Backgrounds: Below are changes to the existing backgrounds in the PHB, and following that are new backgrounds. Any background can be customized by agreement between player and DM.
Acolyte: No Change
Charlatan: No Change
Criminal: No Change
Entertainer: No Change
Folk Hero: No Change
Guild Artisans: Additions to the guild business list: 2 can include gunsmiths 6: Cartography can include stellar cartography, requires a separate specialty from normal cartography. 15 can include spelljamming shipwrights as it's own specialty
Hermit: No Change
Noble: No Change
Outlander: No Change-in the context of space, the "outland" may be a distant crystal sphere rather than a remote part of a world.
Sage: No Change, but there are many more specializations available, such as Crystal spheres or exo species.
Sailor: No Change, but see Spacer below
Soldier: No Change
Urchin: No Change
New Backgrounds:
Spacer: similar to the sailor, but in space. Spacers often are born and live their entire lives in space, working on the same ship or for the same merchant company their entire lives. The navigator's tools earned by a spacer are specifically for navigating in wildspace; they are not transferable to a planet, nor are the reverse.