Laythe orbital refuel

[bjerrang]

So spacestation and lander is on its way to laythe.

How can i refuel this ,  looking for a good solution.

I have a spacestation , refuelers , ore at pol , medium grabber 5000dV

 

Should i land at Laythe , produce fuel the rendezvous with space station.

Or refuel at pol , transfer the fuel to laythe ?

 

Or build a huge grabber with a Kerbodyne S3-14400 Tank  & Rhino / Vector ?

[Draalo]

Laythe has a thick atmo which makes a lift off hard and fuel consuming.

Pol has no atmo and less gravity...

... question answered?

[bjerrang]

5 hours ago, Draalo said:

Laythe has a thick atmo which makes a lift off hard and fuel consuming.

Pol has no atmo and less gravity...

... question answered?

Ii think so , ill send a bigass tanker then

[Aegolius13]

Vall is a decent option too; it's very quick and easy to transfer to Laythe.   But it takes more dv to reach orbit than Pol,  so you will likely get less net fuel on each run. 

I would recommend the Rhino over the Vector for this application, as far as stats go. But you may need a ridiculously big ship to make the Rhino not overkill.  Nukes can also work well,  especially if you mine from Pol, since your TWR need should be minimal. 

[Geschosskopf]

On 12/27/2017 at 12:10 PM, bjerrang said:

Should i land at Laythe , produce fuel the rendezvous with space station.

Or refuel at pol , transfer the fuel to laythe ?

It all depends on how extensively you want to explore/exploit Laythe.  If you're just going to land a rocket lander there, plant a flag, and leave, then what you need is very different from if you want to build a semi-permanent surface base and explore the whole place with airplanes.

For simple landers with parachutes and stuff, it's possible to build them with enough fuel to land 1 time and then return to orbit without refueling.  However, such landers are huge, difficult to control, and also there's the problem of actually being able to hit one of the small spots of land without a bunch of trial and error.  Still, if you're just going a 1-and-done flag plant, this is probably the best option.  Then your Kerbin-return ship would have enough fuel to get home and you wouldn't refuel at all.

Now suppose you want to thoroughly explore Laythe with airplanes that can't get back to space, and you have an SSTO spaceplane to move crew back and forth between the surface and a station in Low Laythe Orbit.  All this happens out of a surface base.  And your Kerbin-return ship needs fuel to get home.  In this case, you need 2 separate fuel operations.  One on the surface of Laythe, at your base there.  This one refuels the airplanes and the SSTO spaceplane.  Then you need another one in space to refuel the Kerbin-return ship (and any vacuum-only ships exploring the other moons).  The fuel for the space ships must come from somewhere else in the Jool system, NOT the surface of Laythe, because you burn nearly as much fuel getting to LLO as you do LKO.

For spaceship fuel, you have several options:

Vall:

• Pros:  Closest to Laythe so short travel time.  Lots of flat ground to land on (usually with decent amounts of fuel).  Has Vall-Henge to go look at.
• Cons:  Higher gravity than other options, which requires more complexity to minimize the issues that causes

Bop:

• Pros:  Low gravity simplifies fuel system.  Can visit the Kraken.
• Cons:  Still relatively far from Laythe, so long trips.  Inclined orbit increases transfer costs.

Pol

• Pros:  very little gravity so no need for complexity on the surface fuel side.
• Cons:  VERY far from Laythe so trips take weeks and the transfers are more expensive than from Vall, even if the take-off and landing is cheaper.  Has BUGGED surface collider that frequently causes ships to explode when landing or taking off.

Asteroids (IOW, small Joolean moonlets created with Custom Asteroids or Kopernicus)

• Pros:  no gravity whatsoever.  Can be relatively close to Laythe.
• Cons:  Luck-of-the-draw on location and resource abundance.  Finite resources (but renewable).  Those inside Laythe orbit are rather expensive to get to and back from.

On the whole, I prefer using Vall myself.  Pol's surface collider bugs are so dangerous that I would not stake the survival of a complex Jool mission on them.  I only land 1-shot probes and my most expendable Kerbals on Pol, and don';t expect them to return.  Bop's better, but I just don't like the long travel times.  So I'm willing to spend the money on a complex (but fast and reliable) Vall system, composed of:

• Surface base to mine/refine
• A collection of fuel tanks in Vall orbit (not really a station, just a transshipment point)
• 1 or 2 dedicated fuel lifter than just goes back and forth between the surface base and the orbital fuel tanks.  Having 2 means 1 can be loading while the other is flying.  It's either this or have large storage tanks at the surface base.
• 1 or 2 dedicated fuel transport that just goes back and forth between the Vall orbital tanks and the Laythe station.  2 so while one is going to Laythe, the other is coming back to Vall to reload.

That might sound like a lot, but if you're going to Jool in a big way, seeing all the stuff, establishing permanent colonies, etc., you need a substantial fuel infrastructure and Bop and Pol just can't do that.

 

 

 

Edited December 29, 2017 by Geschosskopf