Found it.  Southeast corner of "The Hole" (south of The Gash, southeast of starsheep)

What do you mean hanger? They're all inside the Ark right? you mean the airlock?

First is in right wall (when watching from front of bar) where you start mission :3

I'm stuck on the last leaflet i need to put up. 
So far i have:  
1. Hanger: On the left pillar before the Hanger as you enter  
2. Medical bay: On the right pillar as you enter  
3. Hallway: Behind the "Alpha" statue  
4. Greenery: On the wall between the two big areas with Greenery everywhere, right were it says "Big Sale!" on the wall in white  

Anyone know where the last one is?

Advertising Space Locations?