Secret U.F.O.
Go to Minefield, go north towards Vault 92. Follow the only road to the vault,(make sure you stay on the road) a little before the road turns right and splits you will pick up a radio signal from the ship. Go left and you will enter a radiation field but dont worry its only 1+ rads. Go to the front of the ship and there is a dead alien and a gun right next to him. This gun is one shot kill, but not a lot of ammo...so use it sparingly.