An electric solar wind sail (E-sail) is a propellantless propulsion system that generates thrust in the interplanetary space by extracting momentum from the stream of solar wind ions by means of a number of long, electrically charged tethers. In its usual configuration, the E-sail consists of a series of radially deployed tethers that belong to a fundamental plane, typically referred to as "nominal plane". Specifically, the tether assembly is unfolded and maintained stretched via centrifugal force by rotating the spacecraft around a spin axis, which must be suitably oriented during the flight to govern, although within certain limits, the direction of the thrust vector induced by the E-sail. In this article, different E-sail geometric configurations are analyzed, in which the addition of azimuthal conducting tethers to the radial ones gives the E-sail a spider web shape, thus allowing its moment of inertia to be reduced significantly compared with a conventional configuration of equal propulsive performance. More precisely, this article presents an analytical model that enables a quick description of both the thrust vector and the inertia characteristics of a web-shaped E-sail.
