Complex sentence: The inner two panes, which were made of aluminosilicate, made up part of the capsules pressure vessel, the fused silica outer pane served as both a debris shield and as part of the capsules heat shield.
Split into simpler sentences: The inner two panes, which were made of aluminosilicate, made up part of the module's pressure vessel. The fused silica outer pane served as both a debris shield and as part of the heat shield.