The Kickstarter edition (the Captain and Admiral Editions) contains the base game and the expansion, Revenant: Reason and Faith which will not come with the retail edition.
This expansion comes with two additional modules that can be added to the core game, together or individually.
Reason Module: In this module, a new type of ship joins the fleet: the Science Vessel. Use it to research and understand the galaxy-devouring Voidborn and its Corruption, discovering unique new technologies by peeing into the Void. Science vessels offer and alternative use for Discovery Data, and if you are willing to expose yourself to corruption, you can gain powerful permanent abilities in return, affecting more than just your Frigate.
Faith Module: The Houses joined forces to save the Revenant, but that does not mean that they have united in their beliefs. In the Faith module, a Paradigm card is revealed each round, dividing the Houses: three Houses support one outcome, three support the other, and one remains neutral on the issue. Each time a player uses a House ship, they are also supporting them in the debate, moving the Balance marker on the Paradigm card in the appropriate direction. At the end of the round, the winning Paradigm is resolved, either as an immediate effect, or as an ongoing modifier affecting the next round.