The resulting deflagration expands against a magnetic nozzle to produce thrust and generate recharge energy for the next pulse. A z-Pinch is a device that is commonly used to compress laboratory plasmas to high pressures (~1 Mbar) for very short timescales (~100 ns). An electrical discharge produces a high axial current along the outer surface of a column of plasma; this current in turn generates a very strong toroidal magnetic field. This self-generated magnetic field interacts with the axial current via the Lorentz force and radially compresses the plasma column, bringing it to very high densities and temperatures. This team is exploring a modified Z-pinch geometry as a propulsion system by encasing the fission- fusion target in a sheath of liquid lithium, providing a current return path. Numerical results have been promising, the level of compression is sufficient to reach fission criticality.