ROY—A multiscale magnetospheric mission

Abstract

The scientific rationale of the ROY multi-satellite mission addresses multiscale investigations of plasma processes in the key magnetospheric regions with strong plasma gradients, turbulence and magnetic field annihilation in the range from electron inertial length to MHD scales. The main scientific aims of ROY mission include explorations of: (a) turbulence on a non-uniform background as a keystone for transport processes; (b) structures and jets in plasma flows associated with anomalously large concentration of kinetic energy; their impact on the energy balance and boundary formation; (c) transport barriers: plasma separation and mixing, Alfvenic collapse of magnetic field lines and turbulent dissipation of kinetic energy; (d) self-organized versus forced reconnection of magnetic field lines; (e) collisionless shocks, plasma discontinuities and associated particle acceleration processes. In the case of autonomous operation, 4 mobile spacecrafts of about 200 kg mass with 60 kg payload equipped with electro-reactive plasma engines will provide 3D measurements at the scales of 100–10000 km and simultaneous 1D measurements at the scales 10–1000 km. The latter smaller scales will be scanned with the use of radio-tomography (phase-shift density measurements within the cone composed of 1 emitting and 3 receiving spacecrafts). We also discuss different opportunities for extra measurement points inside the ROY mission for simultaneous measurements at up to 3 scales for the common international fleet. Combined influence of intermittent turbulence and reconnection on the geomagnetic tail and on the nonlinear dynamics of boundary layers will be explored in situ with fast techniques including particle devices under development, providing plasma moments down to 30 ms resolution. We propose different options for joint measurements in conjunction with the SCOPE and other missions: • simultaneous sampling of low- and high-latitudes magnetopause, bow shock and geomagnetic tail at the same local time; • tracing of magnetosheath streamlines from the bow shock to near-Earth geomagnetic tail; • passing “through” the SCOPE on the inbound orbit leg; • common measurements (with SCOPE and other equatorial spacecraft) at distances of ∼ few thousand km for durations of ∼several hours per orbit. The orbit options and scientific payload of possible common interest are discussed in this work, including FREGAT cargo opportunities for extra payload launching and the “Swarm” campaigns with ejection of nano- and pico-satellites.