Chapter 1: Hello, Farewell 

I went up to the observatory today, to look down upon the remnants of the Earth-bound people, before we got underway. In the last days of preparing the ship for its voyage to Sagittarius, rumors were afloat that all the cities were a charred cinder, and the only people alive were those who still lived off the land. Though our ship, the Nautilus, is capable of recording the procession of the Earth in fine detail, all the video links from it were killed and the area closed off - until now. 

Making my way onto the first deck, which contains both the bridge and the only passageway leading out to the observation room, I saw the Captain standing guard in front of the door, checking everyone's name before he let them in. "Joshua," he said with eyes half-opened, "you cannot come in, just yet. I've posted a standing order to stay under the maximum occupancy to avoid overcrowding this place. Please, go wait outside until someone else leaves." 

A word about the ship in the meantime, then. The Nautilus, sponsored by the United States, is the first and only ship among the diaspora fleet to "live off the land". In other words, it fuels both itself and the crew completely while underway. The body of the ship is fifty football fields long, contoured into a cylindrical shaft that rotates on its axis, to produce a centrifugal force the crew needs to keep their bones from degenerating in the weightless interstices of empty space. 

The observation room is aft. It looks like an inglorious, giant, plastic bulb with an antenna jutting out of the rear end of the ship, but it serves as an extrasolar planetarium in a microgravity environment. Armed with a parabolic dish two kilometers in diameter, it can take navigational markers from anyone who puts their request onto the queue, with the caveat that the bridge can take control whenever necessary. This is one telescope that any member of the crew can get time on. 

Forward, the neck opens up to a ramscoop drive, looking somewhat vaguely like the working end of a saxophone. The ramscoop is used as a kind of rake; it pulls in hydrogen species from space and fuses them into complex hydrocarbons for food and fuel the crew needs while onboard the ship. The main means of propulsion are six solar sails that are only unfurled while the ship is underway. They are hoisted by six mechanical arms, each a mast, that are stowed away by locking them to the sides of the ship.