Evolution of Magnetic Field Fluctuations and Their Spectral Properties within the Heliosphere: Statistical Approach

We present the first comprehensive statistical study of the evolution of compressive and noncompressive magnetic field fluctuations in the inner heliosphere. Based on Parker Solar Probe (PSP) and Solar Orbiter data at various distances from the Sun, we show the general trends and compare them with Wind observations near 1 au. The paper analyzes solar wind power spectra of magnetic field fluctuations in the inertial and kinetic ranges of frequencies. We find a systematic steepening of the spectrum in the inertial range with the spectral index of around −3/2 at closest approach to the Sun toward −5/3 at larger distances (above 0.4 au), the spectrum of the field component perpendicular to the background field being steeper at all distances. In the kinetic range, the spectral indices increase with distance from −4.8 at closest PSP approach to ≈−3 at 0.4 au and this value remains approximately constant toward 1 au. We show that the radial profiles of spectral slopes, fluctuation amplitudes, spectral breaks, and their mutual relations undergo rapid changes near 0.4 au

Space plasma physics science opportunities for the lunar orbital platform - Gateway

The Lunar Orbital Platform - Gateway (LOP - Gateway, or simply Gateway) is a crewed platform that will be assembled and operated in the vicinity of the Moon by NASA and international partner organizations, including ESA, starting from the mid-2020s. It will offer new opportunities for fundamental and applied scientific research. The Moon is a unique location to study the deep space plasma environment. Moreover, the lunar surface and the surface-bounded exosphere are interacting with this environment, constituting a complex multi-scale interacting system. This paper examines the opportunities provided by externally mounted payloads on the Gateway in the field of space plasma physics, heliophysics and space weather, and also examines the impact of the space environment on an inhabited platform in the vicinity of the Moon. It then presents the conceptual design of a model payload, required to perform these space plasma measurements and observations. It results that the Gateway is very well-suited for space plasma physics research. It allows a series of scientific objectives with a multi-disciplinary dimension to be addressed

Evolution of Magnetic Field Fluctuations and Their Spectral Properties within the Heliosphere: Statistical Approach

We present the first comprehensive statistical study of the evolution of compressive and noncompressive magnetic field fluctuations in the inner heliosphere. Based on Parker Solar Probe (PSP) and Solar Orbiter data at various distances from the Sun, we show the general trends and compare them with Wind observations near 1 au. The paper analyzes solar wind power spectra of magnetic field fluctuations in the inertial and kinetic ranges of frequencies. We find a systematic steepening of the spectrum in the inertial range with the spectral index of around −3/2 at closest approach to the Sun toward −5/3 at larger distances (above 0.4 au), the spectrum of the field component perpendicular to the background field being steeper at all distances. In the kinetic range, the spectral indices increase with distance from −4.8 at closest PSP approach to ≈−3 at 0.4 au and this value remains approximately constant toward 1 au. We show that the radial profiles of spectral slopes, fluctuation amplitudes, spectral breaks, and their mutual relations undergo rapid changes near 0.4 au

SP4GATEWAY: a Space Plasma Physics Payload Package conceptual design for the Deep Space Gateway Lunar Orbital Platform

International audienceThe Deep Space Gateway is a crewed platform that will be assembled and operated in the vicinity of the Moon by ESA and its international partners in the early 2020s and will offer new opportunities for fundamental and applied scientific research. The Moon is a unique location to study the deep space plasma environment, due to the absence of a substantial intrinsic magnetic field and the direct exposure to the solar wind, galactic cosmic rays (GCRs) and solar energetic particles (SEPs). However, 5-6 days each orbit, the Moon crosses the tail of the terrestrial magnetosphere facilitating the in-situ study of the terrestrial magnetotail plasma environment as well as atmospheric escape from the ionosphere. When back outside of the magnetosphere, a variety of these and other phenomena, e.g. those driving solar-terrestrial relationships, can be investigated through remote sensing using a variety of imaging techniques. Most importantly, the lunar environment offers a unique opportunity to study the interaction of the solar wind and the magnetosphere with the lunar surface and the lunar surface-bounded exosphere. In preparation of the scientific payload of the Deep Space Gateway, we have undertaken a conceptual design study for a Space Plasma Physics Payload Package onboard the Gateway (SP4GATEWAY). The main goal is first to provide a science rationale for hosting space plasma physics instrumentation on the Gateway and to translate that into a set of technical requirements. A conceptual payload design, that identifies a strawman payload and is compatible with the technical requirements, is then put forward. The final outcome of this project, which is undertaken following an ESA AO, is an implementation plan for this space plasma physics payload package

Space Plasma Physics Science Opportunities for the Lunar Orbital Platform -Gateway

The Lunar Orbital Platform-Gateway (LOP-Gateway, or simply Gateway) is a crewed platform that will be assembled and operated in the vicinity of the Moon by NASA and international partner organizations, including ESA, starting from the mid-2020s. It will offer new opportunities for fundamental and applied scientific research. The Moon is a unique location to study the deep space plasma environment. Moreover, the lunar surface and the surface-bounded exosphere are interacting with this environment, constituting a complex multi-scale interacting system. This paper examines the opportunities provided by externally mounted payloads on the Gateway in the field of space plasma physics, heliophysics and space weather, but also examines the impact of the space environment on an inhabited platform in the vicinity of the Moon. It then presents the conceptual design of a model payload, required to perform these space plasma measurements and observations. It results that the Gateway is very well-suited for space plasma physics research. It allows a series of scientific objectives with a multidisciplinary dimension to be addressed