Kethane Spaceplane

[VR_Dev]

I'm trying to develop a spaceplane to explore planets with atmosphere such as Eve and Duna. Ideally I would like the kethane turbine engines to get me to the top of the atmosphere then use a liquid engine to get me into orbit.

I have encountered several problems regarding the kethane turbines however.

1)

I have tweaked the airscoop and ramAirIntake to intake KIntakeAir but they don't seem to increase my flame-out height the way the stock intake parts do with stock engines. I have been testing my plane on Kerbin and the engines tend to flame out consistently around 20KM. Is there some aspect of the intakes I'm not understanding besides what resource it uses? Does the fact that the kethane turbines have their own intake have anything to do with it? I created a copy of the engines that doesn't but they seem to perform worse.

2)

Then I created some tanks to hold KIntakeAir which work pretty perfectly. Right when the engines would flame-out it starts sucking KIntakeAir from the tanks. The problem is by this time the engine thrust is so low it doesn't matter that the engines are still running.

In theory if the engines were getting air straight from a tank they would be producing the same thrust as they would be at sea level. Is there a way to trick the engines to think they're at sea level when getting KIntakeAir from the tanks?

I would preferably not want to use KIntakeAir tanks because it adds considerably weight to my ship, which is why I wish I could figure out how to get the ramAirIntakes to pump KIntakeAir into the engine at high altitudes like it's designed to do.

Any suggestions would be much appreciated as I have spent a fair amount of time on this ship and I like to believe what I'm trying is possible.

As a side note I have yet to try this plane on Duna. I have to build a rocket to get it there which I would like to leave in orbit around the planet for the return trip. Maybe even one which could land on one of Duna's moons and refuel itself. I know the delta v on Duna and the low atmosphere means my current plane might work perfectly but I am still interested in making my ramKIntakes work out of curiosity and practice.

Thanks for any advice,

[Ralathon]

The kethane turbine scales negatively with velocity. So it gives less and less thrust as it goes faster and faster.

    atmosphereCurve
    {
        key = 0 1000
        key = 0.45 1900
        key = 1 2300
    }
    velocityCurve
    {
        key = 1000 0 0 0
        key = 850 0.2 0 0
        key = 0 1 0 0
    }

You should probably either tweak that or remove the velocityCurve before you can use it as a orbital boost engine.

[KhaosCorp]

The kethane turbine was meant for slowish vehicles. It really shines on rover and airships. Not the think you want to try and break atmo, not even Duna's thin atmo.

[VR_Dev]

thanks for the help. I didn't realize the velocity curve was negative. I tweaked it a little and increased the gas consumption to make up for the increased thrust. made this sweet kethane jumpjet http://i.imgur.com/DlOeBZS.png

[Hodo]

It is actually easier and more efficient to make a craft that can convert Kethane when on other worlds and refuel itself.

That is what I did with 3 of my most successful interplanetary SSTO space planes.

Like this one..

I had a minor design issue, I made the gear to tall for the drills so I had to raise the nose gear in order to drill for Kethane..lol.

[keeper]

How confusing, I was under the impression the kethane engine would work even after it had no air.

I got my "kethane-2-space-launcher/lander" ship (equipped with 4 of those bad boy kethane engines ) all the way to minmus only to find it got flameout and wont start.

I'm sure it says after it runs out of intake air it runs on just kethane, alas i guess not

Really nice space planes though! Amazing that they're working with kethane i still haven't seen, heard or felt that engine.

I did wonder about adding the intake air tanks, but there's no way to refill them i dont think.