[en] High Mach number shockwaves were launched in laboratory plasmas to simulate supernova shockwave propagation. The experiments were carried out at inertial fusion facilities using large lasers. Spherical shocks were created by focusing laser pulses onto the tip of a solid pin surrounded by ambient gas. Ablated material from the pin would rapidly expand and launch a shock through the surrounding gas. Planar shocks were created by ablating material from one end of a cylindrical shocktube. Laser pulses were typically 1 ns in duration with ablative energies ranging from <1 J to >4 kJ. Shocks were propagated through various plasmas, and observed at spatial scales of up to 5 cm using optical and x-ray cameras. Interferometry techniques were used to deduce densities, and emission spectroscopy data were obtained to infer electron temperatures. Experimental results confirm that spherical shocks are Taylor-Sedov, and that radiative shocks stall sooner than non-radiative shocks. Unexpected results include the birth of a second shock ahead of the original, stalling shock, at the edge of the radiatively preheated region. We have begun experiments to simulate the interaction between shocks and interstellar material (ISM), and the subsequent turbulent mixing. Comparisons between experimental data and numerical simulations of shock evolution, stall, second shock birth, and interstellar material (ISM) interaction will be presented