A Multi?Purpose Heliophysics L4 Mission

The Earth-Sun Lagrangian point 4 is a meta-stable location at 1 AU from the Sun, 60° ahead of Earth's orbit. It has an uninterrupted view solar photosphere centered on W60, nominal magnetic field connection to Sun. Such mission its own would serve as remote sensing observatory that oversee entire radiation hemisphere with significant relevance for protecting Moon and Mars explorers exposure. In combination appropriately planned observatories L1 L5, three spacecraft provide 300° longitude coverage photospheric structure, allow continuous viewing both poles, >3.6° elevation. Ideally, L4 L5 missions orbit Sun 7.2° inclination out heliographic equator, 14.5° ecliptic plane. We discuss impact extending observations in latitude improve global wind modeling and, development local helioseismology, potential long-term activity forecasting. unique opportunity interplanetary interstellar dust science. significantly add reliability operational fast coronal mass ejections directed Earth human their round-trip journey. concept technically feasible, scientifically compelling.