Image of a gaseous discharge in microgravity

The electrode gap length of a gaseous discharge in a low-pressure 1 g environment is compared with its length in a low-pressure microgravity environment for pressures ranging from 30 kPa to atmospheric pressure. The maximum gap length obtained is measured for both conditions using three separate gases. Video images of the discharge in microgravity make apparent both the lack of gravity-induced convection, which gives rise to the arching of the 1 g discharge, and the increase in gap length.