Kethane, Jool & You

[Cashen]

Hello everyone! I have a poll for all of you Kethane miners out there. Or Kethane drillers (I like to use oil terminology for Kethane over mineral terminology, since I view Kethane as a liquid or a pressurized gas, but that's neither here or there!)

Let's assume you have a long-term project to explore/colonize the Jool system, primary Laythe, and your main base of operations is therefore on/orbiting Laythe. Laythe is gorgeous, has an atmosphere with oxygen, clear blue water, a fantastic view of Jool (for half of the surface anyway), but it has issues. Only a small part of its surface is land, and like always Kethane deposits are scattered about. So, let's start off with some basic assumptions:

1. Kethane deposits on Laythe are all under the oceans and essentially unobtainable.
   
2. You wish to use Kethane to sustain your operation far away from Kerbin, and because of point 1 above, you are forced to set up drilling operations on one of Jool's other moons and import it to Laythe.
   

The question now becomes, which other moon do you set up extraction operations on? You have four choices. Here are the pros and cons of each:

VALL

• Ideal delta-v to transfer from Laythe: 546.25m/s
  
• Delta-v to land or take off: 1180m/s
  
• Surface gravity: 2.31m/s²
  
• Inclination: 0
  
• Eccentricity: 0
  

Pros:

• Closest moon to Laythe, requires the least delta-v to reach
  
• On a circular orbit in the same plane as Laythe, transfers are easy and no plane changes required
  

Cons:

• Fairly high surface gravity, will require a higher thrust-to-weight ratio and more delta-v to land and launch from.
  
• Fairly uneven surface, landings may not be easy.
  

TYLO

• Ideal delta-v to transfer from Laythe: 592.27m/s
  
• Delta-v to land or take off: 3070m/s
  
• Surface gravity: 7.85m/s²
  
• Inclination: 0
  
• Eccentricity: 0
  

Pros:

• On a circular orbit in the same plane as Laythe, transfers are easy and no plane changes required.
  

Cons:

• Highest surface gravity. Probably the least suitable moon due to the high delta-v required to land and take off from.
  
• The only pro for Tylo is also a Pro for Vall, and Vall is much easier to land on. This more or less eliminates Tylo, honestly.
  

BOP

• Ideal delta-v to transfer from Laythe: 645.90m/s
  
• Delta-v to land or take off: 276m/s
  
• Surface gravity: 0.589m/s²
  
• Inclination: 15
  
• Eccentricity: 0.24
  

Pros:

• Very low surface gravity, landings would be easy and require very little fuel.
  
• Probably the easiest terrain to land on, less rugged than the other moons.
  

Cons:

• Slightly more delta-v to reach than the larger, inner moons.
  
• Highly inclined and eccentric orbit makes a significant plane change required, and transfer delta-v may vary from ideal.
  

POL

• Ideal delta-v to transfer from Laythe: 673.17m/s
  
• Delta-v to land or take off: 180m/s
  
• Surface gravity: 0.373m/s²
  
• Inclination: 4.25
  
• Eccentricity: 0.17
  

Pros:

• Lowest surface gravity. Easiest to take off and land from. Would require the least delta-v.
  
• Orbit much less inclined and eccentric than Bop, may actually require less delta-v to reach when plane changing considered.
  
• Slowest orbital velocity relative to Laythe, means phase angles align more frequently.
  

Cons:

• Furthest moon. Requires the most delta-v to reach in ideal terms (ignoring plane changes and eccentricity).
  
• Very rugged terrain, probably fewer good landing spots than Bop.
  
• Furthest moon, means transfers back and forth would take the longest.
  

[Majiir]

I cast my vote for Bop because it's easy to lift fuel from and its terrain is much nicer than Pol. I've never actually landed there, but I found when tuning the grid radii that Bop was among the smoothest of the small moons. It has a lot of peaks, but there are many flat areas for landing. That's a significant advantage over Pol, and the lower surface gravity makes the higher transfer delta-V completely irrelevant, especially since you can use low-thrust, high-efficiency engines for the transfers.

I wonder how this would work in practice. If you have MechJeb or happen to be good at precision landings, you can use a simple parachute lander and transfer fuel that way, but otherwise a reusable spaceplane might work best.

[Cashen]

I was leaning more towards Pol myself. More rugged, yes, but much less inclined orbit and its gravity is lower than Bop. In terms of straight up efficiency, I think Pol wins, but, like you said, in practical terms, its advantages over Bop are small enough that the smoother terrain of Bop and ease of landing make Bop highly attractive as well.

I actually plan on doing exactly this in my upcoming mission logs. I'm going to use a rocket powered lander with high efficiency engines optimized to get a thrust-to-weight ratio between 1.5 and 2.0 on whichever moon when fully loaded - basically, maximize the percentage of the vessel's loaded mass that is Kethane, with minimum fuel, engine, structural and drill weight. Just enough fuel for enough delta-v to reach an orbital station at the moon in question where the converters will be (again avoiding extra mass of converters on the drilling rocket).

Edited July 18, 2013 by Cashen

[KhaosCorp]

1. Kethane deposits on Laythe are all under the oceans and essentially unobtainable.
   
2. You wish to use Kethane to sustain your operation far away from Kerbin, and because of point 1 above, you are forced to set up drilling operations on one of Jool's other moons and import it to Laythe.
   

#1 is a poor assumption to make. Off-shore drilling is very possible and actually not hard to do...just very time consuming.

As for places other than Laythe Id say Bop, just based on effecincy of gettin fuel in orbit.

[Cashen]

#1 is a poor assumption to make. Off-shore drilling is very possible and actually not hard to do...just very time consuming.

As for places other than Laythe Id say Bop, just based on effecincy of gettin fuel in orbit.

Yep, I'm aware it's possible, but it's kind of a hassle and not something I plan to do, hence why I used it as a starting point.

[KhaosCorp]

Maybe it wont be so much of a hassle in the near future...=P

[Cashen]

Maybe it wont be so much of a hassle in the near future...=P

Maybe. I'd still get it from the other moons likely, since I plan to explore the whole Jool system and not just Laythe (base in orbit instead of on the surface), and hauling fuel or Kethane up from Laythe's gravity well/atmosphere isn't ideal either.

[KhaosCorp]

Maybe. I'd still get it from the other moons likely, since I plan to explore the whole Jool system and not just Laythe (base in orbit instead of on the surface), and hauling fuel or Kethane up from Laythe's gravity well/atmosphere isn't ideal either.

No, and certainly not if its with intents of making a fuel depot in orbit.

I say Bop with the given conditions. Im temped to say Vall, the gravity can be countered with tiny jumpships and lots of trips, but the probable landing sites make it not worthwhile. Kinda the same deal going on with Laythe too. Not the kind of landing you want to do over and over again for sure..

[BlazingAngel665]

I am thinking that using a floating drilling platform might be just as much (if not more) fun. I am still not sure how to keep my Extraplanetary Launch pad floating so this plan is on hold. . . .

Pol is optimal for off world drilling though. When all delta V considerations are made you will save a large amount of fuel by having a permanent outpost with all the mining equipment and a NERVA powered fuel transfer craft. Further reduce Delta V by doing direct ascent injections and aerobraking at laythe and all of a sudden the single NERVA and a rockmax tank might actually work.

[Cashen]

I am thinking that using a floating drilling platform might be just as much (if not more) fun. I am still not sure how to keep my Extraplanetary Launch pad floating so this plan is on hold. . . .

Pol is optimal for off world drilling though. When all delta V considerations are made you will save a large amount of fuel by having a permanent outpost with all the mining equipment and a NERVA powered fuel transfer craft. Further reduce Delta V by doing direct ascent injections and aerobraking at laythe and all of a sudden the single NERVA and a rockmax tank might actually work.

Yeah, what I had envisioned on either Pol or Bop was a purpose built drilling rig that would land, fill up with Kethane, and have just enough TWR and delta-v to make it back up to the low-orbiting refinery station, which would accept the Kethane and convert it. Or at least some of it. Then have another purpose built craft that would simply ferry the Kethane or fuel to the station at Laythe (with aerobreaking of course) to achieve maximum efficiency. All using nuclear rockets.

I'd either be exploring/working on Laythe with SSTO spaceplanes that could refuel at the orbital station, or, more likely, with jet aircraft bound to the atmosphere, so I'd have a vertical SSTO rocket that would ferry jet fuel down to the surface for them and then come back up.

[KhaosCorp]

Yeah, what I had envisioned on either Pol or Bop was a purpose built drilling rig that would land, fill up with Kethane, and have just enough TWR and delta-v to make it back up to the low-orbiting refinery station, which would accept the Kethane and convert it. Or at least some of it. Then have another purpose built craft that would simply ferry the Kethane or fuel to the station at Laythe (with aerobreaking of course) to achieve maximum efficiency. All using nuclear rockets.

This is almost exactly how I run 100% of my mining operations.

The only thing I do different is I have dedicated wellheads that once landed never leave a planet/moon (they do move from deposit to deposit). They drill and store kethane/ore, usually rover based so they can meet the jumpships if I land a bit off.

This allows for smaller, simpler jumpships to do all the exporting, making that bit of the loop a bit more effective.

[Cashen]

This is almost exactly how I run 100% of my mining operations.

The only thing I do different is I have dedicated wellheads that once landed never leave a planet/moon (they do move from deposit to deposit). They drill and store kethane/ore, usually rover based so they can meet the jumpships if I land a bit off.

This allows for smaller, simpler jumpships to do all the exporting, making that bit of the loop a bit more effective.

Yeah that would take the efficiency up even higher since your export ship wouldn't even need the extra weight of drills, and delta-v for rovers is irrelevant. I've thought of going that route too.

[SunJumper]

Would it be more effective to design the lander so that it basically runs out of fuel upon landing on Pol/Bop, and then use fuel from the Kethane to return?

Anyway, I think Kethane generates under the landmasses of Laythe, so if you find a source under land, that is where you ought to have the base. If we pretend Laythe has no Kethane, then Pol or Bop are best. Pol is in a less inclined and less eccentric orbit, so there is that. Also, the long transfer times shouldn't matter too much, I'd presume drilling time would be significant, and Jeb doesn't mind extra zero G time...

[Eric S]

The only time I tried to use kethane on Pol, the overlap of places level enough to land on and places with kethane was virtually nonexistent. Then again, if your mining craft is squat enough, that might not be as much of an issue.

[Cashen]

Would it be more effective to design the lander so that it basically runs out of fuel upon landing on Pol/Bop, and then use fuel from the Kethane to return?

Anyway, I think Kethane generates under the landmasses of Laythe, so if you find a source under land, that is where you ought to have the base. If we pretend Laythe has no Kethane, then Pol or Bop are best. Pol is in a less inclined and less eccentric orbit, so there is that. Also, the long transfer times shouldn't matter too much, I'd presume drilling time would be significant, and Jeb doesn't mind extra zero G time...

It will always take more fuel to take off with a full load than it will to land with, because of the extra weight. However I see your point - you should design it with only enough fuel to take off with, which implies that the landing will consume some of that and you'd have to make up the difference by converting some. However the weight of the converter would have to factor into that, which would require still more delta-v.

[KhaosCorp]

The only time I tried to use kethane on Pol, the overlap of places level enough to land on and places with kethane was virtually nonexistent. Then again, if your mining craft is squat enough, that might not be as much of an issue.

Once MSI animation control is released I will be releasing some industrial lander-legs to make this issue a thing of the past.

[Eric S]

Once MSI animation control is released I will be releasing some industrial lander-legs to make this issue a thing of the past.

Sounds good, last time I built a lander that was an all-in-one kethane processing plant, I put Weyland's ED-209 legs on it, and called it Frankenlander.

[Snarfield]

I'd set up a small mining operation on Vall for when your Laythe colony is low and needs emergency Kethane, and a much larger, primary mining operation on Pol which delivers massive amounts of Kethane to Laythe, but much less frequently.

[Captain Sierra]

Personally, I'm not out to Jool yet. I was just about to start launching and assembling a mobile base that was going to go out to the Mun and set up the first of 3 major kethane operations but I canceled that plan after the announcement that .21 would be save breaking. What mods will be broken in .21 I wonder. I'm an avid user of KSPX, Kethane, and a few others.

EDIT: my next target was planning to be Duna, where I'd be using a lot of probes (no need for return) for a roving kethane operation supported by a manned space station orbiting. The manned operation (if I have one) would be on Ike. (watch out for the magic boulder ; )

Edited July 21, 2013 by Captain Sierra

[Cashen]

I'd set up a small mining operation on Vall for when your Laythe colony is low and needs emergency Kethane, and a much larger, primary mining operation on Pol which delivers massive amounts of Kethane to Laythe, but much less frequently.

The problem with Vall, aside from it having much higher gravity than the two outer moons, is that its closeness to Laythe is deceptive. Yes, transit times are much shorter, but the closeness also means the phase angles align less frequently since Vall moves quite quick relative to Laythe, so it takes Laythe longer to catch up in orbit. If you've ever tried to do a rendezvous in Kerbin orbit between two craft at different orbital altitudes, you know that the closer your orbits are together, the less delta-v you need but the longer you have to wait to get the alignment right.

My plan is to have an excess of stuff in the system. Using the big spherical tanks mod, the stations will have a full tank of propellant plus a full tank of Kethane, which should last a long time.

[Captain Sierra]

After some thinking (and a failed mission in which I lost 2 of 4 scouting probes; I have yet to attempt the burns on the other two, so I may lose them as well), I figure the best way to operate (assuming you use extraplanetary launch pads) is to set up a base on Lathe supported by a small orbital station. Then you'd set up a large orbital station around tylo. It's large gravity well makes for easy SoI captures and it being the 2rd of 5 moons makes it the ideal location for a large space station (just not so much ground operations). I'd keep a small mobile ground operation going on Vall because it is close and even at peak time, it can deliver to Lathe rather quickly if it needs it. The big land ops would be obviously on bop and pol. I personally lean towards pol because it's less inclined and easier to transfer to. Both would be good locations for large scale ground operations but I imagine my Pol operation would be bigger given it's easier to get to (IMO) but that could change if I get a big deposit under a flat spot on Bop.

EDIT: What is a good way to access offshore kethane deposits on Lathe? I can't figure out how to do it. If it is any help, I read something about using KAS and I do have that.

[Kimberly]

EDIT: What is a good way to access offshore kethane deposits on Lathe? I can't figure out how to do it. If it is any help, I read something about using KAS and I do have that.

You need something to make yourself sink. You can do this with thrust from engines, or just attaching something really heavy to your craft. If you use KAS, you can attach the drill to a winch and attach the heavy stuff to the winch, while your main craft remains on the surface (you'll have to edit the winch to make it longer). Alternatively, you can push your whole craft down through any means and use the grappling hook to attach it to the sea floor.

[Captain Sierra]

Hmmm, the second option gives me an idea. Grapple the floor and pull a small drill rig down while using a second KAS which to hook to a floating surface platform that can dock with other stuff and serve as a pipeline. You did say I do need to edit the .cfg and make a duplicate which with a rediculous range to hit seabed though. Easy enough . . .

[Kimberly]

This should work on paper, but I've never actually tried it, so please don't blame me if there any explosions. But I think that as long as the sea bottom is within the rendering range, you should be able to have a submersed rig and a connected platform on the surface, sure. The camera will probably get awkward, though.

[Millitron]

The problem with a drilling rig on the surface is that the KAS cable can only be at maximum, 2.5km, since that's the limit for physics. This means you can't drill anywhere deeper than 2.5km. Probably even less since it's doubtful you'll go perfectly straight down.

I propose a drilling submarine. Instead of leaving a rig on the surface, take the whole operation to the bottom. That way you can drill in any depth of water.

Just be careful not to leave the base on the bottom. A couple versions ago, I tried a submerged base, and when I reloaded it, none of my controls worked. Even the camera controls and IVA were broken. I doubt that's been looked at by Squad, since submerged bases aren't high on their list of priorities.