[douglas]

When you are approved to join the game, PBW will send you an email with the previous player's password. Depending on whether the player entered it correctly and kept it updated on PBW any time he changed it in game, it may or may not be correct. If the password emailed to you doesn't work, you will have to let the game host know to run the turn manually and reset your empire's password. The new password will be a randomly generated number, but you can change it once you get the next turn.

The warp cores and nacelles are specific to the Star Trek Mod, which I have not played. My understanding from reading the forums is that the nacelles provide standard movement points (and maybe some bonus) and determine supply usage for movement, while the warp core provides the bulk of a ship's actual speed through bonus movement points and has most of the supply storage, and maybe some supply generation.