Flying a Four-Spacecraft Formation by the Moon...Twice

Spacecraft flying in tetrahedron formations are excellent for electromagnetic and plasma studies. To better understand the Earth s magnetosphere and its interaction with the solar wind, the NASA Goddard Magnetospheric Multiscale (MMS) mission will fly a tetrahedron formation through different regions of the magnetosphere close to the magnetic equatorial plane. However, to explore regions that are almost perpendicular to the ecliptic plane a dramatic plane change is needed. To minimize fuel, a double lunar swingby can be used to perform the plane change. This paper investigates the feasibility of flying a four-spacecraft formation through the required double lunar swingby.