Trajectory design for a solar polar observing constellation

Space-based observatories are an invaluable resource for forecasting geomagnetic storms caused by solar activity. Currently, most space weather satellites obtain measurements of the Sun’s magnetic field along the Sun-Earth line and in the ecliptic plane. To obtain complete and regular polar coverage of the Sun’s magnetic field, the University of Colorado Boulder’s Space Weather Technology, Research, and Education Center (SWx TREC) and Ball Aerospace are currently developing a mission concept labeled the Solar Polar Observing Constellation (SPOC). This concept comprises two spacecraft in low-eccentricity and high-inclination heliocentric orbits at less than 1 astronomical unit (AU) from the Sun. The focus of this paper is the design of a trajectory for the SPOC concept that satisfies a variety of hardware and mission constraints to improve solar magnetic field models and wind forecasts via polar viewpoints of the Sun.