the idea of "outer space" being this big empty black void that things are inside is purely in the heliocentric model. flat earthers can't claim to know what is beyond the corners of the earth because no free travel is allowed beyond these red lines. im using your globe map so its more understandable. no one can go beyond the 55th north latittude, the dew and nws systems have been in place for 80 years near canada, iceland, greenland, poland, etc and they act as a set of vritual tripwires. beyond the 60th south latitude the antarctic treaty has been in place for 80 years preventing anyone from free, unguided travel beyond the red line at the bottom
Canada