Green Solid Propellants for Launchers

State of the art solid propellants are based on the oxidizer ammonium perchlorate, AP. AP is in many ways an excellent oxidizer but unfortunately it has negative impacts on the environment and on personal health due to: * Ozone depletion * Ground water contamination * Thyroid gland interference * Acid rain formation The ESA Clean Space initiative emphasize the development of green technologies to reduce the environmental impact of space programs, taking into consideration the overall life-cycle and the management of residual waste and pollution resulting from space activities, both in the Earth eco-sphere and in space. Finding substitutes to AP is thus of interest. This paper presents ways to reduce the environmental impact of solid propellants by replacing AP with alternative oxidizers such as AN, ADN and HNF. Results from the recently completed EU FP7 project HISP ( and the current Horizon 2020 project GRAIL will be presented.