And the winner of my hand-wringing about which TTRPG to run is ... Savage Worlds!
What won me over:
* You get to use the polyhedral dice plus, for good measure, a deck of playing cards.
* It seems to have the right intermediate level of crunch, between the extremes of "creating writing workshop" and "tax accounting". I generated a character and ran a short combat, and my eyes didn't roll out of my head.
* The character record sheet fits on one side of one sheet of paper and includes both words AND numbers.
* It uses skills rather than classes.
* The rulebook is reasonably concise, clear, and well-illustrated.
* A character has just a few wounds, not scores of hit points.
* Exploding ("acing") dice will produce occasional epic results.
* People report that combat is faster and more interesting than, e.g., Pathfinder.
* It seems to have an active community and publisher support.
* The Last Parsec setting looks like it will work. Many reviews call it an homage to Star Frontiers. Pre-written adventures exist.
@peterdrake Savage Worlds is my favorite TTRPG that I can't find a group willing to play.