Stabilize the observation deck near the Ridgeline

How do you complete "Stabilize the observation deck near the Ridgeline"?

This is step 1 of 4 in A First Foothold, given by Apollo. It is completed on The Blue Gate. The exact location is marked on the The Blue Gate map.

• A First Foothold
• The Blue Gate

What are the other objectives in A First Foothold?

A First Foothold has 4 objectives in total: Stabilize the observation deck near the Ridgeline, Enable the comms terminal near the Olive Grove, Rotate the satellite dishes on the church roof, north of the Data Vault and Nail down the roof plates on the Raider structure near Trapper's Glade.