Abstract
This paper will describe the development, testing, and preliminary flight results of a 16 m2 drag-deorbiting sail system launched as part of the SSO-A mission in late 2018. The sail consists of four triangular quadrants of 12 micron thick mylar metalized membrane, which are `Z' folded before being wrapped around a central free-spinning hub. A brushless DC motor is used to drive the extension of four co-coiled bistable carbon booms, which in turn pull the wrapped sail off the hub during deployment. The packaged module sits within a housing with four fold-out panels, and is attached to an outer panel of the host spacecraft. On-board electronics and a battery pack allow completely independent operation from the host spacecraft bus, with the system programmed to deploy at a predetermined time after a separation indication. Two commercial units of the sail system were launched on Monday December 3 2018, on 260 kg, and 1250 kg host spacecraft to a Sun Synchronous orbit at an altitude of 575 km, with deployment of the sails taking place shortly after launch. The time to demise for these systems is estimated to be between 5 years for the 260 kg, and 13 years for the 1250 kg spacecraft, with the spacecraft already having lost 750 m and 300 m of altitude respectively.