the dome is double layer. i wasn't going to make it airtight, but that could be done.

the ground is a different story. i can't really see putting a 'double hull' in the whole crater floor to reduce slow leaks that could build up over time.

i'm not sure what approach to take with it. i was going to fuse a whole layer of it into glass, and then put lots of dirt overtop. but there should be maybe another layer of glass after some space filled with dirt, and maybe there could be sensors in that which could detect changes in gas content to identify slow leaks over time.

Anyhow. Of course there is a tremendous temptation to have a giant asteroid that is extraordinarily unlikely strike the city, or very near to the city.

How can a person make something like that without instantly playing that Godzilla attacks, as it were. :D

well, that took me a long time to write. here's hoping they can help me on this.

docs.google.com/spreadsheets/d/…

^ a man by the name of Michael Turner sent me that spreadsheet a few days ago. It looks at using basalt fiber in a sling launcher on the lunar surface.

for one reason or another i never adopted that approach, though i've thought a lot about basalt fiber. He made good points that i was probably under-rating the capability of basalt fiber to be used this way, though a ton of testing would be needed.

um, maybe...