Solar sails have offered tremendous potential for spacecraft propulsion in missions requiring low levels of thrust over many months or years without the mass and volumes associated with a propellant. However, until now there have been no suitable sail materials available to fabricate a solar sail.
Solar sails develop thrust from the pressure exerted on the film by reflected sun light.
As the sail reflects these photons, the momentum transferred to the sail is equal to two times the incident photon momentum. Due to the extremely low-pressure produced by the solar flux on the sail, a solar sail must be very light and have an extremely large area in order to produce usable accelerations. This requires space resistant films with densities less than about 7.2 grams per square meter that incorporate highly reflective surfaces and rip stop properties. LaRC -CP1 polyimides are the only space resistant materials that can be fabricated as large area films with thicknesses of 5 micron or less incorporating advanced reflective coating and rip stop fibers. In addition, SRS has produced 4-feet wide rolls of 1.5 micron thick CP1 with embedded rip stop fibers in lengths of up to thirty feet.