Kethane mining. All in one VS separate task vehicles.

[Galane]

I've run through a series of all in one Kethane mining rovers, started with a 4,000 unit model that went through some revisions, then a failed 8,000 unit design with two 4,000 unit tanks, followed by a single tank 8,000 unit model and a single tank 16,000 unit rover and finally a 32,000 unit dual tank lander.

All of them eventually successful but the 4K and 8K ones don't haul enough Kethane to be worth the trip up from Mun and the 16K and 32K ones suffer from the needs more fuel/add more fuel/needs more fuel to lift the extra fuel loop. As they are, they need to sit and make fuel for a bit to rendezvous with the tankers/refineries in Mun orbit. The first 4,000 unit versions don't have an onboard converter so they can't make fuel and don't carry enough to get back up to orbit after landing. They do work on Minmus, enough fuel to get down, tank up on Kethane then lift and rendezvous then refuel from the refinery.

So last night I tried my Kethane drilling rover with two heavy drills and a DROMOMAN+Infernal Robotics docking arm along with a 32K lander with its two heavy drills removed and a couple of side mounted clampotrons added. (The rover turned out to not be able to reach the top mounted port, even after I took out the short girder supporting the port.)

Results were disappointing. Aligning the port on the arm and on the lander weren't too difficult. I positioned the camera behind the port and drove back and forth a few times to align sideways then used the arm for fine sideways alignment and to adjust for height and tilt.

The problems came from the ports not wanting to lock together. I had to nearly crash the rover into the lander and come close to joint failure on the arm before they'd connect. That ate up quite a bit of time, so did landing over 3KM away from the rover. Not wanting to have MechJeb land ON the rover, when it got to just before the final descent burn I quickly aborted the landing then clicked land somewhere. (Need to develop a low profile, self sustaining, targetable beacon.)

Once connected I transferred all remaining rover fuel to the lander and jettisoned the rover's tanks and engines. (With Seperatrons so they'd go high and crash land. I like self-terminating debris.) Tanking up on Kethane proceded same as with the drills on the lander.

The last nail in this project's failbox came when the lander hardly used any less fuel getting back up to orbit than it did as an all in one with the two heavy drills. After making delivery and refinement of the 32K units of Kethane I crashed the lander then blew off some time driving the drill rover to destruction.

I'm thinking I should bring the whole operation down to a 10KM Mun orbit from its current 15KM orbit. Think that would make much difference in the rovers' and landers' fuel use?

How do you go about mining Kethane? Everything on the same vehicle or leave vehicles on the surface to do the drilling and other vehicles to carry it up to orbit or do you refine it on the surface and carry the fuel and other products up to orbit?

[spiritplumber]

I find it more efficient to have a "gas station" on the surface, it cuts down on the number of landings and dockings. On occasion I may use a refuel truck.

[KhaosCorp]

Ok, first off your higher Mun orbit is actually a bit better..the little extra Dv to pop up to the correct altitude will be made up when it comes to everything else (redevs and docking).

Best way to mine Kethane really depends on playstyle and desired end result. I find the multi-role 'all in one' harvesters are grossly ineffective at doing anything but refilling their own tanks..maybe feeding a few smaller ships. For long term, mass harvesting operations I prefer to make several smaller single-role craft.

First on the ground in the Wellhead, small lander type craft with drills and decent kethane storage. These ships typicaly dont leave planet once deployed(they they are able to move, either via short jumps or skycrane).

Next in line would be the transport truck. The sole purpose of these is delivering kethane to the dropships.

Next, of course, would be the dropships and planetside processing. At this point I either load the kethane into a ground based refinery (this is only done if the fuel made will be used on said planet), or it gets loaded into a dropship. These are small lander type craft that can carry a large amount of kethane up to orbit...they are tailor made for the planet they will be operating on/around. The dropships have just enough engine/fuel to touch down, make orbit, and redevs once...anything more cuts into overall productivity.

One in orbit the kethane is transfered to orbital station, where its either processed into needed fuels, or later transfered to a larger facility where the fuel is needed.

Really though it comes down to playstyle....you can mine kethane 100 different ways, and unless you are just down right horrible at craft design your gonna see a net gain from your mining ops.

[maltesh]

For the most part, I don't ship Kethane.

99% of what my spacecraft need is Fuel and Oxidizer. The vast majority of my dockings use less than 15 units of monoprop. The only ion drive spacecraft I use, I consider one-way probes, or toys. As a result, I tend to refine on the surface, and ship fuel and oxidizer to orbit. Kethane patches are huge, and if I decide it needs to be stored, I usually leave it in the ground.

Invaluable to my setup were two mods:

Kerbal Attachment System (To allow Kerbals to connect the various spacecraft together)

TAC Fuel Balancer (To automatically pump fuel and oxidizer from one part of a spacecraft to another, and back)

This was the basic setup I wound up running over the Mun in 0.21.

In the Left foreground, the Wellhead. Left in place on the Mun, it used three large drills, and a single large converter, powered by three Kethane reactors to mine and refine Kethane. Kerbals stationed in a Habshack nearby used one of its three KAS Winches to attach to the Citrus-Class Spheretanker, shown in the background, whose spherical tank holds appoximately 3/4 the voulme of a Rockomax Jumbo-64.

Also shown: A flag being used in the capacity of "low-profile, self-sustaining targetable beacon," as per Galane's musing in the original post.

If you are not going to be using them in that capacity, it can be helpful to remember that if you divide the radius of the world you're landing on by 200 km, the result is very nearly the linear distance in meters of one second of arc Latitude. e.g, 0°0'10" North of target on the Munar surface is approximately 10m North of the target.

The Citrus-class Spheretanker uses paired LV-Ns as its landing and drive engines; as a result, it typically only used about 1/7 of its capacity to go from the munar surface to a 50 kilometer altitude orbit for rendezvous with the Depotsphere, as shown above. The particular depotsphere in the image holds about 6 Rockomax Jumbo-64's worth of fuel when filled. I never even came close to emptying the monoprop tanks it had.

The Ultimate setup I wound up using over Minmus was different, primarily because I got tired of needing to make nine trips to fill a depotphere, and I had decided to send two depotspheres as part of the 20-ship Dunar fleet. Minmus' significantly lower gravity, and having to get twenty other spacecraft ready before the window made me decide to go with the "Ship Kethane" option.

It is hard to tell from this viewpoint, but the Minmal Sphereminer has four Rockomax-16 fuel tanks clipped into its sides, which, if I recall correctly, turned out to be something like 4-8 times the fuel capacity it actually needed to perform its mission. It used four small drills powered by a single Kethane reactor to fill its 96,000 unit spherical tank Kethane capacity, after which it used its four LV-Ns to return to orbit.

Once in orbit, it would dock with the nuclear-powered refining station, and fill up the storage depotsphere with refined fuel and oxidizer. I would later ship other depotspheres to Minmus, fill them up from this facility, and send two of them to Duna, and one to Eve.

[KhaosCorp]

Really the only reason I like to boost the kethane into orbit rather than actual fuel is it allows to you to keep the Jumpship design very basic. This comes in handy when using kethane alongside EPLP mod. Simple design = less part count = less rocket part to build away from KSC.....in the event I crash a jumpship =)