Go aft and go outside. Go down to the roof and go in to the lobby. Look at the elevator. Press the button. Wait. Wait. Wait. Wait some more. You can do more interesting things while you're waiting, if you want.
The elevator door opens. Enter the elevator. Push the down button. Wait some more, or look at things.
When the elevator doors open again, go outside. A spooky hallway. Enter the brushed steel door to find a weird basement. There's a table and a chair, so sit down. The console on the table lights up, and strange text appears on the screen.
Hint 1
The text on the screen is encoded with a simple substitution cipher. If you're good at this kind of thing, you can use frequency analysis and other amateur cryptographic techniques to solve it.
Hint 2
If you're not good at ciphers, press the button. It will make things easier for you by decoding one particular letter (like all the "t"s will turn into "B"s).
Hint 3
If you keep pressing the button, the cipher will slowly solve itself for you.
Hint 4
The coordinate is 19683.
Get off the chair. Enter the brushed steel door. Push the elevator button. Wait. Wait. Wait. Wait. Enter the elevator. Push the up button. Wait. Wait. Wait. Wait. Wait. Wait.
Exit. Go outside. Go up the ramp. Go inside the ship. Go fore.
Set the autopilot to the correct coordinate.