Ae parallaxing nomap2
The parallaxed space textures make an ordinary sector become lethal.
There are two special textures called MOONSKY1 (#80) and BIGORBIT1 (#84). These are useful for creating a space-themed atmosphere. If either of these textures are parallaxed on the ceiling or floor of a sector, they will kill any player who enters that sector. If you want to nullify the death effect, give the ceiling a palette of anything other than 0. A value of 3 works great because it does not actually change the texture's colour.