How much will having a 2nd child in college impact our EFC?

Pick the cheapest school and go to that one. Any on your list are fine.

Source: been 'round this block before. Done a bunch of aerospace stuff, then retired from it.

Btw, to that end, DON’T major in aerospace. MechE majors can work in Aerospace; doing it the other way around is a lot harder.

Most kids graduating from my school with AE degrees are unemployed or forced into other areas of engineering.