The protagonist, Lester, enters a code of 4511932 on the keypad to access a further part of his underground laboratory. This code is actually used in an even older game, Another World from 1991.The code itself was originally the entry combination to LookingGlass Technologies office (0451). The code 451 is a nod to the original System Shock (keypad combination for the door leading out of the Healing Suite), and is referenced in several other games including: Bioshock series (original, sequel, Infinite), Deus Ex series (original, Invisible War, Human Revolution, The Fall, Mankind Divided, GO), Thief, Sanitarium, Firewatch, Gone Home, The Novelist, Dishonored 1 and 2, and Prey (2017).The enormous flight bays on this level are sealed off by environmental integrity screens. This level serves to launch, receive and house the various shuttle craft that regularly conduct business with TriOptimum Earth.

I think Grassi just likes to make work for me. The Flight Deck is the Level 5 of Citadel Station. I've got to change the access codes out of Cryo A again! Like I've got nothing better to do.

System shock 2 sub armory code