Characterising the mechanical properties of minor bodies is essential for understanding their origin and evolution. Past missions such as Hayabusa2 have landed on asteroids to sample and discover what these bodies are made of. However, there has been conflicting evidence and reports into the physical properties of the granular surface material of these bodies. With future missions such as Japan Aerospace eXploration Agency's Martian Moons eXploration mission landing on Phobos, the understanding and identification of these physical properties is crucial to maximising the scientific output from these missions. Penetrometry, the determination of the reaction force that an object experiences as it penetrates a surface, can help to understand the essential properties of regolith, such as grain size, porosity and cohesion. Results of penetrometry experiments are largely analysed based on empirical models, which presents us with a challenge if we want to apply them to understand granular materials on asteroid surfaces because gravity cannot be eliminated in the laboratory. Hence, it is essential to verify penetrometry as a method and validate penetrometry instrument designs in microgravity. For this purpose, we conducted a microgravity experiment onboard a parabolic flight campaign. Our experiment tested the use of penetrometry in asteroid-analogue environments by investigating samples with varying properties, such as grain size distribution and shape, and then compared to 1 g experiments to understand the role microgravity plays. The experiment provided a substantial database for future analysis. This paper will focus on the design of the experiment and the parabolic flight campaign in which the experiments were conducted. The design decisions and the variables adjusted during the experiment will be discussed, evaluating how these influenced the campaign and its outcomes. We will also provide a snapshot of preliminary results of the data captured during this experiment. For example, we show the effect of cohesion on penetrometer reaction force, with more cohesive materials providing larger reaction forces nearly of the same magnitude of their 1 g counterparts. We also show that penetrometer tip shapes provide different reaction forces and that flat tips provide the largest reaction force compared to the others. The influence of penetration velocity will be investigated further with the aid of theoretical models. Early indications from the results seen so far are promising for future analyses and will provide key information for the analysis of penetrometry data on future missions.

Particle-particle and particle-gas processes significantly impact planetary precursors such as dust aggregates and planetesimals. We investigate gas permeability (kappa) in 12 granular samples, mimicking planetesimal dust regoliths. Using parabolic flights, this study assesses how gravitational compression - and lack thereof - influences gas permeation, impacting the equilibrium state of low-gravity objects. Transitioning between micro- and hyper-gravity induces granular sedimentation dynamics, revealing collective dust-grain aerodynamics. Our experiments measure kappa across Knudsen number (Kn) ranges, reflecting transitional flow. Using mass and momentum conservation, we derive kappa and calculate pressure gradients within the granular matrix. Key findings: (i) As confinement pressure increases with gravitational load and mass flow, kappa and average pore space decrease. This implies that a planetesimal's unique dust-compaction history limits subsurface volatile outflows. (ii) The derived pressure gradient enables tensile strength determination for asteroid regolith simulants with cohesion. This offers a unique approach to studying dust-layer properties when suspended in confinement pressures comparable to the equilibrium state on planetesimals surfaces, which will be valuable for modelling their collisional evolution. (iii) We observe a dynamical flow symmetry breaking when granular material moves against the pressure gradient. This occurs even at low Reynolds numbers, suggesting that Stokes numbers for drifting dust aggregates near the Stokes-Epstein transition require a drag force modification based on permeability.