I am creating a forge map on HALO 4. It is made for 4v4, and I know I need ordnance drops on the map for it to work in HALO 4's Community Forge Tester playlist (I think). I am using the map IMPACT, and I am creating a space station with no way in or out from the outside to remove the fact of using safe and kill zones.
No, you don't need a path to the sky. You can call ordnance drops from indoors just fine. Instead of flying in like a drop pod, they just materialize out of thin air.