It is a quest added after finding dad or Docter Li.
start project purity
just continue on with the main quest and you'll be able to do it.
id say about half way through the main quest.
All you need is to get into the chamber with the purifier and type in the code 2:16 (the waters of life) The code the character's dad told you was your mother's favorite verse
Do the main mission the waters of life then docter li will talk on an intercom outside of the citadal then the brotherhood of steel will let u in
you have to complete the quest (The Waters of Life) to get access to the Citadel. http://fallout.wikia.com/wiki/Portal:Fallout_3
You must first complete a quest called "The Waters of Life". First you have to track down James, the player character's father, and the story progresses from there.
pip boy from fallout 3 made life and the universe
He is in the citadel. You will reach it after the waters of life quest. After the Cutscene with li and lyons talk to lyons about power armor training. Gunny will be in the courtyard during the day.
Occasionally Fallout: New Vegas will freeze, but not as frequently as Fallout 3.
fallout 3 psp??????
There is no such place in fallout 3.
anything is possible...except for this