Saltpeter

You don't have to make the depot with kethane equipment, I'll just add it myself via ports. I have KAS, and I think it's not installed properly. I prefer not to use it when I can avoid it.

Not a good time to realize you forgot to put RCS thrusters on the tug.

The fuel depot of Minmusopolis does have its engine, yes. That's how it got there in the first place! Suppose I was to commission you to build a super-big fuel depot custom-made for Laythian orbit, intended to fill up by refining kethane from any of the moons in the Joolian system. I'd want it to have 21 large tanks(7 stacks of 3 in the same familiar hexagon shape), at least four engines for moving around(3x nuclear blocks or big engines, your choice), 6 Senior ports (3 front, 3 rear), one regular port, a Hitchhiker for permanent staffing, and lighting for all the important bits. It has to have a monoprop and xenon capacity of at least 10,000 units each. As it stands, the Triskelion has failed in its mission. Not as a fault of the ship, but due to a lack of testing of the kethane equipment. KSP scientists are trying to shift the blame onto Donory Kerman, but the kerbs watching the mission on TV have rallied to support him.

It's not powerful enough. And apparently the description of the kethane engine is misleading, in that it doesn't actually function without air. Maybe it is only meant to suggest that it works in any kind of atmosphere. I will have to create a bigger tug, and use a standard engine to lift the ferry. A shame, that.

I've fashioned a small tug with a grabbing arm to get the ferry high enough to turn around, activate its kethan engines, and get the kerb out of there.

I have a small problem. The RCS thrusters cannot lift full kethane tanks off of Minmus, but I'd hate for so much kethane to go to waste. I have to figure out a way to get the ferry ship off of Minmus without simply terminating it. I have an idea. Stand by.

Minmusopolis is complete! Now to try and get the ferry back on kethane engines.

The new kethane ferry is stable when full now. Scientists insist that the landing gear on the tank unit digging into the ground is an intended feature for stability. Yes, stability, that's it.

So the wide fuel tanks under the kethane tanks can't route to the engine. No big deal.

The new Tank. This one has beams to stabilize the ferry ship when it lands. It's also got threefold symmetry and is much wider than it is tall, so it's much less likely to tip over when a top-heavy ferry lands on its center port.

The tank unit lives though! However, I feel the flaw in this design may be the tank. I can't really change the shape of the ferry much. I know what I must do!

The tank, when full, makes the construct far too top-heavy. This happened. A redesign is necessary.

The tank and ferry on Minmus. The ferry has capacity for over 100K units of kethane. KSP scientists are excited to explore this mysterious hydrokerbon. Among the practical applications with rocketry, military-sanctioned medical experiments with kethamphetamines as performance-boosting drugs are also underway. The official statement is that it is to find a cure for Bill Kerman's deep psychological traumas incurred on the surface of Ike.

The Kethane tank on Minmus despawned. I am going to deliver it to Minmus with the test rocket and pretend this never happened. In the meantime, the kethane ferry has arrived in low-Minmus orbit.

It took nearly all of the monoprop to land the module safely. There's just barely enough left to fill up the SPACE TRUCK once. But now mining can commence!

The SPACE TRUCK and the tanks are now properly assembled and awaiting deorbit. 1650 monoprop should be more than enough.

One of the tanks had no monoprop when I undocked it. It turns out these tanks are really hard to dock. I need to get the tanks back to the triskelion to fill up on monoprop before I take it to Minmus.

The Triskelion is not going to go right to Minmusopolis. First it will deliver the SPACE TRUCK and the Tank unit to the surface of Minmus. And it just occurred to me. I forgot to make and deliver the kethane-fueled shuttle to the Triskelion. Oops.

Slingshot maneuver, anyone?

The Triskelion has disembarked from Hexaflexagon Station with 30% fuel. The mission specs indicated 20% fuel cap, but honestly, 10% of fuel would be enough, so the wiggle room is permissible.

Before we embark, presenting the standing Triskelion Crew! Captain and Helmsman, Donory Kerman, has been heading the Triskelion project ever since Mk. II of the station design. Lander pilot and second-in-command, Jerwin Kerman, is one of the KSP's steadiest hands. He likes to do the "Lets-go-to-the-moon" dance whenever he goes to the moon. Kerbal legend and rocketry entrepreneur, Jebediah Kerman, kinda decided he wanted to go along and no one disagreed. Science officer, Sigsey Kerman, keeps to himself in the lab module. What a nerd. Lander pilot understudy, Merkin Kerman, doesn't mind not having to fly the lander as much. He eats all of Jerwin's snacks. Internal staff, Jim Kerman, spends his time entertaining the crew with his ability to breathe in vacuum. He will make his permanent home in the SPACE TRUCK Kerbal legend and internal staff, Bill Kerman, was asked to come along by Jebediah because the rest of the crew wasn't famous enough for Jeb's standards.

Shot of the pods after a successful mission. The plane is in the background. The time has come for the Triskelion to head out to Minmus!

The second load of kerbals to return home are Kirk, Lobal, and Kelbald, the three former residents of Dres. After they get home, the Triskelion will set off for Minmus.

The plane locates the KSC and prepares to release the payload! Away they go! Err...there appear to be technical difficulties. Hundreds of people watched them land! Calbart confirmed the landing! They must've been whisked away by the Kerbal Military for debriefing. There is still one more plane load of kerbals to bring home! (They unloaded when the jet left grid while they were still descending. I'm not going to try and redo this until it works within the confines of the game's limitations. D: )

Good luck, and kerbspeed, brave heroes!