a single hit.

Edited October 1, 2014 by Wanderfound

[RizzoTheRat]

Given how low the gravity is on Minimus is it easier to land the science lab as well as the experiments and do a series of short suborbital hops to cover various biomes rather than docking with an orbiting lab every time? I put 2 landers on Minimus last night, both with 4 x Materials labs and 4 x goo canisters. With that configuration it was easiest to have 4 fuel tanks and 4 engines which means it's massively over powered and over fuelled so ought to cope with a lab too. After I'd done all the experiments in a crater I had Bill hop his lander up on to the highlands to take another soil sample and EVA reports, and hardly used any fuel doing it.

[capi3101]

Given how low the gravity is on Minimus is it easier to land the science lab as well as the experiments and do a series of short suborbital hops to cover various biomes rather than docking with an orbiting lab every time? I put 2 landers on Minimus last night, both with 4 x Materials labs and 4 x goo canisters. With that configuration it was easiest to have 4 fuel tanks and 4 engines which means it's massively over powered and over fuelled so ought to cope with a lab too. After I'd done all the experiments in a crater I had Bill hop his lander up on to the highlands to take another soil sample and EVA reports, and hardly used any fuel doing it.

You can definitely do a lab-lander and I think that configuration works pretty well for Minmus, less so for Mun. The trick with lab-landers becomes making sure you've got enough chutes to successfully retrieve the lab when you get back to Kerbin - labs have a notoriously low impact tolerance (just 6 m/s). Lab-landers also have a tendency to be bulky and top heavy, so be mindful of how you put the thing together.

Minmus is a worthy target to be sure; there are nine biomes, and the sci multiplier is 5x for surface experiments (as opposed to 4x for Mun - though it has fifteen biomes).

[RizzoTheRat]

Given that this is my current lander configuration I don't think adding a lab would make it too top heavy. Not sure of the dimensions but as an alternative to sticking the lab on top, I might be able to get 3 materials bays and 3 tank/engines arranged around the lab with the 4th materials bay on top and the capsule on top of that.

Good point about re-entry parachutes though. Si the crash tolerance higher if you splash down rather than landing on..er..land.

[capi3101]

Looks like your design is missing a couple of chutes as is (the side chutes and the top chute) on the capsule. You could also stick that solar panel over on the fuel tanks...by the time you're in re-entry they won't be any good anyway.

You probably could set up a lab-lander the way you proposed without issue; might have to try that kind of design my own self. Bear in mind that your TWR will be a bit lower; you could offset that with an X200-8 tank and engine under the lab, unless you've still got oodles of TWR.

[Wanderfound]

Here's my original Minimus lander. It's evolved slightly as it's done 2 Mun shots since then so I've researched some new parts. The next iteration will be wider as it was tricky landing last time as I hit a slope

https://dl.dropboxusercontent.com/u/12134283/KSP/Minimus%201.jpg

Looks okay, although there's a bit that could be polished if you wanted.

* Lose the ladders, just EVA in. Anywhere with enough gravity to stop that will have too much gravity for this lander anyway.

* It looks like you decouple the engine and tank just prior to reentry? Those are expensive; if you care about √, you could get them back down with you fairly easily. You've probably got enough parachutes on there already.

* Not seeing any RCS. You certainly don't need it, but it does make landing and docking a lot easier, and comes in handy as emergency backup thrusters occasionally. Four thruster blocks and a small RCS tank don't weigh much. If you do stay RCS-free, make sure you empty the RCS fuel supply from the command pod to save weight.

* Your lander legs could be mounted lower. As it is, a hard landing will probably cause enough leg flex to destroy the engine.

* You've got at least twice as much as you need in the way of solar panels and batteries.

* The reaction wheel is overkill. The capsule torque alone is more than enough to spin a lander around.

* Losing the decoupler and reaction wheel will substantially reduce your height. Changing the Rockomax tank for several FLT-200's attached radially around the materials bay would chop is still further, while giving you an even wider base.

* A downward pointing light or two is handy for providing visual altitude cues. Worked for the Dambusters...

EDIT: just saw the revised version. Looks like you're already there...

This is more of a FAR/DRE issue, but I always like to have at least one chute directly attached to the crew capsule. That way, if the ship breaks up during reentry, you've usually still got something to land with.

Edited October 1, 2014 by Wanderfound

[Wanderfound]

BTW, landers at the other ends of the spectrum:

Designed to fit in SP+ cargo bays. More stable than it looks.

Exactly as unstable as it looks. You can land nearly anything with sufficient fuel and patience.

[tsotha]

Exactly as unstable as it looks. You can land nearly anything with sufficient fuel and patience.

On Minmus, yes. The gravity is low and you know where the flat spots are. When I send a lander to Minmus and end up with extra fuel in the transfer stage there's no need to waste the extra fuel - I just set it down on the on the transfer stage rocket cone.

[Skylab]

Thanks for all of your suggestions. I made a lander with a wider base, and for the first time, landed on the Mun and came back.

[capi3101]

Awesome. Your first successful Mun landing is definitely one of the major benchmarks in playing the game. Congratulations on a successful mission.

[Sirrobert]

Looks good. Next up: Science!