STORM, the Solar-Terrestrial Observer for Reconnection in the Magnetosphere mission, quantifies the global circulation of energy through the coupled solar wind-magnetosphere system that powers space weather.  For the first time, STORM provides global and continuous images of the magnetosphere at multiple wavelengths to diagnose and quantify the importance of proposed reconnection modes and plasma acceleration, transport, and loss in the circulation of energy throughout the magnetosphere. STORM quantifies the energy transfer at the dayside magnetopause. STORM quantifies the energy circulation through the magnetotail. STORM quantifies the sources and losses of ring current plasma in the inner magnetosphere. STORM quantifies the feedback of the inner magnetosphere on dayside and nightside processes. In this way STORM provides the first ever end-to-end quantification of energy circulation in the coupled solar wind-magnetosphere system.

STORM achieves these objectives with a comprehensive instrument payload that combines multispectral magnetospheric imaging with nearby solar wind monitoring.  The X-ray imager (XRI) captures global images of the dayside magnetosphere from the soft X-rays generated when high charge state solar wind ions encounter exospheric neutrals.  It provides the first wide field-of-view observations of magnetopause and cusp motion which characterize the circulation of energy through the coupled solar wind-magnetosphere system. By sending each X-ray count to the ground, XRI constructs magnetopause and cusp images on cadences and spatial scales appropriate to the physics being studied, ranging from bursty magnetopause erosion (3min and 0.25 RE) to the development of substorms, the ring current, and geomagnetic storms (10 min, 0.1 RE).  Prototype XRI instruments flew successfully on two recent DXL rocket flights, will fly on NASA’s forthcoming  CuPID (Cusp Plasma Imaging Detector) cubesat mission, and will fly to the moon as LEXI (Lunar Environment heliophysics X-ray Imager), part of the Artemis program. Global observations are needed to understand the circulation of energy controlling the dynamics of Space Weather, just as global weather satellites are required to understand the terrestrial weather system [personal communication C. Schiff, 2019].

These pages compile information concerning soft X-ray imaging that will be useful for those seeking an introduction to the science objectives, a description of the requisite hardware, or presentation material.