Maelstrom
Novella 21,373 words Recommended by 2 award/anthology sources
"One hundred and fifty years ago, before plans for the star port on Ius Prime were finalized, ships launched out of Ciudad Orilla on the northern-most edge of Yaguni. One of those ships, the Maria Segunda, took off on a Monday to explore the rim of the deepest crater on Ius Prime’s largest moon."
Quasar links out; the story lives on Asimov's, where the author gets the click.