Ultra-large Solar Sail Technology

UltraSail is a complete sail system for the launch, deployment, stabilization and control of very large (km^2 size) solar sails enabling reduced mission times for interplanetary and deep space spacecraft. UltraSail is an innovative, non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation-flying microsatellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 km^2, sail subsystem area densities of 1 gm/m^2, and thrust levels 20 times those of ion thrusters used for comparable deep space missions. UltraSail can conceivably even achieve outer planetary rendezvous, a deep space capability now reserved for high-mass nuclear and chemical systems. The primary innovation is the near-elimination of sail supporting structures by attaching the sail tip to a number of formation-flying microsatellites which deploy the sail, and then articulate the sail to provide attitude control, including spin stabilization and precession of the spin axis. These tip microsatellites are controlled by a laser metrology system and maneuvered by a 3-axis microthruster system using solar-power to maintain low, constant velocity and proper sail film tension during deployment with negligible propellant mass.