  NASA's proposed WFIRST-AFTA mission will discover thousands of exoplanets
with separations from the habitable zone out to unbound planets, using the
technique of gravitational microlensing. The Study Analysis Group 11 of the
NASA Exoplanet Program Analysis Group was convened to explore scientific
programs that can be undertaken now, and in the years leading up to WFIRST's
launch, in order to maximize the mission's scientific return and to reduce
technical and scientific risk. This report presents those findings, which
include suggested precursor Hubble Space Telescope observations, a
ground-based, NIR microlensing survey, and other programs to develop and deepen
community scientific expertise prior to the mission.

Earth and Planetary Astrophysics