The amount of available propellant limits low-Earth orbit satellite lifetime due to the necessity of drag makeup. An electric propulsion device that uses in situ ions as propellants is considered as an alternative method for satellite drag makeup. This work presents a tool that consists of a one-dimensional thruster mathematical model integrated with the NASA International Reference Ionosphere to provide ion and neutral species densities for an electrostatic electric propulsion approach. This mathematical model predicts thrust, drag, and thruster power. The thrust-to-drag ratio and thruster power are averaged over the entire mission duration of one year and compared with various circular orbits and satellite configurations: 300–1000 km orbit altitude, 0–60 deg orbit inclination, low to high solar activity, 0.1–5.0 m2 satellite frontal area, 1–10 kV acceleration voltage, and 1–10 m2 total grid area. The Satellite Tool Kit provides orbit propagation. An average thrust-to-drag ratio greater than one is ach...