Vapor bubble dynamics in microgravity are crucial in determining the effectiveness of two-phase thermal management systems for next-gen electronic devices. Negligible buoyancy forces in reduced gravity create stagnant vapor masses that cover the heated surface, rapidly increasing the surface temperature. Utilizing asymmetric sawtoothed structures, a mesoscale-engineered surface has been created in this investigation to facilitate vapor mobility and improve heat dissipation in microgravity. The test chambers were glass ampoules with square cross sections and thin film nichrome heater deposited on a flat face of the ampoule. The test and instrumentation hardware were developed by NASA's implementation partner to adhere to stringent flight requirements. Experiments were carried out on the International Space Station after terrestrial research on various surface morphologies and under varied subcooling levels. The surface was fabricated using wire electric discharge machining, with hammerhead slots (250 µm mouth) featuring on every third sawtooth. The slots act as engineered nucleation sites, ejecting vapor at an angle perpendicular to the long slope of the microstructure. Vapor bubbles nucleated from the engineered sites at heat fluxes as low as 0.8 W/cm², and the number of active slots increased as the heat input increased. The departure frequency also increased with increasing heat flux, and each slot consisted of multiple nucleation sites. Vapor slugs moved toward the pressure relief membrane in the sealed ampoule at velocities as high as 20.4 mm/s and interacted with liquid pockets between the crest and trough of the microstructure. Individual slug departures increased the cold zone temperature by 19°C at 2.4 W/cm². The observed vapor bubble ejection from the surface and slug mobility suggests that the surface enhancement can facilitate vapor mobility and heat transfer enhancement in reduced gravity environments.