Whitepaper #178 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: space-based missions/projects; system science.
We resolve the long-standing Dungey vs. Axford-Hines dichotomy via simultaneous measurements of dayside reconnection (2 polar-orbiters) and flank-side process (2 equator-orbiters at dawn and dusk flanks). Another equator-orbiter probing the near-midnight plasma sheet, for the first time, enables us to address causality between unstable central magnetotail current sheets and flank-side dynamics.