Starfield will receive updates "roughly every six weeks starting in February" if Bethesda hit their target, according to an end of year wrap-up. "These updates will include everything from quality-of-life improvements to content and feature updates," including previously mentioned city maps, mod support and new methods of travel.
The updates will also include expanded ship customisation, "with ship decorations, new ship building options, and more" according to the post.
Bethesda will also add "all new Gameplay options" to let players make their experience easier or harder beyond the existing difficulty settings. "These will allow you to easily customize carry capacity, cargo access distance, ship damage, vendor credits, how you suffer afflictions, new survival mechanics, and more," they say.
Official mod support will also arrive early next year with the release of the Creation Kit for those who want to make their own mods. The announcement also refers to this as the "launch of Creations". Earlier this month, Skyrim introduced Creations as a merger of what were previously separate "Creation Club" and "Mods" menus within Bethesda's fantasy RPG - and with it brought back paid mods to Skyrim with the launch of the "Bethesda Game Studios Verified Creator Program". At the time, Bethesda did not confirm that they would be bringing the same program to Starfield, although this strongly implies that they will.
Next year will also see the release of Starfield's "first major expansion", Shattered Space, which will add new story content, locations, gear "and much more."