Recovering the Magnetic Image of Mars from Satellite Observations

One of the possible approaches to reconstructing the map of the distribution of magnetization parameters in the crust of Mars from the data of the Mars MAVEN orbiter mission is considered. Possible ways of increasing the accuracy of reconstruction of the magnetic image of Mars are discussed.

Overview of the Flight Dynamics Subsystem for Korea Pathfinder Lunar Orbiter Mission

Korea’s first lunar mission, the Korea Pathfinder Lunar Orbiter (KPLO), aims to launch in mid-2022 via the Space-X Falcon-9 launch vehicle. For the successful flight operation of KPLO, the Korea Aerospace Research Institute (KARI) has designed and developed the Flight Dynamics Subsystem (FDS). FDS is one of the subsystems in the KPLO Deep-Space Ground System (KDGS), which is responsible for the overall flight dynamics-related operation. FDS is currently successfully implemented and meets all of the requirements derived from the critical design phases. The current work addresses the design and implementation results for the KPLO FDS. Starting from overviews on KPLO payloads, bus systems, and mission trajectory characteristics, a review on KDGS is also treated briefly. Details on the design philosophy, unique characteristics, and functionalities of all six different modules nested inside the FDS with its Graphical User Interface (GUI) design are discussed. Moreover, efforts currently devoted to the flight operation preparation of the KPLO are summarized, including many collaborative works between KARI and the National Aeronautics and Space Administration (NASA) teams.

Recoverability of Callisto gravity field influenced by orbiter mission characteristics

<p>The exploration of Callisto is part of the extensive interest in the icy moons characterization. Indeed, Callisto is the Galilean moon with the best-preserved records of the Jovian system formation. Led by the National Space Science Center (NSSC), Chinese Academy of Science (CAS), the planned Gan De mission aims to send an orbiter around Callisto in order to characterize its surface and interior. Potential orbit configurations are currently under study for the Gan De mission proposal.</p><p>As part of a global characterization of Callisto, its gravity field can be inferred using radio tracking data from an orbiter. Mission characteristics such as orbit type, Earth beta angle and solar elongation will have a direct influence on the recoverability of its gravity field parameters. In this study, we will analyse this influence from closed-loop simulations using the planetary extension of the Bernese GNSS Softwareai.</p><p>A number of reference orbits with different orbital characteristics will be selected for the Gan De mission and, using an extended force model, will be propagated from different starting dates and different initial Earth beta angles. Realistic Doppler tracking data (2-way X-band Doppler range rate) will be simulated as measurements from ground stations, with a dedicated noise model. These observations will then be used to reconstruct the orbit along with dynamical parameters. The focus of this presentation will be on the quality of the retrieved gravity field parameters and tidal Love number k2.</p>

The solar wind angular-momentum flux observed during Solar Orbiter's first orbit

<p>The Solar Orbiter mission is currently in its cruise phase, during which the spacecraft's in-situ instrumentation measures the solar wind and the electromagnetic fields at different heliocentric distances. </p><p>We evaluate the solar wind angular-momentum flux by combining proton data from the Solar Wind Analyser (SWA) Proton-Alpha Sensor (PAS) and magnetic-field data from the Magnetometer (MAG) instruments on board Solar Orbiter during its first orbit. This allows us to evaluate the angular momentum in the protons in addition to that stored in magnetic-field stresses, and compare these to previous observations from other spacecraft. We discuss the statistical properties of the angular-momentum flux and its dependence on solar-wind properties. </p><p>Our results largely agree with previous measurements of the solar wind’s angular-momentum flux in the inner heliosphere and demonstrate the potential for future detailed studies of large-scale properties of the solar wind with the data from Solar Orbiter.</p>

Solar observations with the Nancay Radioheliograph in support of the Solar Orbiter and Parker Solar Probe missions

<p>The Nancay Radioheliograph is dedicated to imaging the solar corona at decimetre-to-metre wavelengths. The imaged structures are the quiet corona, through thermal bremsstrahlung, and bright collective emissions due to electrons accelerated in quiescent, flaring and eruptive active regions. The instrument produced nearly daily maps of the Sun between 1996 and 2015, at several frequencies in the 150-450 MHz range with sub-second cadence. The observations were stopped in 2015 for a major technical upgrade through the replacement of the correlator and the data acquisition system. They were resumed in November 2020, and at the time of writing the commissioning of the instrument is well underway. This contribution will give a brief overview of the technical changes and present observations at eight frequencies of solar activity since November 2020, including the coronal mass ejection (CME) of December 14 seen in some images of the total solar eclipse, observations conducted during the present perihelion passage of the Parker Solar Probe mission, as well as during periods of interest to the Solar Orbiter mission. The data are freely available, and special products of common visualisation with the space missions will be illustrated.</p>