Mitigation strategies to eliminate existing space debris, such as with Active Space Debris Removal (ASDR) missions, have become increasingly important. Among the considered ASDR approaches, one involves using a net as a capturing mechanism. A fundamental requirement for any ASDR mission is that the capture process itself should not give rise to new space debris. However, in simulations of net capturing, the potential for structural breaking is often overlooked. A discrete Multi-Spring-Damper net model was employed to simulate the impact of a 30 m × 30 m net travelling at 20 m/s onto an ESA Envisat mock-up. The Envisat was modelled as a two-rigid-body system comprised of the main body and a large solar array with a hinge connection. The analysis revealed that more than two significant substructures had a notable likelihood of breaking, prompting the recommendation of limiting the impacting velocity. The generation of secondary space debris indicates that net capturing is riskier than previously assumed in the literature.@en

We show that the Global Navigation Satellite System (GNSS) and gravimeters on Earth and in space can potentially offer the most accurate direct measurement of local density of near-Earth asteroid-mass primordial black holes (PBHs) and dark matter (DM) clumps in the Solar System by means of gravitational influence. Using semianalytical methods and Monte Carlo simulation, this paper revisits the analysis of the trajectories of DM clumps in the Solar System, including both captured objects and hyperbolic trajectories. A link is thus made between the frequency and distance of Earth overflights for a given mass flux, and a direct measure of dark matter clump density in the Solar System. We then model the signature of a close fly-by of a DM object on orbital data from GNSS satellites and gravity measurements from gravimeters. We thus obtain a first assessment of the single probe sensitivity. It paves the way for an exhaustive statistical analysis of 28 years of gravimeters and GNSS data to obtain observational constraints on the density of the PBHs and DM clumps within the Solar System, for the mass range [10 8–10 17]  kg. In addition, our methodology offers a possibility of direct detection in cases where DM clumps are endowed with an additional long-range clump-matter fifth force beyond gravity.@en

In this proceedings, we study the possible gravitational impact of primordial black holes (PBHs) or dark matter (DM) clumps on GNSS satellite orbits and gravimeter measurements. It provides a preliminary step to the future exhaustive statistical analysis over 28 years of gravimeter and GNSS data to get constraints over the density of asteroid-mass PBH and DM clumps inside the solar system. Such constraints would be the first to be obtained by direct observation on a terrestrial scale.@en

This study proposes a strategy to incorporate control and stability aspects into the preliminarydesign of a tandem-wing, long-range eVTOL aircraft concept. Four operational phases areconsidered: cruise, transition, hover, and ground operation. For cruise, a method to designfor open-loop stability and size aerodynamic control surfaces is presented. Furthermore, acontroller is designed to improve handling qualities. For hover controllability by differentialthrust is considered, and for ground operation, the positioning of the landing gear is performedaccording to clearance and tip-over requirements. A novel analytical model is derived for thetandem wing aircraft in order to estimate during the preliminary design phase the stabilityderivatives of the aerodynamic forces and moments. The transition manoeuvre between verticaland horizontal flight is only treated with qualitative considerations, due to the highly nonlineardynamics involved during this flight phase.@en