Has anyone tried the claw for rover deployment/retrieval?

[cephalo]

Here's the idea, I have a large duna lander, I want to deploy a small science rover to finish up the tech tree. I was thinking that underneath the lander I could have an appendage with a claw attached, that I could back into with the rover when were ready to take off and land somewhere else.

Has anyone tried something similar? I've heard the claw can cause bugs and I've only used it once for a part retrieval contract.

Edited June 11, 2015 by cephalo

[Snark]

Yeah, the claw is serious kraken-bait; I've taken to avoiding it completely, even at the cost of having to ignore all asteroids. It's just not worth the hassle.

For your rover scenario, why not just use a docking port? Put one on top of the rover, and one beneath the lander. To pick up the rover, just drive it under the lander. It shouldn't be too hard to design things so that it comes close enough to engage the docking field, and pulling the rover up should be OK in Duna's gravity, as long as the rover isn't too heavy.

[cephalo]

I tried docking ports on Mun, and I found it very difficult to dock that way. I got it to dock, but only after fiddling with various landing gear positions for 40 minutes. I was hoping the claw would be less fussy.

[pincushionman]

Driving into a Claw is asking for trouble. In the please-don't-blow-up-the-planet sense.

If you can find a way to drive on top of a docking port inside a service bay of some kind, that would be ideal. But you'd have to rig up some kind of deployable ramp, which is easier said than done, even with IR.

[cephalo]

Maybe overhead docking would be easier with the docking alignment mod. Surface docking requires extreme precision and closeness. Maybe there's a way to horizontally dock a rover, which might be a bit easier than overhead since you can more precisely align things with landing struts.

EDIT: of course then you would likely have problems with rigidity when taking off... nm.

Edited June 11, 2015 by cephalo

[georgTF]

Well the answer is obvious but not very easy to engineer. Build your lander as a rover.

What good is a craft that gets you to surface but can't really do anything or move you about without using a lot of fuel and performing dangerous surface hops? Make the whole thing a rover first, then figure out how to position engines so that it can function as an orbiter, THEN work on getting the whole thing balanced on top of a rocket.

The engineering difficulty is in having to solve two diffrent sets of problems with the same vehicle. Orbting and generally behaving as a space craft is one thing. Driving on the surface is obviously another (Then factor in wings for a spaceplane design and you're in KSP hell. Or heaven). An all-in-one solution is not going to be as efficient as a dedicated lander nor rover but it doesn't have to be. Nothing is perfect, though it could perfectly suit your needs.

I have dirtside bases that feature engines and tanks so they can land themselves. They would be more efficient if they were delivered via skycrane, but do i allways feel like bothering with a skycrane? Or would i rather pilot them down to where they need to be then shutoff the engine and forget it exists? The anwser is that i regret not having built them as rovers because now i'm unhappy about where i landed them.

In any case, i find that in the long run, things without wheels feel badly lacking and as a result i try to build bases/landers as rovers with a secondary purpose. Ground vehicles generally don't care much about CoM position, but when orbiting, it's crucial. Fuel lines can be used to ensure fuel is depleted evenly, and building craft symetricaly helps. If you forego symmetry, then use parts as balast to ensure CoM is as fixed as possible. And never use tanks as ballast. Never do that!

It will be frustrating, but owning a nice land based vehicle with rocket engines that can propel it through space and takeoff-land feels like one of KSPs achievements. If it's accidentally also the lander you're looking for, even better!

[edit] On the subject of re-docking a rover on the surface with a mother craft. I wouldn't bother. Docking is way to fiddly on the surface, and the claw only works when you claw into things. When things drive into the claw, the game crashes. Not that it can't be done with docks, but if you're going to invest that much time and energy into it, you might as well try what i originally suggested instead.

Edited June 11, 2015 by georgTF

[cephalo]

Well the answer is obvious but not very easy to engineer. Build your lander as a rover.

I actually did that on the Mun, and made a very nice science lab bus that could land, drive around indefinitely and then launch itself back into orbit. What I didn't like about it was that while it was a great rover, it didn't have enough dv to be a versatile flyer. The result was that I spent 3 whole evenings driving around on Mun to reach different biomes until I wanted to throw up. I did see some cool things, but not 3 evenings worth. I'm ready for a minimum of driving on Duna.