<p>Meteors ablation is a source of dust particles in the upper atmosphere. The remnants of meteor ablation that prevail in the mesosphere condense to nm-sized particles, denoted as Meteoric Smoke Particles (MSPs). Theory suggest that MSPs act as condensation nuclei for ice particles in the summer mesosphere, which form during summer months around the mesopause at high and mid latitudes. They are related to mesospheric phenomena such as the Noctilucent Clouds, Polar Mesospheric Summer and Winter Echoes (PMSE/PMWE). However, due to their altitude location, the only means of in situ measurement is with rocket experiments. There have been several attempts to collect these MSP particles with probes on rockets over the years, but no conclusive results have been reported so far.</p><p>UiT have proposed a new sample collector, the MEteoric Smoke Sampler (MESS). We report on the progress of the work that has focused on the design of the detector and simulation of the entry and impact of dust onto the detector. The focus of the planned measurements is on collecting ice particles, since the airflow affect them less than smaller MSPs. Estimations of the collection surface properties and impact energy are presented. An estimate of the expected mass in the traversed volume of one collecting plate, diameter of 3 mm diameter over 1 km, suggest that the volume contains ~1e8 particles. This corresponds to a mass of 7e16 amu. These estimates are made assuming spherical particles with average density 2.8 g per m<sup>3</sup> and radius 1 nm, and an MSP density of 1e10 per m<sup>3.</sup> </p>

Abstract. We report and discuss the design of a rocket instrument to collect mesospheric dust particles that are composed of ice and include smaller refractory meteoric smoke particles (MSP). We expect that the ice components melt and that MSP are collected. The instrument consists of a collection device with an opening and closure mechanism and an attached conic funnel. Attaching the funnel increases the sampling area in comparison to the collection area which is kept small since this determines the size of the closure device which is a critical component to be designed for sea recovery. The instrument will collect primary particles that directly hit the collection area and secondary particles that form from mesospheric dust hitting the funnel. We simulate the entry and impact of dust onto the detector considering their trajectories in the airflow and the fragmentation at the funnel. We estimate the collection efficiency of the instrument and the impact energy of particles at the collecting area. The design considered has a sampling area of 5 cm diameter and a collection area of 1.8 cm diameter. To estimate the expected amount of collected dust we assume collection during rocket flight through a 0.5 to 4 km dust layer with dust number densities and dust sizes at 85 km as derived from lidar observations (Kiliani et al., 2015). Assuming the collected particles contain 3 % volume fraction of MSP, we find that the instrument would collect of the order of 1014 to 1015 amu of refractory MSP particles. The estimate basis on the assumption that the ice components are melting and the flow conditions in the instruments are for typical atmospheric pressures at 85 km.