The true ending, as far as I know is detailed below.

Go back to the room where you saw the security port and telescope, and cosmic window, if you've forgotten how, from the entrance to the tunnel its, left, down, left, left and up. Once inside the room use the telescope. Then use the Mecubarz key on the security port. Save game here as you have to be quick once inside.

Go inside the security port and press the red button in the middle chair, then use the chair quickly, and sit back and watch, what I thought was a miserable unhappy ending to a brilliant game.

Anyone else have any thoughts on the ending, its rather depressing dont you think??