LSCS (Lightweight Space Coronagraph Simulator) simulates realistic high-contrast space imaging instruments in their linear regime of small wavefront perturbations about the nominal dark hole. The code can be used for testing high-order wavefront sensing and control as well as post-processing algorithms. It models broadband images with sensor noise, wavefront drift, actuators drift, and residual effects from low-order wavefront sensing, and supports a model of the Roman Space Telescope Hybrid Lyot Coronagraph based on its FALCO (ascl:2304.004, ascl:2304.005) model. The LSCS package provides an example of dark hole maintenance using an Extended Kalman Filter and Electric Field Conjugation.