Dust impact rate onto the spacecraft. Dots show the same data as the one presented in Fig. 3. The green curve shows the expected impact rate for beta meteoroids having a constant outward velocity v_β = 50 km s⁻¹, and a flux density F_1 AU = 8 × 10⁻⁵ m⁻² s⁻¹ at 1 AU. The red curve shows the flux from Eq. (10) with F_1 AU = 8 × 10⁻⁵ m⁻² s⁻¹ and αδ = 1.3. The black curve shows the prediction from numerical simulation based on a model of production of dust by collisional fragmentation. The collecting area is assumed to be equal to the heat shield’s surface, S_col = 8 m².