  Progress in understanding quantum systems has been driven by the exploration
of the geometry, topology, and dimensionality of ultracold atomic systems. The
NASA Cold Atom Laboratory (CAL) aboard the International Space Station has
enabled the study of ultracold atomic bubbles, a terrestrially-inaccessible
topology. Proof-of-principle bubble experiments have been performed on CAL with
an rf-dressing technique; an alternate technique (dual-species
interaction-driven bubbles) has also been proposed. Both techniques can drive
discovery in the next decade of fundamental physics research in microgravity.
