APOGEE RAISING TECHNIQUE FOR THE MAGNETOSPHERIC MULTISCALE FORMATION FLYING MISSION

The NASA Goddard Space Flight Center's Magnetospheric Multiscale (MMS) program involves a four-spacecraft tetrahedral formation flying mission intended for launch in 2014. The mission's high Earth orbits are designed to provide repeated excursions through the magnetosphere and magnetotail for measurement of interaction phenomena between the solar wind and magnetosphere, including magnetic reconnection events. The first of two main science mission phases requires a 1.2 by 12 Earth radii (Re) orbit, while the second phase requires a 1.2 by 25 Re orbit. A transition between the two science phases is for independently raising the apogees of the four spacecraft to 25 Re in stages, followed by re-initialization of the tetrahedral formation. A variety of stringent operational requirements and constraints, plus design features of these spinning spacecraft, pose significant challenges to the apogee raising design. This paper has two main parts. The first part focuses on the strategy and methodology for, and the solutions to, the apogee raising design problem. The second part presents and discusses nominal solutions to the problem of recovery from off-nominal finite burns and maneuver contingency scenarios.