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I've designed a SSTO shuttle using mostly B9 Aerospace parts that flies pretty well with Ferram Aerospace Research. The only problem being that it doesn't really like to slow down that much, and landing at speeds approaching mach 1 is ill-advised at best. The solution, of course, is to use air-brakes.

The problem is that for air-brakes to be effective, they need to be in the airstream, and if they're in the airstream, they tend to heat up. When they heat up, they tend to explode, and exploding air-brakes is not good.

This doesn't only happen during re-entry either; on the first full test mission for this craft, I lost a few of them on the ascent. In fact, the ascent is when I'm more likely to experience this, since I'm flying at a smaller angle of attack during the air-breathing phase, limiting my ability to shield the air-brakes with the wings and body of the shuttle. There's also the problem that sometimes the air-brakes aren't destroyed in pairs, leading to a situation where I introduce a yaw on the vessel when I apply them.

Is there any way to enable heat shielding to these parts specifically, and any part in general? Adding a construction time option similar to how B9 lets you toggle the various landing gear between unshielded and shielded would be optimal.

  • I'm no DR expert but I assume you could place your airbrakes on the top side of your wings to use the the wings as heat shields. When you slow enough for atmospheric flight the angle of attack would decrease sufficiently to use the airbrakes. – Coomie Feb 19 '15 at 3:07
  • @Coomie: That's what I was doing. As I said in the question, they were still heating up because in the air-breathing stage of the launch, I'm flying at a reasonable AoA. – MBraedley Feb 19 '15 at 3:13
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    Aside, if you're getting heating effects on ascent, you're probably just going too fast—it's inefficient because fuel is wasted when you exceed the terminal velocity of the atmosphere. – SevenSidedDie Feb 19 '15 at 5:30
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    Not for SSTO shuttles. You want as much horizontal velocity as possible before switching to internal oxidizer. – MBraedley Feb 19 '15 at 11:06
  • The air-brakes thing could probably be achieved by cfg file editing, but that would be fixing the wrong problem. If your still going Mach 1 when your about to land, that would indicate that your decent angle is too steep. What's your orbit like when you start re-entry? – CyanAngel Feb 20 '15 at 9:39
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You can add heat shielding to any part by editing the part's .cfg file. These are located in GameData/<plugin>/Parts/ ('squad` is the directory name for default parts)

A part config looks something like this:

PART
{
    // stuff
    MODULE
    {
          // stuff
    }
    MODULE
    {
          // stuff
    }
    RESOURCE
    {
          // stuff
    }
    RESOURCE
    {
          // stuff
    }

}

To add some capability offered by a mod, you usually add some new MODULE sections and possibly RESOURCE sections.

Checking one of DRE's heatshield configs, here are the sections that add shielding:

MODULE
{
    name = ModuleHeatShield
    direction = 0, -1, 0 // bottom of pod
    reflective = 0.05 // 5% of heat is ignored at correct angle
    ablative = AblativeShielding
    conductivity = 0.01
    loss
    { // loss is based on the shockwave temperature (also based on density)
        key = 650 0 0 0 // start ablating at 650 degrees C
        key = 1000 64 0 0 // peak ablation at 1000 degrees C
        key = 3000 80 0 0 // max ablation at 3000 degrees C
    }
    dissipation
    { // dissipation is based on the part's current temperature
            key = 300 0 0 0 // begin ablating at 300 degrees C
            key = 500 180 0 0 // maximum dissipation at 500 degrees C
    }
}
RESOURCE
{
    name = AblativeShielding
    amount = 250
    maxAmount = 250
}

Add those two sections to your part and tweak the setting to get it right. In addition, you will want to increase the part's maxTemp. You can set the direction to 0, 0, 0 to make it shielded from any angle. The AblativeShielding resource is what starts being used then the heatshield starts ablating (loss section)

I haven't played around with adding shielding, so I can't help much with the parameters, but the DRE thread should already have plenty of information. Google the thread for a particular parameter with a search query like

direction site:http://forum.kerbalspaceprogram.com/threads/54954-0-90-Deadly-Reentry-v6-5-3-Beta-Mar-6-2015

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