Abstract-The marching-on-in-time solution of the time domain electric field integral equation (TD-EFIE) has traditionally suffered from a number of issues, including the emergence of spurious static currents (DC instability) and ill-conditioning at large time steps (low frequencies). In this contribution, a spacetime Galerkin discretization of the TD-EFIE is proposed, which separates the loop and star components of both the equation and the unknown. Judiciously integrating or differentiating these components with respect to time leads to an equation which is free from DC instability. By choosing the correct temporal basis and testing functions for each of the components, a stable marchingon-in-time system is obtained. Furthermore, the scaling of these basis and testing functions ensure that the system remains wellconditioned for large time steps. The loop-star decomposition is performed using quasi-Helmholtz projectors in order to avoid the explicit transformation to the unstable bases of loops and stars (or trees), and to avoid the search for global loops, which is a computationally expensive operation.Index Terms-time domain, electric field integral equation, DC instability, low frequency breakdown.