Connecting Tanker to ISRU Factory: Alternatives to KAS/KIS?

[Srpadget]

A while back, I developed a sweet little highly-efficient, all-stock ISRU mining operation involving a dedicated mining/refining factory, a tanker rocket that shuttles between the mining operation on the ground and a refueling station in low orbit, and a fuel truck that runs between the refinery and the landed tanker rocket.  As it's all stock, it uses carefully-placed Junior docking ports to handle fuel transfers between vehicles.  Which, of course, means the whole setup is really only suited for use in one place: the flats of Minmus.

So now I'm working on the bigger and more important problem of ISRU operations out around other planets.  The obvious way to go is to develop a system that works on Mun--because anything optimized for Mun is also going to be pretty well suited for Ike and Dres.

And as I'm jealous of mass fraction, I don't want to go with an all-in-one solution that keeps hauling all the mining infrastructure (drills, ore tanks, converter, power/cooling, engineer's control pod) up and down the Mun's gravity well.  And I am decidedly NOT the sort of ace pilot who's ever going to be able to land the tanker ON the mining station and dock directly to it. So I'm leaning toward a refinery/truck/tanker setup similar to what I've already got working on Minmus...but I'll need some method other than conventional docking ports to connect the truck to the refinery and tanker.

In stock, there's the Klaw.  But that's aesthetically displeasing to me, and well-known Kraken bait.

That seems to leave KAS/KIS as the obvious way to go.  But I am given to understand that KAS/KIS is a hugely-capable pair of mods (with associated learning curve) and overkill for the single job I am intending here.

So, educate me:  is there a smaller simpler mod that can solve the "ground-based docking/connecting/fuel transfer" problem?  Or, alternately, is there a decent KAS/KIS tutorial out there that can help me with the learning curve?

Note: I prefer to READ tutorials, with still screenshots where visual examples are useful. That way I can reference back and forth between sections easily and go at my own pace--and I read fast.  With videos, I inevitably get tripped up when I miss something vital that whizzes by in what looked like a momentary insignificant aside, and I end up spending endless hours watching the dang thing a half dozen times before I 'get it'.  So videos tend to actively ANNOY me.  (Yes, I'm aware this makes me a fossilized relic of the last century.)

[Nightside]

You could try dMagic's EVA Transfer modlet. KAS also has issues with bouncing vessels when loading, which can be disastrous for a big base.

[Plusck]

I have found stock to be perfecty workable on the Mun. I built three sections in the SPH - the miner/ISRU section, a big ore tank (orbitable) and a big fuel tank (orbitable). Each of the tank sections is on the largest legs (simply placed midline) and has an additional docking port on the belly for my ultra-low-profle rover to attach to once the legs are raised. Each can also orbit and return with the rover attacher (far easier that way when returning).

Sure, they need a few seconds of juggling to match up the ports, but it works fine on flat-ish ground. Each section has standard docking ports on the ends, RCS, and reaction wheels.

The only problem I've had is getting impatient and crashing the tanker while driving to the miner (I generally end up landing about 600-800m away. Haven't really perfected my aim yet).

Edited February 27, 2016 by Plusck

[Somtaaw]

KAS used to be pretty simply, if you used the tow lines. A single Kerbal would EVA, and drag the tow line from Part A to part B, and attachs it. Once the tow line is attached, it's function to the game is the same as a docking, so you could then transfer anything & everything. So after you EVA your Kerbal with towline and attacj and do your fuel transfer, you'd simply disconnect the towline and hop back into part A (your orbital tanker), right-click the towline to auto-reel in (like a fishing line) and you'd fly back into orbit while it does so.

 

 

Whether KAS still functions like that, I don't entirely know I stopped using it around 0.90 to 1.0 era. But that's a virtually non-existant "learning curve" I always found KAS to be pretty stupid-friendly.

[Snark]

You could always install KAS and just delete the parts you don't want, if you're leery of overkill.

For your use case, you really only need one part from KAS, the "connector port" that an EVA kerbal can use to hook up two craft that are parked near each other.  It's simple and easy to use.

[Srpadget]

Nightside: That EVA Transfer modlet looks like it should do exactly what I need.  Thanks!

Plusk:  I've heard of people who do ground-based docking the way you describe, but I've always been afraid I'd drive into a landing leg and send the whole base crashing down

Somtaw and Snark:  You make a good case for using KAS and just ignoring all the bits that are extraneous to my needs.  You have convinced me to give it more serious consideration.  (I'm trying to remember when and in what context I saw the "KAS/KIS is complex and overkill just for fuel transfer on the ground" statement.  It's doubtless somewhere in the Forum histories.)

I've never used a part mod before.  But seeing as I recently hand-tweaked myself some 2.5-m LF-only tanks to resuscitate some of my older NERV designs, I guess I can't exactly claim ideological purity.  At least until Squad gets around to giving us stock solutions for these two biggest remaining holes in the current version of the game...

[Snark]

1 hour ago, Srpadget said:

Somtaw and Snark:  You make a good case for using KAS and just ignoring all the bits that are extraneous to my needs.  You have convinced me to give it more serious consideration.  (I'm trying to remember when and in what context I saw the "KAS/KIS is complex and overkill just for fuel transfer on the ground" statement.  It's doubtless somewhere in the Forum histories.)

If all you need is the fuel transfer, you can skip KIS and just install KAS.  Two parts in particular are invaluable and I really wish were in stock:  the "connector ports" for joining together ships on the ground, and the "strut sockets" that let you deploy struts on EVA.

The latter one has nothing to do with your current problem, they're just really handy.  They're primarily useful when you want to construct a multi-section ship in orbit via docking ports.  Docking ports are notoriously floppy, and this part lets you send out a kerbal on EVA to attach struts between docked ships to make the connection more rigid.  Opens up lots of play opportunities, plus gives your kerbals a reason to go EVA and do something "astronauty".

Edited February 28, 2016 by Snark

[Srpadget]

Snark, Thanks for the confirmation that KIS is not necessary for this.  The KAS blurb was unclear to me regarding the need for KIS for this sort of activity.

I absolutely agree about the EVA-deployable struts, as well.  (Insert rant of frustrated professional:  "I got to use deployable struts for on-orbit assembly of the REAL space station! Why can't I use 'em for my PRETEND space station?!?")

And I can't even use Kerbal Joint Reinforcement to beef up the floppy joints.  Turns out that my standard multipurpose space station core has a vestigial Kraken drive somewhere in its design, and KJR magnifies it to the point that I've inadvertently dropped it right out of a stable 20km circular orbit and crashed onto the Mun in less than half an orbit upon installing KJR and focusing on the station.  Though I do note the experiment made me MUCH more adept at docking quickly! 

[Snark]

37 minutes ago, Srpadget said:

I absolutely agree about the EVA-deployable struts, as well.  (Insert rant of frustrated professional:  "I got to use deployable struts for on-orbit assembly of the REAL space station! Why can't I use 'em for my PRETEND space station?!?")

Yeah, I adore those things.  I really, really like the idea of assembling big ships in orbit, and it's just not practical in stock KSP because they're floppy noodles due to the way docking ports work.  Yes, it's possible to cobble something together (e.g. a "space train" with an engine module in front that pulls everything), but that really rubs me the wrong way-- building a dorky-looking ship due to an artificial constraint of the game.

In general, I like the floppy nature of KSP ships:  it's an interesting design constraint that adds fun challenge to the game for me, which is why I have never and will never install KJR.  However, docking port connections are so floppy, with no good way to stiffen them in stock, that there's basically no good way to build large ships.  (I'm specifically excluding the make-it-stiffer-by-connecting-multiple-docking-ports solution, because that is outside my personal boundaries of what "good" is.)

So I really, really like KAS' deployable struts.  They don't remove the floppiness of KSP as a whole (which I like), or the fact that docking ports are floppier than other joints (which I also like):  they just give a reasonable, plausible, in-game way to design around that limitation, while providing fun EVA activity along the way.  Should totally be stock. 

I recently sent an extended deep-space mission to the outer solar system (I'm running Outer Planets, so by "outer solar system" I mean four planets and eleven moons out beyond Jool).  The mothership was a real juggernaut.  Launching the components, hooking them up, seeing this big thing come together and then launching it into deep space with its twelve crew... was some of the most fun I've had in KSP for a long time.

[Srpadget]

Thanks everyone for all the suggestions!

KAS has been installed, and the pipe function checked out on ground at KSC.  I don't foresee much need for winches, etc., but I am casting a lustful eye at the strut connector.  I suspect a minor redesign of all my standard space station modules will be happening soonish...

[Plusck]

3 hours ago, Srpadget said:

Plusk:  I've heard of people who do ground-based docking the way you describe, but I've always been afraid I'd drive into a landing leg and send the whole base crashing down

Well, I can't say my system is sophisticated or that it would have far to fall if I bumped into it. I tend to end up rolling my tanker and breaking solar panels due to lack of patience driving at 5 m/s over the ground.

You can see how basic and cobbled-together the ground bit is here:

Spoiler

That's my ugly standard mining/ISRU craft, with a probably-unnecessary ore craft (I never got around to putting ISRU in orbit, and I'm pretty sure it would never lift off the ground with full tanks with those engines, anyway). My tanker (built like the ore tanker, with one orange tank and 4 Twitches) is so feeble that it wastes a ton of fuel trying to get to orbit.

This is a new, improved and beefed-up fuel tanker for Moho:

Spoiler

I have wondered about whether it is better to take ore up instead of fuel.

Advantages of taking fuel up with this set-up are:

- when docking on the ground, the fuel tanker is empty but the ore tanks can be filled or emptied easily. Since the fuel tank sits lower on its wheels than on its legs, and since it sits higher on legs when empty than the full ore tanks, there is no incurable mismatched-docking situation;

- no worry about running out of fuel on the way up;

- no need to land immediately because the miner can be left filling up with ore again.

 

But I guess this is all academic now

[Wemb]

On 28/02/2016 at 8:03 PM, Srpadget said:

Thanks everyone for all the suggestions!

KAS has been installed, and the pipe function checked out on ground at KSC.  I don't foresee much need for winches, etc., but I am casting a lustful eye at the strut connector.  I suspect a minor redesign of all my standard space station modules will be happening soonish...

I started to use winches after my Mun bases pipe infrastructure kept either (apparently) randomly disconnecting itself from the struts and parts it was connected to and/or exploding.  Winches, work pretty much the same way, but they didn't seem to self-terminate as often for me.

 

Wemb

[RizzoTheRat]

I'd also recommend carrying a few of the concrete ground base things as well as the connector ports.  There's a limit to how long a KAS/KIS pipe can be, so putting a concrete base down at the range limit, with a connector port connected to the base, allows you to double the range with a connector port on the other side of the concrete base going to the port on the ship.  Alternatively I now have connector ports at either end of my rover so I can park it half way between the base and the ship and connect them through the rover.

Just don't forget to take a screwdriver.

[KerikBalm]

the claw's kraken bait attributes seem to have vanished, at least I haven't had problems with it since the last update.

Otherwise, I find that action groupings to landing struts or wheels can be very useful for raising/lowering a docking port that is close but not quite in position - get it close enoug hand as the docking port starts to raise/lower according to your change of the struts/landing gear, it will lock in position as it moves by, even if the fully deployed or fully retracted states don't align with the docking ports.

At least... that's been my experience when designing 2.5m rovers that dock up inside of a mk3 cargobay.

I was able to get that to dock up... but I had to play around quite a bit with retracting and extending the from pair of landing gear.

The top docking port was even aligned close enough for the magnetic forces to stabilize the payload and prevent it from clipping through the bottom of the cargobay (which seems to immediately happen when the front docking port connects, requiring me to retractthe landing gear of the big plane, and extend landing gear of the rover to get the top to pull it into proper position, and the gear to again not clip through the cargobay doors

So... if this works, I don't see why it wouldn't work on the Mun, with a fuel tanker and a ISRU

[Norcalplanner]

I've found it helpful to add reaction wheels and O-10 engines to a truck/rover which docks with things on the ground. The ability to jostle the connection in this manner, in addition to clever use of landing legs, has saved my bacon a few times.

[zolotiyeruki]

I like to put docking ports at a uniform height among all the modules of a mining station.  And give my shuttle rover wheels and a docking port at the same height.  So the shuttle lands, drives over to the station, docks and fills up, then drives away and launches.

[Kamenjar]

I know that you said that you don't want the Klaw for aesthetics reasons, but I'll point out a few things that are in favor of it in hopes of changing your mind:

• My general rule of thumb is - if it's supposed to dock - put a claw on it! Why? Well first, you don't need RCS to dock with klaws. You have a huge leeway for docking - anything flat will do, so you don't have to aim for a specific spot. Docking time is just order of magnitude easier than with docking ports. I put at least two klaws on every station; or more on every harvester and tanker that I have. The only use for docking ports is if the klaw is simply not practical (mini landers due to weight, and planes due to drag/heat tolerance, or if I need some piece on both top and bottom of the rocket) and in cases where I want to be able to potentially expand the ship/rover in the future (though I still put a klaw on them, and even put klaws on some docking ports so I can "pop it" if I end up needing the port)
• Klaws are actually great landing gear replacement for tipover tankers because of their good impact tolerance. My minmus tanker looks like a plane with landing gears and can deorbit to 90 km apo / 25km peri in one single aerobrake from Minmus. It weighs 250T or so wet, and delivers most of that weight to LKO station. That tanker has the klaw on the rear, and uses it for docking, but also to bounce off the ground when landing at minmus, in order to tip over to land on the landing gears. Having the klaw also adds the potential for emergency refueling for missions that would fail otherwise.
• You can use klaws on your harvesters to dock refuel pretty much any possibe ship you can think of. I can dock with a 1-by-1 meter mini lander or 500T ore tanker. Use more than 2 sets of (landing) gears to raise elevation or "kneel" down to grab on. Use more than one klaw at different elevations to dock with small or tall ships.

I hope this helps.

Edited March 3, 2016 by Kamenjar

[tsotha]

KIS/KAS is fine.  There aren't that many extra parts.

One thing I would do, though, is hook the ships up though one of the ground pylons instead of hooking them up directly.  Things tend to be more stable, and if you put out a grid of pylons you don't have to worry about ground handling with the tanker.

Edited March 4, 2016 by tsotha