Progress on studying ultracold atomic bubbles aboard the International Space Station using Science Module 3 of the Cold Atom Laboratory

Bose-Einstein condensates (BECs) formed on a thin, hollow shell have a novel topology and are predicted to exhibit interesting collective modes, expansion dynamics, and vortex behavior. Although shell-shaped electromagnetic potentials can be created for dilute atomic clouds by dressing a static magnetic field with radio frequency radiation, the force of gravity in a typical laboratory causes the atoms to pool earthward. NASA's Cold Atom Laboratory (CAL) offers an elegant solution to this problem by allowing ultracold atom experiments to be conducted in the microgravity environment of the International Space Station. We report progress on studying bubbles of ultracold rubidium-87 atoms in rf-dressed potentials using CAL's Science Module 3 (SM3). Bragg spectroscopy is used to explore the momentum properties of the cloud, from which the temperature of the thermal component and presence of the condensed fraction may be determined. We also discuss using CAL's microwave capabilities to create microwave-dressed atomic bubbles.