Comment Re: Windows are cool but (Score 1) 23
The fracture toughness quoted for that material is about 3 times higher than that for soda glass. Which is "better". But not compellingly better. Replacing the porthole with a metal panel matching the rest of the skin, and maybe a CCTV external port for communication between ground crew and contents of the spacecraft would probably be better value for money.
Which is a parameter everyone pays attention to. It might not be an overwhelming factor, but it is considered.