Whitepaper #061 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: space weather applications; basic research. Additional topics: fundamental space plasma theory; other space weather; space-based missions/projects; system science.
We recommend to bring into reality the following within the next decade: 1. Measurements from multiple spacecraft covering a 3D volume and simultaneously spanning the MHD to kinetic scales (such as HelioSwarm). 2. Coordination of the new multi-scale mission(s) with existing multi-spacecraft missions such as MMS to maximize the power of cross-scale ion and electron measurements.