Worldwide developments are ongoing to develop new and more energetic composite solid propellant formulations for space transportation and military applications. Since the 90's, the use of HNF as a new high performance oxidiser is being reinvestigated. Within European development programmes, significant improvements have been achieved with respect to the oxidiser itself as well as possible propellant formulations. Being more energetic, the newly developed formulations have the potential of significantly lowering the launch costs per kilogram weight. Although solid propellant motor launches are not considered to be of a major environmental issue, these new propellant formulations have the additional advantage of being less pollutive (no HCl in the exhaust). Recent achievements of the new propellant development work is presented in this paper, showing the potential of the actual introduction of new and more energetic propellant formulations within the next decade.