A Hohmann transfer is a propellant-optimal two-impulse orbital maneuver used to transfer a spacecraft between two coplanar circular orbits. The spacecraft executes a first prograde velocity increment (Δv₁) at periapsis to enter an elliptical transfer orbit having its apoapsis at the radius of the outer target orbit. Upon arrival at apoapsis, a second prograde impulse (Δv₂) circularizes the orbit at the outer radius.