Part of the "UNC: Geth Incursions" Assignment. The Grissom System will only open up once you've cleared out the other four Geth Outposts in Gagarin (Rayingri), Hong (Casbin), Tereshkova (Antibaar), and Vamshi (Maji). Clear the three Rocket Troopers and the two Collosi, then head inside the building. Kill the Geth in here, and you'll get a dialog box concluding the Assignment.
Inside the Geth Mercenary Base, Decrypt the Geth Terminal for the Assignment "Tali and the Geth." Talk to Tali once you're back aboard the Normandy.
Asari Capsule with a Writing for "UNC: Asari Writings."
Crashed Probe from which you can Salvage some upgrades.

last modified 5 July 2012