Closely-Spaced Multi-Satellite Project Roy to Study Small-Scale Structures during Magnetic Field Annihilation and Strong Turbulence in Critical Magnetospheric Regions: Results of the Phase A

Abstract

The ROY Project (now at the end of phase A) is aimed to study previously unexplored small-scale phenomena within the so called “diffusion region” where strong plasma turbulence, and magnetic “reconnection” occur in the critical magnetospheric domains. At the dayside these are mainly outer cusps and subsolar magnetopause, but recent findings from the INTERBALL Project show that flanks of the magnetosphere can also be sites of these active plasma processes leading to larger scale bulk flows and particle acceleration. On the nightside the most interesting regions are at the earthward edge of the cross-tail current, but their locations are variable. To study these phenomena multi-point measurements are essential at scales down to Larmor radius and lower. The main aim of these measurements is to determine spatial scales of the strong plasma turbulence, characteristic amplitudes and velocities of plasma and magnetic field inhomogeneities, their dynamic spectra, accompanying waves and particles characteristics. The project includes a group of satellites (called Roy Space System or RSS) consisting of the main (BASE) satellite and 4 subsatellites at distances 10–300 (1000) km. The BASE satellite is equipped with omnidirectional emitting MW-antennas, the full set of particle, field and wave plasma diagnostic instrumentation. It carries also directed antenna for telemetry transmission to a ground station, and large onboard memory (~10 Gbytes) for the data storage from all the spacecrafts. Its partial onboard treatment and selection of interesting features is planned with further compression and transmission to the Earth of selected high data rate measurements at most interesting intervals only. The subsatellites (of the order of 100 kg each) will have thrusters to control orbital configuration and their distance from the BASE. They will perform comprehensive in situ plasma measurements and also receive coherent MF radiowaves emitted from the BASE to provide the data for a crude tomography of the rarefied space plasma at small scales. We solicit proposals of our colleagues from Russia and abroad for scientific payload, service systems and/or the whole subsatellite design and construction. Optimistic estimates show that the Roy project might be accomplished in the first half of the next decade.