Cumulative distributions of particle and aggregate radii for the three different particle materials and the different experiment types performed in the two microgravity drop-tower campaigns. a) Black SiO₂ (monomer radii 0.5 μm). b) Olivine (monomer radii 0.5−15 μm). c) Transparent SiO₂ particles (monomer radii 0.75 μm). The different symbols and colours indicate the size distributions generated by the cogwheel injection (around 1 μm) and by the vibrating sieve injection with different mesh sizes, respectively (units in μm, see inset).