As soon as you exit the first airlock, with your back to the airlock, go around the corner to your left and it will be right there on the wall.
After exiting the first airlock, go to the end of the path ahead of you, where you can either use a jump pad to continue through the area or drop down a long chute. This chute has levels you can get to by using your boost jump and you'll want to get onto the first one as soon as you start dropping down (hug the north wall). The symbol will be on the north wall.
From the previous symbol, drop down one more level in the chute and you should see an exit into the airless environment. Look to the east and you'll notice a worker drone moving a platform with two holes in it back and forth. Jump onto this platform and when it reaches the far end, jump off the northern end to a platform with a jump pad. Look at the wall nearby for the symbol.
Head to the platform overlooking Central Maintenance, which has two jump pads, one leading east and the other heading back to the starting area. There's three buildings surrounding the entrance to Central Maintenance and you'll want to jump on top of the western one from the overlooking platform. Go to the north ledge of this building and look south to spot the symbol on the structure.
Go through Central Maintenance and out the northern airlock (Airlock #3). Facing the airlock, go to the right ledge and look down to see some pipes. Jump onto them, then jump onto the thin ledge of the eastern building. Follow this thin ledge around the corner and you'll eventually spot the symbol on the wall.