A Reusable Laythe Fuel Tanker

[Sauron]

So, this is a tricky one. I'm building a permanent base on Laythe (yeah, right before .21, I know ) but I have a problem. I'm mining kethane on Pol and moving it by tanker into Laythe orbit. However, I'd really like to bring fuel down to the surface. Right now I can only refuel my SSTOs in orbit which greatly complicates things if I get stranded.

So this calls for a reusable spaceplane, but one that can actually move a large amount of extra fuel down in one go (ideally about half of a Big Orange Tank per mission) and then reliably take off with enough fuel left to make orbit and rendezvous. Unfortunately, I haven't really figured out large SSTOs.

While this mission will be greatly simplified by the fact that I'll be taking off with a lot of empty tanks, I'm not really sure how to handle the construction of such a large spaceplane or the balancing of such a large amount of empty space. Also, I see a lot of LV-Ns on spaceplanes, but I've never figured out how to make this work.

[Captain Sierra]

You do know you can save your Lathe base. Here is how to do it: Go copy your save folder just before updating. Open the persistent.sfs in a text editor (I like notepad). Update KSP, create new save. Close KSP, open the new save's persistent.sfs in a text editor (new window). Copy the contents of the old one to the new one. You may as well remove all landed craft on the Mun and on Kerbin since the terrain changes will likely put them underground (and they then go boom). Everything else is now saved. This means in my case, I have to update BEFORE landing any modules of my Munar kethane base.

[Starwaster]

Maybe B9's Sabre engines? Or for that matter the entire B9 pack. Geared entirely to large space planes. I don't know if there are any B9 specific kethane tank conversions but you could probably solve that with the custom (procedural? modular?) fuel tank mod. I have yet to try that; it's on my 'very soon' list.

Failing that, the cargo hold could have kethane tanks added to it. (connected via the small docking ports?)

Also, nuclear planes? That sounds messed up, the ISP is way too low in atmo.

There WERE serious designs for nuclear air breathing engines decades ago that never came to fruition (I'm sure you can think of some obvious environmental / safety reasons...) but those worked entirely different from the LVN which is based on something else entirely. I dunno, sounds wacky to me.

[Johnno]

Also, nuclear planes? That sounds messed up, the ISP is way too low in atmo.

If I recall correctly the LV-N has around 400 ISP at sealevel on Laythe. Before 2000 meters in altitude it has 500 ISP. Around 17km you should have nearly full 800 ISP.

[draeath]

There WERE serious designs for nuclear air breathing engines decades ago that never came to fruition (I'm sure you can think of some obvious environmental / safety reasons...) but those worked entirely different from the LVN which is based on something else entirely. I dunno, sounds wacky to me.

Probably superheat the intake air and use it to spin the compressor blades of the engine.

[numerobis]

the balancing of such a large amount of empty space.

The easy solution is just to make sure the tanks are aligned with the center of mass. That way, whether they are empty or full, your center of mass doesn't move.

The easiest place to put them to achieve this is out on the wings. Spreading the mass out over the wings also helps spread out the forces (lift versus gravity) so you don't get a huge torque at the attachment point between your wings and your fuselage.

As for how to use an LV-N on a spaceplane: easy. A spaceplane can easily reach orbital speed on Laythe, given its reduced gravity, even with just one intake per jet. So you just need a tiny amount of thrust to make orbit. If you're then going to do interplanetary maneuvers, might as well get that tiny amount of thrust from an LV-N to save fuel.

Edited July 23, 2013 by numerobis

[Captain Sierra]

something scary: a cold war era Lockheed research facility (underground reactor and everything) for said nuclear planes is in the woods near where I live, just on the other side of the county. Even though the surface structures are demolished and the underground areas are mostly cemented in, you can still get into parts of it under there.

[Kimberly]

something scary: a cold war era Lockheed research facility (underground reactor and everything) for said nuclear planes is in the woods near where I live, just on the other side of the county. Even though the surface structures are demolished and the underground areas are mostly cemented in, you can still get into parts of it under there.

What's scary about that? That sounds awesome!

[Captain Sierra]

Many of my friends hunt in that area. 3 eyed deer, 2 headed sqirrel, all kinds of radioactively mutated stuff is around there. The only thing to keep people out is a 2 foot high fence (looks like a hitching post painted yellow).

[Cashen]

I plan to do something similar, maintaining a base on Laythe using Kethane from Bop. My plan however is to use a vertically launched and vertically landing rocket to accomplish the fuel transfers. A SSTO rocket on Laythe is easy because you only need about 2800m/s of delta v to get into orbit, so you can build a single stage rocket with a large payload mass fraction.

[draeath]

Many of my friends hunt in that area. 3 eyed deer, 2 headed sqirrel, all kinds of radioactively mutated stuff is around there. The only thing to keep people out is a 2 foot high fence (looks like a hitching post painted yellow).

Pardon me if I don't buy that without photos. That much mutagens in the area would be mostly fatal (enough so that hunting would not be viable)

[HoY]

My Laythe base gets its fuel from Vall. Its much easier to land on and take off from

[Captain Sierra]

When school is back in session I will ask them if they have any. If I post a pic of a 5 legged deer, will you buy it then?

EDIT: This discussion is off topic. Back to helping that guy with a Lathe tanker SSTO.

[draeath]

So long as it's more than 50dpi, yes

[Starwaster]

something scary: a cold war era Lockheed research facility (underground reactor and everything) for said nuclear planes is in the woods near where I live, just on the other side of the county. Even though the surface structures are demolished and the underground areas are mostly cemented in, you can still get into parts of it under there.

They don't post guards or anything to keep people out?

[bsalis]

I have done this. A complete system for exploring Laythe by plane. However I shipped fuel and oxidiser from Kerbin. I don't use Kethane.

You can read my complete (pic heavy) exploration mission if you want. Post #19 on Page #2 has more details on refueling.

I'm not sure what you are planning, however if you are just exploring Laythe with SSTO spaceplanes, you should not need to bring large amounts of fuel down. The reason being is that when you take the plane down to the surface, you fill it to full with fuel, and only as much oxidiser needed to get back to orbit. Then offload the back-to-orbit fuel and oxidiser into the tanker.

This will give you plenty of fuel to fly around efficiently. Then you load up on fuel and oxidiser from the tanker when you want to go back to orbit. I explored all of Laythe with dozens of flights, and only did two fuel runs from orbit.

[Sephta]

The question is, do you need a spaceplane for Kethane mining on Laythe?

If yes:

you can use air breathing engines on Laythe, so slam enough intakes on it or use the sabre-engines from the B9-Pack (very useful for larger planes! I also recommend the procedural wings to lower the part count.) Nukes are a good choice there, because the air is thinner than on Kerbal. therefore: use more wings!

If you can fly it on Kerbin with 50m/s at ground level and 2000m/s at 26000m, you're good. I'll try and get a design together today evening...

the other thing you can try: a mining jet: get a big tank, slap a reactor to it and some drills, practice water landings and off you go for Kethane mining directly on Laythe

[Joshiewowa]

Where is said facility? Lat and long?

Edited August 15, 2013 by Joshiewowa

[Sauron]

I have done this. A complete system for exploring Laythe by plane. However I shipped fuel and oxidiser from Kerbin. I don't use Kethane.

You can read my complete (pic heavy) exploration mission if you want. Post #19 on Page #2 has more details on refueling.

I'm not sure what you are planning, however if you are just exploring Laythe with SSTO spaceplanes, you should not need to bring large amounts of fuel down. The reason being is that when you take the plane down to the surface, you fill it to full with fuel, and only as much oxidiser needed to get back to orbit. Then offload the back-to-orbit fuel and oxidiser into the tanker.

This will give you plenty of fuel to fly around efficiently. Then you load up on fuel and oxidiser from the tanker when you want to go back to orbit. I explored all of Laythe with dozens of flights, and only did two fuel runs from orbit.

The mission has been delayed due to my irritation with .21/the reset, but the mission profile I was going for was fairly complex. I'm running several non SSTO jets and helicopters for exploration/crew recovery/base assembly etc. So my fuel demands are pretty heavy, especially considering that I'm leaving fuel dumps at various useful points. So I'd have to bring new ones each time I run out.

Also, I'm sustaining a manned presence on Vall and Pol, and around Jool as well as cutting the required DV for my resupply missions in half.

All this said, there has been some progress. My largest SSTO now weighs in at a shade over 55 tons. It's a touch lighter than I'd have liked, but it'll do. I just need to be sure it flies very safely empty. If I can get a decent transfer stage together, I may use this as my workhorse rather than my smaller crew shuttles. It'll reduce the number of ships at least.

My Laythe base gets its fuel from Vall. Its much easier to land on and take off from

Easier? Yes. Way less efficient though. Pol is really the best choice IMO. Less rugged than Bop without the inclined orbit but still small enough to be trivial to take off and land from.

Edited August 15, 2013 by Sauron