Need help landing this

[Der Anfang]

I wanna land this on Mun and Minmus. It's a mobile lab. Eventually, I would also like to land it on Duna. I've got a descent stage (about 390 m/s dv) to help aid, but actually getting it off of Kerbin may be the hard part. And landing it on Duna as well. The mun would be priority, as well. Could any body help me come up with some rocket designs for both Kerbin's moons and Duna? Here's the craft file (ajd I hope the download actually works, my first time using Dropbox)...

https://www.dropbox.com/s/ptukd8pky8h23ei/Mobile%20Base%20MK%20I.craft?dl=0

[Foxster]

I'd reduce the weight a lot. 

Do you really need all that crew? All the iron-work weighs a huge amount. Do you need so many ore tanks? Why two drills? What are all the fuel cell arrays for?

Maybe something like this?...

Edited January 25, 2016 by Foxster

[Der Anfang]

2 hours ago, Foxster said:

I'd reduce the weight a lot. 

Do you really need all that crew? All the iron-work weighs a huge amount. Do you need so many ore tanks? Why two drills? What are all the fuel cell arrays for?

Maybe something like this?...

You make an excellent point. Since I might be travelling a lot with this, I'd want it to have sufficient power during the long nights on the Mun. The drills are to add fuel for the fuel cell arrays, but it is also meant as a refueling station for any landers, which is why it will have the fuel tanks. It will have the solar panels for daytime travel as well, obviously. But primarily the fuel cells are to keep a constant power supply, since the wheels will drain a lot of power. If I am correct, the amount of all the wheels operating should provide enough torque when climbing hills(?)

Finally, the metalwork is also meant as a landing platform, in case for some reason I want to add a docking port on the tops to utilize smaller landers, but I'm probably willing to do a redesign as you have suggested. Since I am playing career mode, I haven't unlocked the large ore tank, which is why I have the small ones.

 

Also, I'll admit... the metal work is somewhat meant for looks. I think it looks cool, personally. But you are right... I could save a lot of weight if I eliminate those.

Edited January 25, 2016 by Der Anfang

[Plusck]

As for landing things on top of it... you should try before you buy.

I've successfully landed a lander on top of a station on Minmus, but it was a total nightmare, and it was on the flats so when I overshot I could simply land, get my bearings and retry. I do not intend to ever try this on the Mun, never on a platform that is not entirely flat, and certainly never ever on a small platform that isn't flat that is sitting on a slight slope on the Mun.

I'm not too sure about the fuel cells either. Certainly that would make your design workable going to Jool, but my philosophy is: you can't guarantee that you'll get a decent ore rate when you first land; when you first land you desperately need to refuel; to maximise your fuel you mustn't burn it for energy; if your solar energy is low you can wait and recharge, but if your fuel is low you're screwed.

 

And for the wheels, if I really intend to drive at night then fuel cells would be a help, but during the day they won't draw more than my drills would, so if I have sufficient solar for drills then I'll have enough to drive around.

[Der Anfang]

Interesting feedback. So I guess landing on top of a platform is a no-go (which makes sense). So I guess I could sacrifice aesthetics and just reduce the weight. To be honest, I have no idea why those metal platforms are so heavy.

[wibou7]

7 hours ago, Der Anfang said:

I've got a descent stage (about 390 m/s dv) to help aid, but actually getting it off of Kerbin may be the hard part.

390 m/s might do it for Minmus if you are efficient AND if you have another engine for orbital manoeuver. However it will NEVER do it on the Mun. (Duna is another story as you could add a sufficient amount of parachutes/airbrakes).

However, you are right, you will need a HUGE rocket to get it off Kerbin. Forget about standard launch procedure, you will have to launch straight up until ~25 000m, otherwise the drag will make you spin. And pack a lot more delta-v, probably around 5000m/s for the launch; the drag is going to be very expensive fuel wise.

[Temstar]

For rovers on that kind of scale it's best if it lands using an integrated landing stage, that is the landing equipment is built into the rover. It only needs enough delta-V to land, it doesn't have to do the deorbit burn or anything, that can be handled by a rocket stage:

Notice the wreckages of the orbital stage, jettisoned not long before switching to integrated landing engines shortly before touch down.

[Plusck]

3 hours ago, Der Anfang said:

Interesting feedback. So I guess landing on top of a platform is a no-go (which makes sense). So I guess I could sacrifice aesthetics and just reduce the weight. To be honest, I have no idea why those metal platforms are so heavy.

Don't not try it just because I say so. Definitely try - maybe you're far better at it than I am/was the last time I tried it. And certainly the addition of the platform will help for that since if you misjudge by a small amount you wlll be stationary and able to make a jump, rather than toppled and falling (which is what would happen without the platform). However, do be prepared for the very real possibility that it's far more effort than it's worth.

I find the project interesting because it's massively overambitious. But it's also massively overambitious

[Der Anfang]

6 hours ago, Temstar said:

For rovers on that kind of scale it's best if it lands using an integrated landing stage, that is the landing equipment is built into the rover. It only needs enough delta-V to land, it doesn't have to do the deorbit burn or anything, that can be handled by a rocket stage:

Notice the wreckages of the orbital stage, jettisoned not long before switching to integrated landing engines shortly before touch down.

I have a feeling that I might have seen this exact rover design in google images a long time ago. Is this an older design or something you just whipped up? Keep in mind that I am still relatively new on the forums, so the familiarity may just be coincidential.

Edited January 26, 2016 by Der Anfang

[Temstar]

34 minutes ago, Der Anfang said:

I have a feeling that I might have seen this exact rover design in google images a long time ago. Is this an older design or something you just whipped up? Keep in mind that I am still relatively new on the forums, so the familiarity may just be coincidential.

Yeah it's a giant rover from KSP 0.19 days by yours truly:

http://forum.kerbalspaceprogram.com/index.php?/topic/22798-0191-molab-heavy-manned-munar-rover/

That's around the time when rover wheels were first added so we were all experimenting with it. I recall someone wrote an excellent guide back then on the different landing methods available to put a rover down, let me try to find it.

Edit: found it:
http://forum.kerbalspaceprogram.com/index.php?/topic/26721-landing-rovers/&do=findComment&comment=351980

Edited January 26, 2016 by Temstar

[Der Anfang]

10 minutes ago, Temstar said:

Yeah it's a giant rover from KSP 0.19 days by yours truly:

http://forum.kerbalspaceprogram.com/index.php?/topic/22798-0191-molab-heavy-manned-munar-rover/

Holy cow! Yeah, I remember visiting that page before I even joined the forums. I thought it looked familiar. Actually, I was somewhat inspired by that design when I came across that. I tried to build large rovers before, but they were always impractical in my opinion. I guess you can tell by the way I added the platform and solar posts on mine...  not that I was blatantly copying, of course.

Mainly why I am asking how to land my design now is because we have to consider now the new aero and the fact that we may want to use fairings (or not). There's a lot of new stuff to consider so launching absurdly large rovers like that now seem significantly more difficult or impractical when trying to get it off of Kerbin.

[Temstar]

New aero does mess with things a bit. Recently I had to put a manned rover with science lab on the Mun for a contract, not as big as MOLAB but still big enough that you couldn't really put it in a fairing.



So if you look at the way the stages are arranged, the first two stages put the rover into orbit. I then hang onto the 2nd stage and dock the rover to my propellent depot to refuel that upper stage, putting 1381 m/s back in its tank. I then fired up the 2nd stage again to get the rover to Mun orbit, do the deorbit burn and get it close to the surface. Then the 2nd stage runs out of fuel and it gets cut loose to crash onto the mun while I switch the rover to belly landing mode (there's a probe core under the rover's belly), do a 90 degree flip in the air and fire up the integrated landing engines to soft land on the Mun.

 

[FyunchClick]

I had to land a huge rover on the Mun once for a contract, that required 4.000 units of Liquid Fuel and house 7. I ended up putting a big ISRU and two big drills on it as I figured it'd be easier to land empty and make the 4k of LF there, and a mobile lab as I figured why not. It was pretty big. 

I put the ungainly thing together, then mounted it on top of decoupler, put a big fairing underneath, disabled the engines and put a random engine/tank on the bottom. I then used either Kerbal Engineer Redux or RCS Build Aid (both can give you readouts for the thrust offset) and the offset tool to offset the rover on the decoupler until the thrust offset was about a tenth of a degree.

With the trust offset minimized like that, plenty of strutting to prevent the payload wobbling too much, and a big ole fairing to prevent the whole thing disintegrating upon going supersonic, getting it to LKO was relatively easy, but without KER or RCS Build Aid to give your an offset readout, it would've been very hard to do.