Electric solar wind sail applications overview

AbstractWe analyse the potential of the electric solar wind sail for solar systemspace missions. Applications studied include y-by missions to terrestrialplanets (Venus, Mars and Phobos, Mercury) and asteroids, missions basedon non-Keplerian orbits (orbits that can be maintained only by applyingcontinuous propulsive force), one-way boosting to outer solar system, o -Lagrange point space weather forecasting and low-cost impactor probesfor added science value to other missions. We also discuss the generic ideaof data clippers (returning large volumes of high resolution scienti c datafrom distant targets packed in memory chips) and possible exploitation ofasteroid resources. Possible orbits were estimated by orbit calculations as-suming circular and coplanar orbits for planets. Some particular challengeareas requiring further research work and related to some more ambitiousmission scenarios are also identi ed and discussed. 1 Introduction The electric solar wind sail (E-sail) is an advanced concept for spacecraft propul-sion, based on momentum transfer from the solar wind plasma stream, inter-cepted by long and charged tethers [1]. The electrostatic eld created by thetethers deects trajectories of solar wind protons so that their ow-aligned mo-mentum component decreases. The ow-aligned momentum lost by the protonsis transferred to the charged tether by a Coulomb force (the charged tether ispulled by the plasma charge separation electric eld) and then transmitted tothe spacecraft as thrust. The concept is attractive for applications because nopropellant is needed for travelling over long distances. The E-sail’s operatingprinciple is di erent from other propellantless propulsion technologies such asthe solar photon sail [2] and the solar wind magnetic sail. The former is based1