Roberts Space Industry will be adding modules to Star Citizen up until the beta release in 2014. As a feature for those who have bought into the alpha mode, people will have access to modules that will be released every so often for Star Citizen. The first one “Hangar Module” will be coming in August for customers who paid their way in.
In “Hangar Module” you will not be able to fly your ship, but according to Chris Roberts you will be able to see your ship and customize it to some degree. Then in December they will release a “Dogfighting Module” where you will be able to go out with your ship and “dogfight sort of deathmatch style with other people”.
However, the “Dogfighting Module” will not have the persistent universe or story implemented as the module will mostly be used to test and balance the combat, weapons, and the online structure.
Roberts Space Industry will continue to release more modules next year until the game hits the beta stage sometime late in 2014. You can still get in on the action through pledging money to the game here.