Due to the dynamic nature of file-sharing and open-source development, the exact location of this file can change. However, here are the three safest methods to locate the authentic top version:

These features combine to place Apollo RT among the most visually impressive shader packs available for Minecraft.

I traced the code. Version 1.5.2 had a vertex shader that included a hidden uniform: uniform bool isOriginalCrew . If true, the shader rendered a faint wireframe overlay over the astronaut model—a skeleton made of light. If false, the model rendered normally.