Rovers (or Elsewise Moving Around) on Gilly?

[Srpadget]

I'm going to be headed to Gilly for the first time.  And OF COURSE I will be setting up an ISRU refueling facility (like ya do...) for the eventual assault on um, i mean Eve sample return mission.

Now, I have this whole set of standardized infrastructure set up that works with only very minor tweaks on Mun, Minmus, and Ike (so far).  Basic setup is 1) a permanent mining-and-refining base that converts sunlight and regolith into LF/O/Mono, 2) a tanker rocket to haul the fuel to an orbiting refueling depot, and 3) a tanker truck rover to cover the 100 meters-ish between the mining base and the landed tanker (because that transfer-truck scheme was way easier for me than learning to reliably land within KAS pipe range of the refinery yet outside the "gigantor-array shatter zone").

And I'm wondering if I should rethink this for Gilly.  I've never been there yet, but by all accounts you can SNEEZE your way to an escape trajectory on Gilly.  So does it make any sense at all to bother with a tanker truck?  How much trouble am I going to have keeping a wheeled vehicle on the ground (or gaining enough traction to start/stop the thing's movement)?  Note that this particular use case is NOT a long-haul, high-speed off-road exploration vehicle--it's a tanker truck whose ONLY ROLE is to move at a few m/s max speed across a few dozen meters of the flattest ground I could find in the high-Ore zone, sidle its forty-ton-ish bulk close enough to the tanker rocket to attach a KAS pipe, then head back to the refinery likewise.

This scheme works just fine on Minmus, the lowest-gee place I've ever been.  But... GILLY....

I'm wondering if I should nail the refinery to the surface with a set of KAS harpoons, stick a docking port on top of it, and treat this whole Gilly operation as a "docking maneuver" rather than a "landing".

Tips? Tricks? Advice?

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EDIT:  Also, how big a hassle is physics-loading on Gilly?  My permanent infrastructure seems to do a little "jump/settle" number on physics-load every time I pop on over there from map view.  Do things on landing legs jump right off the ground if they're landed on Gilly at loading time?

Edited June 7, 2017 by Srpadget

[HvP]

Wheels just straight up don't work on Gilly. You can do all of your hauling using RCS thrusters with no problem. Heck I wouldn't even call it landing on Gilly; more like a low speed rendezvous with the surface.

Everyone has their own creative solutions for mining on Gilly but the few times I've mined there I simply used the entire lander as one whole lander/miner/tanker combo in one ship to avoid the problems you mention.

I think the jumping you are experiencing has more to do with the KAS pipes than the moon. The further separated different parts of the structure are from each other the more likely it is that there will be floating point errors in their location measurements when they all load in. KAS just makes it easier to make wide expansive structures that stretch out over uneven ground.

Edited June 7, 2017 by HvP

[Ohm is Futile]

Well, there is a somewhat universal solution if you really want to go wheel. Depending on the size of the vehicle, it could be anywhere from crazy impractical to pretty trivial. Basically, you could put the smallest thrusters on your vehicle facing downwards and then muck around with thrust limits and throttle to see how much you need to stay on the ground... It shouldn't be too expensive in terms of fuel, at least for the very short trips you would be doing.

That said, Gilly is probably just too small to apply even this. RCS and other lightweight solutions should be fine and probably more desirable. Heck, you could probably cut the middle man and just straight up dock the hauler with the mining rig since the gravity is so low.

[Spricigo]

1 hour ago, Srpadget said:

I'm wondering if I should nail the refinery to the surface with a set of KAS harpoons, stick a docking port on top of it, and treat this whole Gilly operation as a "docking maneuver" rather than a "landing".

Pretty much it.Gily landing/lifting off requires 30m/s deltaV, so small you have trouble to notice.

Also, you know how when landing on Minmus thing seems to happens in slow motion? On Gily is more like a picture book.

 

[ARS]

You wouldn't want to use wheels on gilly. Last time I'm landing on that ball of rock with my SSTO, it wasn't treated like a landing, more like a rendezvous with surface

If you want to build a tanker for hauling stuff on gilly just slap a probe core, some reaction wheel, battery, antenna, RTG (or solar panel) and an array of RCS thrusters to move around. Trust me, when you use a wheel on gilly, most of your time will be spent making it move normally instead of hauling stuff. It's okay if you want to set up a mining base there, but generally, due to gilly's very low gravity, it's much more efficient to just use a lander as a miner and a tanker. It doesn't take a lot of Dv to get into gilly orbit

Anchoring the whole mining rig on gilly is a viable solution to make it stand firm as you do your mining operation. 

[Human Person]

You shouldn't build a permanent base. It's very inexpensive to take stuff up to Gilly Orbit, so why not take the whole mining Rig up into Gilly orbit instead of docking with it on the surface?

[Srpadget]

Thanks, all, and sorry for the delay in replying.  (Real Life(tm) does have a habit of getting in the way of gaming time!)

Yes, for Gilly the smartest solution is probably to slap an engine (Terrier?  Maybe even a Spark?  Gotta go run the numbers...) under the ISRU rig, a docking port up top, and a few RCS blocks around the sides, and just treat it as a miner/refiner/tanker all-in-one solution.

Which brings me to a follow-on question, but it's specific to KAS harpoons, so that's a question best asked off in the Mod area....

[Srpadget]

On 6/6/2017 at 8:53 PM, HvP said:

I think the jumping you are experiencing has more to do with the KAS pipes than the moon. The further separated different parts of the structure are from each other the more likely it is that there will be floating point errors in their location measurements when they all load in. KAS just makes it easier to make wide expansive structures that stretch out over uneven ground.

I can't imagine it would be.  I treat those pipes as nothing more than fuel hoses. I hook up, transfer fuel, and unhook.  I don't even warp while I'm doing that.  After seeing how the various components move around while I'm shifting fuel, and then jump when I detach the pipe, I've always been a bit nervous about what would happen if I unloaded/reloaded physics while things were "piped together".

I may have some 'phantom forces' somewhere in the mining rig, actually.  I've noticed across multiple KSP versions, on multiple worlds, on varying types of terrain, that the mining rig will slowly (over multiple visits/reloads) drift east (even if east is UPHILL!) and rotate counter-clockwise.  I never see it move, but over multiple game sessions it keeps turning up slighly further east compared to flag, tanker truck, and nearby terrain features (I could live with that) and the solar arrays no longer track the  sun properly (which is really QUITE annoying at dawn/dusk when the dang thing is 90 degrees rotated from its original orientation).  I've taken to saving its post-landing state vector in a text file and then periodically copying that back into the save, to force it back to its original location/orientation....

[HvP]

23 minutes ago, Srpadget said:

I can't imagine it would be.  I treat those pipes as nothing more than fuel hoses. I hook up, transfer fuel, and unhook.  I don't even warp while I'm doing that.  After seeing how the various components move around while I'm shifting fuel, and then jump when I detach the pipe, I've always been a bit nervous about what would happen if I unloaded/reloaded physics while things were "piped together".

I may have some 'phantom forces' somewhere in the mining rig, actually.  I've noticed across multiple KSP versions, on multiple worlds, on varying types of terrain, that the mining rig will slowly (over multiple visits/reloads) drift east (even if east is UPHILL!) and rotate counter-clockwise.  I never see it move, but over multiple game sessions it keeps turning up slighly further east compared to flag, tanker truck, and nearby terrain features (I could live with that) and the solar arrays no longer track the  sun properly (which is really QUITE annoying at dawn/dusk when the dang thing is 90 degrees rotated from its original orientation).  I've taken to saving its post-landing state vector in a text file and then periodically copying that back into the save, to force it back to its original location/orientation....

I know that the drifting along the ground bug was a big problem when 1.0 came out, but I thought it had been minimized in more recent updates, although not completely eliminated. The references I've seen implicating KAS probably was a result of wide hooked-together structures amplifying the underlying physics problem you are running into. Thinking about it more, I've noticed that switching focus between widely separated ships when both are within physics range exacerbates the problem -- they don't have to be connected after all.

Having BD Armory installed, for example, extends the physics range by about 10 times normal and I was getting bad discontinuities with my surface bases when craft would come into that 20km range or when I switched between them. I had to uninstall it to make my life easier.

It's possible that phantom forces could be at work, of course. Clipping service bays, cargo bays, air brakes and landing legs against other craft seem to be the biggest offenders creating phantom forces in my experience.

Edited June 8, 2017 by HvP