What would be the minimum mun science exploration ship?

[Nyypsy]

Hi! I played the demo way too much and now had to buy the game, I started career mode and gathered up science in kerbal, eventually I visited and returned from mun with a rather ridiculous looking contraption and I was wondering would there be a way to make it... smaller?

My lander had "SC-9001 Science Jr" and "Mystery Gooâ„¢ Containment Unit" for science and ~2600m/s of delta-v which I roughly calculated would be enough to land to mun from orbit and get back to kerbin (and it barely was enough since I'm bad). Well, then I figured I need around 1000m/s to traverse from kerbin->mun, and that part was fine... now getting that 4500m/s to get up from kerbin was a... pain in the ass, my rocket ended up being a horrible contraption with the first stage having like... ~18x "Rockomax BACC Solid Fuel Booster" and a ton of LV-T30/45... it was pretty similar to my now planned minmus explorer... but even more hectic as I didn't have bigger fuel tanks and/or fuel lines...

So what would be the most minimal/optimal mun explorer like this?

-Thank you for answers.

Edited January 16, 2014 by Nyypsy

[Decent Weasel]

Finally another minimalist!

I generally just build standardized seven-motor Asparagus stages and slap them on the bottom of missions, so I probably am not going to be much help on the lifter side of it, but I've taken to making ships that consist of a capsule and chute, a complete science suite (one goo container, one material bay, a thermometer, a seismometer and an accelerometer), and I loft it all with a 48-7s. Power is provided by trusses paneled on all sides with the little fixed solar panels. Data recovery is by return to Kerbin.

The trick here is that bringing a Kerbal along lets you not only take samples and reports, but it also lets you unload all of your experiments so you only have to fly the capsule home, not the science suite.

[Nyypsy]

Hmm yeah that sounds like a good idea, the trip back wasn't that much of a problem in the end though, but everything helps.

I only have "Rockomax Mark 55" currently for the lander though so fuel efficiency is pretty horrible vs your 48-7s

I did get fuel lines now so I can build asparagus stages too, I did the second stage for getting to orbit on my minmus explorer with that... but I can't get enough TWR it seems after that with asparagus though... and once again I had to resort to an unsightly amount of solid fuel boosters to get up.

[tavert]

Don't use the Mark 55, it's pretty lousy. For early-tree rockets, you should use the LV-T30 when you need TWR (replace a couple of them with T45's if you need more control), and LV-909 when you don't.

You also don't need RCS if you aren't docking. I remove the monopropellant from the capsules pretty much every time for a little extra dV.

[Nyypsy]

Well I don't have LV-909, so can't use those.

Nice info about RCS though, wasn't really ever sure about those.

Edited January 16, 2014 by Nyypsy

[tavert]

In the stock tech tree the LV-909 is at Survivability, the same tech as the basic medium-sized landing legs. Unless you're unlocking techs one component at a time, you probably do have the LV-909. You might need to scroll the propulsion page to see it?

On the subject of landing legs, 12 is probably overkill. You rarely need more than 4.

[Nyypsy]

Yeah you were right, I do have LV-909, I'm just absurdly blind... well that got me extra 700m/s.. in atmo, even more in vacuum.

This Is what I ended up with, it should work, and is much more neat than my original thing...

Lander: 3stage 6engine 7tank asparagus.

Turn+Orbit+Travel: 4stage 7engine 7tank asparagus.

Liftoff: 2stage 6engine 7tank asparagus. + 6x large solid boosters.

It kinda stalls just before the turn phase with just 3engines running from the original liftoff... but I'm hoping it will be fine.

[tavert]

Looking better. You can probably get away with only 1 or 2 engines on your lander, you don't need much TWR for the Mun.

If you're already building asparagus, try to use as many of your engines as possible at all times. An engine that isn't burning is dead weight and hurts your delta-V (unless it's got lower Isp than the engines that are currently burning, then it just hurts TWR).

If you're using SRB's, a neat trick is to put a few fuel tanks on top of the SRB's, with fuel lines feeding your core stages. If you set it up with slightly less than the SRB's burn time worth of fuel for your inner liquid engines, then you'll drop some tank mass along with the empty SRB's.

[Superfluous J]

I just sent this to Minmus. It's a multi-biome hopper that's designed to be able to get all the non-one-shot science including crew reports, eva reports, and surface samples. I've not completed the mission yet but I'm hoping for thousands of science points. It should be sufficient to get the science from a single biome on Mun, or if you plan well 2 or 3 nearby biomes before you have to head home.

Note: The 3 pods below the payload were to transport 3 Kerbals to other places and aren't related to the science part of the mission. They add a little weight so if you removed them you might be able to do a bigger hop on Mun to get the science from up to 6 biomes if you choose REALLY wisely, or 4 if you plan ahead even a little bit (Land near the crater wall of one of he HUGE craters. Take science from either side of that wall)

The lifter is asparagus staged, with the gimbaled engine in the center and the higher thrust engine on the 6 outer rungs. Those 6 drop off 2 at a time and feed fuel in to the next tank. I used the really light radial decopulers in every place. The lander's engine is that tiny, awesomely ISP'd engine that works great on Minmus but may have trouble on Mun, don't know. The science (I had 4 of them but left the barometer at home, so there are "only" 3 there) are all within easy reach of the door and are tied (along with a crew report) to action group 5 (5cience!). So I land, hit 5, go EVA, collect the reports, do an EVA report on the ladder, store everything in the pod, jump off the ladder and do an EVA report and surface sample, get back in the pod, and hop to the next location to repeat.

Once I've only got enough fuel left to get home, I go home

One problem I had was the solar panels were not blocking the door, but were making the Kerbal fly off whenever he went EVA. I have KAS installed though so I moved those two panels so they weren't blocking the door.

Note: The staging is slightly wrong there. I took this picture before moving the landing struts to the lowest stage.

Edited January 16, 2014 by 5thHorseman

[Nyypsy]

Ah yeah I was meaning to put less engines for my lander last time, but I didn't have fuel lines yet so it didn't make that much sense, could do that now indeed.

Yeah I have all engines on at all times when burning, but the liftoff stage wasn't working as 2stage asparagus+boost so I changed it to just liquid+solid boost stage and it got me to orbit with 3800 delta-v left, so I suppose its okay.

I have to test that SBR fuel tank trick, sounds awesome

[Markus Reese]

With mun, if you can get orbit, and have radial decouplers, you pretty much can get to the mun. My landers are always a five engine lander. I use five to decel to moon, deactivate outer four, then use just a single engine for speed control. Liftoff and return, I drain my outside engines, then can return on just the single without problem. The following pictures have stuff from when I roleplay. This first one is a full setup with the probe underneath used to pinpoint a landing spot first. It can be made much simpler than that as I had done my mun landing before solar panels and the long tanks.

It is a bit of overkill for the mun, but the main point to note is the core of the lander design engines. If you can build that lander, you are on the mun.

[Tokay Gris]

Just as a suggestion: You don't actually need to bring the containers (Goocontainer, Science Jr.) back to kerbin. You could leave them on the surface of Mun and just take the data out of them during EVA.

Thats what I just did on the missions to Duna and Ike. Containers are still in the respective surfaces. Weeeell... Not the two on Duna. I dropped them on ascent, so they most likely left a hole in the ground.

[Tokay Gris]

Here are two of my rather "minimal" Mun landers.

This one uses only the LV-T30 and LV-T45.

And this one uses the "Skipper"

Both are a bit overpowered. In both cases at least part of the ascent stage can be used to transfer to Mun and the transfer stage can be used for the deorbit burn around Mun.

[Nyypsy]

Wow those two are really nice ones, how much delta do you have on the lander? Can you hop around in mun for different biomes or is it just a single landing and return?

[Dave Kerbin]

Advice like reducing the number of engines is very good. Reducing mass has cumulative benefits. Removing 1 ton from the lander might let you remove 3 tons from the transit which might let you remove 10 tons from the orbit which might remove 50 tons from the booster. To move mass you need fuel, and fuel is mass so you need even more fuel to move that fuel and so on.

Once you are out of the atmosphere TWR doesn't really matter (unless you use those tiny LV1 engines meant for probes). Landing on the Mun or Minmus should be possible with just 1 engine as long as your lander doesn't resemble a building.

Figure out the minimum you need to carry on your lander (mass wise) before you add fuel. Then add fuel until you have the delta-v you want. It's also useful to consider using decouplers to remove mass that is no longer needed. In .23 you no longer have to return science experiments to get the data, your kerbal can retrieve it and store it in the command pod.

This really isn't the best rocket for beginners, but with minimal tech this was my most recent Mun mission (two landings): http://forum.kerbalspaceprogram.com/threads/62464-Dave-s-Voyage

[Tokay Gris]

Wow those two are really nice ones, how much delta do you have on the lander? Can you hop around in mun for different biomes or is it just a single landing and return?

Delta-V on that lander is about 2200 m/s, IIRC. So not for hopping around. Just single use. (Will check, though)

Used it two or three times, actually, until I had the science lab. Then I build a slightly larger lander that collected all the rest of the science and got its experiments cleaned out after each landing.

And STILL without the mainsail...

[Nyypsy]

Hehe I'm waiting for mainsail too, could make much more interesting things I bet.

[Max Grant]

I think everyone who plays this game should go find this series on Youtube called The Moon Machines. I watched it avidly and it helped me understand, much more, what the engineering of space travel required.

I especially enjoyed learning that the ascent stage of the Moon lander was powered by such a corrosive fuel that it destroyed itself during the burn, and therefore every Moon lander's ascent stage was an un-tested engine.

[Tokay Gris]

Hehe I'm waiting for mainsail too, could make much more interesting things I bet.

Weeell... not really. Well, yes, of course.

But with the Mainsails and much bigger Payloads, you also get lag.

So, what the career mode taught me, actually, was to build small.

In sandbox, I put together incredibly large ships. They did work. And nice. In slideshow.

But now, in career, there actually is something to accomplish. Get the science!

So there is a goal. And smaller ships can do that task just as easy - or even easier - than my huge behemoths.

(Am currently writing the mission report of my Duna-Ike mission. If interested: http://minionsinspace.wordpress.com )