Staged microgravity deployment of a pressurizing scale-model spacecraft

The experiments described were conducted with the goal of obtaining quantitative pressure and motion data for deployment of an inflatable scale-model spacecraft structure in an environment free of gravity. The experiments included a series of staged deployments of two identical unfolding, inflating scale-model solar concentrators, each consisting of three struts and a torus. The experiments were conducted aboard NASA's KC-135 aircraft. Internal pressure was simultaneously measured at six locations in the deploying structure at the bottom and top of each strut. Deployment motions were tracked using two video cameras and were compared to measured pressures. Consistent trends in pressurization and motion were seen in 11 staged deployments, including nearly constant pressure as the internal volume increased and increasing pressure as volume remained constant. Pressure equalization was observed to occur at different times for different struts, and motion analysis showed varied directions of deployment correlating to these differing pressure equalization times.