Jean-Jacques Goldman: pop-rock, currently the highest-grossing French-language artist alive in the genre. (Jean-Jacques Goldman playlist.)
Julia Ecklar: filk (SFF-themed folk music produced by fandom), in between being a sci-fi writer. Covers the gamut from “earnest odes to space exploration” to “comedy songs about tribbles.” (Julia Ecklar playlist.)
(See also: To Touch The Stars playlist, a multi-artist album of space-exploration tribute songs.)
Anderson Bruford Wakeman Howe: progressive rock, four former members of Yes that released a single album as their own group. No specific homages (that I know of), but IMO it has the same general weird/hopeful/cosmic vibe of ’70s-’80s SF. (ABWH playlist.)