Inspired by how the windows work in star wars. When your canopy breaks, a steal shutter automatically slams down, closing off the window, preventing oxygen from exiting the cockpit. The shutter would impair your vision, but maintain your HUD allowing you to still see the leads and triangle outline of your target. I believe this would add an interesting game mechanic, as it would force someone who has lost their canopy to rely completely on their sensors and provide an advantage to stealth ships that try to maintain sensor invisibility. It would also be extremely useful for long distance explorers that might have gotten too close to a neutron star and broke their canopy 15000ly from civilized space. The shutter could also be toggled, either by hot key or functions panel to re-open the window causing your life support to drain once more but restoring your vision. This could be implemented as an engineer specific life support module, or as a optional internal.