For comparison to conventionally used propellants based on hydrazine, the [Isp.sub.vac] and [rho][Isp.sub.vac] of hydrazine-oxidizer systems (neat hydrazine, monomethylhydrazine (MMH), unsymmetrical dimethylhydrazine (UDMH), and Aerozine 50) are shown in Figures 11 and 12, respectively.