"Six degree-of-freedom, rigid body equations of motion are described suitable for modeling the dynamic characteristics of multistaged rocket-boosted maneuvering aerial targets such as the DRES developed ROBOT-X. These equations of motion form the core of a Fortran simulation package called FLISIM. FLISIM is currently installed on a VAX 11/780 computer and allows for modeling of vehicle thrust and structural asymmetries, time-varying mass and inertia characteristics, autopilot control laws, autopilot update rates, autopilot sensor non-idealities, nonlinear aerodynamic characteristics, variable wind conditions, turbulence, nonstandard atmospheric conditions, stage and individual motor failures, different rocket motor types, and parachute deceleration dynamics. The FLISIM software package has been developed in two versions (FLISIMV1 and FLISIMV2) using two different aerodynamic models. Both are written in VAX 11 Fortran and run under the VMS Operating System. FLISIM is fully supported with a plotting software package (PLTSIM) developed around Tektronix PLOT 10 core software"--abstract.