Search research rig for Precursor facility is a mission in The Lost Frontier. Once all three coordinate spheres were installed into the eco seeker, it pointed back to the abandoned research rig. Phoenix remembered the location was built over "strange formations", and Keira deduces it must be a Precursor facility and decides that "we have to go back and dig deeper." Once Jak has reached the research rig he discovers it is encased in a large energy shield, powered by three generators surrounding the structure, which he has to destroy to access the rig.
Each generator is armed with a turret on top, which should be priority one to remove the main source of danger to your plane. To destroy each generator you must first destroy all the repair tenders that surround it, but to destroy all the tenders you must destroy each hangar that keeps deploying new tenders. There is a hangar near each generator and once they have been destroyed you can start shooting down the repair tenders. A generator that is not being continuously repaired by a small swarm of repair tenders will ultimately fall to the damage dealt by your weapons.