How to install it?
Download the GlidingHeatShield.dll file available here.
Navigate to your SFS installation directory and go to your MODS folder. The path should look like something like this:
C:\Program Files (x86)\Steam\steamapps\common\Spaceflight Simulator\Spaceflight Simulator Game\Spaceflight Simulator_Data\MODS
You will have to create the "MODS" folder if you don't already have it.
Under that MODS folder, create a "GlidingHeatShield" directory, then move the dll into it.
Now start your game, the mod should be available in it. Enjoy!