Stretching Every Kilogram: Using Small Satellites to Support Solar Sailing Missions

One competing technology proposed for the New Millennium Program Space Technology 9 (ST9) mission demonstrates controlled propulsion using a solar sail deployed from Orbital’s MicroStarTM spacecraft bus platform. The ST9 Solar Sail Mission’s (ST9-SSM) proposed solar sail allowed nearly 1,000 m2 of reflective area by extending four gossamer sail quadrants along inflatable, thermally rigidized 24.2 m booms. To measure sail performance from the ground, a 1250 km circular, sun-synchronous dawn-dusk orbit was selected to maximize available sunlight on the sail and minimize the atmospheric drag and radiation effects. Several performance challenges drove the ST9-SSM spacecraft bus design: minimum mass, stable attitude control, high-capacity image processing, and a propulsion subsystem capable of achieving the starting mission orbit, as well as successful end of life disposal, all while minimizing mass and maintaining compatibility with both of the two NASA-directed launch vehicles. Additionally, ST9-SSM also posed programmatic challenges in the areas of risk management and cost control. The ST9 Solar Sail mission concept not only demonstrates solar sail technology as a feasible means of propulsion, but it also illustrates how a microsatellite platform can be used to deploy and execute such a mission for a low cost with relatively low risk